Correlations between the alpha angle and femoral head asphericity: Implications and recommendations for the diagnosis of cam femoroacetabular impingement

Three-dimensional analysis of age and sex differences in femoral head asphericity in asymptomatic hips in the United States

BACKGROUND

The sphericity of the femoral head is a metric used to evaluate hip pathologies and is associated with the development of osteoarthritis and femoral-acetabular impingement.

AIM

To analyze the three-dimensional asphericity of the femoral head of asymptomatic pediatric hips. We hypothesized that femoral head asphericity will vary significantly between male and female pediatric hips and increase with age in both sexes.

METHODS

Computed tomography scans were obtained on 158 children and adolescents from a single institution in the United States (8-18 years; 50% male) without hip pain. Proximal femoral measurements including the femoral head diameter, femoral head volume, residual volume, asphericity index, and local diameter difference were used to evaluate femoral head sphericity.

RESULTS

In both sexes, the residual volume increased by age (P < 0.05). Despite significantly smaller femoral head size in older ages (> 13 years) in females, there were no sex-differences in residual volume and aspherity index. There were no age-related changes in mean diameter difference in both sexes (P = 0.07) with no significant sex-differences across different age groups (P = 0.06). In contrast, there were significant increases in local aspherity (maximum diameter difference) across whole surface of the femoral head and all quadrants except the inferior regions in males (P = 0.03). There were no sex-differences in maximum diameter difference at any regions and age group (P > 0.05). Increased alpha angle was only correlated to increased mean diameter difference across overall surface of the femoral head (P = 0.024).

CONCLUSION

There is a substantial localized asphericity in asymptomatic hips which increases with age in. While 2D measured alpha angle can capture overall asphericity of the femoral head, it may not be sensitive enough to represent regional asphericity patterns.

Radiomics features outperform standard radiological measurements in detecting femoroacetabular impingement on three-dimensional magnetic resonance imaging

Femoroacetabular impingement (FAI) is a cause of hip pain and can lead to hip osteoarthritis. Radiological measurements obtained from radiographs or magnetic resonance imaging (MRI) are normally used for FAI diagnosis, but they require time-consuming manual interaction, which limits accuracy and reproducibility. This study compares standard radiologic measurements against radiomics features automatically extracted from MRI for the identification of FAI patients versus healthy subjects. Three-dimensional Dixon MRI of the pelvis were retrospectively collected for 10 patients with confirmed FAI and acquired for 10 healthy subjects. The femur and acetabulum were segmented bilaterally and associated radiomics features were extracted from the four MRI contrasts of the Dixon sequence (water-only, fat-only, in-phase, and out-of-phase). A radiologist collected 21 radiological measurements typically used in FAI. The Gini importance was used to define 9 subsets with the most predictive radiomics features and one subset for the most diagnostically relevant radiological measurements. For each subset, 100 Random Forest machine learning models were trained with different data splits and fivefold cross-validation to classify healthy subjects versus FAI patients. The average performance among the 100 models was computed for each subset and compared against the performance of the radiological measurements. One model trained using the radiomics features datasets yielded 100% accuracy in the detection of FAI, whereas all other radiomics features exceeded 80% accuracy. Radiological measurements yielded 74% accuracy, consistent with previous work. The results of this preliminary work highlight for the first time the potential of radiomics for fully automated FAI diagnosis.

Femurs in patients with hip dysplasia have fundamental shape differences compared with cam femoroacetabular impingement

Femoral deformities are common in developmental dysplasia of the hip (DDH), but decisions about how to treat them are not standardized. Of interest are deformities that may be akin to cam femoroacetabular impingement (FAI). We used three-dimensional and two-dimensional measures to clarify the similarities and differences in proximal femur shape variation among female patients with DDH (n = 68) or cam FAI (n = 60). Three-dimensional measures included femoral head asphericity, as well as shape variation using statistical shape modeling and principal component analysis (PCA). Two-dimensional measures included the α-angle, head-neck offset (HNO) and the neck-shaft angle (NSA). Significant shape variations were captured in the first five PCA modes, with the greatest shared variation between groups being the length from the lesser trochanter to the femoral head and greater trochanter height. Variations unique to DDH were irregularities at different areas of the femoral head, but not at the lateral femoral head-neck junction where variation was strong in FAI. The FAI group also had unique variations in greater trochanter shape. DDH femoral heads were less spherical, as indicated by larger sphere-fitting errors (P < 0.001). Radiographically, the DDH group had significantly smaller α-angles (P < 0.001), larger head-neck offsets (P = 0.02) and larger NSAs (P < 0.001). Both the articular and extra-articular regions of the proximal femur have distinct shape features in DDH and cam FAI that can uniquely affect the biomechanics of each disorder. Accordingly, approaches to addressing each disorder should be unique.

Dancers Show Significant Improvement in Outcomes and Favorable Return-to-Dance Rates After Primary Hip Arthroscopy With Femoral Head Cartilage Status Being a Predictor of Secondary Surgical Procedures at Mid-Term Follow-Up

PURPOSE

To report minimum 5-year follow-up patient-reported outcome measurement (PROM) scores and return-to-dance rates in dancers who underwent primary hip arthroscopy and to identify predictors of secondary surgical procedures.

METHODS

Prospectively collected data from patients who underwent hip arthroscopy between May 2010 and June 2016 were retrospectively reviewed. Patients were included if they participated in dance at any level 1 year prior to surgery and had preoperative and minimum 5-year follow-up scores consisting of the modified Harris Hip Score, Nonarthritic Hip Score, Hip Outcome Score-Sports Specific Subscale, and visual analog scale pain score. The exclusion criteria were previous hip conditions, previous ipsilateral hip surgery, Tönnis grade greater than 1, or lateral center-edge angle less than 18°. The minimal clinically important difference (MCID) was reported. Dancers who discontinued dance for reasons other than pain in the operative hip were excluded from the return-to-dance analysis. A logistic regression model was used to identify predictors of secondary surgical procedures.

RESULTS

Fifty-one hips (48 female dancers) were included. The average age and average follow-up period were 29.8 ± 17.2 years and 79.1 ± 23.2 months, respectively. Improvement in all PROM scores (P < .001) was reported. Achievement rates of the MCID for the modified Harris Hip Score, Nonarthritic Hip Score, and visual analog scale pain score were 83.3%, 85.7%, and 85.7%, respectively. Revision hip arthroscopy was performed in 5 dancers (9.8%). Conversion to total hip arthroplasty was performed in 4 dancers (7.8%). The return-to-dance rate was 78.6%, with 57.6% returning to the preinjury performance level or a higher level. Higher femoral head Outerbridge grade was identified as a predictor of secondary surgical procedures (P = .045; odds ratio, 6.752 [95% confidence interval, 1.043-43.688]).

CONCLUSIONS

After primary hip arthroscopy, dancers experienced significant improvement in all PROM scores collected and achieved the MCID at a high rate at minimum 5-year follow-up. The return-to-dance rate in dancers who did not discontinue dance because of lifestyle transitions was 78.6%, with 57.6% returning to the preinjury performance level or a higher level. Higher femoral head Outerbridge grade was found to be a predictor of secondary surgical procedures.

LEVEL OF EVIDENCE

Level IV, case series.

Femoroacetabular Impingement Measurements Obtained From Two-Dimensional Radiographs Versus Three-Dimensional-Reconstructed Computed Tomography Images Result in Different Values

Purpose

To compare the reliability and accuracy of radiographic measurements obtained from 2-dimensional (2D) radiographs and 3-dimensional (3D)-reconstructed computed tomography (CT) images in the assessment of femoroacetabular impingement syndrome (FAIS).

Methods

Consecutive patients with FAIS from January 2018 to December 2020 were identified and included in this study. Two fellowship-trained surgeons and 2 fellows performed blinded radiographic measurements. Lateral center-edge angle (LCEA) and Tönnis angles were measured on anteroposterior pelvic radiographs, and alpha angles were measured on frog lateral radiographs. Reliability coefficients for individual measurement accuracy were performed using the Cronbach alpha and intra- and inter-rater intraclass correlation coefficients (ICCs). Composite measurements for LCEA, Tönnis angle, and alpha angle were compared with the corresponding 3D value using paired sample t-tests.

Results

Fifty-three patients with FAIS with standardized 2D radiographic and 3D-reconstructed CT imaging were included. All reliability metrics met thresholds for internal reliability. Inter-rater ICCs for LCEA, Tönnis angle, and alpha angle were (0.928, 0.888, 0.857, all P < .001). When we compared 2D radiographic measurements with 3D-reconstructed CT values, there was a significant difference in the LCEA for 2 authors: surgeon 1 (mean [M] = -9.14, standard deviation [SD] = 5.7); t(52) = -11.6, P < .001, and surgeon 2 (M = -5.9°, SD = 4.7); t(52) = -9.2, P < .001. Significant differences were seen for Tönnis angle for 2 authors: fellow 2 (M = 3.9°, SD = 5.6); t(52) = 5.1, P < .001, and surgeon 2 (M = -2.6°, SD = 4.1); t(52) = -4.6, P < .001. Alpha angle measurements compared to the 3D-reconstructed alpha angle at 2 o'clock was significantly different for 3 authors: fellow 1 (M = 11.9°, SD = 16.2); t(52) = 5.3, P < .001; fellow 2 (M = 10.4°, SD = 18.6); t(52) = 4.1, P = .002; and surgeon 2 (M = -6.5°, SD = 16.2); t(52) = -2.9, P = .005. Positive mean values indicate 2D radiographic measurements overestimated 3D reconstruction values and negative mean values indicate underestimation.

Conclusions

The use of 2D radiographs alone for preoperative planning of FAIS may lead to inaccuracies in radiographic measurements.

Level of Evidence

Level, III retrospective cohort study.

Image Correlation Between Digitally Reconstructed Radiographs, C-arm Fluoroscopic Radiographs, and X-ray: A Phantom Study

OBJECTIVE

Digitally reconstructed radiographs (DRRs) are planar two-dimensional (2D) X-rays derived from a three-dimensional (3D) computed tomography (CT) dataset. DRRs allow the simulation of radiographs of all desired views and facilitate preoperative planning. However, orthopedic surgeons rely on C-arm fluoroscopic imaging during surgery to verify fracture reduction and implant placement. Pincushion distortion represents a technical limitation of fluoroscopic imaging, resulting in a greater distance between points at the periphery of the image compared to the center. This project, therefore, aimed to assess the image correlation between digitally reconstructed radiographs (DRRs) and fluoroscopic imaging (C-arm) using conventional radiographs (X-ray) as a control.

METHODS

A 3D-printed cubic prototype and an anatomical humerus bone model were used. C-arm fluoroscopic radiographs and conventional X-ray images were taken in an anteroposterior (AP) view at 10-degree steps while rotating the objects from 0 to 90 degrees. CT scans were made and used to compute and export DRRs in AP view at 10-degree rotational steps from 0 to 90 degrees. The surface area (cm2) was measured and compared between the different modalities. For automated image analysis of the anatomical humerus model, matching (%) between modalities was calculated using the structural similarity index (SSIM).

RESULTS

The overall regression was statistically significant in all models, with an R2 >0.99 when comparing all three imaging modalities of the prototype. Surface correlation in the anatomical humerus model was R2 0.99 between X-ray and C-arm and R2 0.95 between C-arm and X-ray to DRRs, respectively. The SSIM was highest for comparing DRR and C-arm images (0.84±0.01%).

CONCLUSIONS

The study indicates a strong agreement between digitally reconstructed radiographs and X-ray/C-arm images. DRRs, therefore, represent a valuable tool for research and clinical application.

Above knee socket prosthesis use changes proximal femur morphology

Patients with transfemoral amputation (TFA) are up to six times more likely to develop hip osteoarthritis (OA) in either or both the intact and residual limb, which is primarily attributed to habitually altered joint loading due to compensatory movement patterns. However, joint loading patterns differ between limbs, which confounds the understanding of loading-induced OA etiology across limbs. It remains unknown if altered loading due to amputation results in bony shape changes at the hip, which is a known etiological factor in the development of hip OA. Retrospective computed tomography images were collected of the residual limb for 31 patients with unilateral TFA (13F/18M; age: 51.7 ± 9.9 y/o; time since amputation: 13.7 ± 12.4 years) and proximal femur for a control group of 29 patients (13F/16M; age: 42.0 ± 12.27 years) and used to create 3D geometries of the proximal femur. Femoral 3D geometric variation was quantified using statistical shape modeling (SSM), a computational tool which placed 2048 corresponding particles on each geometry. Independent modes of variation were created using principal component analysis. 2D radiographic measures of the proximal femur, including common measures such as α-angle, head neck offset, and neck shaft angle, were quantified on digitally reconstructed radiographs (DRRs). SSM results were then compared to 2D measures using Pearson correlation coefficients (r). Two-sample t-tests were used to determine if there were significant differences between the TFA and control group means of 2D radiographic measurements (p < 0.05). Patients with TFA had greater femoral head asphericity within the SSM, which was moderately correlated to head-neck offset (r = -0.54) and α-angle (r = 0.63), as well as greater trochanteric torsion, which was strongly correlated to the novel radiographic measure of trochanteric torsion (r = -0.78), compared to controls. For 2D measures, the neck-shaft angle was smaller in the TFA group compared to the control group (p = 0.01) while greater trochanter height was larger in the TFA group compared to the control group (p = 0.04). These results indicate altered loading from transfemoral prosthesis use changes proximal femur bony morphology, including femoral head asphericity and greater trochanter changes. Greater trochanter morphologic changes, though not a known factor to OA, affect moment arm and line of action of the primary hip abductors, the major muscles which contribute to joint loading and hip stability. Thus, chronic altered loading of the amputated limb hip, whether under- or overloading, results in bony changes to the proximal femur which may contribute to the etiological progression and development of OA.

A radiomics approach to the diagnosis of femoroacetabular impingement

Introduction

Femoroacetabular Impingement (FAI) is a hip pathology characterized by impingement of the femoral head-neck junction against the acetabular rim, due to abnormalities in bone morphology. FAI is normally diagnosed by manual evaluation of morphologic features on magnetic resonance imaging (MRI). In this study, we assess, for the first time, the feasibility of using radiomics to detect FAI by automatically extracting quantitative features from images.

Material and methods

17 patients diagnosed with monolateral FAI underwent pre-surgical MR imaging, including a 3D Dixon sequence of the pelvis. An expert radiologist drew regions of interest on the water-only Dixon images outlining femur and acetabulum in both impingement (IJ) and healthy joints (HJ). 182 radiomic features were extracted for each hip. The dataset numerosity was increased by 60 times with an ad-hoc data augmentation tool. Features were subdivided by type and region in 24 subsets. For each, a univariate ANOVA F-value analysis was applied to find the 5 features most correlated with IJ based on p-value, for a total of 48 subsets. For each subset, a K-nearest neighbor model was trained to differentiate between IJ and HJ using the values of the radiomic features in the subset as input. The training was repeated 100 times, randomly subdividing the data with 75%/25% training/testing.

Results

The texture-based gray level features yielded the highest prediction max accuracy (0.972) with the smallest subset of features. This suggests that the gray image values are more homogeneously distributed in the HJ in comparison to IJ, which could be due to stress-related inflammation resulting from impingement.

Conclusions

We showed that radiomics can automatically distinguish IJ from HJ using water-only Dixon MRI. To our knowledge, this is the first application of radiomics for FAI diagnosis. We reported an accuracy greater than 97%, which is higher than the 90% accuracy for detecting FAI reported for standard diagnostic tests (90%). Our proposed radiomic analysis could be combined with methods for automated joint segmentation to rapidly identify patients with FAI, avoiding time-consuming radiological measurements of bone morphology.

Reliability and accuracy of the critical shoulder angle measured by anteroposterior radiographs: using digitally reconstructed radiograph from 3-dimensional computed tomography images

BACKGROUND

Accuracy of current standard radiographic measurement of the critical shoulder angle (CSA) is not well established. This study analyzed the reliability and accuracy of the CSA measurements obtained via anteroposterior (AP) radiographs, using a digitally reconstructed radiograph (true AP view) generated from a computed tomography image as the gold standard.

METHODS

The CSA was measured on the radiographs and true AP views of 88 consecutive patients who had undergone shoulder arthroscopy for rotator cuff tears. Intraobserver and interobserver reliabilities of the CSA, measured by 2 orthopedic surgeons, were evaluated, and the average deviation of the CSA between radiographs and true AP views was calculated. Moreover, we compared the deviation of CSA between standard AP films (types A1 and C1) and nonstandard AP films (other types) against the Suter-Henninger criteria.

RESULTS

Intraobserver and interobserver reliabilities were almost perfect on radiographs (0.96, 0.86) and true AP views (0.93, 0.85). The average deviation of CSA was 2.1° ± 1.6° for observer 1 and 2.2° ± 1.9° for observer 2. The percentage of cases with deviations of 2° or more when compared with the true AP view was 42% (37 of 88) for observer 1 and 53% (47 of 88) for observer 2. Only 22% (19 of 88) of films were standard AP films. The average deviation of CSA was not significantly different between standard and nonstandard AP films for observer 1 (standard 1.9° ± 1.3°; nonstandard 2.1° ± 1.7°; P = .76) and observer 2 (standard 1.6° ± 1.5°; nonstandard 2.4° ± 1.9°; P = .09).

CONCLUSION

The CSA measurements using radiography were highly congruent, but a large measurement deviation occurred between radiographs and true AP views. The clinical usefulness and role of CSA in diagnosis require careful consideration.

Propensity-Matched Patients Undergoing Revision Hip Arthroscopy Older Than the Age of 40 Years Had Greater Risk of Conversion to Total Hip Arthroplasty Compared With Their Primary Counterparts

PURPOSE

To report patient-reported outcomes (PROs) and survivorship following revision hip arthroscopy in patients aged ≥40 years and to compare these results with a propensity-matched primary hip arthroscopy control group.

METHODS

Data were prospectively collected and retrospectively reviewed for all patients who underwent revision hip arthroscopy between June 2008 and January 2019. Patients were included if they were ≥40 years of age at the time of surgery and had minimum 2-year follow-up for the modified Harris Hip Score, Nonarthritic Hip Score, Visual Analog Scale for pain, and the Hip Outcome Score-Sports Specific Subscale. Patients who had a previous hip condition, or those who lacked minimum 2-year follow-up, were excluded. The revision group was further analyzed by conducting a 1:1 propensity-matched sub-analysis to a primary hip arthroscopy control group based on age, sex, body mass index, and acetabular labrum articular disruption grade. Statistical significance was set at P < .05.

RESULTS

Eighty-nine hips (92.7% follow-up) were included, with 66.3% being females. The mean age, body mass index, and follow-up time were 49.4 ± 8.0 years, 26.6 ± 4.1, and 62.7 ± 38.5 months, respectively. Significant improvement in all PROs (P < .001) was reported, and 71.8%, 58 74.4%, and 65.2% achieved the minimal clinically important difference for the modified Harris Hip Score, Nonarthritic Hip Score, and Hip Outcome Score-Sports Specific Subscale, respectively. Eighty-seven revision hips were successfully propensity-matched to 87 primary hips. Both groups reported similar improvement for all PROs, but the relative risk of conversion to total hip arthroplasty was 2.63 times greater (95% confidence interval 1.20-5.79) for the revision group.

CONCLUSIONS

Patients aged ≥40 years who underwent revision hip arthroscopy reported significant improvement in all PROs at a mean follow-up of 62.7 months with favorable rates of achieving the minimal clinically important difference. When compared to the propensity-matched control group, both achieved similar rates of improvement, but the revision group was 2.63 times more likely to convert to total hip arthroplasty.

LEVEL OF EVIDENCE

III. case-control study.

Competitive Athletes Who Underwent Hip Arthroscopy With Capsular Repair Showed Greater Improvement in Patient-Reported Outcome Scores Compared With Those Who Did Not Undergo Repair

PURPOSE

To compare minimum 2-year postoperative patient-reported outcome (PRO) scores and return to sport between competitive athletes undergoing primary hip arthroscopy for femoroacetabular impingement syndrome with interportal capsulotomy repair and competitive athletes with an unrepaired interportal capsulotomy.

METHODS

Data on all consecutive competitive athletes who underwent primary hip arthroscopy for femoroacetabular impingement syndrome between February 2012 and December 2018 were collected. Athletes were divided into 2 groups: those who underwent repair and those without repair. Athletes were considered eligible if they participated in sports within 1 year prior to surgery. Patients were eligible if the return-to-sport status and the following preoperative and minimum 2-year postoperative PROs were available: modified Harris Hip Score, Nonarthritic Hip Score (NAHS), Hip Outcome Score-Sport-Specific Subscale (HOS-SSS), and visual analog scale (VAS) score for pain. Patients were excluded if they underwent prior hip surgery, had Workers' Compensation, were unwilling to consent, had a Tönnis grade greater than 1, or had a previous hip condition. The percentages of patients achieving the minimal clinically important difference (MCID) and maximum outcome improvement satisfaction threshold were recorded. Athletes who underwent interportal capsulotomy repair were propensity score matched in a ratio of 2:1 to athletes without interportal capsulotomy repair according to age, sex, body mass index, sport level, and acetabular labrum articular disruption grade.

RESULTS

Forty-nine athletes (53 hips) without repair with an average follow-up time of 36.5 ± 10.2 months and age of 32.1 ± 13.3 years were matched to 79 athletes (84 hips) with repair with an average follow-up time of 41.3 ± 9.4 months and age of 30.1 ± 12.1 years. Athletes in the repaired group showed significantly greater improvements in the NAHS, HOS-SSS, and VAS score and significantly higher rates of achievement of the MCID for the HOS-SSS compared with athletes in the unrepaired group.

CONCLUSIONS

Competitive athletes who underwent primary hip arthroscopy with interportal capsulotomy repair showed a significantly greater magnitude of improvement in PRO scores (NAHS, HOS-SSS, and VAS score) and rates of achieving the MCID (HOS-SSS) compared with a propensity score-matched control group of competitive athletes with an unrepaired interportal capsulotomy.

LEVEL OF EVIDENCE

Level III, retrospective comparative therapeutic trial.

Noninvasive shape-fitting method quantifies cam morphology in femoroacetabular impingement syndrome: Implications for diagnosis and surgical planning

There are considerable limitations associated with the standard 2D imaging currently used for the diagnosis and surgical planning of cam-type femoroacetabular impingement syndrome (FAIS). The aim of this study was to determine the accuracy of a new patient-specific shape-fitting method that quantifies cam morphology in 3D based solely on preoperative MRI imaging. Preoperative and postoperative 1.5T MRI scans were performed on n = 15 patients to generate 3D models of the proximal femur, in turn used to create the actual and the virtual cam. The actual cams were reconstructed by subtracting the postoperative from the preoperative 3D model and used as reference, while the virtual cams were generated by subtracting the preoperative 3D model from the virtual shape template produced with the shape-fitting method based solely on preoperative MRI scans. The accuracy of the shape-fitting method was tested on all patients by evaluating the agreement between the metrics of height, surface area, and volume that quantified virtual and actual cams. Accuracy of the shape-fitting method was demonstrated obtaining a 97.8% average level of agreement between these metrics. In conclusion, the shape-fitting technique is a noninvasive and patient-specific tool for the quantification and localization of cam morphology. Future studies will include the implementation of the technique within a clinically based software for diagnosis and surgical planning for cam-type FAIS.

Determining Clinically Meaningful Thresholds for the Hip Outcome Score Sport-Specific Subscale in Athletes Undergoing Hip Arthroscopy for Femoroacetabular Impingement Syndrome

BACKGROUND

The minimal clinically important difference (MCID), Patient Acceptable Symptom State (PASS), substantial clinical benefit (SCB), and maximum outcome improvement (MOI) satisfaction threshold for the Hip Outcome Score Sport-Specific Subscale (HOS-SSS) have not been established in athletes undergoing hip arthroscopy for femoroacetabular impingement syndrome (FAIS).

PURPOSE

To determine threshold MCID, PASS, SCB, and MOI satisfaction threshold values for the HOS-SSS in athletes undergoing hip arthroscopy for FAIS at minimum 2-year follow-up.

STUDY DESIGN

Cohort study (Diagnosis); Level of evidence, 3.

METHODS

Anchor questions were administered to recreational, organized amateur, high school, college, and professional athletes who underwent primary hip arthroscopy for FAIS between May 2015 and March 2019. Patients were included if they were younger than 50 years, answered the anchor questions, and had preoperative and minimum 2-year follow-up for the HOS-SSS, modified Harris Hip Score (mHHS), Non-Arthritic Hip Score (NAHS), and visual analog scale (VAS) for pain. Exclusion criteria were Tönnis grade >1, hip dysplasia (lateral center-edge angle <18°), and previous ipsilateral hip surgery or conditions. Receiver operating characteristic (ROC) analysis was used to determine PASS, SCB, and MOI satisfaction for the HOS-SSS. Two distribution methods were used to calculate MCID for HOS-SSS.

RESULTS

A total of 225 athletes who underwent primary hip arthroscopy met the inclusion criteria. Of those athletes, 200 (88.9%) who had minimum 2-year follow-up and information regarding return to sport (RTS) were included. The cohort included 124 (62.0%) women and 76 (38.0%) men with a mean ± standard deviation age of 29.4 ± 10.4 years, body mass index of 25.6 ± 5.4, and follow-up of 29.5 ± 5.1 months. Athletes experienced significant improvements in HOS-SSS, mHHS, NAHS, and VAS from preoperative to latest postoperative follow-up (P < .001), and mean satisfaction was 8.2. The RTS rate was 83.7%. ROC analysis determined that the PASS, MOI satisfaction threshold, SCB absolute score, SCB change score, and MCID (baseline/change score methods) for the HOS-SSS were 77.0, 44.6%, 92.7, 30.6, and 10.6, respectively, with athletes achieving thresholds at high rates (80.0%, 80.5%, 45.0%, 54.0%, and 79.5%, respectively).

CONCLUSION

This study identified values for the HOS-SSS that can be used to define clinically meaningful outcomes in athletes after primary hip arthroscopy for FAIS. The PASS, MOI satisfaction threshold, SCB absolute score, SCB change score, and MCID for the HOS-SSS at minimum 2-year follow-up in athletes after primary hip arthroscopy were 77.0, 44.6%, 92.7, 30.6, and 10.6, respectively.

Hip Arthroscopy Results in Similar Short-Term Function Compared to THA in Patients of Similar Demographic Profiles

Purpose

To review short-term functional outcomes in patients who underwent hip arthroscopy and to compare their outcomes to those of a demographically similar cohort who underwent total hip arthroplasty (THA).

Methods

Data were prospectively collected and retrospectively reviewed for patients undergoing hip arthroscopy (SCOPE) between April 2008 and October 2015. SCOPE patients were included if they were ≥35 years, had preoperative and postoperative 2-year follow-up, and had no prior hip condition or ipsilateral hip surgery. SCOPE patients were matched 1:1 to a demographically similar cohort of patients who underwent THA at our institution. Matching criteria included similar age (within 5 years), gender, and body mass index (within 5). SCOPE patients were assessed with modified Harris Hip Score (mHHS), non-arthritic hip score, and visual analogue scale (VAS). THA patients were assessed with mHHS, forgotten joint score, and VAS.

Results

Sixty-seven patients were included in each cohort. Patients who underwent hip arthroscopy for management of labral tears achieved nearly equivalent mHHS, Health Survey Short Form (SF-12) Mental, SF-12 Physical, Veterans RAND 12 Item Health Survey (VR-12) Mental, VR-12 Physical scores at latest follow-up compared to demographically similar patients who underwent THA. There was no significant difference in mHHS scores (SCOPE = 82.9 ± 16.4 vs THA = 87.3 ± 15, P = .095) between the 2 group groups. In addition, average patient satisfaction on a 10-point scale was 8.1 for the SCOPE cohort and 8.8 for the THA cohort (P = .052).

Conclusions

Our results show that hip arthroscopy, when performed in patients with the appropriate indications, can lead to comparably excellent outcomes as total hip arthroplasty with significant pain relief at short term follow-up.

Level of Evidence

Level III, retrospective cohort study.

After Revision Hip Arthroscopy, Patients Having Either Circumferential or Segmental Labral Reconstructions for the Management of Irreparable Labra Show Clinical Improvement Based on Proper Indications

PURPOSE

To compare a minimum of two-year follow-up patient-reported outcome scores (PROs) in patients who underwent revision hip arthroscopy for acetabular circumferential labral reconstruction (CLR) and segmental labral reconstruction (SLR) using propensity-matched groups, in the setting of irreparable labral tear.

METHODS

Prospectively collected data were retrospectively reviewed for patients who underwent revision hip arthroscopy from April 2010 to September 2018. Patients were included if they underwent labral reconstruction and had preoperative and minimum 2-year PROs. Patients unwilling to participate, with Tönnis grade >1, or hip dysplasia were excluded. Patients in the CLR group were propensity-matched on the basis of age, sex, body mass index, and Tönnis grade to patients in the SLR group in a 1:1 ratio. The minimal clinically important difference (MCID) and the patient-acceptable symptomatic state (PASS) rates were calculated.

RESULTS

Twenty-six hips (25 patients) with CLR were propensity-matched to 26 hips (26 patients) with SRL. The mean follow-up time 25.92 and 27.78 months for the CLR and SLR, respectively (P = .845). Groups reported comparable findings for sex (P = .773), age (P = .197), body mass index (P = .124), preoperative Tönnis grade (P = .124), lateral-center edge angle (P = .144), and alpha angle (P = .264), and comparable improvement for all PROs at minimum 2-year follow-up. Patient satisfaction was similar (P = .612). Rates of achievement for the MCID and PASS were comparable.

CONCLUSION

Following revision hip arthroscopy, patients who underwent CLR or SLR for complete and segmental irreparable labral tears, respectively, reported significant and comparable postoperative improvement for all PROs and rate of achievement for the MCID and PASS at a minimum 2-year follow-up.

LEVEL OF EVIDENCE

III, retrospective comparative therapeutic trial.

Intra-articular Damage and Patient Outcome Comparison Between Athletes and Nonathletes After Hip Arthroscopy

BACKGROUND

The body of literature comparing hip arthroscopy between athletes and nonathletes is relatively scarce. Analyzing these groups can help to shed light on the severity of intra-articular damage and end-stage osteoarthritis that may result from participation in strenuous activities.

PURPOSE

(1) To compare the intra-articular damage at the time of hip arthroscopy between athletes and nonathletes, and (2) to compare the pre- and postoperative outcomes between the groups.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Patients were considered eligible for analysis if they had received a primary hip arthroscopy between August 2008 and June 2018, were participating in competitive athletics, and had preoperative baseline scores and minimum 2-year follow-up for the following patient-reported outcomes: modified Harris Hip Score, Nonarthritic Hip Score (NAHS), Hip Outcome Score-Sports Specific Subscale, and visual analog scale. Propensity score matching was used to match eligible patients in a 1:1 ratio to patients who were not participating in any sports greater than a recreational level before surgery.

RESULTS

A total of 234 patients were included. There were no significant differences in the severity of labral tears, ligamentum teres tears, or cartilage damage (P > .05). The procedures performed between cohorts were similar (P > .05). The athlete population had higher preoperative means scores for the modified Harris Hip Score and NAHS (each P < .001). Likewise, the athlete population had higher postoperative means scores for the NAHS, Hip Outcome Score-Sports Specific Subscale, and visual analog scale (P = .031, P = .030, and P = .032, respectively). Additionally, the athlete cohort reported higher minimum 2-year outcomes than the nonathlete cohort for the 12-Item Short Form Health Survey (mental component; P = .003) and Veterans RAND 12-Item Health Survey (mental component, P = .032; physical component, P = .005).

CONCLUSION

At the time of hip arthroscopy, athletes demonstrate similar intra-articular damage to their nonathlete counterparts. Given their higher preoperative scores, it is possible that athletes better tolerate the damage to the hip joint. Despite their strenuous activities and potentially higher tolerance to pain, athletes should not necessarily be expected to have greater severity of intra-articular pathology.

Assessment of Flatfoot Deformity Using Digitally Reconstructed Radiographs: Reliability and Comparison to Conventional Radiographs

BACKGROUND

Digitally reconstructed radiographs (DRRs) generated from weightbearing computed tomography (WBCT) may potentially substitute for weightbearing plain radiographs (XRs) but have not been clinically validated. This study aims to test the reliability of 6 radiographic parameters of progressive collapsing foot deformity (PCFD) as measured on DRR, to investigate whether DRR represents comparably to XR through the same measurements, and to compare agreement of DRR and XR measurements of a standardized arch height parameter with reference measurements made on WBCT.

METHODS

DRR generated from preoperative WBCT of 71 patients (72 feet) treated surgically for PCFD were retrospectively compared with preoperative weight-bearing XR after exclusion criteria were applied. Six radiographic measurements were performed, including Meary angle, calcaneal pitch (CPA), medial cuneiform height (MCH), AP talar-first metatarsal angle (T-1MT), talonavicular coverage (TNCA), and talar incongruency (TIA). Arch height was measured on XR, DRR, and WBCT using a validated, standardized, navicular-based index. Intraclass correlation coefficients assessed DRR intraobserver and interobserver reliability. Paired samples t tests tested differences between XR and DRR. Bland-Altman limits of agreement analysis compared DRR and XR agreement with WBCT measurements.

RESULTS

Measurements were within standard PCFD ranges on XR and DRR. All measurements demonstrated excellent intrarater reliability and good to excellent interrater agreement, consistent with previous literature on XR. No differences were found for Meary, CPA, or TNCA. Minor differences were observed for MCH, T-1MT, and TIA. DRR measurements demonstrated greater agreement with WBCT than XR measurements.

CONCLUSION

DRR from WBCT may be a promising substitute for XR in the clinical evaluation of PCFD. Radiographic measurements made on DRR demonstrated good to excellent reliability. Although small differences were found between XR and DRR for certain measurements, DRR more accurately represented medial arch anatomy compared to gold standard WBCT data than XR. If validated as a clinical substitute, DRR could eventually obviate XR where WBCT is available.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

Outcomes and Return-to-Sport Rates for Elite Athletes With Femoral Retroversion Undergoing Hip Arthroscopy: A Propensity-Matched Analysis With Minimum 2-Year Follow-up

Background:

Return to sports (RTS) and patient-reported outcomes (PROs) for elite athletes with femoral version abnormalities undergoing hip arthroscopy have not been well established.

Purposes:

To (1) report minimum 2-year PROs and RTS rates in elite athletes with femoral retroversion who underwent primary hip arthroscopy and (2) compare clinical results to those of a propensity-matched control group of elite athletes with normal femoral version who underwent primary hip arthroscopy.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Data were prospectively collected and retrospectively reviewed for elite (professional and collegiate) athletes with femoral version <5°, as measured on magnetic resonance imaging scans, who underwent hip arthroscopy for femoroacetabular impingement syndrome between March 2010 and April 2018. Inclusion criteria were preoperative and minimum 2-year follow-up PROs for the modified Harris Hip Score, Nonarthritic Hip Score, Hip Outcome Score–Sports Specific Subscale (HOS-SSS), and visual analog scale for pain. Exclusion criteria were Tönnis grade >1, hip dysplasia, and previous ipsilateral hip surgery or conditions. Rates of achieving the minimal clinically important difference (MCID), Patient Acceptable Symptom State (PASS), and maximum outcome improvement satisfaction threshold were recorded in addition to RTS. Athletes with retroversion were propensity matched in a 1:2 ratio to elite athletes with normal femoral version (5°-20°) for comparison.

Results:

A total of 33 elite athletes (33 hips) with femoral retroversion who underwent hip arthroscopy met the inclusion criteria, and follow-up was available for 30 hips in 30 athletes (90.9%) at an average of 36.1 ± 25.6 months. Elite athletes with femoral retroversion demonstrated significant improvements in all recorded PROs, achieved the MCID and PASS for the HOS-SSS at high rates (86.7%), and returned to sports at a rate of 83.3%. PROs, rates of achieving MCID and PASS for the HOS-SSS, and RTS rates were similar between the study and propensity-matched control group.

Conclusion:

Elite athletes with femoral retroversion undergoing primary hip arthroscopy demonstrated favorable PROs and high RTS rates at a minimum 2-year follow-up. These results were comparable with those of a propensity-matched control group of elite athletes with normal femoral version.

Sex-Based Differences in Athletes Undergoing Primary Hip Arthroscopy With Labral Reconstruction: A Propensity-Matched Analysis With Minimum 2-Year Follow-up

Background:

There is a paucity of literature comparing sex-based outcome differences in athletes after primary hip arthroscopy with labral reconstruction for femoroacetabular impingement syndrome (FAIS) and irreparable labral tears.

Purpose:

To report sex-based differences in clinical characteristics, patient-reported outcome (PRO) scores, and return-to-sports (RTS) rates in athlete who underwent primary hip arthroscopy with labral reconstruction.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Data were reviewed for recreational, organized amateur, high school, collegiate, and professional athletes who underwent primary hip arthroscopy with labral reconstruction for FAIS and irreparable labral tears between July 2014 and May 2019. Inclusion criteria included preoperative and minimum 2-year postoperative PRO scores (modified Harris Hip Score, Non-Arthritic Hip Score, Hip Outcome Score–Sports Specific Subscale, International Hip Outcome Tool [iHOT-12], and visual analog scale [VAS] for pain). Exclusion criteria were Tönnis grade >1, hip dysplasia (lateral center-edge angle, <18°), or prior ipsilateral hip surgery/conditions. Patients were divided into groups by sex and were propensity-matched in a 1:1 ratio by age, body mass index, graft type, labral tear size, and sports level.

Results:

A total of 101 hips were eligible, and 94 hips (93.1%) had a minimum 2-year follow-up. Twenty-nine female athlete hips were propensity-matched to 29 male athlete hips. Female athletes underwent higher rates of capsular repair (79.3% vs 24.1% for men; P < .001) and lower rates of acetabular microfracture (0.0% vs 20.7% for men; P = .024). Both female and male athletes experienced significant improvement on all PRO scores (P < .001 for all), high RTS rates (women, 84% vs men, 80.8%), and high rates of achieving the minimal clinically important difference for the iHOT-12 and VAS pain (women, 88.5% vs men, 71.4% for both) and achieving the patient acceptable symptom state for the iHOT-12 (women, 88.5% vs men, 71.4%), with no significant difference between the sexes.

Conclusion:

Despite different clinical characteristics and surgical procedures, both female and male athletes undergoing primary hip arthroscopy with labral reconstruction had significant improvements in all PROs at the minimum 2-year follow-up, high RTS rates, and similar rates of achieving the minimal clinically important difference and patient acceptable symptom state.

Minimum 5-Year Outcomes After Primary Segmental Labral Reconstruction for Irreparable Labral Tears in the Hip With Hamstring Grafts: With a Subanalysis Comparing Autograft Versus Allograft

BACKGROUND

Comparable short-term outcomes have been obtained using hamstring allografts versus autografts after primary segmental labral reconstruction (SLR). Midterm results have not yet been determined.

PURPOSE

(1) To evaluate minimum 5-year patient-reported outcome (PRO) scores in patients who underwent primary SLR with hamstring grafts in the setting of femoroacetabular impingement syndrome (FAIS) and irreparable labral tears and (2) to compare the outcomes of hamstring autografts versus allografts in a subanalysis using propensity-matched groups.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Prospectively collected data were retrospectively reviewed for patients who underwent primary hip arthroscopy between September 2010 and November 2015. Patients were included if they underwent SLR using hamstring autografts or allografts and had preoperative and minimum 5-year PROs. The exclusion criteria were previous ipsilateral hip surgery or conditions, dysplasia, or Tönnis grade >1. Patients with autograft SLR were propensity matched 1 to 1 based on age, sex, and body mass index (BMI) to patients who underwent SLR using hamstring allografts. The minimal clinically important difference (MCID) and the Patient Acceptable Symptom State (PASS) were calculated.

RESULTS

Overall, 48 patients (N = hips 48) were eligible to be included in this study, and 41 patients (n = 41 hips [85.4%]) had a minimum 5-year follow-up reporting significant improvements in all PROs. Within the entire cohort, 9.8% required a secondary arthroscopy, with a mean time of 19 ± 1.8 months, and survivorship was 82.9%. Of the 41 included patients, 15 underwent an SLR with a hamstring autograft and were matched to 15 patients with labral reconstruction using a hamstring allograft. Groups were similar for sex (P > .999), age (P = .775), and BMI (P = .486). The mean follow-up times were 80.8 ± 25.5 and 66.1 ± 8.3 months (P = .223) for the autograft and allograft groups, respectively. Baseline PROs, preoperative radiographic measurements, surgical findings, and intraoperative procedures were similar. The groups achieved significant and comparable improvements for all PROs (P < .0001), satisfaction (P = .187), and the rate of achieving the MCID and the PASS. However, a tendency for higher postoperative PROs favoring allograft reconstruction was found.

CONCLUSION

At a minimum 5-year follow-up, patients who underwent primary arthroscopic SLR in the context of FAIS and irreparable labra, with either autograft or allograft hamstring tendons, reported significant improvements and comparable postoperative scores for all PROs, patient satisfaction, MCID, and PASS.

Basketball Players Undergoing Primary Hip Arthroscopy Exhibit Higher Grades of Acetabular Cartilage Damage but Achieve Favorable Midterm Outcomes and Return to Sports Rates Comparable With a Propensity-Matched Group of Other Cutting Sports Athletes

BACKGROUND

Favorable short-term outcomes in competitive basketball players have been reported. Midterm outcomes in these athletes and how they compare with athletes in sports with similar demands have not been well established.

PURPOSE

(1) To report minimum 5-year patient-reported outcomes (PROs) and return to sports data in competitive basketball players undergoing primary hip arthroscopy for femoroacetabular impingement syndrome (FAIS) and (2) to compare outcomes with a propensity-matched control group of other cutting sports athletes.

STUDY DESIGN

Cohort study, Level of evidence, 3.

METHODS

Data were prospectively collected and retrospectively reviewed for basketball players who competed at the professional, collegiate, high school, or competitive amateur levels and underwent primary hip arthroscopy for FAIS between May 2009 and March 2016. Patients with preoperative and minimum 5-year postoperative outcomes for the modified Harris Hip Score (mHHS), Nonarthritic Hip Score (NAHS), Hip Outcome Score-Sports Specific Subscale (HOS-SSS), and visual analog scale (VAS) for pain were included. Patients were propensity matched to athletes in other cutting sports (soccer, lacrosse, field hockey, and tennis) according to age, sex, body mass index (BMI), and preoperative competition level for comparison.

RESULTS

A total of 28 competitive basketball players were included, with a mean follow-up time of 67.1 ± 5.1 months and a mean BMI of 23.7 ± 4; there were 12 (42.9%) female athletes. The cohort was composed of 1 professional, 10 collegiate, 13 high school, and 4 organized amateur athletes. They demonstrated significant improvements in all recorded PROs from baseline to the minimum 5-year follow-up (P < .001) and had high rates of achieving the minimal clinically important difference (MCID) for the mHHS (75%), NAHS (75%), HOS-SSS (67.9%), and VAS for pain (71.4%). Furthermore, 76.5% of basketball players who returned to sports were still competing at a minimum of 5 years postoperatively. When compared with a propensity-matched cohort of other cutting athletes, basketball athletes demonstrated a significantly higher acetabular labrum articular disruption (ALAD) grade (P < .001) and trended toward a higher Outerbridge grade of the acetabular cartilage (P = .067). Despite this, basketball players demonstrated similar preoperative, postoperative, and improvement scores in all recorded PROs. Moreover, both groups exhibited similar rates of achieving psychometric thresholds and rates of continued sports participation at minimum 5-year follow-up.

CONCLUSION

Competitive basketball players undergoing primary hip arthroscopy for FAIS demonstrated significant improvements in all recorded PROs and high rates of continued play at a minimum 5-year follow-up. When compared with a control group of other cutting sports athletes, basketball players exhibited more severe ALAD grades intraoperatively but similar midterm outcomes.

Effect of Cigarette Smoking on Midterm Outcomes After Arthroscopic Surgery for Femoroacetabular Impingement Syndrome: A Propensity-Matched Controlled Study With Minimum 5-Year Follow-up

Background:

There is limited literature evaluating patient-reported outcomes (PROs) in cigarette smokers undergoing hip arthroscopy for femoroacetabular impingement syndrome (FAIS) at midterm follow-up.

Purpose:

(1) To report minimum 5-year PROs for cigarette-smoking patients who underwent primary hip arthroscopy for FAIS and (2) to compare these results with a propensity-matched control group of never-smoking patients.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Data were collected for all patients who underwent primary hip arthroscopy for FAIS between June 2009 and March 2016. Patients were eligible if they indicated that they smoked cigarettes within 1 month of surgery and had minimum 5-year postoperative outcomes for the modified Harris Hip Score, Nonarthritic Hip Score, Hip Outcome Score–Sport Specific Subscale (HOS-SSS), and International Hip Outcome Tool–12 (iHOT-12). The percentages of patients achieving the Patient Acceptable Symptom State (PASS) and maximum outcome improvement satisfaction threshold were recorded. The study group was then propensity matched in a 1:2 ratio to patients who had never smoked for comparison.

Results:

Included were 35 patients (35 hips) with a mean age of 39.4 ± 13.0 years and mean follow-up of 64.6 ± 4.1 months. These patients demonstrated significant improvement from preoperatively to a minimum 5-year follow-up for all recorded PROs (P < .05). When compared with 70 control patients (70 hips), smoking patients demonstrated significantly worse preoperative scores for all PROs (P < .05). Study patients also demonstrated worse minimum 5-year scores for all recorded PROs compared with control patients, which did not reach statistical significance but trended toward significance for HOS-SSS (70.4 vs 81.9; P = .076) and iHOT-12 (74.7 vs 82.2; P = .122). Smoking patients also trended toward lower rates of achieving PASS for the iHOT-12 compared with never-smoking patients (50.0% vs 68.2%; P = .120).

Conclusion:

Patients who smoked cigarettes and underwent primary hip arthroscopy for FAIS demonstrated significant improvement in PROs at a minimum 5-year follow-up. When compared with a propensity-matched control group of never-smokers, they trended toward lower postoperative HOS-SSS and iHOT-12 scores and lower rates of achieving PASS on the iHOT-12.

Revision Hip Arthroscopy With Labral Reconstruction for Irreparable Labral Tears in Athletes: Minimum 2-Year Outcomes With a Benchmark Control Group

BACKGROUND

The incidence of revision hip arthroscopy with labral reconstruction in athletes is increasing. However, the outcomes of revision hip arthroscopy with labral reconstruction in athletes have not been well established.

PURPOSES

(1) To report minimum 2-year patient-reported outcome (PRO) scores and return to sports (RTS) characteristics for high-level athletes undergoing revision hip arthroscopy with labral reconstruction and (2) to compare clinical results with those of a propensity-matched control group of high-level athletes undergoing revision hip arthroscopy with labral repair.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Data were prospectively collected and retrospectively reviewed for athletes at any level who underwent a revision hip arthroscopy and a labral reconstruction between April 2010 and March 2019. Minimum 2-year PROs were reported for the modified Harris Hip Score (mHHS), the Nonarthritic Hip Score (NAHS), the Hip Outcome Score-Sport Specific Subscale (HOS-SSS), the visual analog scale (VAS) for pain, and RTS. The percentages of athletes achieving the minimal clinically important difference (MCID) and the maximum outcome improvement satisfaction threshold (MOIST) were also recorded. These patients were propensity matched in a 1: 1 ratio to athletes undergoing revision hip arthroscopy with labral repair for comparison.

RESULTS

A total of 46 athletes (N = 47 hips) were reported from 50 (n = 51 hips) athletes who underwent revision with labral reconstruction. A subanalysis of 30 propensity-matched athletes undergoing revision labral reconstruction was performed, with a mean follow-up time of 26.3 ± 2.4 months and an age of 28.5 ± 10.1 years, and compared with a revision labral repair group. Significant improvements were obtained for the mHHS, the NAHS, the HOS-SSS, and the VAS from preoperative to the latest follow-up (P < .001), with an achievement MCID rate of 61.5%, 72%, 62.5%, and 76.9% for the mHHS, the NAHS, the HOS-SSS, and the VAS, respectively. The rate for re-revision surgery (2 tertiary arthroscopy and 1 conversion to total hip arthroplasty) was 10%, and 14 patients (63.6%) were able to RTS. Improvements in PROs, rates of achieving MCID/MOIST, rate of re-revision surgery (re-revision hip arthroscopy, P = .671; conversion to total hip arthroplasty, P > .999), and RTS rate (P = .337) were similar when compared with those of the propensity-matched control labral repair group (P > .05).

CONCLUSION

Revision hip arthroscopy with labral reconstruction, in the context of an irreparable labral tear, seems to be a valid treatment option in the athletic population, demonstrating significant improvements in all PROs and low rates of undergoing revision surgery. Athletes experienced a similar magnitude of improvement in PROs, RTS rate, and revision surgery rate to that of a propensity-matched control group of athletes undergoing revision hip arthroscopy with labral repair.

Competitive Athletes with Femoroacetabular Impingement and Painful Internal Snapping Treated Arthroscopically with Intrabursal Iliopsoas Fractional Lengthening: High Rate of Return to Sport and Favorable Midterm Functional Outcomes

BACKGROUND

Athletes with femoroacetabular impingement syndrome (FAIS) who undergo hip arthroscopy with iliopsoas fractional lengthening (IFL) in the context of painful internal snapping have demonstrated favorable patient-reported outcomes (PROs), return to sport (RTS), and resolution of internal snapping symptoms at short term follow-up. Midterm outcomes have not been established.

PURPOSES

(1) To report minimum 5-year PROs and RTS rate in competitive athletes who underwent primary hip arthroscopy for FAIS and intra-bursal IFL for painful internal snapping and (2) to compare these clinical results with those of a propensity score-matched control group of competitive athletes who underwent primary hip arthroscopy without painful internal snapping and IFL.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Data were reviewed for consecutive surgeries performed by a single surgeon between February 2010 and December 2013. Patients were considered eligible if they were professional, collegiate, or high school athletes and received a primary hip arthroscopy for FAIS and intra-bursal IFL without extended capsulotomy for painful internal snapping. Indications for IFL were painful internal snapping on preoperative physical examination. Inclusion criteria were preoperative and minimum 5-year follow-up scores for the modified Harris Hip Score, Nonarthritic Hip Score, Hip Outcome Score-Sport Specific Subscale, and visual analog scale for pain. Rates of achieving the minimal clinically important difference were also reported. For comparison, athletes in the IFL group were propensity matched by age, sex, body mass index, lateral and anterior center-edge angles, and sports level to a control group of athletes without internal snapping who underwent primary hip arthroscopy for FAIS without IFL.

RESULTS

A total of 105 competitive athletes in the IFL group were included in the study with a follow-up of 66.8 ± 6.9 months (mean ± SD). The IFL cohort showed significant improvement in all recorded PROs at minimum 5-year follow-up (P < .001). Furthermore, they demonstrated favorable rates of achieving the minimal clinically important difference for the modified Harris Hip Score (82.0%), Nonarthritic Hip Score (85.4%), and Hip Outcome Score-Sport Specific Subscale (82.8%). Further, 89.5% of athletes in the IFL cohort successfully returned to sport. A total of 42 athletes in the IFL group were propensity matched to 54 control athletes. When groups were compared, they demonstrated similar improvement in PROs and rates of RTS, revision arthroscopy, and achieving psychometric thresholds.

CONCLUSION

Competitive athletes undergoing primary hip arthroscopy and intra-bursal IFL in the context of FAIS and painful internal snapping demonstrated favorable PROs and RTS rate at minimum 5-year follow-up. These results were comparable with those of a control group of athletes not requiring IFL.

Minimum 2-Year Outcomes and Return to Sports of Competitive Athletes Who Undergo Subspine Decompression During Primary Hip Arthroscopy for Femoroacetabular Impingement Syndrome and Subspine Impingement: A Propensity-Matched Controlled Study

BACKGROUND

Patient-reported outcomes (PROs) and return to sports (RTS) have not been established in athletes undergoing primary hip arthroscopy and subspine decompression for femoroacetabular impingement syndrome (FAIS) and subspine impingement (SSI).

PURPOSE

(1) To report minimum 2-year PROs and RTS in competitive athletes undergoing primary hip arthroscopy for treatment of FAIS with subspine decompression for treatment of SSI and (2) to compare clinical results with a matched control group of athletes without SSI.

STUDY DESIGN

Cohort study, Level of evidence, 3.

METHODS

Data were reviewed for professional, collegiate, and high school athletes undergoing primary hip arthroscopy for FAIS with arthroscopic subspine decompression for SSI between February 2011 and October 2018. Inclusion criteria included preoperative and minimum 2-year follow-up scores for the modified Harris Hip Score, Nonarthritic Hip Score, Hip Outcome Score-Sport Specific Subscale, and visual analog scale for pain. Rates of achieving the minimal clinically important difference (MCID) were also calculated. For comparison, athletes in the SSI group were propensity matched according to age at the time of surgery, sex, body mass index, lateral center-edge angle, alpha angle, sport level, acetabular labrum articular disruption grade, and sport type to a control group of athletes without SSI.

RESULTS

A total of 30 SSI athletes were included in the study, with a mean plus or minus standard deviation follow-up of 32.1 ± 7.1 months and age of 20.9 ± 5.7 years. The SSI cohort demonstrated significant improvement in all recorded PROs (P < .001), returned to sports at high rates (88.5%), and achieved the MCID for the Hip Outcome Score-Sport Specific Subscale at a high rate (80.0%). Furthermore, these patients had a low rate of undergoing revision surgery (6.7%). When compared with a propensity-matched control group of 59 athletes, the SSI group demonstrated similar rates of RTS, revision, and achieving the MCID for all PROs.

CONCLUSION

Competitive athletes with FAIS and SSI who underwent primary hip arthroscopy and subspine decompression had favorable outcomes and high RTS rates at minimum 2-year follow-up. These results were comparable with those of a control group of athletes without SSI undergoing primary hip arthroscopy.

Dunn View Alpha Angle More Useful Than Femoral Head-Neck Offset to Predict Acetabular Cartilage Damage in Patients With Femoroacetabular Impingement Syndrome Undergoing Hip Arthroscopy

PURPOSE

To identify radiographic measurements and demographics that are predictive of acetabular cartilage damage in patients with femoroacetabular impingement syndrome (FAIS) undergoing hip arthroscopy. More specifically, to compare the predictive value of alpha angle and femoral head-neck offset, as measured on Dunn view radiographs, in determining the preoperative likelihood and severity of acetabular cartilage damage.

METHODS

Patients were included if they underwent primary hip arthroscopy for FAIS between February 2008 and June 2020. Exclusion criteria were prior ipsilateral hip conditions, Tönnis grade of osteoarthritis >1, unwilling to participate, missing intraoperative, demographic or radiographic variables of interest, and lateral center-edge angle (LCEA) >40° or ≤25°. Fourteen variables were assessed in a bivariate comparison and analyzed in a multivariate logistic model. The Acetabular Labrum Articular Disruption (ALAD) and Outerbridge (OB) classifications were used to define acetabular cartilage defects. Those without damage or those with mild acetabular cartilage damage belonged to the ALAD/OB ≤2 group and those with severe damage belonged to the ALAD/OB ≥ 3 group.

RESULTS

A total of 1485 patients were analyzed, including 1038 patients with ALAD/OB ≤2 and 447 patients with ALAD/OB ≥3. There was a greater proportion of males in the ALAD/OB ≥3 group (64.21% vs 25.82%; P <.001). The multivariate logistic regression selected age, sex, anterior center-edge angle (ACEA), and alpha angle. Every additional degree in the alpha angle was associated with a 6% increase in the odds of severe acetabular cartilage damage (odds ratio [OR], 1.06 [95% confidence interval [CI], 0.12-8.11]). The multivariate analysis did not identify femoral head-neck offset as a predictor. The odds of severe acetabular cartilage damage were 3.73 times higher in males than females (OR, 3.73 [95% CI, 0.01-1705.96]). Higher age was found to increase the likelihood of ALAD/OB ≥3 (OR, 1.04 [95% CI, 0.13-7.75]).

CONCLUSIONS

In a multivariate analysis, factors identified as preoperative predictors of acetabular cartilage damage in patients with FAIS were age, sex, ACEA, and alpha angle. Femoral head-neck offset was not predictive, suggesting that Dunn view alpha angle may take precedence as a predictor of acetabular cartilage damage.

LEVEL OF EVIDENCE

Level III, cohort study.

Effect of Cigarette Smoking on Outcomes in Patients Undergoing Primary Hip Arthroscopy and Labral Reconstruction: A Propensity-Matched Controlled Study With Minimum 2-Year Follow-up

Background:

There is a paucity of literature evaluating the effect of cigarette smoking on outcomes in patients undergoing hip arthroscopy and labral reconstruction.

Purpose:

(1) To report minimum 2-year patient-reported outcome (PRO) scores for patients who smoke cigarettes and underwent primary hip arthroscopic labral reconstruction and (2) to compare these results with those of a propensity-matched control group of patients who have never smoked.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Data were collected for all patients who underwent primary hip arthroscopy for labral reconstruction between January 2011 and January 2019. Patients were eligible for the study if they indicated that they smoked cigarettes within 1 month of surgery and had minimum 2-year postoperative outcome scores for the modified Harris Hip Score (mHHS), Nonarthritic Hip Score (NAHS), and the visual analog scale (VAS) for pain. The percentage of patients achieving the minimal clinically important difference (MCID) and patient-acceptable symptom state (PASS) was recorded. Rates of revision surgery were also documented. These patients were then propensity matched in a 1:3 ratio to patients who had never smoked (controls) for comparison.

Results:

A total of 20 patients (20 hips) were included with a mean follow-up of 39.9 ± 13.0 months and mean age of 41.4 ± 10.4 years. These patients demonstrated significant improvement from preoperatively to the minimum 2-year follow-up for mHHS, NAHS, and VAS (P < .05). They also achieved MCID for mHHS and VAS at acceptable rates, 70% for both. When outcomes were compared with those of 60 control patients (60 hips), patients who smoke demonstrated lower preoperative PRO scores but similar minimum 2-year postoperative PRO scores for mHHS and NAHS. Patients who smoke demonstrated lower rates of achieving PASS for mHHS (55% vs 75%) and NAHS (40% vs 61.7%) compared with controls; however, these findings were not statistically significant. Rates of secondary surgery were statistically significantly higher in the smoking group compared with controls (25% vs 5%; P = .031). Survivorship for the smoking patients was 80% and 98.3% for the control group. At the two-year mark survivorship was 90% for the smoking group and 100% for the control group (P = .06)

Conclusion:

While smokers can still derive significant improvement from hip arthroscopy, their ultimate functional outcome and rate of secondary surgeries are inferior to those of nonsmokers. As smoking is a significant and modifiable risk factor, we should continue to counsel smokers on smoking cessation prior to and after surgery

Effect of Patient Positioning on Measurement of the Anterior Center-Edge Angle on False-Profile Radiographs and Its 3-Dimensional Mapping to the Acetabular Rim

Background:

The anterior center-edge angle (ACEA) is used to quantify anterior coverage of the femoral head by the acetabulum. However, its measurement has not been evaluated in a manner consistent with routine use, and the precise 3-dimensional (3D) anatomic location where it measures coverage is not known.

Purpose:

To determine the effect of patient positioning on ACEA measurement reliability, magnitude, and 3D location.

Study Design:

Descriptive laboratory study.

Methods:

Included were 18 adults; 7 participants had cam morphology and femoroacetabular impingement syndrome, and 11 participants had no radiographic evidence of hip abnormalities and no history of hip pain or injuries. Ultimately, 3D femur and pelvis models were generated from computed tomography images. Radiographs were generated with the models in different degrees of pelvic rotation, tilt, and obliquity relative to the standard false-profile view. The ACEA was measured by 2 raters by selecting the location of the bone edge on each radiograph. Selections were projected onto the pelvis model and expressed as a clockface location on the acetabular rim. The clockface was mirrored on left hips to allow a direct comparison of locations between hips. Interrater and intrarater reliability were quantified via the intraclass correlation coefficient (ICC). The effect of position on ACEA measurements and clockface locations was determined via linear regression.

Results:

Intrarater and interrater reliability were excellent (ICC ≥0.97 for all). For every degree increase in rotation, tilt, and obliquity, the ACEA changed by +0.53°, +0.93°, and –0.04°, respectively. The mean clockface location (hour:minute:second) in the false-profile view was 2:09:32 ± 0:12:00 and changed by +0:02:08, –0:00:35, and –0:00:05 for every degree increase in rotation, tilt, and obliquity, respectively.

Conclusion:

ACEA measurements were reliable even with differences in patient positioning. Rotation and tilt were associated with notable changes in ACEA measurements. ACEA bone edge measurements mapped to the anterosuperior acetabular rim, typically in proximity to the anterior inferior iliac spine. Mapped location was most sensitive to rotation.

Clinical Relevance:

Pelvic rotation and tilt affected ACEA measurements, which could alter the clinical classification and treatment of borderline abnormalities. Rotation in particular must be well controlled during patient imaging to preserve measurement reliability and accuracy and to describe coverage from the intended 3D rim location.

Comparable Minimum 2-Year Patient-Reported Outcome Scores Between Circumferential and Segmental Labral Reconstruction for the Management of Irreparable Labral Tear and Femoroacetabular Impingement Syndrome in the Primary Setting: A Propensity-Matched Study

PURPOSE

To compare minimum 2-year follow-up patient-reported outcome scores (PROs) in patients who underwent primary acetabular circumferential and segmental labral reconstruction for irreparable labral tears and femoroacetabular impingement syndrome (FAIS).

METHODS

Data were reviewed from August 2010 to December 2017. Patients with primary labral reconstruction and minimum 2-year follow-up for the modified Harris Hip Score (mHHS), Non-Arthritic Hip Score (NAHS), Hip Outcome Score-Sports Specific Subscale (HOS-SSS), and visual analog scale (VAS) for pain were included. Circumferential and segmental reconstruction were selected in each case based on the extent of the labral pathology. Exclusion criteria were previous ipsilateral hip surgery/conditions, dysplasia, or Tönnis grade >1. Patients were propensity matched 1:1 based on age, sex, and body mass index. Secondary surgeries were reported. The P value was set at <.05.

RESULTS

In total, 144 hips were eligible, and 17 hips were lost to follow-up, leaving 127 hips (88.2%) for analysis. Eighty hips underwent a segmental reconstruction, and 47 hips underwent a circumferential reconstruction. Forty-seven hips with circumferential reconstruction were matched to 47 hips with segmental reconstruction. The average follow-up and age for the segmental and circumferential groups were 29.0 ± 7.8 and 27.9 ± 7.0 months (P = .732) and 43.1 ± 9.4 and 44.7 ± 10.2 years (P = .442) respectively. The segmental and circumferential groups were 48.9% and 51.1% female, respectively. The groups achieved significant and comparable improvement for all PROs and rates of secondary surgeries. No differences were found for achieving the minimal clinically important difference (MCID) and the patient acceptable symptomatic state (PASS). The MCIDs for the segmental and circumferential groups were 76.7% and 77.8% for the mHHS, 64.9% and 77.8% for the HOS-SSS, 71.1% and 68.9% for the VAS, and 68.9% and 73.9% for the NAHS, respectively. The PASSs for the segmental and circumferential groups were 78.3% and 73.3% for the mHHS, 55.3% and 55.0% for the HOS-SSS, and 75.6% and 71.1% for the International Hip Outcome Tool 12, respectively.

CONCLUSIONS

At minimum 2-year follow-up, patients who underwent primary hip arthroscopy for either circumferential or segmental labral reconstruction for irreparable labra and FAIS reported significant improvement and similar postoperative scores for all PROs, with no difference in psychometric outcomes and rate of secondary surgeries. A customized approach, using the extent of the irreparable labral tear, seems to be an appropriate strategy.

LEVEL OF EVIDENCE

Level III, retrospective comparative therapeutic trial.

Multicenter Outcomes After Primary Hip Arthroscopy: A Comparative Analysis of Two-Year Outcomes After Labral Repair, Segmental Labral Reconstruction, or Circumferential Labral Reconstruction

PURPOSE

(1) To report minimum 2-year follow-up patient-reported outcome measures in patients undergoing labral repair (LR), segmental labral reconstruction (SLR), or circumferential labral reconstruction (CLR) in the primary setting; and (2) to compare minimum 2-year follow-up patient-reported outcome measures among these groups.

METHODS

A retrospective review of a prospectively maintained multicenter database of patients undergoing hip arthroscopy was performed. Inclusion criteria were patients undergoing hip arthroscopy for treatment of labral tear and femoroacetabular impingement syndrome between January 2014 and October 2017, and completion of minimum 2-year postoperative outcome scores. Exclusion criteria were patients undergoing revision hip surgery, labral treatment limited to debridement, lateral center-edge angle <20°, osteoarthritis (Tönnis grade > 1), slipped capital femoral epiphysis, workers compensation status, and patients undergoing concomitant gluteus medius and/or minimus repair. Labral reconstruction patients were matched (1:3) with labral repair patients on age, sex, and body mass index. The labral reconstruction group was further stratified into SLR, and CLR groups. Patient demographic characteristics and clinical outcomes including Hip Outcome Score - Activities of Daily Living, Hip Outcome Score - Sport Subscale, modified Harris Hip Score, international Hip Outcome Tool, and visual analog scale for pain were analyzed, as well as achievement of the minimal clinical improvement difference (MCID). A P-value less than .05 indicated statistical significance.

RESULTS

A total of 416 patients were included (LR, n = 312; SLR, n = 53; CLR, n = 51). The age, body mass index, and sex of the matched cohort were 42.3 ± 11.2 years, 24.7 ± 3.7, and 55.0% female. At a minimum of 2-year after hip arthroscopic surgery, no differences were found in preoperative, postoperative, or the delta visual analog scale for pain, modified Harris Hip Score, Hip Outcome Score - Activities of Daily Living, Hip Outcome Score - Sport Subscale, or international Hip Outcome Tool. Subsequently, the proportion of patients achieving the MCID and the PASS at latest follow-up were analyzed. This analysis revealed that no significant differences in the rate of MCID or PASS achievement for any outcome measure existed based on labral treatment.

CONCLUSIONS

In this multicenter study on labral treatment in the primary setting, patients undergoing LR, SLR, and CLR demonstrated no difference in preoperative or postoperative scores, nor the proportion of patients achieving clinically significant outcome improvement.

LEVEL OF EVIDENCE

III; therapeutic outcome study with controls.

Return to Sports and Minimum 2-Year Outcomes of Hip Arthroscopy in Elite Athletes With and Without Coexisting Low Back Pain: A Propensity-Matched Comparison

BACKGROUND

Patient-reported outcomes (PROs) and return to sports (RTS) after hip arthroscopy for femoroacetabular impingement syndrome (FAIS) have not been established in elite athletes with coexisting low back pain (LBP).

PURPOSE

(1) To report minimum 2-year PROs and RTS rates after primary hip arthroscopy for FAIS in elite athletes with coexisting LBP and (2) to compare clinical results with a propensity-matched control group of elite athletes without back pain.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Data were reviewed for elite athletes (college and professional) who underwent hip arthroscopy for FAIS and had coexisting LBP between October 2009 and October 2018. Inclusion criteria were preoperative and minimum 2-year follow-up for the modified Harris Hip Score, Nonarthritic Hip Score, Hip Outcome Score-Sports Specific Subscale (HOS-SSS), and visual analog scale for pain. Exclusion criteria were Tönnis grade >1, hip dysplasia (lateral center-edge angle <18°), and previous ipsilateral hip or spine surgery or conditions. Rates of achieving the minimal clinically importance difference (MCID), patient acceptable symptomatic state (PASS), and maximum outcome improvement satisfaction threshold were recorded in addition to RTS. For the subanalysis, the elite athlete study group was propensity matched to an elite athlete control group without back pain.

RESULTS

A total of 48 elite athletes with LBP who underwent primary hip arthroscopy met inclusion criteria, and follow-up was available for 42 (87.5%) at 53.2 ± 31.6 months (mean ± SD). Elite athletes with coexisting LBP demonstrated significant improvements in all recorded PROs and achieved the MCID and PASS for the HOS-SSS at rates of 82.5% and 67.5%, respectively. They also returned to sports at a high rate (75.8%), and 79% of them did not report LBP postoperatively. PROs, rates of achieving the MCID and PASS for the HOS-SSS, and RTS rates were similar between the study group and propensity-matched control group.

CONCLUSION

Elite athletes with coexisting LBP who undergo primary hip arthroscopy for FAIS may expect favorable PROs, rates of achieving the MCID and PASS for the HOS-SSS, and RTS rates at minimum 2-year follow-up. These results were comparable to those of a propensity-matched control group of elite athletes without back pain. In athletes with hip-spine syndrome, successful treatment of their hip pathology may help resolve their back pain.

Labral Tear Management in Patients Aged 40 Years and Older Undergoing Primary Hip Arthroscopy: A Propensity-Matched Case-Control Study With Minimum 2-Year Follow-up

BACKGROUND

Previous literature has suggested that primary acetabular labral reconstruction leads to lower secondary surgery rates than does labral repair for patients aged ≥40 years.

PURPOSE

To report minimum 2-year patient-reported outcome (PRO) scores, survivorship, and secondary surgeries in patients aged ≥40 years who underwent primary hip arthroscopy with labral reconstruction compared with a propensity-matched primary labral repair group.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

Data were prospectively collected and retrospectively reviewed for patients who underwent a primary hip arthroscopy for femoroacetabular impingement syndrome between January 2014 and June 2018. Patients aged ≥40 years who underwent a labral reconstruction or a labral repair and had preoperative and minimum 2-year PROs for the modified Harris Hip Score, Nonarthritic Hip Score, and visual analog scale (VAS) for pain were included. Patients with previous ipsilateral hip conditions and surgery, Tönnis grade >1, hip dysplasia, or workers' compensation status were excluded. Patients in the reconstruction group were propensity matched 1:2 to patients in the repair group based on age, sex, and body mass index. Secondary surgeries and achievement of the minimal clinically important difference (MCID), patient acceptable symptom state (PASS), and maximum outcome improvement (MOI) were recorded.

RESULTS

A total of 53 and 106 hips were included in the labral reconstruction and repair groups, respectively. The average follow-up time was 37.6 months. The average ages for the reconstruction and repair groups were 48.01 ± 5.4 years and 48.61 ± 6.0 years, respectively. Both groups achieved significant improvements in all PROs at a minimum of 2 years, with similar achievements of MCID, PASS, and MOI, and comparable secondary surgery rates.

CONCLUSION

Patients aged ≥40 years who received primary labral repair and primary labral reconstruction achieved similar significant improvements in all PROs, VAS pain, and patient satisfaction at the minimum 2-year follow-up, with comparable rates of secondary surgeries and achieving MCID, PASS, and MOI. Based on these findings, labral repair remains the gold standard treatment for viable labrum in this population group, while reconstruction is a useful alternative for irreparable labrum.

Return to Sports and Minimum 2-Year Outcomes of Bilateral Hip Arthroscopy in High-Level Athletes With a Propensity-Matched Benchmarking Against a Unilateral Control Group

BACKGROUND

Return to sports (RTS) and patient-reported outcomes (PROs) for high-level athletes after bilateral hip arthroscopy have not been well established.

PURPOSE

(1) To report minimum 2-year PROs and RTS rates in high-level athletes who underwent staged bilateral primary hip arthroscopies and (2) to compare clinical results against a propensity-matched control group of high-level athletes who underwent unilateral primary hip arthroscopy.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Data were prospectively collected and retrospectively reviewed for high-level athletes (professional, college, or high school) who underwent staged bilateral hip arthroscopy for femoroacetabular impingement syndrome between September 2009 and October 2018. Inclusion criteria were preoperative and minimum 2-year follow-up for modified Harris Hip Score, Non-arthritic Hip Score, Hip Outcome Score-Sports Specific Subscale (HOS-SSS), and visual analog scale for pain. Exclusion criteria were Tönnis grade >1, hip dysplasia (lateral center-edge angle <18°), and previous ipsilateral hip surgery/conditions. Rates of achieving the minimal clinically important difference (MCID), patient acceptable symptomatic state (PASS), and maximum outcome improvement satisfaction threshold were recorded in addition to RTS. These athletes were then propensity matched in a 1:3 ratio to high-level athletes who underwent unilateral arthroscopy for comparison. Outcomes were compared among the first hip of the study group, the second hip of the study group, and the control group.

RESULTS

A total of 74 high-level athletes who underwent bilateral hip arthroscopy met the inclusion criteria, and follow-up was available for 68 (91.9%) at 58.9 ± 24.5 months (mean ± SD). Athletes undergoing bilateral hip arthroscopy returned to sports at a high rate (81.7%), demonstrated significant improvements in all recorded PROs, and achieved the MCID and PASS for the HOS-SSS at rates of 80.9% and 64.7%, respectively. PROs, RTS rate, and rates of achieving the MCID and PASS for the HOS-SSS were similar when the bilateral study group was compared with the unilateral control group (P > .05).

CONCLUSION

High-level athletes who undergo staged bilateral primary hip arthroscopy for femoroacetabular impingement syndrome may expect favorable PROs and RTS rates at minimum 2-year follow-up. These results were comparable with those of a propensity-matched control group of high-level athletes who underwent unilateral primary hip arthroscopy.

Measuring 3D growth plate shape: Methodology and application to cam morphology

Physeal changes corresponding to cam morphology are currently measured using two-dimensional (2D) methods. These methods are limited by definitions of the femoral neck axis and head center that are dependent on the radiographic plane of view. To address these limitations, we developed three-dimensional (3D) methods for analyzing continuous growth plate shape using magnetic resonance imaging scans. These new methods rely on a single definition of the femoral neck axis and head center that are both nondependent on the radiographic plane of view and allow for analysis of growth plate shape across the growth plate surface (performed using statistical parametric mapping). Using our 3D method, we analyzed the position of the growth plate in the femoral head (relative to a plane tangent to the femoral head) and the curvature of the growth plate (relative to a plane through the center of the growth plate) in 9-16-year-old males at risk for cam morphology and their recreationally active peers (n = 17/cohort). These two measurements provide an avenue to separately analyze the effects of these variables in the overall growth plate shape. We detected differences in growth plate shape with age in recreationally active adolescents but did not detect differences between at risk and recreationally adolescents.

Intraoperative Computer Vision Integrated Interactive Fluoroscopy Correlates With Successful Femoroplasty on Clinic-Based Radiographs

PURPOSE

To quantitatively evaluate computer vision interface (CVI)-guided femoroplasty in the arthroscopic treatment of femoroacetabular impingement syndrome and compare those results with traditional unguided resections.

METHODS

Consecutive patients undergoing hip arthroscopy for femoroacetabular impingement syndrome between July 2019 and October 2019 were evaluated. Cases with CVI were identified along with controls, consisting of patients from the same study period who underwent surgery without the CVI and were balanced for age, sex, laterality, and preoperative alpha angles. Alpha angles were measured on pre- and postoperative clinic radiographs, as well as intraoperatively for the CVI group. Cam resections were quantified by measuring pre- and postresection alpha angles and compared between groups. The correlation between CVI views and office-based radiographs was assessed, and the 3 CVI views that best correlated with each of the 3 standard clinic radiographs were evaluated for accuracy and performance in detection of cam deformity with alpha angle ≥48° with the clinic-based films as the reference.

RESULTS

A total of 49 patients (51 hips) (average age, 28.7; 33 female patients) in the CVI group, and 51 patients (51 hips) (average age: 29.9; 35 female patients) in the control group. There were no significant differences between groups with respect to age, sex, laterality, or preoperative alpha angle (all P > .05). Significant alpha angle reduction occurred on all intraoperative and postoperative clinic views (all P < .01). The CVI views that best correlated with the clinic radiographs were 11:45 with the anteroposterior (ρ = 0.588, P = .0025), 12:30 with the Dunn lateral (ρ = 0.632, P = .0009), and 1:45 with the false-profile (ρ = 0.575, P = .0033). Greater reliability was observed with 12:30/Dunn (accuracy = 83.33%, P < .0001; sensitivity = 77.14%; specificity = 87.76%) and 1:45/false-profile (accuracy = 82.35%, P = .0051; sensitivity = 81.82%; specificity = 82.61%) than with 11:45/anteroposterior (accuracy = 69.15%, P = .0077; sensitivity = 56.10%; specificity = 79.25%).

CONCLUSIONS

CVI-guided cam resection results in successful resection of proximal femur cam lesions and represents a femoroplasty templating method that does not require preoperative computed tomography imaging or additional invasive intraoperative referencing modules. The accuracy and adequacy of this resection was validated by comparison with routine clinic radiographs.

LEVEL OF EVIDENCE

Therapeutic Level III: retrospective comparative analysis.

Impaired Lower Extremity Biomechanics, Hip External Rotation Muscle Weakness, and Proximal Femoral Morphology Predict Impaired Single-Leg Squat Performance in People With FAI Syndrome

BACKGROUND

Impairments in squat depth have been reported in patients with femoroacetabular impingement syndrome (FAIS). However, little is known about single-leg squat (SLS) performance in these patients, despite this task being commonly used in the rehabilitation and training settings.

PURPOSE/HYPOTHESIS

The aims of this study were (1) to investigate whether patients with FAIS demonstrate differences in SLS performance compared with healthy controls and (2) to determine whether dynamic range of motion (ROM), muscle strength, hip morphologic measures, hip pain, and hip-specific function predict SLS performance in patients with FAIS. We hypothesized that patients with FAIS would demonstrate impaired SLS performance and that impaired hip biomechanics, muscle strength, and hip-specific function would predict squat performance in patients with FAIS.

STUDY DESIGN

Controlled laboratory study.

METHODS

Three-dimensional (3D) kinematic data were collected at 100 Hz using a 20-camera 3D motion capture system during 3 SLS trials in 34 patients with FAIS and 26 healthy controls. Isometric muscle strength was tested with a stationary handheld dynamometer in all participants. Squat performance was quantified by squat depth (in meters), and the biomechanical variables of dynamic ROM of the pelvis, the hip, the knee, and the ankle in all planes were calculated. In patients with FAIS, femoral and acetabular morphology were measured using radiographic alpha angles and lateral center-edge angles. Hip pain and hip-specific function were measured using the visual analog scale for pain and the Hip Outcome Score Activities of Daily Living subscale, respectively. Two-tailed independent-samples t tests were used to determine between-group differences for squat depth, dynamic ROM variables, and muscle strength. A hierarchical multiple linear regression (MLR) model was used to determine whether biomechanical variables, muscle strength, hip morphology measures, hip pain, and hip-specific function were predictors of squat depth. All statistical analyses were performed using SPSS Version 26.

RESULTS

There were no between-group differences in age (FAIS, 30.0 ± 7.0 years vs controls, 27.3 ± 7.0 years; P = .18) or body mass index (FAIS, 23.1 ± 2.8 vs controls, 22.6 ± 3.2; P = .51). Squat depth was less in patients with FAIS compared with healthy controls (FAIS, 0.24 ± 0.4 m vs controls, 0.29 ± 0.05 m; P < .001). In the sagittal plane, patients with FAIS demonstrated less dynamic ROM of the hip (FAIS, 67.8°± 12.4° vs controls, 79.2°± 12.5°; P = .001) and the knee (FAIS, 71.9°± 9.4° vs controls, 78.9°± 13.2°; P = .02) compared with controls. Patients with FAIS also demonstrated a less dynamic coronal plane pelvis ROM (FAIS, 11.3°± 5.0° vs controls, 14.4°± 6.7°; P = .044). Patients with FAIS had reduced hip muscle strength of the hip external rotator (FAIS, 1 ± 0.3 N/kg vs controls, 1.2 ± 0.3 N/kg; P = .034), hip internal rotator (FAIS, 0.8 ± 0.3 N/kg vs controls 1 ± 0.3 N/kg; P = .03), and hip flexor (FAIS, 4 ± 1.1 N/kg vs controls, 4.8 ± 1.2 N/kg; P = .013) muscle groups. The hierarchical MLR revealed that the dynamic ROM of the hip, the knee, and the pelvis, the hip external rotation muscle strength, and the femoral alpha angles were all significant predictors of squat performance, and the final MLR model explained 92.4% of the total variance in squat depth in patients with FAIS.

CONCLUSION

Patients with FAIS demonstrate impaired SLS squat performance compared with healthy controls. This impaired squat performance is predominantly predicted by sagittal plane knee and hip biomechanics and hip external rotator strength, and less by frontal plane pelvic ROM and hip morphology in patients with FAIS.

CLINICAL RELEVANCE

Clinicians should focus treatment on improving dynamic ROM and hip external rotator muscle strength to improve squat performance; however, femoral morphology should also be considered in the treatment paradigm.

How does the cam morphology develop in athletes? A systematic review and meta-analysis

OBJECTIVE

A higher prevalence of cam morphology has been reported in the athletic population but the development of the cam morphology is not fully understood. The purpose of this systematic review is to establish the timing of development of the cam morphology in athletes, the proximal femoral morphologies associated with its development, and other associated factors.

DESIGN

Embase, MEDLINE and the Cochrane Library were searched for articles related to development of the cam morphology, and PRISMA guidelines were followed. Data was pooled using random effects meta-analysis. Study quality was assessed using the Downs and Black criteria and evidence quality using the GRADE framework.

RESULTS

This search identified 16 articles involving 2,028 participants. In males, alpha angle was higher in athletes with closed physes than open physes (SMD 0.71; 95% CI 0.23, 1.19). Prevalence of cam morphology was associated with age during adolescence when measured per hip (β 0.055; 95% CI 0.020, 0.091) and per individual (β 0.049; 95% CI 0.034, 0.064). Lateral extension of the epiphysis was associated with an increased alpha angle (r 0.68; 95% CI 0.63, 0.73). A dose-response relationship was frequently reported between sporting frequency and cam morphology. There was a paucity of data regarding the development of cam morphology in females.

CONCLUSIONS

Very low and low quality evidence suggests that in the majority of adolescent male athletes, osseous cam morphology developed during skeletal immaturity, and that prevalence increases with age. Very low quality evidence suggests that osseous cam morphology development was related to lateral extension of the proximal femoral epiphysis.

A three-dimensional measurement method on MR arthrography of the hip to classify femoro-acetabular impingement

PURPOSE

(1) To investigate correlations between different types of FAI and the ratio of acetabular volume (AV) to femoral head volume (FV) on MR arthrography. (2) To assess 2D/3D measurements in identifying different types of FAI by means of cut-off values of AV/FV ratio (AFR).

MATERIALS AND METHODS

Alpha angle, cranial acetabular version, acetabular depth, lateral center edge angle, AV, and FV of 52 hip MR arthrography were measured. ANOVA test correlated different types of FAI with AFR. ROC curves classified FAI by cut-off values of AFR. Accuracy of 2D/3D measurements was calculated.

RESULTS

ANOVA test showed a significant difference of AFR (p value < 0.001) among the three types of FAI. The mean values of AFR were 0.64, 0.74, and 0.89 in cam, mixed, and pincer types, respectively. Cut-off values of AFR were 0.70 to distinguish cam types from mixed and pincer types, and 0.79 to distinguish pincer types from cam and mixed types. Cut-off values identified 100%, 73.9%, and 55.6% of pincer, cam, and mixed types. 2D and 3D classifications of FAI showed accuracy of 40.4% and 73.0%.

CONCLUSIONS

3D measurements were clearly more accurate than 2D measurements. Distinct cut-off values of AFR discriminated cam types from pincer types and identified pincer types in all cases. Cam and mixed types were not accurately recognized.

Arthroscopic Circumferential Acetabular Labral Reconstruction for Irreparable Labra in the Revision Setting: Patient-Reported Outcome Scores and Rate of Achieving the Minimal Clinically Important Difference at a Minimum 2-Year Follow-up

BACKGROUND

There is a paucity in the literature reporting patient-reported outcome (PRO) scores and the minimal clinically important difference (MCID) after revision hip arthroscopic surgery with circumferential labral reconstruction.

PURPOSE

To report minimum 2-year PRO scores and the rate of achieving the MCID in patients who underwent revision hip arthroscopic surgery with circumferential labral reconstruction in the setting of irreparable labral tears.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Data were retrospectively reviewed for all patients who underwent revision hip arthroscopic surgery between February 2016 and November 2017. Patients were included if they had undergone circumferential labral reconstruction and had preoperative and postoperative scores for the modified Harris Hip Score (mHHS), Non-Arthritic Hip Score (NAHS), Hip Outcome Score Sport-Specific Subscale (HOS-SSS), International Hip Outcome Tool (iHOT-12), 12-Item Short Form Health Survey physical and mental components (SF-12 P and SF-12 M, respectively), Veterans RAND 12-Item Health Survey physical and mental components (VR-12 P and VR-12 M, respectively), and visual analog scale (VAS) for pain. Exclusion criteria were Tönnis grade >1, Legg-Calve-Perthes disease, slipped capital femoral epiphysis, fractures, hip dysplasia, or revision labral treatment different from circumferential labral reconstruction. The MCID was calculated. Secondary surgical procedures were documented.

RESULTS

A total of 26 hips (26 patients; 61.5% female) were included. The mean age and body mass index were 33.2 ± 10.4 years and 25.5 ± 4.9, respectively. Significant improvements were reported for the mHHS (17.0 ± 19.5; P = .0002), NAHS (17.9 ± 16.7; P < .0001), HOS-SSS (21.7 ± 23.1; P = .0005), VAS (-2.2 ± 3.0; P = .006), iHOT-12 (25.8 ± 32.5; P = .0007), SF-12 P (8.5 ± 11.2; P = .001), and VR-12 P (8.9 ± 11.6; P = .001). Rates of meeting the MCID for the mHHS, NAHS, HOS-SSS, iHOT-12, and VAS were 76.9%, 80.0%, 65.0%, 62.5%, and 69.2%, respectively. No case of re-revision arthroscopic surgery was documented, but 1 case of conversion to total hip arthroplasty was documented at 38.6 months.

CONCLUSION

In the setting of revision hip arthroscopic surgery and irreparable labral tears, circumferential labral reconstruction resulted in significant improvements in all PRO and VAS scores at a minimum 2-year follow-up with a high rate of achieving the MCID.

Sclerotic lesions of the femoral head-neck junction for diagnosis of femoroacetabular impingement

The morphological characteristics associated with a diagnosis of femoroacetabular impingement (FAI) observed on plain radiographs can also be seen in subjects without hip joint symptoms. Therefore, the purpose of this study was to investigate whether sclerotic lesions on femoral head-neck junction (FHNJ) could be used as a supplemental diagnostic feature. A total of 128 hips from 119 patients (43 male and 76 female) diagnosed with FAI and 24 hips from 21 patients (2 male and 19 female) with other hip pathologies as control were compared in this study. Using standing frog-leg plain radiographs, the prevalence of sclerotic lesions on the FHNJ was established. Additionally, the pixel intensity (PI) of the sclerotic lesions between the FAI and the control groups were quantitatively compared. Sclerotic lesions were present in 96.1% of FAI hips (123 of 128) and only 37.5% of control hips (9 of 24) (p < 0.05). The ratio of PI in the FAI group was significantly higher (approximately 10%) than in the control group (p < 0.05). The evaluation of sclerotic lesions may be used as a supplement to aid in the diagnosis of FAI.

The Ratio of the Transverse to Longitudinal Diameter of the Glenoid Projection Is of Good Predictive Value for Defining the Reliability of Critical Shoulder Angle in Nonstandard Anteroposterior Radiographs

PURPOSE

To investigate (1) whether measurement of the critical shoulder angle (CSA) is still reliable in some nonstandard anteroposterior radiographs; and (2) whether the ratio of the transverse to longitudinal diameter of the glenoid projection (RTL) could be used to determine the reliability of the CSA in nonstandard anteroposterior radiographs.

METHODS

The authors analyzed radiology records from 2017 to 2019 for patients with computed tomography (CT) scans of the shoulder. According to the Suter-Henninger classification system, each CT scan underwent 3-dimensional (3D) reconstructions to obtain 8 digitally reconstructed radiographs (DRRs), including 1 type A1 film and 7 type D1 films with different rotation angles. CSA and RTL were measured on all films, and 2 blinded reviewers evaluated DRRs. The relationship between RTL and CSA was determined by Pearson correlation test. The threshold value was determined by receiver operating characteristic (ROC) analyses using RTL as predictors and defined reliable CSA as criterion in the logistic regression. Intra- and inter-rater reliability were assessed by the intraclass correlation coefficient (ICC). Discriminative capacity was calculated with ROC analyses and area under the curve (AUC). An optimal measurement cutoff with resultant sensitivity and specificity was calculated.

RESULTS

A total of 86 patients were included, mean age 40.70 ± 18.25 years, 19 of whom had rotator cuff tears (RCTs) and 67 without RCTs. Spearman's correlation test revealed that the deviation of CSA was positively correlated with RTL, correlation coefficient 0.544 (P < .001) in all patients and 0.686 (P < .001) only in patients with RCTs. ROC analysis of all patients showed that the AUC of the RTL was 0.90, and the optimal cutoff point was 0.25 (sensitivity 88%, specificity 87%). ROC analysis only of patients with RCTs showed that the AUC of the RTL was 0.95, and the optimal cutoff point was 0.22 (sensitivity 95%, specificity 92%).

CONCLUSION

The ratio of the transverse to longitudinal diameter of the glenoid projection (RTL) is of good predictive value in defining the reliability of the CSA in malposition films. Based on the results, the CSA can be considered reliable if its RTL is <0.25.

LEVEL OF EVIDENCE

III, retrospective cohort study investigating a diagnostic test.

Revision Hip Arthroscopy in the Borderline Dysplastic Population: Reporting Outcomes With Minimum 2-Year Follow-up, With a Subanalysis Against a Propensity-Matched Nondysplastic Control Group

BACKGROUND

Hip arthroscopy in patients with borderline dysplasia continues to be surrounded by controversy. Even more controversial is the management of the failed hip arthroscopy in this population. There is a paucity of studies in contemporary literature regarding outcomes after arthroscopic revision surgery.

PURPOSE

(1) To report minimum 2-year patient-reported outcome (PRO) scores in patients with borderline dysplasia who underwent revision hip arthroscopy and (2) to compare these PRO scores with those of a propensity-matched control group without dysplasia who underwent revision hip arthroscopy.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Data were prospectively collected between August 2009 and November 2017. Inclusion criteria were revision arthroscopic surgery, capsular plication, and baseline and minimum 2-year follow-up for the following PROs: modified Harris Hip Score (mHHS), Nonarthritic Hip Score (NAHS), Hip Outcome Score-Sports Specific Subscale (HOS-SSS), and visual analog scale (VAS) for pain. Patients with Tönnis grade >1 or previous hip conditions were excluded. Two groups were created: a study group with borderline dysplasia (lateral center-edge angle [LCEA], 18°-25°) and a control group without dysplasia (LCEA, 25°-40°). Groups were propensity-matched in a 1:3 ratio for sex, age, body mass index, and follow-up time.

RESULTS

A total of 22 revision borderline dysplastic hips (21 patients) had a minimum 2-year follow-up during the study period. Patients in this group reported significant improvements for all PROs from baseline and achieved the minimal clinically important difference (MCID) for the mHHS at a rate of 70%. Moreover, 21 borderline dysplastic hips (21 patients) were matched to 63 control hips (63 patients). Mean LCEA for the study and control groups was 22.6 ± 1.7 and 32.0 ± 5.0, respectively. Both groups reported similar improvement in all PROs. The rate for achieving the MCID for the mHHS and VAS was similar between groups; however, the control group had higher rates of meeting the MCID for the HOS-SSS and NAHS (P = .042 and P = .025, respectively). The rates of conversion to hip arthroplasty were 7.9% (n = 5) in the control group and 23.8% (n = 5) in the borderline dysplasia propensity-matched group (P = .052). The rate of re-revision arthroscopy was 11.1% (n = 7) in the control group and 19.0% (n = 4) on the borderline dysplasia group (P = .350).

CONCLUSION

After revision hip arthroscopy, significant improvement was obtained for all PROs in patients with borderline dysplasia at a minimum 2-year follow-up. Moreover, outcomes, patient satisfaction, the rate for achieving the MCID for the mHHS and VAS, and the rate for secondary surgery were similar to those of a propensity-matched control group without dysplasia. Nevertheless, there was a nonsignificant trend toward higher secondary procedures in the study group; therefore, arthroscopic revision surgery in the borderline patients should be approached with measured prognosis.

Hip Arthroscopic Surgery in the Context of Femoroacetabular Impingement Syndrome, Labral Tear, and Acetabular Overcoverage: Minimum 5-Year Outcomes With a Subanalysis Against Patients Without Overcoverage

BACKGROUND

Improvement in patient-reported outcomes (PROs) has been reported in the short term after hip arthroscopy for femoroacetabular impingement syndrome (FAIS) and labral tear in the setting of acetabular overcoverage. Yet, there is a paucity of information in the literature on midterm PROs.

PURPOSE

To (1) report minimum 5-year PROs in patients who underwent primary hip arthroscopy for FAIS and acetabular labral tears in the context of acetabular overcoverage and (2) compare outcomes with those of a propensity-matched control group without acetabular overcoverage.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Data were prospectively collected and retrospectively analyzed on all patients who underwent hip arthroscopy for FAIS and labral tears between February 2008 and November 2013. Inclusion criteria were lateral center-edge angle >40° and minimum 5-year follow-up for the modified Harris Hip Score (mHHS), Nonarthritic Hip Score (NAHS), and the Hip Outcome Score-Sports-Specific Subscale (HOS-SSS). Exclusion criteria were previous ipsilateral hip surgery or conditions, active workers' compensation claims, or lack of minimum 5-year outcomes. A 1:1 propensity-matched comparison was made between the study group and a control group without acetabular overcoverage (lateral center-edge angle, 25°-40°) based on age at surgery, sex, body mass index, Tönnis grade, laterality, and follow-up time. The minimal clinically important difference (MCID) was calculated for the mHHS, HOS-SSS, and NAHS. Secondary surgical procedures were recorded.

RESULTS

A total of 54 patients satisfied the inclusion criteria for the study group, of whom 45 (83.3%; 45 hips) had a minimum 5-year follow-up and were matched without differences in age at surgery, sex, body mass index, or follow-up time. The study and control groups demonstrated significant and comparable improvements for the mHHS (mean ± SD Δ, 24.06 ± 24.19 vs 26.33 ± 17.27; P = .625), NAHS (Δ, 31.22 ± 25.31 vs 27.15 ± 17.61; P = .399), and HOS-SSS (Δ, 33.16 ± 34.73 vs 34.75 ± 26.15; P = .557). The rates for achieving the MCID were similar for the study and control groups for the mHHS (76.7% vs 84.2%; P = .399), HOS-SSS (79.1% vs 75.8%; P = .731), and NAHS (81.4% vs 84.2%; P = .738). Need for revision surgery was similar (P = .748). A lower conversion rate to total hip arthroplasty was reported for the study than for the control group (2.2% vs 15.6%; P = .026).

CONCLUSION

In the context of FAIS, labral tears, and acetabular overcoverage, patients who underwent hip arthroscopy reported significant improvement in several PROs at minimum 5-year follow-up. Moreover, outcomes were comparable with those of a propensity-matched control group without acetabular overcoverage. Furthermore, the rate of achieving the MCID for the mHHS, HOS-SSS, and NAHS was similar between these groups.

Mid-Term Outcomes of Endoscopic Gluteus Medius Repair With Concomitant Arthroscopic Labral Treatment: A Propensity-Matched Controlled Study

PURPOSE

To report mid-term outcomes of patients who underwent endoscopic gluteus medius (GM) repair with arthroscopic labral treatment and to compare them with a control cohort of patients who underwent arthroscopic labral treatment without an endoscopic GM repair.

METHODS

Data were prospectively collected and retrospectively reviewed for all patients who underwent primary hip arthroscopy between February 2008 and August 2013. Patients were included if they underwent arthroscopic labral treatment, endoscopic GM repair, and had preoperative with minimum 5-year follow-up for the following patient-reported outcomes: modified Harris Hip Score (mHHS), Nonarthritic Hip Score (NAHS), and Hip Outcome Score-Sports Specific Subscale (HOS-SSS). Propensity score matching was used to create a control cohort of patients who underwent primary arthroscopic labral treatment without GM repair.

RESULTS

There were a total of 46 patients with GM repair eligible for the current study, of whom 43 (93.5%) had 5-year follow-up. The average follow-up time was 73.4 months. At minimum 5-year follow-up, all PROs significantly improved (P < .001). Among the entire GM repair cohort, rates for achieving the patient acceptable symptomatic state (PASS) for mHHS, HOS-SSS, and international Hip Outcome Tool (iHOT-12) were 74.4%, 51.9%, and 71.8%, respectively. Rates for reaching a minimal clinically important difference for mHHS, NAHS, and HOS-SSS were 79.5%, 89.7%, and 73.1%, respectively. When the GM repair cohort was matched, there were 37 cases in the GM repair cohort and 78 in the control cohort. The GM repair cohort outcomes compared satisfactorily to the control cohort for mHHS (82.3 vs 82.6), NAHS (81.9 vs 82.3), and HOS-SSS (66.3 vs 67.5). Rates of achieving minimal clinically important difference and PASS for mHHS, NAHS, HOS-SSS, and iHOT-12 were also favorable.

CONCLUSIONS

Endoscopic GM repair with arthroscopic labral treatment results in safe, durable, and significant improvement in PROs at a minimum 5-year follow-up. The outcomes compared favorably with a control cohort without GM tears.

LEVEL OF EVIDENCE

III, retrospective comparative study.

Circumferential Labral Reconstruction for Irreparable Labral Tears in the Primary Setting: Minimum 2-Year Outcomes With a Nested Matched-Pair Labral Repair Control Group

PURPOSE

(1) To report minimum 2-year patient-reported outcome (PRO) scores of primary circumferential acetabular labral reconstruction using anterior tibialis allograft and the knotless pull-through technique in the setting of femoroacetabular impingement syndrome (FAIS) and irreparable labral tears and (2) to compare these PROs with a matched-pair primary labral repair group.

METHODS

Data were prospectively collected and retrospectively reviewed. Patients were included if they underwent primary circumferential labral reconstruction with anterior tibialis tendon allograft during February 2016 to April 2017 for irreparable labral tears and FAIS and had preoperative and minimum 2-year follow-up for modified Harris Hip Score (mHHS), Hip Outcome Score-Sport-Specific Subscale, Non-arthritic Hip Score, International Hip Outcome Tool 12 (iHOT-12), 12-Item Short Form Health Survey physical component and mental component, Veterans RAND 12-Item Health Survey physical component and mental component, and visual analog scale for pain. The exclusion criteria were previous ipsilateral hip conditions or surgical procedures, Tönnis grade 2 or higher, or dysplasia (lateral center-edge angle ≤ 18°). Labral tears were considered irreparable if the labrum appeared (1) to be mostly or completely calcified and (2) to be inadequate (nonviable) and not amenable for labral repair. The reconstruction group was matched 1:3 based on age, sex, and body mass index to a benchmark control group of hips undergoing labral repair from the same period. The minimal clinically important difference and patient acceptable symptomatic state for the mHHS and iHOT-12 score were calculated.

RESULTS

A total of 37 hips (37 patients) underwent circumferential labral reconstruction. There were 19 female patients (51.4%) and 18 male patients (48.6%). The mean age was 45.6 ± 11.6 years, and the average body mass index was 27.1 ± 5. At minimum 2-year follow-up, the circumferential labral reconstruction group showed statistically significant improvements in the mHHS, Non-arthritic Hip Score, Hip Outcome Score-Sport-Specific Subscale, iHOT-12 score, and visual analog scale score. All hips in the reconstruction group were successfully matched to 111 labral repair hips. At latest follow-up, improvements in all PROs between the 2 groups were comparable. The revision rates were 0% and 3.6% in the reconstruction and repair groups, respectively.

CONCLUSIONS

After primary hip arthroscopy, primary circumferential labral reconstruction using anterior tibialis allograft and the knotless pull-through technique in the setting of FAIS and irreparable labral tears resulted in significant improvements in several PROs at minimum 2-year follow-up and high patient satisfaction. Primary circumferential labral reconstruction reached comparable functional outcomes to those of a benchmark matched-pair primary labral repair control group.

LEVEL OF EVIDENCE

Level III, case-control study.

Evaluation of three-dimensional acromiohumeral distance in the standing position and comparison with its conventional measuring methods

Background

Narrowing of the acromiohumeral distance (AHD) implies a rotator cuff tear. However, conventional AHD measurements using two-dimensional (2D) imaging or with the patient in the supine position might differ from that while standing during daily activity. This study aimed to evaluate the three-dimensional (3D) actual distance between the acromion and humeral head in the standing position and compare the AHD values with those obtained using conventional measuring methods.

Methods

Computed tomography (CT) images of 166 shoulders from 83 healthy volunteers (31 male and 52 female; mean age 40.1 ± 5.8 years; age range, 30–49 years) were prospectively acquired in the supine and standing positions using conventional and upright CT scanners, respectively. The minimum distance between the acromion and humeral head on the 3D surface models was considered as the 3D AHD. We measured the 2D AHD on anteroposterior digitally reconstructed radiographs. The AHD values were compared between the supine and standing positions and between the 2D and 3D measurements.

Results

The mean values of 2D AHD were 8.8 ± 1.3 mm (range, 5.9–15.4 mm) in the standing position and 8.1 ± 1.2 mm (range, 5.3–14.3 mm) in the supine position. The mean values of 3D AHD were 7.3 ± 1.4 mm (range, 4.7–14.0 mm) in the standing position and 6.6 ± 1.2 mm (range, 4.4–13.7 mm) in the supine position. The values of 3D AHD were significantly lower than those of 2D AHDs in both the standing and supine positions (P < 0.001). The values of 2D and 3D AHDs were significantly lower in the supine position than in the standing position (P < 0.001).

Conclusions

This study evaluated the 3D AHD of normal shoulders in the standing position using an upright CT scanner. The present results indicated that assessments in the supine position can underestimate the value of the AHD compared with those made in the standing position and that assessments using 2D analysis can overestimate the value.

Effect of alcohol consumption on patient-reported outcomes in hip arthroscopy: a matched controlled study with minimum 2-year follow-up

INTRODUCTION

There is a paucity of literature examining the effects of alcohol consumption on patient-reported outcomes (PROs) after hip arthroscopy. The purpose of this study was to report 2-year outcomes of hip arthroscopy in patients who consume alcohol compared to patients who abstain.

METHODS

Registry data were prospectively collected and retrospectively reviewed to identify heavy drinkers at the time of primary hip arthroscopy. Patients were matched 1:1 (heavy drinkers:non-drinkers) based on age, sex, BMI, acetabular Outerbridge grade, and capsular treatment. All patients were assessed with 4 validated PROs: mHHS, NAHS, HOS-SSS, and iHOT-12. Pain was estimated with VAS.

RESULTS

42 patients were pair matched in each group (heavy drinkers:non-drinkers). Both groups demonstrated significant improvement for all PROs and VAS. Heavy drinkers reported lesser improvement in HOS-SSS (p = 0.0169), smaller decrease in VAS (p = 0.0157), and lower final scores on iHOT-12 (p = 0.0302), SF-12 mental (p = 0.0086), and VR-12 mental (p = 0.0151). Significantly fewer patients in the heavy-drinking group reached PASS for mHHS (p = 0.0464). Odds of achieving PASS for mHHS was 2.5 times higher for patients who abstain from alcohol. The rates of revision hip arthroscopy and conversion to total hip arthroplasty were not statistically different between groups.

CONCLUSION

While hip arthroscopy may still yield clinical benefit in drinkers, patients who consume heavy amounts of alcohol may ultimately achieve an inferior functional status and should be counselled on drinking cessation to optimise their results.

Hips With Acetabular Retroversion Can Be Safely Treated With Advanced Arthroscopic Techniques Without Anteverting Periacetabular Osteotomy: Midterm Outcomes With Propensity-Matched Control Group

BACKGROUND

Different options, from reverse (anteverting) periacetabular osteotomy to hip arthroscopy, have been proposed for surgical treatment of femoroacetabular impingement syndrome (FAIS) in the setting of acetabular retroversion.

PURPOSE

(1) To report and analyze midterm patient-reported outcome scores (PROs) in patients with FAIS and labral tears in the setting of acetabular retroversion after isolated hip arthroscopy and (2) to compare these PROs with those of a propensity-matched control group without acetabular retroversion.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Prospectively collected data were retrospectively reviewed for patients who underwent hip arthroscopy for FAIS and labral tear treatment between June 2008 and March 2014. Inclusion criteria were as follows: acetabular retroversion, pre- and postoperative PROs for modified Harris Hip Score (mHHS), Non-arthritic Hip Score, Hip Outcome Score-Sports Specific Scale (HOS-SSS), and visual analog scale (VAS). Propensity score matching was utilized to identify a control group without acetabular retroversion matched 1:1 with similar age, sex, body mass index, acetabular and femoral head Outerbridge grade, preoperative lateral center-edge angle, and labral treatment. Patient acceptable symptomatic state (PASS) and/or minimal clinically important difference (MCID) for the mHHS, HOS-SSS, International Hip Outcome Tool-12, and VAS was calculated.

RESULTS

A total of 205 hips with acetabular retroversion were matched to a control group. The groups showed no difference in demographic variables. The retroversion group was composed of 139 female and 66 male hips, with a mean ± SD age of 23.81 ± 7.28 years and follow-up time of 65.24 ± 20.31 months. Intraoperative diagnostic data and procedures performed were similar between groups, except more femoroplasties were performed in the retroversion group. Significant improvements for the mHHS, Non-arthritic Hip Score, HOS-SSS, and VAS were seen for both groups at a mean 5-year follow-up. The proportion of patients who reached the PASS and MCID were similar.

CONCLUSION

In the setting of FAIS and labral tears, patients with acetabular retroversion can be safely treated with advanced hip arthroscopic techniques without reverse (anteverting) periacetabular osteotomy in a high-volume surgeon's hands. Patients with acetabular retroversion demonstrated favorable PROs at midterm follow-up. Furthermore, the proportion of patients reaching the MCID and PASS for several PROs were comparable with those of a propensity-matched control group without acetabular retroversion.

Viewing perspective malrotation influences angular measurements on lateral radiographs of the scapula

BACKGROUND

Accurate and reliable assessment of acromial tilt (ATA) and slope (ASA) angles have been important in the clinical evaluation of degenerative and traumatic rotator cuff tears. This study analyzed the influence of radiographic viewing perspective on the ATA and ASA and developed criteria to identify true lateral (TL) view radiographs.

METHODS

Three-dimensional computed tomographic (CT) reconstructions of 52 scapulae without rotator cuff tears or osteoarthritis were studied. Digitally reconstructed radiographs (DRRs) were aligned to obtain a TL view. In 10 random scapulae, incremental ante- and retroversion and up- and downward rotation views were generated (10° increments, ±30°), and ATA and ASA were measured by 2 observers. Clinically applicable criteria were developed and validated to identify TL views.

RESULTS

The mean ATA and ASA on TL views were 33°±4° (range 23°-42°) and 22°±7° (8°-43°), respectively. Mixed effect models showed that DRRs malpositioned in 20° and 30° anteversion and downward rotation decreased the ATA (P ≤ .030). DRRs malpositioned in anteversion and >10° of up- and downward rotation demonstrated a significantly decreased ASA (P ≤ .047). Intra- and interobserver reliability was excellent for TL views (intraclass correlation coefficient ≥ 0.95) but decreased with increasing viewing angle. Anatomic landmark criteria were capable of identifying TL-view radiographs with sensitivity of 81% and specificity of 82%.

CONCLUSION

Both ATA and ASA were significantly affected by malposition in anteversion and downward rotation of the scapula. Reliable ASA measurement was more susceptible in up- and downward rotation than the ATA. New visual criteria can identify TL-view radiographs and should be used in future studies to ensure consistency in ATA and ASA measurement.

Does Femoral Retroversion Adversely Affect Outcomes After Hip Arthroscopy for Femoroacetabular Impingement Syndrome? A Midterm Analysis

PURPOSE

To report 5-year outcomes of arthroscopic treatment of femoroacetabular impingement syndrome in patients with femoral retroversion compared with a control group of patients with normal femoral anteversion.

METHODS

Data were prospectively collected and retrospectively reviewed for all patients who underwent hip arthroscopy between August 2008 and April 2013. Patients were included in analysis if they underwent hip arthroscopy during this period and had femoral version ≤0° calculated using magnetic resonance imaging. Exclusion criteria included prior ipsilateral hip conditions/surgeries or Tönnis grade >1. These patients were pair matched with patients having femoral anteversion between 10° and 20° based on gender, body mass index ± 10, and age ± 10 years. Patient-reported outcomes (PROs) were collected at 3 months and 1 year postoperatively and annually thereafter. An a priori power analysis was performed.

RESULTS

A total of 59 patients were identified as the experimental group out of 69 eligible for inclusion (86%). All 59 patients were matched, with a mean age of 37.4 years and mean body mass index of 26.9. Twenty patients were female, and 39 were male. These patients demonstrated significant improvement from their preoperative state in all patient-reported outcomes and visual analog score scores (P < .001). Thirty-eight patients met the threshold for minimal clinically important difference, and 35 achieved patient acceptable symptomatic state for the modified Harris Hip Score questionnaire. Seven patients converted to total hip replacement. No differences were noted between retroverted and control patients in any of the outcome measures collected, in pain or satisfaction ratings, in the frequency of or duration to secondary surgeries or in complication rate (P > .05).

CONCLUSIONS

Patients with femoral retroversion demonstrated significantly higher outcomes at minimum 5-year follow-up after undergoing arthroscopic hip surgery. These outcomes were not different from those of patients with normal femoral version. While femoral retroversion should not be considered a contraindication to hip arthroscopy, it should be carefully considered as a factor in patient selection and surgical planning.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.