The Evolution of Hip Arthroscopy: What Has Changed Since 2008-A Single Surgeon's Experience

Statistical fragility analysis of reported outcomes associated with surgical management of acetabular labral pathology

INTRODUCTION

The purpose of this study was to analyse the robustness of comparative research that evaluated arthroscopic labral reconstruction versus other surgical management of labral pathology. Key measures of statistical fragility include the fragility index and fragility quotient.ß.

METHODS

12 comparative studies that evaluated the use of arthroscopic labral reconstruction were included in this study. Particular attention was placed on evaluating trends, either statistically significant or not, of functional improvement, complication rates, need for total hip arthroplasty (THA) and revision rates with associated p-values. The analysis involved in this study was the Fragility Index, which is the median number of events required to change the statistical significance of a particular outcome, thus changing the study conclusions. Fragility quotient was calculated for each study as the fragility index divided by sample size.

RESULTS

Of the 12 studies that were included for analysis, there were a total of 25 reported outcomes, 8 of which were statistically significant (p < 0.05). The statistical fragility for the significant outcomes were 2.5 (interquartile range [IQR]: 1.5-3.5), whereas the median statistical fragility for insignificant results was 6 (IQR 4-9). The overall fragility index was 4 (IQR 3-7). The median of fragility quotients was 0.04 (IQR 0.01-0.07).

CONCLUSIONS

This study demonstrated that comparative research regarding arthroscopic techniques of labral reconstruction may not be as statistically stable as previously hoped. In many of the reported outcomes, particularly the ones that were statistically significant, only a small percentage of event changes was required to change the significance of the study conclusions. This fragility is worrisome, since clinical decisions that rely on these reported outcomes may have a significant impact on long-term patient outcomes. It is, therefore, crucial to optimise patient outcomes by incorporating past literature and reported outcomes.

Global mapping of institutional and hospital-based (Level II-IV) arthroplasty registries: a scoping review

PURPOSE

Four joint arthroplasty registries (JARs) levels exist based on the recorded data type. Level I JARs are national registries that record primary data. Hospital or institutional JARs (Level II-IV) document further data (patient-reported outcomes, demographic, radiographic). A worldwide list of Level II-IV JARs must be created to effectively assess and categorize these data.

METHODS

Our study is a systematic scoping review that followed the PRISMA guidelines and included 648 studies. Based on their publications, the study aimed to map the existing Level II-IV JARs worldwide. The secondary aim was to record their lifetime, publications' number and frequency and recognise differences with national JARs.

RESULTS

One hundred five Level II-IV JARs were identified. Forty-eight hospital-based, 45 institutional, and 12 regional JARs. Fifty JARs were found in America, 39 in Europe, nine in Asia, six in Oceania and one in Africa. They have published 485 cohorts, 91 case-series, 49 case-control, nine cross-sectional studies, eight registry protocols and six randomized trials. Most cohort studies were retrospective. Twenty-three per cent of papers studied patient-reported outcomes, 21.45% surgical complications, 13.73% postoperative clinical and 5.25% radiographic outcomes, and 11.88% were survival analyses. Forty-four JARs have published only one paper. Level I JARs primarily publish implant revision risk annual reports, while Level IV JARs collect comprehensive data to conduct retrospective cohort studies.

CONCLUSIONS

This is the first study mapping all Level II-IV JARs worldwide. Most JARs are found in Europe and America, reporting on retrospective cohorts, but only a few report on studies systematically.

Acetabular Labral Reconstruction Does Not Demonstrate Superior Biomechanical Properties Compared to Labral Repair or Intact Native Labrum but Is Superior to Labral Excision: A Systematic Review of Cadaveric Studies

PURPOSE

To systematically review and compare biomechanical properties of labral reconstruction to labral repair, intact native labrum, and labral excision in cadaveric studies.

METHODS

A search of the PubMed and Embase databases was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and checklist. Cadaveric studies focused on hip biomechanics related to intact labrum, labral repair, labral reconstruction, labral augmentation, and labral excision were included. Investigated parameters included biomechanical data measures, such as distraction force, distance to suction seal rupture, peak negative pressure, contact area, and fluid efflux. Review articles, duplicates, technique reports, case reports, opinion articles, articles written in a language other than English, clinical studies focusing on patient-reported outcomes, studies performed in animals, and articles with no abstract available were also excluded.

RESULTS

Fourteen cadaveric biomechanical studies were included that compared labral reconstruction to labral repair (4 studies), labral reconstruction to labral excision (4 studies); and evaluation of distractive force of the labrum (3 studies), the distance to suction seal rupture (3 studies), fluid dynamics (2 studies), displacement at peak force (1 study), and stability ratio (1 study). Data pooling was not performed because of methodological heterogenicity of the studies. Labral reconstruction did not outperform labral repair in restoring the hip suction seal or any other biomechanical property. Labral repair significantly prevented greater fluid efflux when compared to labral reconstruction. Labral repair and reconstruction improved the distractive stability of the hip fluid seal from the labral tear and labral excision stage, respectively. Furthermore, labral reconstruction demonstrated to have better biomechanical properties than labral excision.

CONCLUSIONS

In cadaveric studies, labral repair or intact native labrum was biomechanically more superior than labral reconstruction; however, labral reconstruction can restore acetabular labral biomechanical properties and was biomechanically superior to labral excision.

CLINICAL RELEVANCE

In cadaveric models, labral repair outperforms segmental labral reconstruction in preserving the hip suction seal; nonetheless, segmental labral reconstruction biomechanically outperforms labral excision at time 0.

Ten-Year Survivorship, Outcomes, and Sports Participation in Athletes After Primary Hip Arthroscopy for Femoroacetabular Impingement Syndrome

BACKGROUND

Hip arthroscopy is an effective treatment tool for athletes with femoroacetabular impingement (FAI) syndrome. However, long-term data are scarce.

PURPOSE

To assess survivorship, minimum 10-year patient-reported outcome measures (PROMs), and sports participation after primary hip arthroscopy for FAI syndrome in athletes and to perform a propensity-matched comparison between patients undergoing labral debridement and labral repair.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Athletes who underwent hip arthroscopy for FAI syndrome between February 2008 and December 2010 were eligible. Exclusion criteria were other ipsilateral hip condition, Tönnis grade ≥2, or no baseline PROMs. Survivorship was defined as no conversion to total hip arthroplasty. The Patient Acceptable Symptom State (PASS), minimal clinically important difference (MCID), maximum outcome improvement (MOI) satisfaction threshold, and sports participation were reported. A propensity-matched comparison between labral debridement and labral repair was performed. Two additional propensity-matched subanalyses were performed for capsular management and cartilage damage.

RESULTS

In total, 189 hips (177 patients) were included. The mean ± SD follow-up was 127.2 ± 6.0 months. Survivorship was 85.7%. Significant improvement in all PROMs was reported (P < .001). A total of 46 athletes with labral repair were propensity matched to 46 athletes with labral debridement. This subanalysis demonstrated significant and comparable improvement in all PROMs at minimum 10-year follow-up (P < .001). For the labral repair group, the PASS achievement rates were 88.9% for the modified Harris Hip Score (mHHS) and 80% for the Hip Outcome Score-Sport Specific Subscale (HOS-SSS); the MCID achievement rates were 80.6% for the mHHS and 84% for HOS-SSS; and for the MOI satisfaction threshold, rates were 77.8%, 80.6%, and 55.6% for the mHHS, Nonarthritic Hip Score, and visual analog scale, respectively. For the labral debridement group, the PASS achievement rates were 85.3% for the mHHS and 70.4% for the HOS-SSS; the MCID achievement rates were 81.8% for the mHHS and 74.1% for HOS-SSS; and for the MOI satisfaction threshold, rates were 72.7%, 81.8%, and 66.7% for the mHHS, Nonarthritic Hip Score, and visual analog scale. Total hip arthroplasty conversions occurred significantly sooner with labral debridement than labral repair (P = .048). Age was identified as a significant predictor of achieving the PASS.

CONCLUSION

Primary hip arthroscopy for FAI syndrome in athletes results in 85.7% survivorship and sustained PROM improvement at a minimum 10-year follow-up. A significant time delay to total hip arthroplasty conversion at 10-year follow-up was reported with labral repair over debridement, although this should be interpreted with caution, as the total number of conversions was small.

Durable Outcomes After Hip Labral Reconstruction at Minimum 5-Year Follow-Up: A Systematic Review

PURPOSE

To systematically review and report the mid- to long-term patient reported outcomes (PROs) following hip labral reconstruction.

METHODS

A literature search of the Pubmed, Embase, and Cochrane Library databases was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines for clinical studies reporting mid- to long-term PROs at minimum five year follow-up following arthroscopic hip labral reconstruction. A quality assessment was performed using the Methodological Index of Non-Randomized Studies (MINORS) grading system. Data collection included study characteristics, demographics, indications, radiographic metrics, perioperative findings, surgical technique, baseline and most recent PROs, and subsequent surgeries.

RESULTS

Four studies met inclusion criteria, with 182 hips (age range, 27.9 to 38.7 years) undergoing labral reconstruction in primary and revision hip surgery with minimum five year follow-up. There were three level III studies and one level IV study, with an average MINORS score of 16.6. All studies cited labral tissue characteristics as a factor for surgical indications, including the quality and/or size of the labrum. Three studies performed segmental labral reconstructions, while another study utilized a circumferential technique. Varying grafts were selected, including hamstring autograft/allograft, ligamentum teres autograft, iliotibial band autograft, and tensor fascia lata autograft. All studies demonstrated improved PROs from baseline to most recent follow-up, with four studies reporting modified Harris Hip Score (mHHS) values that increased from baseline (range, 58.9 to 66.8) to most recent follow-up (range, 80.1 to 86.3). After labral reconstruction, rates of revision arthroscopy ranged from 4.8% to 13.3% and conversion to total hip arthroplasty ranged from 1.6% to 27%.

CONCLUSION

Improved PROs were observed in all studies at minimum 5-year follow-up, suggesting that labral reconstruction can offer durable results beyond short-term follow-up. While surgical indications for all studies included labral tissue characteristics, differing graft selection and surgical techniques were utilized across studies, limiting the ability to determine an optimal treatment approach.

Minimum 10-year Survivorship and Clinical Outcomes Following Primary Hip Arthroscopy with Acetabular Microfracture

PURPOSE

To report minimum 10-year follow-up survivorship, defined as non-conversion to total hip arthroplasty (THA), and patient-reported outcome scores (PROS) after primary hip arthroscopy with acetabular microfracture in the setting of femoroacetabular impingement syndrome (FAIS) and acetabular chondral lesions, respectively.

METHODS

Data were prospectively collected and retrospectively analyzed on all patients who underwent a primary hip arthroscopy and received an acetabular microfracture between June 2009 and January 2011. Patients with a minimum 10-year follow-up for the modified Harris Hip Score (mHHS), Nonarthritic Hip Score (NAHS), and the visual analog scale (VAS) for pain were included. If available, the minimum 10-year follow-up for the Hip Outcome Score-Sport-Specific Subscale was reported. The demographics, intraoperative findings, surgical procedures, PROS, rate of achieving the minimal clinical important difference (MCID), and secondary surgeries were analyzed and reported.

RESULTS

Twenty-two hips (20 patients) were included in the study, and the mean follow-up time was 124.5 ± 2.2 months. There were 17 hips (77.3%) from males and 5 hips (22.7%) from females. The average patient age at the time of surgery was 42.3 years ± 9.6. All patients on average experienced statistically significant improvement (P < .05) between preoperative and minimum 10-year follow-up scores for all PROs. In total, 77.3% of the patients did not require conversion to THA. Additionally, 83.3% of the patients achieved the MCID for the mHHS, NAHS, and VAS for pain.

CONCLUSION

At a minimum 10-year follow-up, survivorship of 77.3% was reported for patients who underwent primary hip arthroscopy with acetabular microfracture for the treatment of FAIS and focal/full-thickness acetabular cartilage lesions. Further, in the patients that did not require THA conversion, significant improvement in all PROS was demonstrated.

LEVEL OF EVIDENCE

IV, case-series study.

Preoperative Magnetic Resonance Imaging Offers Questionable Clinical Utility, Delays Time to Hip Arthroscopy, and Lacks Cost-Effectiveness in Patients Aged ≤40 Years With Femoroacetabular Impingement Syndrome: A Retrospective 5-Year Analysis

PURPOSE

To assess the clinical utility of preoperative magnetic resonance imaging (MRI) and quantify the delay in surgical care for patients aged ≤40 years undergoing primary hip arthroscopy with history, physical examination, and radiographs concordant with femoroacetabular impingement syndrome (FAIS).

METHODS

From August 2015 to December 2020, 1,786 consecutive patients were reviewed from the practice of 1 fellowship-trained hip arthroscopist. Inclusion criteria were FAIS, primary surgery, and age ≤40 years. Exclusion criteria were MRI contraindication, reattempt of conservative management, or concomitant periacetabular osteotomy. After nonoperative treatment options were exhausted and a surgical plan was established, patients were stratified by those who presented with versus without MRI. Those without existing MRI received one, and any deviations from the surgical plan were noted. All preoperative MRIs were compared with office evaluation and intraoperative findings to assess agreement. Demographic data, Hip Disability and Osteoarthritis Outcome Score (HOOS)-Pain, and time from office to MRI or arthroscopy were recorded.

RESULTS

Of the patients indicated by history, physical examination, and radiographs alone (70% female, body mass index 24.8 kg/m², age 25.9 years), 198 patients presented without MRI and 934 with MRI. None of the 198 had surgical plans altered after MRI. Patients in both groups had MRI findings demonstrating anterosuperior labral tears that were visualized and repaired intraoperatively. Mean time from office to arthroscopy for patients without MRI versus those with was 107.0 ± 67 and 85.0 ± 53 days, respectively (P < .001). Time to MRI was 22.8 days. No difference between groups was observed among the 85% of patients who surpassed the HOOS-Pain minimal clinically important difference (MCID).

CONCLUSION

Once indicated for surgery based on history, physical examination, and radiographs, preoperative MRI did not alter the surgical plan for patients aged ≤40 years with FAIS undergoing primary hip arthroscopy. Moreover, preoperative MRI delayed time to arthroscopy. The necessity of routine preoperative MRI in the young primary FAIS population should be challenged.

Females and Males Achieved Comparable Outcomes and Clinical Benefits Following Primary Hip Arthroscopy with Labral Repair, but Age Affected Outcomes and Conversion to Total Hip Arthroplasty. A Short and Mid-Term Follow-Up Analysis with Dual Stratification

PURPOSE

To report and compare, according to sex and age, minimum 2-and minimum 5-year patient-reported outcome scores (PROs) and survivorship in a large cohort of patients who underwent primary hip arthroscopy for femoroacetabular impingement syndrome (FAIS).

METHODS

Data from February 2008 to September 2018 were reviewed. Patients aged 60 and younger who underwent primary hip arthroscopy with minimum 2-year follow-up were included. Exclusion criteria were Tönnis grade >1, hip dysplasia, previous hip conditions, or any labral treatment different than repair. Minimum 5-year PROs were also collected. All patients included were divided into groups by sex. For further analysis, males and females were stratified according to age: < 21 years old, 21-30 years old, 31-40 years old, 41-50 years old, and 51-60 years old.

RESULTS

In total, 1,326 hips had minimum 2-year follow-up, including 860 (64.9%) females and 466 males (35.1%), with a mean age of 31.6 years (range, 12.8-60.9 years) and a mean follow-up of 58.7 ± 28.9 months. Of those, 772 had minimum 5-year follow-up, 515 females (66.7%), and 257 males (33.3%) with a mean age of 31.7 years (range, 13.1-60.7 years) and a mean follow-up of 78.5 ± 23.0 months. All patients showed significant improvements in PROs at minimum 2-and 5-year follow-up (P < .001). Between sex analysis revealed comparable PROs at latest follow-up between females and males across any age group. Within sexes, and when sexes were combined, patients <21 years old had significantly better outcomes compared to other age groups. There were more females <21 years old that required revision arthroscopy than males <21 years old (P = .015). Conversion to total hip arthroplasty (THA) showed no significant difference between sexes (P > .05). Rates of THA were <21 years (.8%), 21-30 years (2.1%), 31-40 years (4%), 41-50 years (8.9%), and 51-60 years (14.3%).

CONCLUSIONS

Following primary hip arthroscopy for FAIS, all patients reported significant improvements in all PROs at minimum 2-and minimum 5-year follow-up, with females and males achieving similar success. Age affected outcomes, with patients under 21 years old reporting better scores regardless of sex. Although the conversion rate to THA was similar between the sexes, it was lower in the younger ages groups in both sexes.

LEVEL OF EVIDENCE

III, retrospective comparative observation trial.

Personalized Medicine Using Predictive Analytics: A Machine Learning-Based Prognostic Model for Patients Undergoing Hip Arthroscopy

BACKGROUND

Personalized medicine models to predict outcomes of orthopaedic surgery are scarce. Many have required data that are only available postoperatively, mitigating their usefulness in preoperative decision making.

PURPOSE

To establish a method for predictive modeling to enable individualized prognostication and shared decision making based on preoperative patient factors using data from a prospective hip preservation registry.

STUDY DESIGN

Cohort study (Prognosis); Level of evidence, 2.

METHODS

Preoperative data of 2415 patients undergoing hip arthroscopy for femoroacetabular impingement syndrome between February 2008 and November 2017 were retrospectively analyzed. Two machine-learning analyses were evaluated: Tree-structured survival analysis (TSSA) and Cox proportional hazards modeling for predicting time to event and for computing hazard ratios for survivorship after hip arthroscopy. The Fine-Gray model was similarly used for repeat hip arthroscopy. Variables were selected for inclusion using the minimum Akaike Information Criterion (AIC). The stepwise selection was used for the Cox and Fine-Gray models. A web-based calculator was created based on the final models.

RESULTS

Prognostic models were successfully created using Cox proportional hazards modeling and Fine-Gray models for survivorship and repeat hip arthroscopy, respectively. The Harrell C-statistics of the Cox model calculators for survivorship after hip arthroscopy and the Fine-Gray model for repeat hip arthroscopy were 0.848 and 0.662, respectively. Using the AIC, 13 preoperative variables were identified as predictors of survivorship, and 6 variables were identified as predictors for repeat hip arthroscopy. In contrast, the TSSA model performed poorly, resulting in a Harrell C-statistic <0.6, rendering it inaccurate and not interpretable. A web-based calculator was created based on these models.

CONCLUSION

This study successfully created an institution-specific machine learning-based prognostic model for predictive analytics in patients undergoing hip arthroscopy. Prognostic models to predict survivorship and the need for repeat surgeries were both adapted into web-based tools to assist the physician with shared decision making. This prognostic model may be useful at other institutions after performing external validation. Additionally, this study may serve as proof of concept for a methodology for the development of patient-specific prognostic models. This methodology may be used to create other predictive analytics models in different realms of orthopaedic surgery, contributing to the evolution from evidence-based medicine to personalized medicine.

Bone Volumes and Trajectory Angles for Acetabular Anchor Placement Can Be Optimized

Purpose

The purpose of this study was to determine the optimal anchor placement and trajectory when repairing acetabular labral tears during hip arthroscopy with the primary focus on the 12 to 3 o’clock positions on the acetabular rim.

Methods

Three-dimensional computational models of the pelvis were generated from 13 cadaveric specimens using 3D slicer medical imaging software. A set of cones, consistent with the dimensions of a commonly used sutured anchor, were virtually embedded into the models at the 12, 1, 2, and 3 o’clock positions around the acetabulum. Mirror images of the cone were extended toward the superficial aspect of the hip. The volume of bone occupied by the virtual anchor, the trajectory angle, and the volume of overlap between adjacent anchor locations were calculated.

Results

Bone volume was significantly greater at the 1 o’clock position (4196.2 [1190.2] mm³) compared with all other positions (P < .001). The 3 o’clock position had the smallest volume (629.2 [180.0] mm³) and was also significantly less than the 12 (P < .001) and 2 o’clock (P = .014) positions). The trajectory angle of 32.04 [5.05]°) at the 1 o’clock position was significantly greater compared with all other positions (P < .001). The least amount of adjacent position overlap occurred between the 2 and 3 o’clock positions (.12 [.42] mm³), and this was statistically smaller than the overlap between cones at the 12 and 1 o’clock positions (214.28 [251.88] mm³; P = .029) and the 1 and 2 o’clock positions (139.51 [177.14] mm³; P = .044).

Conclusions

Trajectory angles and the thickness of bone around the acetabulum were the greatest at the 12 to 1 o’clock positions, with the 1 o’clock position identified as that with the largest trajectory angle for safe anchor insertion.

Clinical Relevance

The use of a single, workhorse portal, for anchor insertion may not be recommended and careful selection of a portal allowing a direct approach should be used for anterior anchor insertion.

Surgeon-Specific Traction Time During Hip Arthroscopy for Primary Labral Repair Can Continue to Decrease After a Substantial Number of Surgeries

PURPOSE

The purpose of this study was to evaluate the total traction time and traction time as a function of anchors placed (TTAP) for primary labral repair in patients undergoing hip arthroscopy by a single surgeon.

METHODS

Patients were included if they received a primary labral repair with or without acetabuloplasty, chondroplasty, or ligamentum teres debridement as part of the treatment for femoroacetabular impingement (FAI). Patients were excluded if they had a previous ipsilateral hip surgery, prior hip conditions, Tönnis grade >1, open procedures, microfracture, ligamentum teres reconstruction, or labral reconstruction. TTAP was calculated by dividing total traction time by the number of anchors placed.

RESULTS

2,350 hips met the inclusion criteria. The mean age and BMI in this cohort were 34.22 years and 25.72 kg/m², respectively. A total traction time of 60 minutes was first achieved after 268 cases. Mean overall total traction time was 58.16 minutes (95% CI [57.35, 58.97]) and mean TTAP was 16.24 minutes (95% CI [15.93,16.55]) after 2,350 cases. Total traction time plateaued after 374 cases at 55.92 minutes, while TTAP plateaued after 487 cases at 14.93 minutes.

CONCLUSION

Surgeons who introduce hip arthroscopy into their practice can expect to see improvements in traction time during the first 500 surgeries performed, as total traction time plateaued after 374 cases and TTAP plateaued after 487 cases.

LEVEL OF EVIDENCE

IV: case series.

Favorable Outcomes of Revision Hip Arthroscopy Irrespective of Whether Index Surgery was Performed by the Same Surgeon or a Different Surgeon

The purpose of this study was to compare minimum 2-year patient-reported outcomes (PROMs) after revision hip arthroscopy between two different patient cohorts who had undergone primary hip arthroscopy with the same surgeon (SS) and a different surgeon (DS). We hypothesized no difference in clinical outcomes between the groups despite differences in intraoperative findings based on the surgical decision making in a revision setting at a high-volume center.

Minimum 5-Year Outcomes for Revision Hip Arthroscopy With a Prospective Subanalysis Against a Propensity-Matched Control Primary Group

BACKGROUND

There is a paucity of midterm outcome data on hip revision arthroscopic surgery.

PURPOSE

(1) To report minimum 5-year patient-reported outcome measurement scores (PROMSs) in patients who underwent revision hip arthroscopy, (2) to compare minimum 5-year PROMSs with a propensity-matched control group that underwent primary hip arthroscopy, and (3) to compare the rate of achieving the minimal clinically important difference (MCID) at minimum 5-year follow-up between the revision group and the propensity-matched control primary group.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Data were prospectively collected between June 2008 and April 2014. Patients were included who underwent revision hip arthroscopy with preoperative and minimum 5-year follow-up scores 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. Patients with Tönnis grade >1 or with hip conditions such as avascular necrosis, Legg-Calve-Perthes disease, Ehlers-Danlos syndrome, and pigmented villonodular synovitis were excluded. A subanalysis was performed against a propensity-matched control group that underwent primary surgery. Groups were propensity matched in a 1:2 ratio for sex, age, body mass index, and follow-up time.

RESULTS

A total of 127 revision arthroscopies (113 patients) were included, and the mean ± SD follow-up time was 72.8 ± 23.3 months. The revision group was 74.0% female, and the average age and body mass index were 34.9 ± 12.4 years and 24.8 ± 4.2, respectively. The revision group demonstrated improvement for all PROMSs and reached the MCID for the mHHS (66.1%), HOS-SSS (68.4%), NAHS (66.9%), and VAS (80.0%). All revision cases were propensity matched to 254 primary arthroscopy cases. PROMSs in the revision group were lower than those of the control group before and after surgery. Delta values were similar between groups for all PROMSs. There were no differences in rates of achieving the MCID. The relative risk of arthroplasty conversion was 2.6 (95% CI, 1.5-4.6) for the revision group as compared with the primary group.

CONCLUSION

Significant improvement in all PROMSs, including the VAS, and high patient satisfaction at minimum 5-year follow-up were reported after revision hip arthroscopy. A high proportion of patients in the revision cohort reached the MCID for the mHHS, HOS-SSS, NAHS, and VAS, with similar rates and magnitudes of improvement relative to the control group. As expected, these data indicate that patients undergoing primary hip arthroscopy have higher PROMSs before and after surgery and lower rates of conversion to arthroplasty.

Mid- to Long-Term Outcomes of Hip Arthroscopy: A Systematic Review

PURPOSE

To assess mid- to long-term patient-reported outcomes (PROs) of hip arthroscopy as well as the rates of secondary surgery and to identify indications for surgery and noted predictors of failure.

METHODS

A systematic review of the current literature was performed with the terms "hip arthroscopy," "outcomes," "patient-reported outcomes," "mid-term," "5-year," "long-term," and "10-year" in the PubMed, Cochrane, and Embase databases in April of 2020 according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Data for study characteristics, patient demographics, follow-up time, indications for surgery, PROs, predictors of failure or unfavorable PROs, and rates of secondary hip preservation surgery and conversion to total hip arthroplasty were collected.

RESULTS

Thirteen articles were included. Four studies were level III and 9 were level IV. In total, 1571 hips were included, and the average follow-up time ranged from 60 to 240 months. The most common indications for hip arthroscopy were labral tears and femoroacetabular impingement syndrome. Twelve studies reported on PROs and all reported improvement at latest follow-up. The most reported on scores were the modified Harris Hip Score, Harris Hip Score, and the Hip Outcome Score-Sport Specific Subscale. When grouped based on average follow-up time, the conversion rates at the 5- and 10-year time points ranged from 3.0% to 17.9% and 2.4% to 32.5%, respectively. One study with 20-year follow-up reported a conversion rate of 41.0%. Osteoarthritis and increased age were the most cited predictors for secondary surgery or decreased PROs.

CONCLUSIONS

At mid- to long-term follow-up, patients who underwent primary hip arthroscopy demonstrated improvement in several PROs. There was great variability in rates for revision surgery and conversion to total hip arthroplasty. The most common indications for hip arthroscopy were labral tears and femoroacetabular impingement syndrome. Osteoarthritis and increased age were the most cited predictors for unfavorable outcomes.

LEVEL OF EVIDENCE

Level IV, systematic review of Level III and IV studies.

Defining the Clinically Meaningful Outcomes for Arthroscopic Treatment of Femoroacetabular Impingement Syndrome at Minimum 10-Year Follow-up: The Timing of Surgery Is Crucial

Background

Arthroscopic treatment of femoroacetabular impingement syndrome (FAIS) has become a common procedure. However, meaningful long-term clinical outcomes have not been defined.

Purpose

To define the minimal clinically important difference (MCID), substantial clinical benefit (SCB), and patient acceptable symptomatic state (PASS) for the modified Harris Hip Score (mHHS) at a minimum 10-year follow-up in patients undergoing arthroscopic treatment for FAIS and identify preoperative predictors for achievement of the MCID, SCB, and PASS.

Study Design

Case-control study; Level of evidence, 3.

Methods

A consecutive series of patients undergoing arthroscopic treatment for FAIS between 2007 and 2009 with a minimum 10-year follow-up was analyzed. Patient data included patient characteristics, radiographic parameters, and the pre- and postoperative mHHS and visual analog scale (VAS) for pain score. Paired t tests were used to compare the patient-reported outcome measures (PROMs). The MCID was determined by calculating half of the standard deviation, and SCB and PASS were calculated by the anchor method. Correlation and logistic regression analyses were conducted to identify predictors for the achievement of the MCID, SCB, and PASS.

Results

A total of 44 patients (27 men, 17 women) were included. The mean age and body mass index were 42.2 years (range, 16-67 years) and 22.3 kg/m² (range, 16.76-29.78 kg/m²), respectively. The MCID, absolute SCB, net change SCB, and PASS of the mHHS were calculated to be 19.6, 90.1, 31.5, and 84.4 points, respectively. Preoperative symptom duration was identified as an independent predictor for the achievement of meaningful clinical outcomes. The median symptom durations for patients who achieved the MCID, absolute SCB, net change SCB, and PASS were 11.7, 9.1, 9.0, and 10.8 months, respectively. The median symptom duration for patients who did not achieve the MCID, absolute SCB, net change SCB, and PASS were 15.8, 17.4, 17.3, and 18.4 months, respectively. No other statistically significant correlations were found.

Conclusion

The preoperative duration of symptoms was identified as an independent predictor for achievement of the MCID, SCB, and PASS. These findings can be helpful in accelerating the transition to surgical treatment of FAIS.

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.

Predictors of Clinical Outcomes After Hip Arthroscopy: 5-Year Follow-up Analysis of 1038 Patients

BACKGROUND

Although hip arthroscopy has been shown to have favorable results, there is a paucity of literature describing predictive factors of 5-year clinical outcomes.

PURPOSE

To identify predictive factors of midterm outcomes after hip arthroscopy in a cohort of 1038 patients whose outcomes at minimum 2-year follow-up were previously reported. In addition, to provide a comparison of short- and midterm predictive factors in outcome measures after hip arthroscopy.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

Data were prospectively collected and retrospectively reviewed on all patients undergoing hip arthroscopy between February 2008 and June 2012. Patients were included if they had minimum 5-year follow-up on 2 patient-reported outcomes: Nonarthritic Hip Score (NAHS) and modified Harris Hip Score. Patients were excluded if they had any previous ipsilateral hip conditions. Using bivariate and multivariate analyses, we analyzed the effect of 36 pre- and intraoperative variables on the NAHS, modified Harris Hip Score, and conversion to total hip arthroplasty.

RESULTS

A total of 1038 patients met the inclusion criteria for the 2-year study, and 860 met our listed inclusion criteria for the 5-year study. The mean follow-up time was 62.0 months (range, 60.0-120.0 months). The bivariate analysis identified 10 variables (4 categorical and 6 continuous) that were predictive of 5-year postoperative NAHS. For the multivariate analysis, 7 variables were identified as being significant: preoperative NAHS, body mass index (BMI), age, lateral joint space, alpha angle, revision hip arthroscopy, and acetabular microfracture. These 7 variables were also predictive in the bivariate analysis. Age, BMI, revision hip arthroscopy, Tönnis grade, sex, trochanteric bursectomy, femoral head cartilage damage, and acetabular inclination were significant predictors of conversion to total hip arthroplasty.

CONCLUSION

This study reports favorable midterm clinical outcomes in the largest cohort of hip arthroscopies with minimum 5-year follow-up in the literature to date. Seven variables were identified as being significant predictors of postoperative NAHS in the bivariate and multivariate analyses: preoperative NAHS, BMI, age, lateral joint space, alpha angle, revision hip arthroscopy, and acetabular microfracture. Of these, preoperative NAHS, BMI, age, and revision hip arthroscopy were predictive of 2- and 5-year postoperative NAHS. These predictive factors may prove useful to clinicians in determining indications for hip arthroscopy and counseling patients on its expected outcomes.

Surgeon Experience in Hip Arthroscopy Affects Surgical Time, Complication Rate, and Reoperation Rate: A Systematic Review on the Learning Curve

PURPOSE

To systematically review the literature to (1) identify the reported learning curves associated with hip arthroscopy and (2) evaluate the effect of the stated learning curves on outcomes, such as complication rates, surgical and traction time, reoperation rates, and patient-reported outcome score (PRO) improvements.

METHODS

Two independent reviewers screened the PubMed-MEDLINE, Embase, and Cochrane Library electronic databases from inception to January 2020 according to Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. The following search algorithm was used: "hip arthroscopy" paired with "learning curve," "competence," "experience," "performance," and "motor skills." Data regarding study characteristics, patient demographic characteristics, PROs, and learning-curve analyses were collected.

RESULTS

We identified 15 studies that reported the impact of the learning curve on surgical progress or clinical outcome measures. Measures of the surgical process included surgical and traction time, as well as fluoroscopy time, whereas clinical outcome measures encompassed PROs, complication rates, and reoperation rates. Three studies reported that the learning curve plateaued at 30 cases, but other studies suggested cutoff points ranging from 20 to 519. Operative time (75-119 minutes vs 45-99 minutes), traction time (55-127 minutes vs 54-112 minutes), complication rates (0.5%-43.3% vs 0.5%-18.0%), revision arthroscopy rates (3.3%-10% vs 1.0%-4.2%), and rates of conversion to total hip arthroplasty (12.2%-22.5% vs 1.5%-3.7%) decreased as surgeons gained more experience. Favorable PROs were observed throughout the surgeons' experience.

CONCLUSIONS

Progression along the learning curve of hip arthroscopy led to decreases in complication rates, surgical and traction time, and reoperation rates. PROs benefited from surgery throughout the learning curve. Currently, there exists a wide spread of cutoff numbers proposed to achieve proficiency, ranging from 20 to over 500.

LEVEL OF EVIDENCE

Level IV, systematic review of Level IV studies.

Arthroscopic acetabular labral reconstruction: a review

The function and importance of the acetabular labrum in hip biomechanics have been determined. A labral tear is one of the most common findings in the hip preservation field, commonly associated with femoroacetabular impingement (FAI) syndrome. It has been established that the restoration of labral anatomy and function are key factors to improve patient-reported outcome measurements (PROMs) and psychometric tools following arthroscopic hip arthroscopy in the context of FAI syndrome. Labral repair or refixation is currently the gold-standard surgical option when facing labral tears, with clinical mid to long-term data supporting its use. Labral selective debridement has proven to be a valid alternative in selective patients. Acetabular labral reconstruction has risen as an alternative to labral excision or resection when repair is not an option due to labral tissue deficiency. Restoring the labral sealing mechanism is the goal behind the acetabular labral reconstruction. It has been proven that labral reconstruction leads to superior PROMs when compared with resection. This review presents an analysis of the indications, techniques, and outcomes for arthroscopic acetabular labral reconstruction.

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.

Editorial Commentary: Hip Arthroscopy-A Microcosm in the Evolution of Arthroscopy in Sports Medicine

Hip arthroscopy represents a microcosm in the evolution of arthroscopy within sports medicine. It has evolved right before our eyes over a condensed time frame with current-day techniques in arthroscopy and concepts in sports medicine. Early on, arthroscopy identified labral tears and other painful problems that had previously gone unrecognized and untreated because open procedures were rarely performed for these poorly defined conditions. The evolution of hip arthroscopy changed when femoroacetabular impingement was described and open surgical procedures were used for treatment. Open procedures for the hip, like the knee and shoulder before it, then evolved to less invasive arthroscopic methods. Techniques, technology, and understanding of hip disorders have all evolved simultaneously, resulting in a quickly changing landscape in the role of arthroscopy. And an improved focus has been gained on disorders other than femoroacetabular impingement that can lead to hip problems. This evolution is not novel because we have seen it in other joints, as well as among other general surgical procedures; most important, this evolution is not complete. Miles to go before we sleep.