Clinical Outcomes of Hip Arthroscopic Surgery: A Prospective Survival Analysis of Primary and Revision Surgeries in a Large Mixed Cohort

Incidence of Venous Thromboembolism After Hip Arthroscopy Is Low With or Without Prophylaxis but Risk Factors Include Oral Contraceptive Use, Obesity, and Malignancy

PURPOSE

To determine the incidence of and risk factors for symptomatic venous thromboembolism (VTE) after hip arthroscopy (HA) and thromboprophylaxis prescription utilization for this procedure.

METHODS

The PearlDiver Mariner database was queried using Current Procedural Terminology codes to identify adult patients (aged ≥ 18 years) who underwent HA between 2010 and 2020. Patient demographic information, including age, oral contraceptive use, and medical comorbidities, as well as perioperative thromboprophylaxis utilization, was recorded using International Classification of Diseases codes and National Drug Codes. The incidence of postoperative VTE within 90 days was determined. Multivariate logistic regression was used to identify predictors of perioperative thromboprophylaxis utilization and risk factors for VTE.

RESULTS

The queried records identified 60,181 patients who met the inclusion criteria. Of these patients, 367 (0.6%) experienced VTE, including deep venous thrombosis (0.5%) and/or pulmonary embolism (0.2%). Approximately 2.1% of patients used thromboprophylaxis, including aspirin (1.1%), low-molecular-weight heparin (0.9%), and oral factor Xa inhibitors (0.1%). Oral contraceptive pill use (adjusted odds ratio [aOR], 2.16; 95% confidence interval [CI], 1.34-3.46), obesity (aOR, 1.37; 95% CI, 1.05-1.79), and a history of malignancy (aOR, 1.69; 95% CI, 1.12-2.54) were associated with increased odds of experiencing VTE. Perioperative thromboprophylaxis (aOR, 0.52; 95% CI, 0.19-1.39) was not significantly associated with decreased odds of experiencing VTE. However, obesity (aOR, 1.17; 95% CI, 1.00-1.38) and hypertension (aOR, 1.17; 95% CI, 1.02-1.36) were associated with increased odds of thromboprophylaxis prescription utilization.

CONCLUSIONS

Although the overall risk of symptomatic VTE after HA remains low, oral contraceptive use, obesity, and a history of malignancy are associated with increased odds of thromboembolic events within 90 days. Routine thromboprophylaxis after HA may not be indicated in all patients but can be considered based on patient-specific risk factors.

LEVEL OF EVIDENCE

Level III, retrospective prognostic comparative trial.

Staging Bilateral Hip Arthroscopies Less Than 1 Year Apart May Reduce the Risk of Revision Surgery

PURPOSE

To identify the influence of timing between staged bilateral hip arthroscopy on 90-day postoperative medical complications and 2-year surgical complications including revision, conversion to total hip arthroplasty (THA), and infection.

METHODS

The Mariner data set of the PearlDiver all-payer claims database was queried for patients undergoing staged bilateral hip arthroscopy. Patients were stratified into cohorts based on time between arthroscopies: (1) ≤3 months, (2) 3 to ≤6 months, (3) 6 to ≤12 months, and (4) >1 year. Multivariate logistic regression was utilized to control for any confounding variables.

RESULTS

In total, 998 patients underwent staged bilateral hip arthroscopy out of 38,080 patients who underwent primary hip arthroscopy. The 2-year revision rate was 7.6% for all patients undergoing bilateral hip arthroscopy, while 1.9% of patients underwent conversion to THA. Patients with arthroscopy procedures staged less than 1 year apart (cohorts 1, 2, and 3) had significantly decreased risk of revision compared to the greater than 1 year cohort (P = .008, .025, and .044, respectively). There were no differences in rates of major medical, minor medical, or remaining surgical complications between the cohorts. Direct comparisons between the cohorts staged ≤1 year apart showed no significant differences in medical or surgical complications (P > .05).

CONCLUSIONS

The revision rate in all patients undergoing staged bilateral hip arthroscopy was 7.6%. Staging hip arthroscopy ≤1 year apart was associated with a decreased risk of revision when compared to the staged cohort >1 year. Among those staged less than 1 year, the timing of staging had no association with rates of medical or surgical complications. Patients who are indicated for bilateral hip arthroscopy may benefit from staging under 1 year apart to reduce the risk of revision surgery. Optimal timing decisions may be patient specific and rely on the duration of symptoms, severity of pathology, or progression of rehabilitation after the index procedure.

LEVEL OF EVIDENCE

III, retrospective comparative study.

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.

Three-Dimensional Quantification of Cam Resection Using MRI Bone Models: A Comparison of 2 Techniques

Background:

The current clinical standard for the evaluation of cam deformity in femoroacetabular impingement syndrome is based on radiographic measurements, which limit the ability to quantify the complex 3-dimensional (3D) morphology of the proximal femur.

Purpose:

To compare magnetic resonance imaging (MRI)–based metrics for the quantification of cam resection as derived using a best-fit sphere alpha angle (BFS-AA) method and using 3D preoperative-postoperative surface model subtraction (PP-SMS).

Study Design:

Descriptive laboratory study.

Methods:

Seven cadaveric hemipelvises underwent 1.5-T MRI before and after arthroscopic femoral osteochondroplasty, and 3D bone models of the proximal femur were reconstructed from the MRI scans. The alpha angles were measured radially along clockfaces using a BFS-AA method from the literature and plotted as continuous curves for the pre- and postoperative models. The difference between the areas under the curve for the pre- and postoperative models was then introduced in the current study as the BFS-AA–based metric to quantify the cam resection. The cam resection was also quantified using a 3D PP-SMS method, previously described in the literature using the metrics of surface area (FSA), volume (FV), and height (maximum [FH_max] and mean [FH_mean]). Bivariate correlation analyses were performed to compare the metrics quantifying the cam resection as derived from the BFS-AA and PP-SMS methods.

Results:

The mean ± standard deviation maximum pre- and postoperative alpha angle measurements were 59.73° ± 15.38° and 48.02° ± 13.14°, respectively. The mean for each metric quantifying the cam resection with the PP-SMS method was as follows: FSA, 540.9 ± 150.7 mm²; FV, 1019.2 ± 486.2 mm³; FH_max, 3.6 ± 1.0 mm; and FH_mean, 1.8 ± 0.5 mm. Bivariate correlations between the BFS-AA–based and PP-SMS–based metrics were strong: FSA (r = 0.817, P = .012), FV (r = 0.888, P = .004), FH_max (r = 0.786, P = .018), and FH_mean (r = 0.679, P = .047).

Conclusion:

Strong positive correlations were appreciated between the BFS-AA and PP-SMS methods quantifying the cam resection.

Clinical Relevance:

The utility of the BFS-AA technique is primarily during preoperative planning. The utility of the PP-SMS technique is in the postoperative setting when evaluating the adequacy of resection or in patients with persistent hip pain with suspected residual impingement. In combination, the techniques allow surgeons to develop a planned resection while providing a means to evaluate the depth of resection postoperatively.

Repeat Revision Hip Arthroscopy Outcomes Match That of Initial Revision But Not That of Primary Surgery for Femoroacetabular Impingement Syndrome

PURPOSE

To (1) report on pre- and postoperative patient-reported outcome (PRO) scores for patients undergoing repeat revision surgery in short-term follow-up and (2) compare minimal clinically important difference (MCID) and patient acceptable symptomatic state achievement between primary, revision, and repeat revision hip arthroscopy cohorts.

METHODS

Data from consecutive patients undergoing revision hip arthroscopy from January 2012 to February 2019 were retrospectively reviewed. Hips that underwent 2 revision hip arthroscopic surgeries were identified and matched 1:3 to patients undergoing revision surgery and 1:3 to patients undergoing primary surgery by age, sex, and body mass index. Baseline demographic data, surgical indications, and hip-specific PROs were collected were obtained preoperatively and at minimum 1-year follow-up. MCID was calculated individually for each cohort.

RESULTS

Twenty patients who underwent repeat revision were matched to 60 patients who underwent revision and 60 primary patients. Patients who underwent repeat revision achieved MCID on all investigated PROs at a similar rate to patients undergoing primary surgery (90.0% vs 91.7%, P = .588) and at a greater rate than patients undergoing first-time revision surgery (90.0% vs 71.7%, P = .045). Patients who underwent repeat revision achieved patient acceptable symptomatic state on all investigated PROs at a similar rate to patients who underwent first-time revision (30.0% vs 55.0%, P = .053) but at a significantly lower rate than primary patients (30.0% vs 76.7%, P < .001). However, patients undergoing repeat revision surgery had significantly lower preoperative PROs (P < .001 for all) and no significant difference in PROs at minimum 1-year follow-up compared with patients undergoing revision (P > .05). Compared with the primary cohort, patients who underwent repeat revision had significantly lower Hip Outcome Score-Activities of Daily Living (77.3 ± 16.7 vs 86.1 ± 14.4; P = .034), Hip Outcome Score-Sports Subscale (60.6 ± 27.2 vs 76.1 ± 23.8; P < .001), and modified Harris Hip Score (69.2 ± 19.3 vs 81.7 ± 16.1; P = .048) at a minimum of 1-year follow-up.

CONCLUSIONS

Second-time revision hip arthroscopy, which often requires advanced procedures, results in clinically significant improvement in PROs; however, outcomes for repeat revision cases are similar to first-time revision cases but inferior to those obtained following primary surgeries.

LEVEL OF EVIDENCE

Level III, retrospective case-control study.

Failure to Achieve Threshold Scores on Patient-Reported Outcome Measures Within 1 Year Has a Predictive Risk of Subsequent Hip Surgery Within 5 Years of Primary Hip Arthroscopy: A Case-Control Study

Background:

Research has identified factors that influence achievement rates of threshold scores on patient-reported outcome measures (PROMs) after hip arthroscopy. However, little data exist on whether failure to achieve a threshold score (minimal clinically important difference [MCID] or substantial clinical benefit [SCB]) in the short term after hip arthroscopy predicts the risk of future hip surgery.

Purpose/Hypothesis:

The purpose of this study was to determine if failure to achieve the MCID or SCB on PROMs within 1 year of hip arthroscopy can be considered a risk factor for repeat surgery within 5 years of primary hip arthroscopy. It was hypothesized that failure to achieve threshold scores would increase the risk of subsequent hip surgery.

Study Design:

Case-control study; Level of evidence, 3.

Methods:

A retrospective review of prospectively collected data was completed. Four PROMs were collected preoperatively and within 1 year of hip arthroscopy: modified Harris Hip Score, Hip Outcome Score–Activities of Daily Living, Hip Outcome Score–Sports, and the 33-Item International Hip Outcome Tool.

Results:

Two cohorts were formed: (1) a study cohort (n = 88) composed of patients who underwent repeat hip surgery within 5 years of hip arthroscopy and (2) a control cohort (n = 288) composed of patients who did not require repeat hip surgery. The study cohort had significantly (P < .001) lower scores on all postoperative PROMs, and a significantly (P < .001) smaller percentage of the study cohort met the MCID and SCB. Multivariable regression analysis demonstrated that not achieving the MCID or SCB on each of the PROMs is an independent risk factor for repeat hip surgery. For every PROM in which a patient failed to achieve the MCID, the odds of subsequent surgery increased by 1.68 (95% CI, 1.42-1.98; P < .001). For every PROM in which a patient failed to achieve the SCB, the odds of subsequent surgery increased by 1.63 (95% CI, 1.35-1.97; P < .001).

Conclusion:

Failure to meet threshold scores on PROMs after hip arthroscopy was an independent risk factor for subsequent hip surgery. This study establishes a novel utility of PROMs and confirms the importance of these metrics in the orthopaedic literature.

Revision Hip Arthroscopy in High-Level Athletes: Minimum 2-Year Outcomes Comparison to a Propensity-Matched Primary Hip Arthroscopy Control Group

BACKGROUND

Outcomes of revision hip arthroscopy in the athletic population have not been well established.

PURPOSE

(1) To report clinical outcomes for high-level athletes undergoing revision hip arthroscopy in the setting of femoroacetabular impingement syndrome (FAIS) or labral tears and (2) to compare these outcomes against a propensity-matched group of high-level athletes undergoing primary hip arthroscopy.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Data for professional, college, and high school athletes were prospectively collected and retrospectively reviewed between January 2012 and October 2018. Patients were included if they underwent revision or primary hip arthroscopy and had preoperative and minimum 2-year patient-reported outcome (PRO) scores for 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. The findings and outcomes of revision athletes were compared with a propensity-matched control group of high-level athletes undergoing primary hip arthroscopy.

RESULTS

A total of 32 hips (29 patients) undergoing revision hip arthroscopy and 92 hips (88 patients) undergoing primary hip arthroscopy were included in our final analysis with a median follow-up time of 29.5 months (95% CI, 27.2-32.1 months) and 36.5 months (95% CI, 33.5-37.7 months), respectively. Athletes undergoing revision surgery showed significant improvement in all recorded PRO measurements and achieved patient acceptable symptomatic state (PASS) and minimal clinically important difference (MCID) for mHHS at high rates (80.6% and 83.9%, respectively). When compared with a propensity-matched primary control group, patients undergoing revision surgery demonstrated lower preoperative and postoperative scores for mHHS, NAHS, and HOS-SSS, but the magnitude of improvement in functional scores was similar between groups. Athletes undergoing revision surgery achieved PASS for HOS-SSS at lower rates than the control group (P = .005), and they were less likely to attempt to return to sport compared with the control group (62.5% vs 87.0%; P < .01).

CONCLUSION

Revision hip arthroscopy is a viable treatment option to improve PROs in high-level athletes at minimum 2-year follow-up. The study group showed significant improvement in functional scores and a high rate of successful outcomes. They experienced similar magnitude of improvement as that of a propensity-matched control group; however, they achieved lower postoperative PRO scores and attempted to return to sport at lower rates.

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.

Clinical outcomes after revision hip arthroscopy in patients with femoroacetabular impingement syndrome (FAIS) are inferior compared to primary procedures. Results from the Danish Hip Arthroscopy Registry (DHAR)

PURPOSE

As many as 10% of primary hip arthroscopies end up with a revision arthroscopy procedure when treating patients suffering from femoroacetabular impingement syndrome (FAIS). In general, revision procedures are indicated because of residual impingement, but only a few studies present outcome data from revision hip arthroscopy after failed FAIS surgical treatment. The purpose of this study was to evaluate clinical outcomes after revision hip arthroscopy in a FAIS cohort and compare outcomes with a primary FAIS hip arthroscopy cohort and describe potential causes of failure after the primary hip arthroscopy. It was hypothesized that subjective outcomes improve after revision hip arthroscopy although outcomes were expected to be inferior to primary hip arthroscopic outcomes.

METHODS

Three-hundred and thirty-one arthroscopic revision hip FAIS patients were included from the Danish Hip Arthroscopy Registry (DHAR). Patient-related outcome measures (PROM's), Copenhagen Hip and Groin Outcome Scores (HAGOS), Hip Sports Activity Scale (HSAS), EQ-5D and Numeric Rating Scale (NRS) pain, were assessed in the study cohort prior to the primary procedure and at revision and at follow-up one year after the revision procedure. These data were compared with 4154 primary hip arthroscopic FAIS patients.

RESULTS

One-year after revision surgery, mean follow-up (in months ± SD): 12.3 ± 1.6, significant improvements (p < 0.05) in all PROMs was demonstrated, but FAIS patients in the primary hip arthroscopic cohort demonstrated significantly higher outcomes, in all PROMs, when compared at one-year follow-up. Scar tissue, residual osseous impingement and insufficient healing of the labral repair were reported as the main reasons for revision surgery. The conversion to total hip arthroplasty was low (6.4%).

CONCLUSION

Revision hip arthroscopy in FAIS patients improves subjective outcomes significantly, although they are poorer than after primary FAIS hip arthroscopy. Main reasons for revision arthroscopy was scar tissue, residual femoroacetabular impingement and insufficient healing of labral repair.

LEVEL OF EVIDENCE

Level III.

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.

A Biomechanical Comparison of 2 Hip Capsular Reconstruction Techniques: Iliotibial Band Autograft Versus Achilles Tendon Allograft

BACKGROUND

Several techniques for hip capsular reconstruction have been described to address gross instability or microinstability due to capsular deficiency. However, objective biomechanical data to support their use are lacking.

PURPOSE

To compare the kinematic effect of 2 capsular reconstruction techniques (iliotibial band [ITB] graft and Achilles tendon graft). Kinematic effect encompassed rotational range of motion (ROM) as well as joint translation in the coronal, sagittal, and axial planes.

STUDY DESIGN

Controlled laboratory study.

METHODS

8 paired, fresh-frozen hemi-pelvises (16 hips) were tested on a custom-designed joint motion simulator in the intact state and after capsulectomy. Pairs were randomly allocated to either ITB or Achilles reconstruction and retested. Testing was performed at 0°, 45°, and 90° of flexion. Internal-external rotation (IR-ER) torques and abduction-adduction torques of 3 N·m were applied to the femur via a load cell at each position, and rotational ROM and joint translation in the coronal, sagittal, and axial planes were recorded.

RESULTS

At 45° and 90°, there was a significant effect of the condition of the hip on the total IR-ER (P = .004, effect size [ES] = 0.305; and P < .001, ES = 0.497; respectively). At 45°, mean ± SD total rotation was significantly greater for the capsulectomy (59.7°± 15.9°) state compared with intact (53.3°± 13.2°; P = .007). At 90°, reconstruction significantly decreased total rotation to 49.0°± 18.9° compared with a mean total rotation of 52.8°± 18.7° after capsulectomy (P = .02). No difference was seen in the total abduction-adduction of the hip between conditions. Comparisons of the 2 different reconstruction techniques showed no significant differences in total IR-ER or abduction-adduction ROM or joint translation in the coronal, sagittal, or axial planes. For translation, at both 0° and 45° there was a statistically significant effect of the condition on the medial-lateral translation (P = .033; ES = 0.204). Reconstruction, independent of technique, was successful in significantly decreasing (P = .030; P = .014) the mean medial-lateral translation at 0° and 45° of hip flexion from 5.2 ± 3.8 mm and 5.6 ± 4.0 mm to 2.8 ± 1.9 mm and 3.9 ± 3.2 mm, respectively.

CONCLUSION

The integrity of the native hip capsule played a significant role in rotational stability, where capsulectomy significantly increased rotational ROM. Both ITB and Achilles reconstruction techniques restored normal rotational ROM of the hip at 90° of flexion as well as coronal plane stability at 0° and 45° of hip flexion. No differences were seen between ITB and Achilles reconstruction techniques.

CLINICAL RELEVANCE

Both capsular reconstruction techniques provide comparable joint kinematics, restoring rotation and translation to normal values with the exception of rotational ROM at 45°, which remained significantly greater than the intact state. The most significant results were the rotational stability at 90° of hip flexion and coronal plane stability at 0° and 45° of hip flexion, which were significantly improved compared with the capsulectomy state.

Fast Starters and Slow Starters After Hip Arthroscopy for Femoroacetabular Impingement: Correlation of Early Postoperative Pain and 2-Year Outcomes

BACKGROUND

Patients experience varying degrees of pain and symptoms during the early recovery period after hip arthroscopy for femoroacetabular impingement (FAI). Some "fast starters" report minimal discomfort and are eager to advance activities, while "slow starters" describe severe pain and limitations. The relationship between these early postoperative symptoms and 2-year outcomes after hip arthroscopy is unknown.

PURPOSE

To analyze the relationship between early postoperative pain and 2-year patient-reported outcomes (PROs) after hip arthroscopy for FAI.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Patients without arthritis or dysplasia who were undergoing primary hip arthroscopy for FAI were prospectively enrolled and completed validated PROs. Scores for visual analog scale (VAS) for pain were collected preoperatively and at 1 week, 6 weeks, and 2 years postoperatively. Scores for the modified Harris Hip Score (mHHS), Hip disability and Osteoarthritis Outcome Score (HOOS), and 12-Item Short Form Health Survey (SF-12) were collected preoperatively and 2 years postoperatively. Paired t tests were used to evaluate PRO score changes, and correlation analyses were used to assess relationships between early postoperative pain and 2-year postoperative outcomes.

RESULTS

A total of 166 patients were included (55% female; mean ± SD age, 35.29 ± 9.6 years; mean body mass index, 25.07 ± 3.98 kg/m²). Patients demonstrated significant improvements in PRO scores (VAS, SF-12 Physical Component Score, mHHS, and all HOOS subscales) at 2 years after hip arthroscopy for FAI (P < .001). There was a significant correlation between lower 1-week VAS pain level (fast starters) and lower 2-year VAS pain level (R = 0.31; P < .001) as well as higher 2-year PRO scores (SF-12 Physical Component Score, mHHS, and all HOOS subscales: R = -0.21 to -0.3; P < .001). There was no correlation between 1-week VAS pain and 2-year SF-12 Mental Component Score (P = .17). Preoperative VAS pain levels showed positive correlations with 1-week postoperative pain scores (R = 0.39; P < .001) and negative correlations with 2-year patient outcomes (R = -0.15 to -0.33, P < .01). There was no correlation between 6-week postoperative pain scores and 2-year PRO scores.

CONCLUSION

Fast starters after hip arthroscopy for FAI experience sustained improvements in outcomes at 2 years after surgery. Patient pain levels before surgery may delineate potential fast starters and slow starters.

Radiographic Indices Are Not Predictive of Clinical Outcomes Among 1735 Patients Indicated for Hip Arthroscopic Surgery: A Machine Learning Analysis

BACKGROUND

The relationship between the preoperative radiographic indices for femoroacetabular impingement syndrome (FAIS) and postoperative patient-reported outcome measure (PROM) scores continues to be under investigation, with inconsistent findings reported.

PURPOSE

To apply a machine learning model to determine which preoperative radiographic indices, if any, among patients indicated for the arthroscopic correction of FAIS predict whether a patient will achieve the minimal clinically important difference (MCID) for 1- and 2-year PROM scores.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A total of 1735 consecutive patients undergoing primary hip arthroscopic surgery for FAIS were included from an institutional hip preservation registry. Patients underwent preoperative computed tomography of the hip, from which the following radiographic indices were calculated by a musculoskeletal radiologist: alpha angle, beta angle, sagittal center-edge angle, coronal center-edge angle, neck shaft angle, acetabular version angle, and femoral version angle. PROM scores were collected preoperatively, at 1 year postoperatively, and at 2 years postoperatively for the modified Harris Hip Score (mHHS), the Hip Outcome Score (HOS)-Activities of Daily Living (HOS-ADL) and -Sport Specific (HOS-SS), and the International Hip Outcome Tool (iHOT-33). Random forest models were created for each PROM at 1 and 2 years' follow-up, with each PROM's MCID used to establish clinical meaningfulness. Data inputted into the models included ethnicity, laterality, sex, age, body mass index, and radiographic indices. Comprehensive and separate models were built specifically to assess the association of the alpha angle, femoral version angle, coronal center-edge angle, McKibbin index, and hip impingement index with respect to each PROM.

RESULTS

As evidenced by poor area under the curves and P values >.05 for each model created, no combination of radiographic indices or isolated index (alpha angle, coronal center-edge angle, femoral version angle, McKibbin index, hip impingement index) was a significant predictor of a clinically meaningful improvement in scores on the mHHS, HOS-ADL, HOS-SS, or iHOT-33. The mean difference between 1- and 2-year PROM scores compared with preoperative values exceeded the respective MCIDs for the cohort.

CONCLUSION

In patients appropriately indicated for FAIS corrective surgery, clinical improvements can be achieved, regardless of preoperative radiographic indices, such as the femoral version angle, coronal center-edge angle, and alpha angle. No specific radiographic parameter or combination of indices was found to be predictive of reaching the MCID for any of the 4 studied hip-specific PROMs at either 1 or 2 years' follow-up.

Post-operative oral chemoprophylaxis in patients undergoing hip arthroscopy mitigates VTE risk with a low side-effect profile

Hip arthroscopy (HA) has increased exponentially over the last decade. A recent systematic review found that the risk of venous thromboembolism (VTE) is 2%. This was higher than previous reports which may have underestimated the true incidence of VTE in HA. Thus, protocols to mediate VTE may be more necessary than previously thought. The aim of this article is to present a VTE prevention protocol and evaluate its subsequent efficacy. This is a prospective study of 880 consecutive HA cases. All patients were treated according to a predetermined VTE protocol which classified patients as high (≥1 risk factors) or low (no risk factors) risk for post-operative VTE. In high-risk patients, the protocol followed that of low-risk patients but additionally included rivaroxaban for 2 weeks post-operatively. The incidence of VTE was recorded and analysed in this study. A total of 880 HA cases at an average age of 35.4 years were evaluated, with 76.6% (n = 674) undergoing labral repair and concomitant cam and/or pincer resection, 17.2% (n = 151) of cases for isolated labral tear repaired, and 6.1% (n = 55) classified as other. The overall incidence of VTE was 0.45%. The incidence of VTE was 1.2% and 0.16% in high- and low-risk groups, respectively. Oral VTE prophylaxis was not associated with post-operative complications. This study demonstrated a lower rate of VTE in both risk groups. It highlights the value of a predetermined risk-adjusted protocol to VTE prophylaxis. Rivaroxaban prophylaxis is safe and efficacious in HA with a low associated morbidity.

Does failure to meet threshold scores for mHHS and iHOT-12 correlate to secondary operations following hip arthroscopy?

The purpose of this study was to determine (i) if failing to achieve a patient-reported outcome (PRO) threshold at 1 year was associated with secondary operations at minimum 2-year follow-up and (ii)what outcome measure and threshold has the highest association with future surgeries. Inclusion criteria for this study were cases of primary hip arthroscopy between July 2014 and April 2017. Included patients had recorded pre-operative and 1-year post-operative modified Harris Hip Score (mHHS) and 12-item international Hip Outcome Tool (iHOT-12) scores. Patients were classified based on their ability to achieve minimal clinical important difference (MCID), substantial clinical benefit (SCB) and patient acceptable symptom state (PASS) for each PRO and the status of secondary operations at minimum 2-year follow-up. The sensitivity, specificity, accuracy, positive likelihood ratio and negative likelihood ratio for these thresholds were calculated. Of 425 eligible cases, 369 (86.8%) had minimum 2-year follow-up. Of the included patients, 28 underwent secondary operations (7.59%), with 14 undergoing secondary arthroscopies (3.79%) and 14 converting to total hip arthroplasty (3.79%). For mHHS, 267 (72.4%), 173 (46.9%) and 277 (75.1%) hips met MCID, SCB and PASS, respectively. For iHOT-12, 234 (63.4%), 218 (59.1%) and 280 (75.9%) hips met the respective thresholds. The highest specificity, sensitivity and accuracy were identified as for iHOT-12 MCID (0.79), iHOT-12 PASS (0.79) and iHOT-12 MCID (0.77), respectively. Patients not attaining MCID and PASS for mHHS and iHOT-12 at 1-year post-operatively are at increased risk of secondary operation. The most accurate threshold associated with secondary operation (0.77) is not achieving iHOT-12 MCID. Level of evidence: retrospective case series: level IV.

Indications and Outcomes of Secondary Hip Procedures After Failed Hip Arthroscopy: A Systematic Review

PURPOSE

(1) To identify present indications for secondary procedures in patients with failed hip arthroscopy and (2) to assess patient-reported outcomes (PROs) of the secondary procedures, including revision arthroscopy, periacetabular osteotomy (PAO), and total hip arthroplasty (THA).

METHODS

Study groups included patients who had a secondary procedure after failed previous hip arthroscopy whereas the control groups were patients who had a primary procedure but did not require a secondary procedure. Indications and procedures at the time of the secondary operation were documented for each study. Average PROs were recorded, and standardized mean difference was calculated to estimate effect size.

RESULTS

Eighteen studies reporting on patients undergoing a secondary procedure after a previous hip arthroscopy were included. The 3 main secondary procedure groups were revision hip arthroscopy, secondary PAO, and secondary THA. Regarding the revision arthroscopy group, the most common indications were labral tears, cam deformity, and pincer deformity. In addition, the most common procedures were femoroplasty, acetabuloplasty, capsular release, and labral reconstruction. The most common indications for the secondary PAO and THA groups were dysplasia and osteoarthritis respectively. Five of the revision arthroscopy studies found that revision patients had worse outcomes than the primary arthroscopy group. One PAO study found that the previous arthroscopy group had slightly worse outcomes, and 2 studies found no differences in PROs. Two THA studies reported worse outcomes for the prior arthroscopy group, and 2 studies reported no differences in outcomes.

CONCLUSIONS

The most common indications for revision hip arthroscopy were labral tears and femoroacetabular impingement. Patients undergoing a revision hip arthroscopy demonstrated good postoperative outcomes but to an overall lesser extent than their primary counterparts. The secondary PAO and THA groups also had favorable PROs, but the studies were inconclusive in determining superior outcomes between the primary and secondary groups.

LEVEL OF EVIDENCE

IV, Systematic review of Level II-IV investigations.

Staged Bilateral Hip Arthroscopy Compared With a Matched Unilateral Hip Arthroscopy Group: Minimum 2-Year Follow-Up

PURPOSE

To determine the modified Harris Hip Score (mHHS) and Non-Arthritic Hip Score (NAHS) at 2-year follow up in patients who underwent staged bilateral hip arthroscopy versus age-, sex-, and body mass index-matched patients who underwent unilateral hip arthroscopy.

METHODS

Patients who underwent staged bilateral primary hip arthroscopy between January 2007 and December 2017 for the indication of femoroacetabular impingement (FAI) with a minimum 2-year follow-up were identified. The control group comprised patients who underwent a unilateral hip arthroscopy for FAI. The mHHS and the NAHS were analyzed.

RESULTS

Forty-two patients (84 hips) in the bilateral group were matched with 84 patients (84 hips) in the unilateral group. Both groups had significantly improved mHHS and NAHS when comparing preoperative scores with postoperative scores (bilateral group mHHS: 45.5 ± 15.1 to 81.7 ± 17.6, P < .0001, bilateral group NAHS: 49.5 ± 13.8 to 83.6 ± 20.0, P < .0001, unilateral group mHHS 48.5 ± 13.8 to 83.6 ± 15.9, P < .0001, unilateral group NAHS 48.8 ± 12.0 to 85.0 ± 16.6, P < .0001). The patient-acceptable symptomatic state was achieved in 57 hips (68%) in the bilateral group versus 62 hips (74%) in the unilateral group, P = .4. Patients with bilateral hip arthroscopy who had <17 months between index procedure and contralateral hip arthroscopy had significantly better mHHS and NAHS (85.5 ± 18.4 vs 75.71 ± 14.4, P = .013 for mHHS and 88.1 ± 17.1 vs 76.2 ± 22.4, P = .0074 for NAHS).

CONCLUSIONS

Bilateral hip arthroscopy for the indication of FAI has improved mHHS and NAHS at 2 years of follow up compared to baseline. There was no difference in 2-year mHHS and NAHS in patients who underwent bilateral hip arthroscopy and unilateral hip arthroscopy. Patients in the bilateral hip arthroscopy group that had the contralateral surgery longer than 17 months from index procedure had lower 2 year follow up mHHS and NAHS scores than those that underwent the second surgery within 17 months of the index procedure.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Identifying the Most Successful Procedures in Hip Arthroscopy

Hip arthroscopy for femoral and acetabular pathologies has increased dramatically. However, there is little literature analyzing procedures as predictors of revision arthroscopy or arthroplasty. From February 2008 to November 2015, patients undergoing hip arthroscopy for a labral tear with minimum 2-year follow-up and between 18 and 60 years old were retrospectively reviewed. Those with previous surgeries, Tönnis grade greater than 1, and previous hip conditions were excluded. Follow-up was obtained for 1118 patients (1249 hips; 81.7%) with a mean age of 38.7 years (range, 18.0-60.0 years), mean body mass index of 26.4 kg/m² (range, 16.3-48.9 kg/m²), and mean follow-up of 50.2 months (range, 24.0-111.9 months). A total of 122 (9.8%) patients converted to total hip arthroplasty (mean, 35.3 months; range, 1.4-95.2 months). Multivariate analysis for predictors of total hip arthroplasty found age at surgery (hazard ratio, 1.064/y; P<.05), body mass index (nonlinear; P<.05), labral debridement (HR, 1.558; P=.03), and notchplasty (HR, 2.128; P<.05), with trochanteric bursectomy (HR, 0.367; P<.05) identified as associated with higher survivorship. A total of 124 (9.9%) patients underwent revision hip arthroscopy at a mean of 21.7 months (range, 0.10-83.3 months). Multivariate analysis for predictors of revision surgery found workers' compensation (HR, 3.352; P<.05), capsular repair (HR, 1.950; P<.05), and femoral head microfracture (HR, 2.844; P=.04) to be significant, with age at date of surgery (HR, 0.973/y; P<.05) and femoral head chondroplasty (HR, 0.241; P=.05) associated with higher survivorship. Understanding risk factors for conversion to total hip arthroplasty or revision is paramount during discussions with patients. [Orthopedics. 2020;43(3):173-181.].

Clinical Outcomes of Hip Arthroscopy in Patients With Systemic Inflammatory Diseases Compared With Matched Controls at a Minimum of 2-Year Follow-Up

PURPOSE

To evaluate postoperative outcomes and preoperative risk factors for patients with underlying systemic inflammatory disorders after hip arthroscopy.

METHODS

A retrospective analysis of patients who had undergone hip arthroscopy, with a history of systemic inflammatory disease, was performed. This included patients with a diagnosis of lupus, a positive antinuclear antibody test, rheumatoid arthritis, psoriatic arthritis, sarcoidosis, inflammatory bowel disease, Reiter syndrome, and mixed connective tissue disease. These cases were 1:2 matched to a control group of patients with no history of systemic inflammatory disease based on age and sex. An a priori power analysis was conducted and A 1:2 case-control ratio was selected to increase study power. Inclusion criteria included all skeletally mature patients with hip pain refractory to nonoperative management who underwent hip arthroscopy for labral tears and femoroacetabular impingement. Skeletally immature patients, those with Tönnis grades of 2 or more (less than 2 mm of joint space), hip dysplasia, patients undergoing revision hip arthroscopy, and patients whose pain failed to improve after intra-articular injection were excluded. The primary outcome was rate of revision hip arthroscopy or total hip arthroplasty 24 months after surgery. Secondary outcomes included 2 patient-reported outcome scores, the modified Harris Hip Score (mHHS) and Non-Arthritic Hip Score (NAHS).

RESULTS

Twenty patients (21 hip arthroscopy procedures) and 42 controls were included. There was no significant difference in proportion of patients who met failure criteria (28.6% vs 16.7%, P = .271) or 2-year survivorship (76.2% vs 83.3%, P = .496) between the systemic inflammatory disorder and control groups, respectively. Both groups had a significant improvement in mHHS and NAHS at 24 months compared with baseline; however, there was no significant difference in mHHS (P = .28) or NAHS (P = .22) at 24 months between the 2 groups.

CONCLUSIONS

Patients with underlying inflammatory conditions have similar 2-year outcomes after hip arthroscopy for intra-articular pathology compared with patients with no history of inflammatory disease.

LEVEL OF EVIDENCE

III, retrospective comparative study.

Outcomes of Revision Hip Arthroscopic Surgery: A Systematic Review and Meta-analysis

BACKGROUND

While the indications for primary hip arthroscopic surgery in treating femoroacetabular abnormalities continue to be defined, the indications and outcomes for revision hip arthroscopic surgery remain ambiguous. However, revision hip arthroscopic surgery is performed in 5% to 14% of patients after their index procedure. While patient-reported outcomes (PROs) generally improve after revision procedures, the extent of their improvement is not well defined.

PURPOSE

To determine the outcomes and efficacy of revision hip arthroscopic surgery in patients who remain symptomatic after their index procedure.

STUDY DESIGN

Meta-analysis and systematic review.

METHODS

The terms "hip arthroscopy,""revisions,""outcomes," and "femoroacetabular impingement" were searched in PubMed, Web of Science, Scopus, Cochrane Library, and Google Scholar. After screening, 15 studies were included for review. In addition to hip-specific metrics, functional outcome measures were included. Pooled estimates and 95% CIs were calculated using inverse variance methods.

RESULTS

A total of 4765 hips in 4316 patients were identified. The most common indication for revision surgery was inadequate bony resection during the index procedure. Meta-analysis showed that all PROs improved significantly from baseline to final follow-up after revision hip arthroscopic surgery. Notably, the modified Harris Hip Score (mHHS) increased a mean of 17.20 points after revision hip arthroscopic surgery, the Hip Outcome Score-Activities of Daily Living (HOS-ADL) improved by 13.98, and the visual analog scale (VAS) for pain decreased by 3.16. However, when compared with primary hip arthroscopic surgery, the mean PRO scores after revision hip arthroscopic surgery were lower. After revision hip arthroscopic surgery, the rates of conversion to total hip arthroplasty ranged from 0% to 14.3%, and the rates of further arthroscopic revision ranged from 2% to 14%.

CONCLUSION

Inadequate bony resection represents the most common indication for revision hip arthroscopic surgery. PROs improve significantly after revision hip arthroscopic surgery but remain lower than those of patients undergoing primary hip arthroscopic surgery.

Physical Activity Following Hip Arthroscopy in Young and Middle-Aged Adults: A Systematic Review

Background

Hip arthroscopy is a common surgical intervention for young and middle-aged adults with hip-related pain and dysfunction, who have high expectations for returning to physical activity following surgery. The purpose of this review was to evaluate the impact of hip arthroscopy on physical activity post-arthroscopy.

Methods

A systematic search of electronic databases was undertaken in identifying studies from January 1st 1990 to December 5th 2019. The search included English language articles reporting physical activity as an outcome following hip arthroscopy in adults aged 18-50 years. Quality assessment, data extraction and synthesis of included studies were undertaken.

Results

Full text articles (n = 234) were assessed for eligibility following screening of titles and abstracts (n = 2086), yielding 120 studies for inclusion. The majority (86%) of the studies were level 4 evidence. One study reported objective activity data. The most frequently occurring patient-reported outcome measure was the Hip Outcome Score-sport-specific subscale (HOS-SS, 84% of studies). Post--arthroscopy improvement was indicated by large effect sizes for patient-reported outcome measures (standard paired difference [95% confidence interval] −1.35[−1.61 to −1.09] at more than 2 years post-arthroscopy); however, the majority of outcome scores for the HOS-SS did not meet the defined level for a patient-acceptable symptom state.

Conclusion

The current level of available information regarding physical activity for post arthroscopy patients is limited in scope. Outcomes have focused on patients’ perceived difficulties with sport-related activities with a paucity of information on the type, quality and quantity of activity undertaken.

Level of Evidence

Level IV, systematic review of Level 2 through to Level 4 studies

Preoperative Predictors of Achieving Clinically Significant Athletic Functional Status After Hip Arthroscopy for Femoroacetabular Impingement at Minimum 2-Year Follow-Up

PURPOSE

To identify predictors of achieving clinically significant sport function in athletic patients undergoing hip arthroscopy for femoroacetabular impingement syndrome (FAIS).

METHODS

Data were analyzed for all patients who treated for FAIS between 2012 to 2016 and reported being athletes, including recreational and competitive athletes. All patients had a minimum of 2-year follow-up with patient-reported athletic function in the form of the Hip Outcome Score-Sport Specific (HOS-SS), visual analog score-pain, and patient satisfaction. Achieving clinically significant sports function was defined as either reaching the minimally clinical important difference (MCID) or the patient acceptable symptomatic state (PASS) for HOS-SS at 2-year follow-up. An exploratory factor analysis was used to determine specific domains for the predictor variables and to reduce the redundancy in these variables. A logistic regression analysis was used to identify significant predictors of achieving clinically significant sports function [corrected].

RESULTS

Of 780 qualifying patients, 626 completed the 2-year minimum follow-up (80%), with a mean age and body mass index of 31.6 ± 11.9 years and 24.6 ± 8.6, respectively. A total of 500 patients (86.5%) achieved high functional status, with 77.9% achieving MCID HOS-SS and 68.7% achieving PASS HOS-SS. Logistic regression analysis identified increased the α angle (odds ratio [OR] 0.976; P = .027), preoperative pain duration (OR 0.729; P = .011), and body mass index (BMI) (OR 0.919; P = .018), as well as the presence of femoral chondral defects (OR 0.769; P = .013), as negative predictors for achieving MCID. Negative predictors for achieving PASS HOS-SS included the presence of a preoperative limp (OR 0.384; P = .013), anxiety or depression (OR 0.561; P = .041), and increased BMI (OR 0.945; P = .018) and preoperative pain duration (OR 0.987; P < .001).

CONCLUSIONS

Several predictors of achieving clinically significant sport function performance exist, including a history of anxiety or depression, BMI, preoperative α angle, limp, femoral chondral damage, *and preoperative symptom duration. Our results suggest there are both modifiable and nonmodifiable preoperative factors that have the potential to predict achieving high athletic function after hip arthroscopy for FAIS.

LEVEL OF EVIDENCE

IV, Case Series.

Acetabular Subchondral and Cortical Perforation During Labral Repair With Suture Anchors: Influence of Portal Location, Curved Versus Straight Drill Guides, and Drill Starting Point

PURPOSE

To evaluate the impact of the portal used for drilling, the position of the drill guide on the acetabular rim, and the use of straight versus curved drill guides on drill perforation of the acetabular subchondral bone and the outer cortex of the acetabulum.

METHODS

Sixty acetabular models were marked at the 3-, 2-, 1-, 12-, and 11-o'clock positions. Simulated anterior, anterolateral, and distal anterolateral accessory (DALA) portals were created. Twelve groups of 5 acetabula were drilled at each clock-face position using all combinations of variables.

RESULTS

A total of 38 of 300 drillings (12.7%) perforated the subchondral bone, and 45 of 300 (15%) breached the outer cortex. Drilling from the anterior, anterolateral, and DALA portals perforated the acetabular subchondral bone on 21 of 100 attempts (21%), 17 of 100 attempts (17%), and 0 of 100 attempts (0%), respectively (P < .001), and perforated the outer acetabular cortex on 36 of 100 attempts (36%), 1 of 100 attempts (1%), and 8 of 100 attempts (8%), respectively (P < .001). The use of a curved or straight drill guide did not make a statistically significant difference. Drilling with a starting point on the acetabular rim perforated the acetabular subchondral bone on 29 of 150 attempts (19.3%) compared with 9 of 150 attempts (6%) when the starting point was 2 mm removed from the acetabular rim (P < .001).

CONCLUSIONS

The use of the DALA portal and a drill starting point slightly off the acetabular rim was associated with the lowest rate of acetabular subchondral perforation and is recommended to reduce the risk of iatrogenic chondral injury.

CLINICAL RELEVANCE

Iatrogenic chondral injury is a relatively common complication of hip arthroscopy. Increased awareness of factors associated with drill perforation during suture anchor placement can help surgeons mitigate this risk.

Incidence and Risk Factors for Venous Thromboembolism Following Hip Arthroscopy: A Population-Based Study

PURPOSE

To determine the incidence of symptomatic venous thromboembolism (VTE) after hip arthroscopy (HA) using a large national database while considering several patient demographic factors.

METHODS

Patients ≥20 years old who underwent HA between 2007 and 2017 were identified within the Humana administrative claims database using relevant Current Procedural Terminology and International Classification of Diseases Ninth and Tenth Revision codes. Basic demographics, including age, gender, obesity (body mass index ≥ 30 kg/m²), oral contraceptive use, smoking history, diabetes, and chronic obstructive pulmonary disease (CLD) were recorded. Postoperative incidence of deep vein thrombosis, pulmonary embolism, and VTE was identified at 30 and 90 days postoperatively. Multivariate logistic regression analysis was performed to identify independent risk factors for VTE after HA, with statistical significance set at P < .05.

RESULTS

Overall, 9,477 patients underwent HA procedures over the study period, of whom 5,085 (53.7%) were female. The overall incidence of VTE in all patients was 0.77% (n = 73) and 1.14% (n = 108) at 30 and 90 days, respectively. Multivariate analysis identified age ≥ 45 (odds ratio [OR] = 1.82; 95% confidence interval [CI], 1.36-2.49; P = .0001), obesity (OR = 1.54; 95% CI, 1.27-1.86; P < .0001), smoking (OR = 1.26; 95% CI, 1.04-1.53; P = .0177), diabetes (OR = 1.59; 95% CI, 1.32-1.92; P < .0001), and CLD (OR = 2.10; 95% CI, 1.63-2.68; P < .0001) as independent risk factors for higher incidence of VTE after HA. However, neither gender nor oral contraceptive use were risk factors for VTE after HA.

CONCLUSIONS

For patients undergoing HA, the incidence of symptomatic postoperative VTE is low. This study identified age ≥45, obesity, tobacco use, diabetes, and CLD as independent risk factors for VTE after HA.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

Effect of prior ipsilateral lower extremity surgery on 2-year outcomes following hip arthroscopy for femoroacetabular impingement syndrome

The purpose of this study was to determine the influence of prior lower extremity surgery on patient reported outcomes following hip arthroscopy for femoroacetabular impingement syndrome (FAIS). Consecutive patients who underwent hip arthroscopy for FAIS and a prior history of ipsilateral lower extremity surgery were identified and matched 2:1 by age, gender, and body mass index (BMI) to controls without a history of lower extremity surgery. The minimal clinically important difference (MCID) and patient acceptable symptomatic state (PASS) were calculated for HOS–ADL, HOS–SS, and mHHS. Preoperative and 2-year postoperative patient reported outcomes of both groups were compared, and logistic regression was performed to determine whether lower extremity surgery influenced achieving MCID and PASS. A total of 102 patients (24.94%) with prior history of ipsilateral lower extremity surgery were identified. Ipsilateral orthopaedic knee surgery accounted for more than half (53.92%) of all prior surgeries. Patients with a history of ipsilateral lower extremity surgery had significant lower 2-year PROs, satisfaction, and greater pain when compared to patients without lower extremity surgery (P < 0.001 all). A history of ipsilateral lower extremity surgery was a negative predictor of achieving MCID for HOS–ADL and HOS–SS, as well as PASS for HOS–ADL, HOS–SS, and mHHS (P < 0.001 all).

In conclusion, patients with prior lower extremity surgery were found to have inferior outcome scores and a lower likelihood of achieving clinically significant outcome improvement compared to patients without a history of lower extremity surgery at two years postoperatively.

Hip arthroscopy following contralateral total hip arthroplasty: a multicenter matched-pair study

The purpose of this study was to determine if patients undergoing hip arthroscopy for labral pathology with contralateral total hip arthroplasty (THA) have a difference in revision surgeries or patient-reported outcomes (PROs) when compared with those patients undergoing hip arthroscopy for labral pathology with a native contralateral hip. A retrospective review was performed for patients that were undergoing hip arthroscopy between 2008 and 2015. Patients were included in the study group if they met the following inclusion criteria: Tönnis Grade 0 or 1, hip labral pathology, previous contralateral THA, and greater than 2-year follow-up with completion of all PROs or conversion to a THA. Exclusion criteria included the previous surgical history on ipsilateral hip, peritrochanteric or deep gluteal space arthroscopy performed concomitantly, or dysplasia [Lateral Center Edge Angle (LCEA) < 20°]. A 3:1 matched-pair study was conducted. Multiple PRO scores were recorded for both groups. There was no statistically significant difference in the modified Harris hip score, non-arthritic hip score, hip outcome score-sports specific sub-scale, visual analog pain score and patient satisfaction scores between both groups. However, the study group was noted to have six patients converted to THA (67%) at an average of 30 months post-operatively, compared with only four patients (15%) in the control group (P = 0.006). Hip arthroscopy cannot be currently recommended in patients who have undergone contralateral THA due to the high conversion to THA (67%).

Venous thromboembolism prophylaxis after hip preservation surgery: a review and presentation of institutional experience

Venous thromboembolism (VTE) is a serious complication after major orthopedic procedures. The best options for prevention of the VTE are still debated. The most popular evidence-based guidelines for prevention and treatment of VTE in orthopedic surgery addressed the total hip or knee arthroplasty and hip fractures as the major orthopedic surgeries. Majority of studies have evaluated the different modalities of the VTE prophylaxis in patients undergiong hip or knee arthroplasty. Hip preservation surgeries (HPS) including mini-open femoroacetabular osteoplasty, surgical dislocation of the hip, arthroscopic procedures, and periacetabular osteotomy (PAO) are gained popularity in recent two decades. The majority of these patients are young, healthy and active and may not be considered at high risk for VTE. The frequency of VTE in patients undergoing PAO seems to be low between 0 and 5%. There is a paucity of data regarding rates of VTE in young healthy patients undergoing HPS as well as the optimal prevention methods for VTE. Hence current VTE prevention guidelines do not cover HPS adequately. We aimed to review the available literature regarding VTE events and VTE prophylaxis options after HPS. We discussed the available and potential options for prophylaxis of VTE events in these procedures along with our experience in a large cohort of hip preservation surgery.

The Importance of Comprehensive Cam Correction: Radiographic Parameters Are Predictive of Patient-Reported Outcome Measures at 2 Years After Hip Arthroscopy

BACKGROUND

The specific influence of preoperative and postoperative radiographic measurements on patient-reported outcome measures after hip arthroscopy for femoroacetabular impingement (FAI) remains unclear.

PURPOSE

To investigate the relationship between radiographic measurements and 2-year outcomes after hip arthroscopy for the treatment of FAI.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A clinical registry of patients undergoing primary hip arthroscopy for FAI between January 1, 2012, and December 31, 2014, was queried. Outcome measures included the Hip Outcome Score (HOS) Activities of Daily Living (ADL), HOS Sport-Specific Subscale (SSS), modified Harris Hip Score (mHHS), and visual analog scale (VAS) for pain and satisfaction. Preoperative and postoperative radiographic measurements were recorded. Univariate analysis was conducted to identify relationships between all radiographic and demographic variables and outcome scores. A multivariate regression analysis, controlling for demographic factors, was used to identify independent associations between radiographic measurements on plain radiographs and patient-reported outcomes.

RESULTS

The authors identified 707 patients who underwent primary hip arthroscopic management for FAI who were included for analysis. Two-year outcome surveys were completed for 78% to 84% of patients. The mean age of the patients was 33.2 ± 12.3 years, and 64.4% of the patients (n = 456) were female. The mean anteroposterior (AP) alpha angle decreased by 34.3° ( P < .0001), false profile alpha angle by 25.2° ( P < .0001), Dunn lateral alpha angle by 28.9° ( P < .0001), lateral center edge angle by 2.6° ( P < .0001), and anterior center edge angle by 3.4° ( P < .0001). The HOS-ADL score increased from 65.7 ± 18.7 preoperatively to 85.9 ± 16.7 postoperatively ( P < .0001), HOS-SSS increased from 43.4 ± 23.1 to 72.6 ± 27.2 ( P < .0001), and mHHS increased from 57.7 ± 14.0 to 79.1 ± 17.2 ( P < .0001). With multivariate analysis, independent predictors of the postoperative HOS-ADL score included the preoperative false profile alpha angle (beta = -0.16, P = .028). Independent predictors of HOS-SSS score were preoperative AP alpha angle (beta = -0.33, P = .032) and preoperative false profile alpha angle (beta = -0.28, P = .041). For the postoperative mHHS score, independent predictors included preoperative AP alpha angle (beta = -0.18, P = .046), preoperative false profile alpha angle (beta = -0.20, P = .014), and postoperative false profile alpha angle (beta = -0.48, P = .035). The preoperative AP alpha angle (beta = 0.28, P = .024) was a significant predictor for the postoperative VAS pain score. The preoperative false profile alpha angle (beta = -0.34, P = .040) was a significant predictor for the postoperative VAS satisfaction score.

CONCLUSION

The authors observed that radiographic measurements, specifically the preoperative false profile alpha angle, AP alpha angle, and postoperative false profile alpha angle, are independent predictors of 2-year clinical outcomes. The femoral-side measurements were the strongest independent predictors of outcomes, especially measurements of the anterior and lateral-based CAM lesion.

Predictors of Clinical Outcomes After Hip Arthroscopy: A Prospective Analysis of 1038 Patients With 2-Year Follow-up

BACKGROUND

As hip arthroscopy has expanded in popularity and volume, more information is needed about indications for the procedure and the predictive factors of clinical outcomes.

PURPOSE

To evaluate clinical outcomes of hip arthroscopy in a prospective study and to analyze the cohort to identify factors that are predictive of improvement.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

Data were collected prospectively on all patients undergoing hip arthroscopy between February 2008 and June 2012. We included all patients undergoing hip arthroscopy who agreed to participate and who completed 4 patient-reported outcome (PRO) instruments at a minimum 2-year follow-up: the modified Harris Hip Score (mHHS), Nonarthritic Hip Score (NAHS), Hip Outcome Score-Activities of Daily Living (HOS-ADL), and Hip Outcome Score-Sport-Specific Subscale. The NAHS was selected as our primary outcome instrument. All patients with any previous hip conditions were excluded. We analyzed 34 preoperative and intraoperative variables using bivariate and multivariate analyses compared with NAHS.

RESULTS

The cohort consisted of 1038 patients with a mean follow-up of 30.1 months (range, 24.0-61.2 months). Mean age was 36.4 years (range, 13.2-76.4 years). All postoperative PRO scores showed significant improvement ( P < .001) at 2 years compared with preoperative scores. Bivariate analysis identified 15 variables (7 categorical and 8 continuous) and multivariate analysis identified 10 variables that were predictive of 2-year postoperative NAHS. Preoperative NAHS, preoperative HOS-ADL, preoperative mHHS, age, duration of symptoms, body mass index (BMI), and revision hip arthroscopy were identified as predictive factors in both bivariate and multivariate analyses. The predictive value of preoperative NAHS was accentuated for patients with higher BMI.

CONCLUSION

This study reports favorable clinical outcomes in the largest cohort of hip arthroscopies with a minimum 2-year follow-up in the literature to date. Factors identified as predictive in both bivariate and multivariate analyses included preoperative NAHS, HOS-ADL, and mHHS; age; duration of symptoms; BMI; and revision hip arthroscopy. These predictive factors may be useful to the clinician in determining prognosis and operative indications for hip arthroscopy.

Pudendal nerve injury is a relatively common but transient complication of hip arthroscopy

PURPOSE

Hip arthroscopy is emerging as the standard of care for conditions involving the hip, and has a unique set of complications. The purpose of this review was to identify (1) the crude rate of pudendal nerve injury following hip arthroscopy and (2) the specific factors leading to pudendal nerve injury.

METHODS

MEDLINE, EMBASE, and PubMed were searched from database inception to October 2016. Patient demographics, indications, surgical technique, complication rates, treatment approaches, and rehabilitation strategies were extracted.

RESULTS

Twenty-four studies (n = 3405) were included, with the majority (66%) of studies being level IV evidence. The mean age was 33.9 ± 9.7 years (range 12-78) and 48.2% were males. Average follow-up was 30.2 ± 19.1 months. 62 patients were reported to have sustained pudendal nerve injury (1.8%) post-operatively, and all resolved within 6 weeks to 3 months. Of the seven studies that reported using a perineal post, 20 patients were diagnosed with pudendal nerve injury (4.3%), in contrast to two studies (189 patients) reporting only 0.5% pudendal nerve injury without the use of perineal post. Two studies commented on time of traction during surgical intervention with mean times of 98 and 68 min with complication rates of 10% and 6.6%, respectively.

CONCLUSIONS

Pudendal nerve injury is not uncommon following hip arthroscopy, with a reported rate found in this review of 1.8%. Potential risk factors may include the use of a perineal post and long traction times. All reported cases resolved within 3 months. Patients should be informed of complications related to pudendal nerve injury, which include sexual and urinary dysfunction.

LEVEL OF EVIDENCE

Level IV, systematic review of level I-IV studies.

Venous Thromboembolism Events After Hip Arthroscopy: A Systematic Review

PURPOSE

The purpose of this systematic literature review focused on hip arthroscopy was to (1) report the venous thromboembolism (VTE) event incidence in patients who receive VTE prophylaxis and those who do not, (2) report how VTE prophylaxis is currently being administered, and (3) report operative and patient-related risk factors for VTE identified in the literature.

METHODS

The electronic databases MEDLINE, Embase, and PubMed were searched from database inception to October 10, 2016, and screened in duplicate for relevant studies. Data were collected regarding VTE prophylaxis, traction use, surgical time, VTE incidence, patient and operative factors, and postoperative weight bearing and rehabilitation. Study quality was assessed in duplicate with the Methodological Index for Non-Randomized Studies criteria.

RESULTS

Outcome analyses included 14 studies that involved 2,850 patients (2,985 hips). The weighted mean follow-up period was 19 ± 8 months, ranging from 7 days to 103 months. The weighted mean age was 40.7 ± 7 years, ranging from 6 to 82 years, and 39.6% of patients were male patients. The overall weighted proportion of VTE events after hip arthroscopy found in 14 included studies was 2.0% (95% confidence interval, 0.01%-4.1%), with 25 VTE events. Several studies reported patient risk factors, which included increased age, increased body mass index, prolonged traction time, and use of oral contraceptives.

CONCLUSIONS

The use and efficacy of VTE prophylaxis are highly under-reported within hip arthroscopy. The low incidence of VTE events found in this review (2.0%) suggests that prophylaxis may not be necessary in low-risk patients undergoing hip arthroscopy; however, the true rate may be under-reported. Current literature suggests that prophylaxis is typically not prescribed. Early mobility and postoperative rehabilitation may also help to further mitigate the risk of VTE events, but use of these strategies needs further prospective evaluation.

LEVEL OF EVIDENCE

Level IV, systematic review of Level II through IV studies.

Predictors of Hip Pain and Function in Femoroacetabular Impingement: A Prospective Cohort Analysis

Background:

Validated patient-reported outcome measures (PROMs) of hip pain and function at the time of arthroscopy could be predictors of the final outcome. Little is known about how patient factors or pathologic intra-articular findings relate to hip pain or function at the time of surgery for those presenting with femoroacetabular impingement (FAI).

Purpose:

To evaluate all patient and operative factors that contribute to hip pain and dysfunction in patients with FAI.

Study Design:

Cross-sectional study; Level of evidence, 3.

Methods:

A prospective cohort of patients undergoing hip arthroscopy for FAI were electronically enrolled between February 2015 and September 2016. Baseline PROMs were collected, including Hip disability and Osteoarthritis Outcome Score (HOOS) for pain, HOOS–Physical Function Shortform (HOOS-PS), Veterans RAND 12-Item Health Survey (VR-12), and University of California–Los Angeles (UCLA) Activity Score. Surgeons documented intra-articular operative findings and treatment. Multivariable linear regression models were created for continuous scores of HOOS pain, HOOS-PS, and VR-12 Physical Component Score as outcome measures. Risk factors included patient characteristics and intraoperative anatomic and pathologic findings.

Results:

During the study period, 396 patients underwent arthroscopic hip procedures, and 373 (94%) completed preoperative PROMs; 331 patients were undergoing arthroscopic surgery for FAI. The mean patient age was 32.91 ± 12.49 years, mean body mass index was 26.22 ± 4.92 kg/m², and 71% were female. Multivariate analyses demonstrated female sex, lower education levels, smoking, lower mental health scores, and lower activity-level scores predicted HOOS pain preoperatively. According to multivariate analysis, patient factors associated with worse baseline HOOS-PS include smoking, additional years of education, lower mental health, and activity scores. Lower baseline VR-12 functional scores were predicted by female sex, elevated body mass index, smoking, and lower activity levels. For all baseline PROMs, there was no instance where an arthroscopic variable or pathologic finding proved statistically significant after the important patient covariates were controlled for.

Conclusion:

Patient factors, including mental health, activity level, sex, and smoking, are more predictive of baseline hip pain (as measured by HOOS) and function than are intra-articular findings (eg, status of the labrum or articular cartilage) during hip arthroscopy for FAI. Future studies evaluating patient outcomes after surgery for FAI should consider adjusting for these identified patient factors to accurately interpret the effect of treatment on patient-reported outcomes after surgery.

Femoral neck fractures as a complication of hip arthroscopy: a systematic review

The purpose of this study was to identify the causes and risk factors for hip fractures, a rare but devastating complication, following hip arthroscopy. The electronic databases MEDLINE, EMBASE and PubMed were searched and screened in duplicate for relevant clinical and basic sciences studies and pertinent data was abstracted and analysed in Microsoft Excel. Nineteen studies (12 clinical studies and seven biomechanical studies) with a total of 31 392 patients experiencing 43 hip fractures (0.1% of patients) met the inclusion criteria for this systematic review. Femoral osteochondroplasty was performed in 100% of patients who sustained a hip fracture. Six of the 12 (50%) studies identified early weight bearing (prior to 6 weeks post-operatively) as the cause for the hip fracture. Other causes of this complication included over resection during femoral osteochondroplasty, minor trauma and intensive exercise. The results suggest that early weight bearing is the largest modifiable risk factor for hip fracture after femoral osteochondroplasty. For this reason, an extended period of non-weight bearing or restricted weight bearing should be considered in select patients. Studies report a correlation between risk for post-operative hip fracture and increased age. Increased resection during osteochondroplasty has been correlated with increased risk of fracture in various basic science studies. Resection depth has significantly higher impact on risk of fracture than resection length or width. The reported amounts of resection that depth that can be performed before there is a significantly increased risk of fracture of the femoral neck varies from 10 to 30%.