Primary Hip Arthroscopic Surgery Research Articles

Relationship Between Hip Capsular Thickness and Instability After Previous Hip Arthroscopic Surgery: A Matched-Cohort Analysis.

Thinner anterior hip capsules are associated with hip laxity, but there is little known about the impact of capsular thickness on the development of instability after primary hip arthroscopic surgery. To investigate the relationship between hip capsular thickness as measured on preoperative magnetic resonance imaging (MRI) and the development of hip instability after hip arthroscopic surgery for femoroacetabular impingement. Case-control study; Level of evidence, 3. We reviewed revision hip arthroscopic procedures performed between January 1, 2019, and May 1, 2021, at a single institution. Inclusion criteria were preoperative MRI/magnetic resonance arthrography, completion of the study traction protocol, and asymmetric distraction between the hips of ≥3 mm on examination under anesthesia. A comparison group of patients treated for femoroacetabular impingement with primary hip arthroscopic surgery who did not develop capsular instability were matched 1:1 to the patients with instability. Superolateral hip capsular thickness was measured on MRI before index surgery. Analysis was conducted using independent-samples t tests and multivariable linear regression. A total of 44 patients were included, with 22 patients each in the instability and no-instability groups. The mean capsular thickness was lower in the patients with hip instability than in those without (1.9 ± 0.6 vs 3.4 ± 1.1 mm, respectively; P < .001). Decreased capsular thickness was significantly associated with hips with instability versus no-instability (β = -1.468 [95% CI, -2.049 to -0.887]; P < .001). Thinner preoperative hip capsules in the region of the iliofemoral ligament were seen in patients who subsequently underwent revision arthroscopic surgery for hip instability compared to patients who underwent primary hip arthroscopic surgery without subsequent revision. Patients at a higher risk for the development of postoperative hip instability had a superolateral hip capsular thickness of <2 mm.

Hip Arthroscopic Surgery With Chondrolabral Refixation, Osteochondroplasty, and Routine Capsular Closure for Femoroacetabular Impingement Syndrome: Clinical Outcomes at a Minimum 10-Year Follow-up

Background: Hip arthroscopic surgery for femoroacetabular impingement syndrome (FAIS) has proven to be an effective surgical intervention, with high rates of return to sport and work as well as favorable outcomes at short- and midterm follow-up. However, limited data exist on outcomes at long-term follow-up. Purpose: To evaluate patient-reported outcomes (PROs) at a minimum 10-year follow-up after primary hip arthroscopic surgery including labral repair, femoral osteochondroplasty, acetabular osteochondroplasty, and capsular closure for FAIS. Study Design: Case series; Level of evidence, 4. Methods: Patients who underwent primary hip arthroscopic surgery for FAIS between June 2012 and January 2013 were identified. PROs were collected preoperatively and at a minimum of 10 years postoperatively, including the Hip Outcome Score–Activities of Daily Living (HOS-ADL), Hip Outcome Score–Sports Subscale (HOS-SS), modified Harris Hip Score (mHHS), International Hip Outcome Tool–12 (iHOT-12), and visual analog scale (VAS) for pain and satisfaction. Unique minimal clinically important difference (MCID) and patient acceptable symptom state (PASS) thresholds were calculated, and their rates of achievement were analyzed. An alpha level of <.05 was used to determine statistical significance. Results: A total of 94 patients (55 female; mean age, 34.3 ± 12.4 years) were analyzed with a mean follow-up of 10.1 ± 0.3 years (range, 10.0-10.7 years). Patients demonstrated significant 10-year improvement across all PRO measures (P < .001). MCID and PASS thresholds were calculated as follows: HOS-ADL (10.4 and 85.3, respectively), HOS-SS (14.6 and 60.2, respectively), mHHS (8.8 and 76.0, respectively), VAS pain (14.6 and 27.5, respectively), and iHOT-12 (PASS: 71.4). The majority of patients achieved the MCID and PASS for each PRO measure: HOS-ADL (73.4% and 70.9%, respectively), HOS-SS (78.5% and 77.2%, respectively), mHHS (81.0% and 70.9%, respectively), VAS pain (88.6% and 70.9%, respectively), and iHOT-12 (PASS: 73.4%). Overall, 9 patients (9.6%) underwent subsequent revision hip arthroscopic surgery at a mean 4.9 ± 3.7 years (range, 1.1-10.1 years) postoperatively, and 6 patients (6.4%) underwent conversion to total hip arthroplasty at a mean 4.1 ± 3.1 years (range, 0.9-9.3 years) postoperatively. Conclusion: Patients who underwent primary hip arthroscopic surgery for FAIS utilizing contemporary methods of labral repair, acetabular and/or femoral osteochondroplasty, and capsular closure commonly experienced sustained clinical improvement and reported high levels of satisfaction at a minimum 10-year follow-up with low rates of reoperation.

Elite Female Athletes Demonstrate a Comparable Improvement in Midterm Patient-Reported Outcome Scores and Rate of Return to Sport Compared With Elite Male Athletes After Hip Arthroscopic Surgery: A Sex-Based Comparison in Professional and Collegiate Athletes

Background: Few studies have compared outcomes, return to sport (RTS), and continuation of sport (CTS) after primary hip arthroscopic surgery between matched groups of male and female athletes with a minimum 5-year follow-up. Purpose: (1) To report minimum 5-year patient-reported outcome (PRO) scores as well as RTS and CTS rates for elite female athletes undergoing hip arthroscopic surgery for femoroacetabular impingement syndrome (FAIS) and (2) to compare clinical results with those of a matched control group of elite male athletes. Study Design: Cohort study; Level of evidence, 3. Methods: Data were prospectively collected and retrospectively reviewed for elite (collegiate or professional) female athletes who underwent primary hip arthroscopic surgery for FAIS between March 2009 and March 2016. Inclusion criteria were preoperative and minimum 5-year scores for the modified Harris Hip Score, Nonarthritic Hip Score, Hip Outcome Score–Sport Specific Subscale, and visual analog scale for pain. Exclusion criteria were Tönnis grade >1, hip dysplasia, previous ipsilateral hip surgery/conditions, and those unwilling to participate. Rates of achieving the minimal clinically important difference (MCID), Patient Acceptable Symptom State (PASS), and maximum outcome improvement satisfaction threshold (MOIST) were recorded in addition to RTS. CTS was also recorded and defined as athletes reporting continued sport activity at a minimum 5-year follow-up after initially reporting returning to sport. Elite female athletes were propensity matched in a 1:1 ratio to elite male athletes for comparison. Results: A total of 81 hips in elite female athletes that underwent primary hip arthroscopic surgery met the inclusion criteria, and follow-up was available for 65 hips (80.2%) at a mean of 67.6 ± 6.5 months, with a mean age of 24.3 ± 6.8 years. Female athletes demonstrated significant improvements in all recorded PRO scores; achieved the MCID, PASS, and MOIST at high rates; returned to sport at a rate of 80.4%; and continued sport at a rate of 97.1%. Female athletes demonstrated lower preoperative PRO scores compared with male athletes, but postoperative PRO scores; improvements in scores; rates of achieving the MCID, PASS, MOIST; and RTS and CTS rates were similar between female and male athletes. Conclusion: Elite female athletes undergoing primary hip arthroscopic surgery for FAIS demonstrated favorable PRO scores and high RTS and CTS rates at a minimum 5-year follow-up. These results were comparable with those of a propensity-matched control group of elite male athletes.

Effect of Anchor Density on Functional Outcomes After Arthroscopic Hip Labral Repair

Background: While labral repair has been widely adopted as the first line treatment for labral injury during hip arthroscopy, there is no widespread consensus on the procedural technique, including the number of anchors that should be used to avoid recurrent instability and revision surgery. Purpose: To determine if anchor density can predict patient-reported outcomes after arthroscopic labral repair in the hip. Study Design: Cohort study; Level of evidence, 3. Methods: Patients aged 18 to 50 years who underwent primary hip arthroscopic surgery with labral repair between January 2011 and December 2016 were identified from a prospectively collected database. Exclusion criteria consisted of previous ipsilateral surgery, osteoarthritis (Tönnis grade >1), and severe cartilage defects (Outerbridge grade III/IV) or concomitant labral reconstruction, capsular reconstruction, or microfracture. Minimum 2-year patient-reported outcomes (modified Harris Hip Score [mHHS], Hip Outcome Score [HOS]–Activities of Daily Living [ADL], HOS–Sport Specific Subscale [SSS], 12-Item Short Form Health Survey [SF-12]), rates of achieving the minimal clinically important difference (MCID) and patient acceptable symptom state (PASS) for each score, revision surgery rate, and rate of conversion to total hip arthroplasty (THA) were compared based on anchor density (number of anchors per millimeter of labral tear). Results: A total of 634 hips (575 patients) with a mean age of 30.4 ± 9.5 years (range, 18.0-49.9 years) met inclusion criteria. The mean labral tear size was 31 ± 11 mm (range, 2-70 mm) with a median number of anchors used for labral repair of 3 (range, 1-7) and mean anchor density of 0.11 ± 0.08 anchors (range, 0.03-1.33) per millimeter of labral tear. Hips with a minimum 2-year follow-up (451/634 [71.1%]) had significant improvements on the mHHS, HOS-ADL, HOS-SSS, and SF-12 Physical Component Summary (P < .001 for all). There was no significant correlation detected between anchor density or number of anchors used and postoperative scores (correlation coefficient range, –0.05 to 0.17; P > .05 for all). The rate of revision surgery was 6.4% (28 patients), with 8 hips found to have labral tears and/or deficiency on revision. Additionally, 6 hips (1.3%) had to undergo THA at a mean of 3.6 ± 2.1 years (range, 2.0-5.5 years). Conclusion: Anchor density did not have a correlation with postoperative outcomes, achieving the MCID or PASS, revision hip arthroscopic surgery, complications, or conversion to THA.

Outcomes of Staged Bilateral Hip Arthroscopic Surgery in the Context of Femoroacetabular Impingement Syndrome: A Nested Matched-Pair Control Study Focusing on the Effect of Time Between Procedures

Background: Bilateral hip symptoms from femoroacetabular impingement syndrome (FAIS) are a common finding in patients regardless of athletic involvement. Oftentimes, patients and surgeons choose to stage bilateral hip arthroscopic surgery. Purpose/Hypothesis: The purpose of this study was (1) to compare minimum 2-year outcomes between patients who underwent staged bilateral hip arthroscopic surgery for FAIS to a propensity score–matched control group that underwent unilateral hip arthroscopic surgery and (2) to investigate the effect of time between bilateral procedures on patient-reported outcomes (PROs). We hypothesized that, after bilateral hip arthroscopic surgery, the improvement in outcomes would be similar to that after unilateral hip arthroscopic surgery and the time duration between bilateral procedures would not affect the final outcome. Study Design: Cohort study; Level of evidence, 3. Methods: Data were retrospectively reviewed on a consecutive series of patients who underwent primary hip arthroscopic surgery at our institution between June 2008 and November 2017. Patients who underwent bilateral hip arthroscopic surgery with minimum 2-year PROs for the modified Harris Hip Score (mHHS), the Nonarthritic Hip Score (NAHS), the Hip Outcome Score–Sports Specific Subscale (HOS-SSS), patient satisfaction, and a visual analog scale (VAS) for pain were included. The study group was matched 1:1 based on age, sex, and body mass index to a control group that only required unilateral hip arthroscopic surgery. Additionally, a subanalysis was performed on the study group to determine the effect of time between arthroscopic procedures. Rates of achieving the minimal clinically important difference (MCID) and Patient Acceptable Symptom State (PASS) for the mHHS and HOS-SSS were determined. The P value was set at <.05. Results: A total of 205 patients (410 hips) were included. The mean age and body mass index of the study group were 32.3 ± 13.2 years and 25.0 ± 5.1, respectively. All 410 hips that met the inclusion criteria were matched. There were no significant differences in patient, radiographic, or procedural data. A significant and comparable improvement was reported for all PRO measures and the VAS (P < .0001) in both groups. Similarly, rates of achieving the MCID and PASS were comparable. After dividing the study group based on whether the contralateral procedure was performed <3 months or >3 months after the first procedure, it was determined that patients had a significant improvement and favorable outcomes regardless of time between bilateral procedures. Conclusion: Patients who underwent unilateral and bilateral hip arthroscopic surgery for FAIS had a significant and comparable improvement in PROs at a minimum 2-year follow-up. A time interval of <3 months or >3 months between bilateral procedures did not affect PROs.

Patient-Reported Outcomes Measurement Information System Mobility Computerized Adaptive Testing Maintains High Correlation and Low Test Burden Compared With Legacy Hip-Specific Instruments in Patients Undergoing Hip Arthroscopy for Femoroacetabular Impingement

To evaluate the reliability, construct validity, and responsiveness of the lower extremity-specific Patient-Reported Outcomes Measurement Information System (PROMIS) Mobility (MO) bank in patients who underwent hip arthroscopic surgery for femoroacetabular impingement. Patients who underwent primary hip arthroscopic surgery at a large academic musculoskeletal specialty center between November 2019 and November 2020 completed the following baseline and 6-month measures: PROMIS MO, PROMIS Pain Interference (PI), PROMIS Physical Function (PF), modified Harris Hip Score, International Hip Outcome Tool 33, visual analog scale, and Single Assessment Numeric Evaluation. Construct validity was evaluated using Spearman correlation coefficients. The number of questions until completion was recorded as a marker of test burden. The percentage of patients scoring at the extreme high (ceiling) or low (floor) for each measure was recorded to measure inclusivity. Responsiveness was tested by comparing differences between baseline and 6-month measures, controlling for age and sex, using generalized estimating equations. Magnitudes of responsiveness were assessed through the effect size (Cohen d). In this study, 660 patients (50% female patients) aged 32 ± 14 years were evaluated. PROMIS MO showed a strong correlation with PROMIS PF (r = 0.84, P<.001), the International Hip Outcome Tool 33 (r = 0.73, P < .001), PROMIS PI (r= -0.76, P < .001), and the modified Harris Hip Score (r = 0.73, P < .001). Neither PROMIS MO, PROMIS PI, nor PROMIS PF met the conventional criteria for floor or ceiling effects (≥15%). The mean number of questions answered (± standard deviation) was 4.7 ± 2.1 for PROMIS MO, 4.1 ± 0.6 for PROMIS PI, and 4.1 ± 0.6 for PROMIS PF. From baseline to 6 months, the PROMIS and legacy measures exhibited significant responsiveness (P < .05), with similar effect sizes between the patient-reported outcome measures. This longitudinal study reveals that in patients undergoing hip arthroscopy, PROMIS MO computerized adaptive testing maintains high correlation with legacy hip-specific instruments, significant responsiveness to change, and low test burden compared with legacy measures, with no ceiling or floor effects at 6-month postoperative follow-up. Level IV, retrospective case series.

Patient-Reported Outcome Scores and Rate of Return to Sport After Hip Arthroscopic Surgery: A Sex-Based Comparison in Professional and Collegiate Athletes

Background: No studies have compared outcomes and return to sport (RTS) after hip arthroscopic surgery between matched groups of male and female athletes with a minimum 2-year follow-up. Purpose: (1) To report minimum 2-year postoperative patient-reported outcome (PRO) scores and the RTS rate for elite female athletes undergoing hip arthroscopic surgery for femoroacetabular impingement (FAI) and (2) to compare clinical results with a matched control group of elite male athletes. Study Design: Cohort study; Level of evidence, 3. Methods: Data on all consecutive female athletes who underwent primary hip arthroscopic surgery performed at our institution between March 2009 and July 2018 were collected. Patients were eligible if they underwent hip arthroscopic surgery for labral tears or FAI and participated in collegiate or professional athletics within 1 year of surgery. Minimum 2-year postoperative PRO scores were collected for the modified Harris Hip Score (mHHS), Nonarthritic Hip Score (NAHS), Hip Outcome Score–Sport-Specific Subscale (HOS-SSS), and visual analog scale (VAS) for pain as well as RTS status. The percentages of patients achieving the minimal clinically important difference (MCID) and patient acceptable symptomatic state were recorded. These patients were matched to elite male athletes for comparison. Results: A total of 73 female hips were included, with a mean follow-up of 65.1 ± 27.9 months. They demonstrated a significant improvement from preoperatively to latest follow-up on the mHHS, NAHS, HOS-SSS, and VAS (P < .05). When outcomes were compared with a control group of male athletes, female athletes demonstrated lower preoperative scores, similar postoperative scores, and a significantly greater magnitude of improvement (delta value) on the mHHS, NAHS, and VAS. Female athletes also achieved the MCID at higher rates than did male athletes for the HOS-SSS (85.1% vs 70.0%, respectively; P = .035) and NAHS (79.1% vs 62.9%, respectively; P = .037). RTS rates among patients who attempted were similar between the 2 groups (female: 75.4%; male: 83.1%; P = .409). Conclusion: Elite female athletes undergoing primary hip arthroscopic surgery for FAI demonstrated a significant improvement in PRO scores and a high RTS rate. Female athletes exhibited a greater improvement in PRO scores (mHHS, NAHS, VAS) and achieved the MCID (HOS-SSS, NAHS) at higher rates compared with a control group of male athletes.

Influence of Femoral Version on the Outcomes of Hip Arthroscopic Surgery for Femoroacetabular Impingement or Labral Tears: A Systematic Review and Meta-analysis.

Background:It remains controversial whether abnormal femoral version (FV) affects the outcomes of hip arthroscopic surgery for femoroacetabular impingement (FAI) or labral tears.Purpose:To review the outcomes of hip arthroscopic surgery for FAI or labral tears in patients with normal versus abnormal FV.Study Design:Systematic review; Level of evidence, 4.Methods:Embase, PubMed, and the Cochrane Library were searched in July 2020 for studies reporting the outcomes after primary hip arthroscopic surgery for FAI or labral tears in patients with femoral retroversion (<5°), femoral anteversion (>20°), or normal FV (5°-20°). The primary outcome was the modified Harris Hip Score (mHHS), and secondary outcomes were the visual analog scale (VAS) for pain, Hip Outcome Score–Sport-Specific Subscale (HOS-SSS), Non-Arthritic Hip Score (NAHS), failure rate, and patient satisfaction. The difference in preoperative and postoperative scores (Δ) was also calculated when applicable.Results:Included in this review were 5 studies with 822 patients who underwent hip arthroscopic surgery for FAI or labral tears; there were 166 patients with retroversion, 512 patients with normal version, and 144 patients with anteversion. Patients with retroversion and normal version had similar postoperative mHHS scores (mean difference [MD], 2.42 [95% confidence interval (CI), –3.42 to 8.26]; P = .42) and ΔmHHS scores (MD, –0.70 [96% CI, –8.56 to 7.15]; P = .86). Likewise, the patients with anteversion and normal version had similar postoperative mHHS scores (MD, –3.09 [95% CI, –7.66 to 1.48]; P = .18) and ΔmHHS scores (MD, –1.92 [95% CI, –6.18 to 2.34]; P = .38). Regarding secondary outcomes, patients with retroversion and anteversion had similar ΔNAHS scores, ΔHOS-SSS scores, ΔVAS scores, patient satisfaction, and failure rates to those with normal version, although a significant difference was found between the patients with retroversion and normal version regarding postoperative NAHS scores (MD, 5.96 [95% CI, 1.66-10.26]; P = .007) and postoperative HOS-SSS scores (MD, 7.32 [95% CI, 0.19-14.44]; P = .04).Conclusion:The results of this review indicated that abnormal FV did not significantly influence outcomes after hip arthroscopic surgery for FAI or labral tears.

The Learning Curve for Hip Arthroscopic Surgery: A Prospective Evaluation With 2-Year Outcomes in Patients With Femoroacetabular Impingement

Background:The use of hip arthroscopic surgery in the treatment of femoroacetabular impingement (FAI) is increasing, but it is universally known as a technically demanding procedure with a “steep” learning curve. There are limited data investigating the correlation between surgeon experience and patient-reported outcomes (PROs) as well as procedure and traction times.Purpose:To prospectively evaluate the relationship between surgeon experience and PROs after hip arthroscopic surgery for the treatment of FAI.Study Design:Cohort study; Level of evidence, 2.Methods:A total of 190 patients undergoing primary hip arthroscopic surgery for FAI were prospectively enrolled during a sports medicine fellowship–trained surgeon’s first 36 months of practice. A radiographic evaluation as well as PRO surveys including the 12-Item Short Form Health Survey (SF-12), the modified Harris Hip Score (mHHS), and the Hip disability and Osteoarthritis Outcome Score (HOOS) were administered preoperatively and at 2 years postoperatively. Logistic regression as well as analysis of variance was performed to evaluate for correlations between surgical experience and PROs, procedure time, and traction time.Results:Of the 190 patients, 168 (88%; mean age, 35.3 ± 9.6 years; mean body mass index, 25.07 ± 3.98) completed a 2-year follow-up and were included for analysis. The mean procedure time was 91.5 ± 23.9 minutes, and the mean traction time was 54.0 ± 17.7 minutes. Patients demonstrated significant improvements at 2 years after surgery for all PRO scores (mHHS, HOOS, and SF-12 physical component summary; P < .001), except the SF-12 mental component summary, which had no change (P = .43). The procedure time significantly decreased after 70 cases, while the traction time continued to decrease until 110 cases (R 2 = 0.99; P < .0001). There was no correlation between increasing case volume and 2-year PRO scores (P > .2 for mHHS, HOOS, and SF-12). There was also no difference with increasing case volume and amount of improvement from preoperative to 2-year postoperative PRO scores for the SF-12 and HOOS. Case volume did not affect the complication rate, as this cohort experienced 4 minor cases of neurapraxia.Conclusion:Surgical efficiency in hip arthroscopic surgery for the treatment of FAI was maximized after 110 cases in this cohort. However, significant PRO improvements can be achieved early in a surgeon’s practice prior to maximizing surgical efficiency.

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.

Postoperative Deep Gluteal Syndrome After Hip Arthroscopic Surgery.

Background:Deep gluteal syndrome (DGS) is an uncommon source of buttock and groin pain, resulting from entrapment of the sciatic nerve in the deep gluteal space. The incidence and risk factors of postoperative DGS after primary hip arthroscopic surgery are currently unknown.Purpose:To investigate the incidence and risk factors of postoperative DGS after primary hip arthroscopic surgery.Study Design:Case-control study; Level of evidence, 3.Methods:This study reviewed 1167 patients who underwent arthroscopic surgery between 2010 and 2018 by a single surgeon at a single center in Japan. DGS was defined using the seated piriformis stretch test, active hamstring test, and evidence of a hypertrophic sciatic nerve on magnetic resonance imaging. Overall, 11 of 1167 patients were diagnosed with DGS postoperatively. The DGS group (n = 11) was compared with the non-DGS group (n = 1156). Patient age, sex, body mass index (BMI), generalized joint laxity (GJL; Beighton score >6), number of hip arthroscopic procedures, and radiographic parameters including lateral center-edge angle, Sharp angle, vertical center anterior angle, Tönnis angle, alpha angle, ischiofemoral distance, ischiofemoral space, and quadratus femoris space were compared. The prevalence of developmental dysplasia of the hip (DDH) and borderline DDH (BDDH) was also compared. Logistic regression analysis was conducted to identify potential predictors for a postoperative DGS diagnosis.Results:The incidence of postoperative DGS in our study was 0.9%. Female sex (male:female ratio: 0:11 in DGS group vs 568:588 in non-DGS group; P < .01), mean number of hip surgical procedures (1.8 ± 0.9 in DGS group vs 1.1 ± 0.4 in non-DGS group; P < .01), and GJL (P < .01) were significantly higher in the DGS group, while the mean BMI was significantly lower in the DGS group (19.8 ± 1.8 vs 22.7 ± 3.6 kg/m2, respectively; P < .01). Radiographic parameters were not significantly different between groups. Logistic regression analysis revealed that female sex (odds ratio [OR], 22.0 [95% CI, 1.29-374.56]), multiple surgical procedures (OR, 7.8 [95% CI, 2.36-25.95]), GJL (OR, 40.9 [95% CI, 8.74-191.70]), lower BMI (OR, 0.77 [95% CI, 0.644-0.914]), and DDH/BDDH (OR, 18.1 [95% CI, 2.30-142.10]) were potential predictors of postoperative DGS.Conclusion:The incidence of postoperative DGS in our study was 0.9%. The predictors for postoperative DGS after hip arthroscopic surgery were female sex, GJL, multiple hip surgical procedures, and DDH/BDDH. Although hip arthroscopic surgery can provide favorable clinical outcomes, surgeons should be aware of the risk factors for DGS as a complication of hip arthroscopic surgery.

Patients With Borderline Hip Dysplasia Achieve Clinically Significant Improvement After Arthroscopic Femoroacetabular Impingement Surgery: A Case-Control Study With a Minimum 5-Year Follow-up

Background: Hip arthroscopy for the treatment of femoroacetabular impingement syndrome (FAIS) in patients with borderline hip dysplasia (BHD) is becoming a more common practice. However, the literature on achieving meaningful outcomes at midterm follow-up, as well as predictors of these outcomes, is limited. Purpose: To (1) compare the rates of achieving meaningful clinical outcomes between patients with and without BHD and (2) identify the predictors for achieving clinical success among patients with BHD 5 years after undergoing hip arthroscopic surgery for FAIS. Study Design: Cohort study; Level of evidence, 3. Methods: Data from consecutive patients who underwent primary hip arthroscopic surgery with routine capsular closure for the treatment of FAIS between January 2012 and August 2014 were collected and retrospectively analyzed. Patients with BHD (lateral center-edge angle [LCEA] 20°-25°) were matched 1:2 by age (±1 year) and body mass index (BMI; ±5 kg/m2) to control patients with normal acetabular coverage (LCEA 25°-40°). Data collected included baseline and 5-year postoperative patient-reported outcomes. The minimal clinically important difference (MCID) and patient acceptable symptom state (PASS) were calculated for each patient-reported outcome measure and compared between the 2 groups. A binary logistic regression analysis was used to identify significant predictors of achieving the MCID and PASS in the BHD group. Results: The MCID in the BHD group was defined as 9.6, 14.1, and 9.5 for the Hip Outcome Score–Activities of Daily Living, Hip Outcome Score–Sports Subscale, and modified Harris Hip Score, respectively. Threshold scores for achieving the PASS in both groups were 90.9, 76.6, and 81.9, respectively. A total of 88 patients were identified with having BHD and were matched to 176 controls. No statistical differences were identified for age, BMI, or sex. Both the BHD and the non-BHD groups had statistically significant increases in patient-reported outcome scores over the 5-year period, but the difference in both groups was not statistically significant (P > .05 for all). There was no statistical difference in the frequency of patients in the BHD and non-BHD groups achieving the MCID (86.6% vs 85.2%, respectively; P = .804) or PASS (76.0% vs 73.7%, respectively; P = .675) on at least 1 outcome measure. The logistic regression model demonstrated that being physically active (odds ratio [OR], 27.59; P = .005) and being female (OR, 14.64; P = .025) were independent predictors of achieving the MCID, while running (OR, 11.1; P = .002), being female (OR, 7.6; P = .011), and a larger preoperative LCEA (OR, 2.3; P = .001) were independent preoperative predictors of achieving the PASS. Conclusion: The rates of achieving clinical success 5 years after undergoing arthroscopic treatment with capsular closure for FAIS were not significantly different between patients with BHD and those with normal acetabular coverage. Being physically active, running for exercise, female sex, and a larger LCEA were preoperative predictors of achieving clinical success at 5 years in patients with BHD.

No association between femoral or acetabular angles and patient-reported outcomes in patients with femoroacetabular impingement syndrome-results from the HAFAI cohort.

Patients with femoroacetabular impingement syndrome (FAIS) are diagnosed using imaging, but detailed description especially the acetabular shape is lacking and may help give more insight to the pathogenesis of FAIS. Furthermore, associations between patient-reported outcomes (PROs) and the radiological angles might highlight which radiological angles affect outcomes experienced by the patients. Hence, the aims of this study were (i) to describe computer tomography (CT) acquired angles in patients with FAIS and (ii) to investigate the association between radiological angles and the Copenhagen Hip and Groin Outcome Score (HAGOS) in patients with FAIS. Patients scheduled for primary hip arthroscopic surgery for FAIS were included. Based on CT, following angles were measured before and 1 year after surgery; femoral anteversion, alpha, lateral centre edge, acetabular index, anterior sector, posterior sector and acetabular anteversion. All patients completed the HAGOS. Sixty patients (63% females) aged 36 ± 9 were included. One year after surgery, significant alterations in the alpha angle and the acetabular index angle were found. Neither baseline PROs nor changes in PROs were associated with the radiological angles or changes in angles. Since neither changes in CT angles nor baseline scores were associated with HAGOS, the improvements felt by patients must origin from somewhere else. These findings further underlines that morphological changes seen at imaging should not be treated arthroscopically without a patient history of symptoms and clinical findings.

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.

Prevalence and Clinical Implications of Chondral Injuries After Hip Arthroscopic Surgery for Femoroacetabular Impingement Syndrome

Background: Studies on the effect of partial- and full-thickness chondral damage of the hip on outcomes and the ability to achieve meaningful clinical outcomes are limited. Purpose: To determine the effect of full- and partial-thickness chondral injuries on 2-year outcomes in patients undergoing hip arthroscopic surgery for femoroacetabular impingement syndrome (FAIS) compared with patients without chondral damage, and to identify significant predictors of achieving the patient acceptable symptomatic state (PASS) and minimal clinically important difference (MCID). Study Design: Case-control study; Level of evidence, 3. Methods: Data from consecutive patients with evidence of chondromalacia at the time of primary hip arthroscopic surgery with routine capsular closure for the treatment of FAIS by a single fellowship-trained surgeon between January 2012 and September 2016 were reviewed. Patients were divided into groups with partial-thickness (grade I-III) or full-thickness (grade IV) chondral defects and matched by age and body mass index (BMI) to patients without chondral injuries. Preoperative and postoperative outcomes were compared among the 3 groups, and a binary logistic regression analysis was utilized to identify significant predictors of achieving the MCID and PASS. Results: There were 634 patients included in the analysis, with a mean age of 34.5 ± 10.9 years and a mean BMI of 25.2 ± 4.7 kg/m2. A total of 493 (77.8%) patients had no evidence of chondral damage, 92 (14.5%) patients had partial-thickness chondral defects, and 49 (7.7%) patients had full-thickness chondral defects. There were statistically significant differences in the Hip Outcome Score (HOS)–Activities of Daily Living, HOS–Sports Subscale, modified Harris Hip Score, pain, and satisfaction (P < .01) among the 3 groups. Patients with grade IV chondromalacia experienced the poorest outcomes and lowest percentage of achieving the PASS. Predictors for achieving any PASS threshold included preoperative alpha angle (odds ratio [OR], 0.96; P = .016), absence of preoperative limping (OR, 7.25; P = .002), absence of preoperative chronic pain (OR, 5.83; P = .019), primary hip arthroscopic surgery (OR, 0.17; P = .050), patients who self-identified as runners (OR, 2.27; P = .037), and Tönnis grade 0 (OR, 2.86; P = .032). Male sex (OR, 2.49; P = .015) was the only predictor of achieving any MCID threshold. Conclusion: Patients with grade IV chondral defects experienced worse functional outcomes, lower satisfaction, and increased pain when compared with both patients without chondral damage or grade I-III chondromalacia at 2-year follow-up. Several predictors were associated with achieving clinically significant function in patients undergoing hip arthroscopic surgery for FAIS.

Preoperative Performance of the PROMIS in Patients Undergoing Hip Arthroscopic Surgery for Femoroacetabular Impingement Syndrome

Background:The Patient-Reported Outcomes Measurement Information System (PROMIS) is being increasingly evaluated for use in orthopaedic surgery. The performance of the PROMIS in patients undergoing hip preservation surgery is unknown.Purpose:To investigate the psychometric performance of the PROMIS compared with legacy patient-reported outcome measures (PROMs) in patients indicated for hip arthroscopic surgery for femoroacetabular impingement syndrome (FAIS).Study Design:Cohort study (diagnosis); Level of evidence, 2.Methods:Data from consecutive patients who underwent primary hip arthroscopic surgery between January and October 2018 for the treatment of FAIS were collected and analyzed. Baseline data, including preoperative PROM scores and demographics, were recorded. PROMs included the PROMIS Physical Function (PF), the Hip Outcome Score (HOS), the modified Harris Hip Score (mHHS), the International Hip Outcome Tool–12 (iHOT-12), and the Veterans RAND 12-item health survey (VR-12). Pearson and Spearman coefficient analyses were used to identify correlations between continuous and noncontinuous variables, respectively. Correlation was defined as excellent (>0.80), very good (0.71-0.80), good (0.61-0.70), fair (0.41-0.60), or poor (0.21-0.40). A multivariate linear regression analysis was used to identify preoperative predictors of having higher preoperative PROMIS scores.Results:A total of 197 patients with a mean age and body mass index (BMI) of 32.8 ± 12.6 years and 25.7 ± 5.6 kg/m2, respectively, were included in the final analysis. There were no ceiling or floor effects for the PROMIS PF score observed in the study group. With regard to hip-specific measures, PROMIS PF scores demonstrated excellent correlation with HOS–Activities of Daily Living (r = 0.801; P < .001) scores, very good correlation with mHHS (r = 0.721; P < .001) and iHOT-12 (r = 0.722; P < .001) scores, and good correlation with HOS–Sports Specific (r = 0.675; P < .001) scores. With regard to general health–related quality of life (HRQoL) measures, PROMIS PF scores demonstrated very good correlation with VR-12 mental (r = 0.721; P < .001) scores, good correlation with VR-12 physical (r = 0.618; P < .001) scores, and poor correlation with visual analog scale for pain (r = –0.365; P < .001) scores. Patients who reported being physically active were more likely to have a higher preoperative PROMIS score (β = 3.216; P = .004). Lower PROMIS scores were found in patients with a higher BMI (β = –0.236; P = .005) and in female patients (β = –2.608; P = .014).Conclusion:In patients with FAIS, the preoperative PROMIS PF scores demonstrated excellent to good correlation with legacy hip-specific instruments as well as with HRQoL measures. No ceiling or floor effects were identified. Notably, of the hip-specific PROMs administered, the PROMIS PF demonstrated the weakest correlation with the HOS–Sports Specific subscale. Physical activity, BMI, and sex were predictors of preoperative PROMIS scores in our patient population.

Predicting Severe Cartilage Damage in the Hip: A Model Using Patient-Specific Data From 2,396 Hip Arthroscopies

To determine patient-specific factors that can be used to predict the presence of severe articular cartilage damage in the hip in patients without osteoarthritis. The prevalence of severe (Outerbridge grade III or IV) cartilage damage to the acetabulum and femoral head was prospectively recorded at hip arthroscopy. Patients who underwent primary hip arthroscopic surgery between 2006 and 2016 performed by a single surgeon were included. Patients were excluded if they underwent previous hip surgery, had poor-quality radiographs, were younger than 16years at the time of surgery, or had a minimal joint space of 2mm or less. The relation between severe cartilage damage and preoperative patient characteristics was examined using multivariable logistic regression analysis with restricted cubic splines. Of the 2,396 hips presenting for hip arthroscopy, 995 (41%) had severe cartilage damage to the acetabulum and 257 (11%) had severe cartilage damage to the femoral head. Older age was a significant risk factor for severe cartilage damage both to the acetabulum (χ2= 69.5, P < .001) and to the femoral head (χ2= 53.9, P < .001). An age of 45years was associated with a 1.96 (95% confidence interval, 1.54-2.49) increase in the odds of severe acetabular cartilage damage and a 3.94 (95% confidence interval, 2.61-5.94) increase in the odds of severe femoral head cartilage damage relative to an age of 20years. Male sex was associated with severe cartilage damage to the acetabulum (χ2= 66.7, P < .001), and a lower center-edge angle was a significant risk factor for severe cartilage damage to the femoral head (χ2= 78.5, P < .001). Predictive nomograms were established for severe cartilage lesions. The primary risk factors for severe hip cartilage damage were older age for both the femoral head and acetabulum; a lower center-edge angle and larger Tönnis angle for the femoral head; and male sex, body mass index, alpha angle, and joint space for the acetabulum. The likelihood of cartilage damage to the hip can be estimated clinically using a prediction nomogram. Level III, cross-sectional study.

Understanding Preoperative Demographics and Risk Factors for Early Revision Surgery in Patients Undergoing Hip Arthroscopic Surgery: A Large Database Study.

Background:Hip arthroscopic surgery has become an increasingly common surgical technique to diagnose and treat various hip abnormalities. While increased efficacy has been reported, debate remains regarding appropriate surgical indications. Multiple factors including patient demographics, surgical procedure, and underlying disease have been associated with poor surgical outcomes. Preoperative diagnostic and treatment interventions including physical therapy and injections may affect surgical indications and outcomes.Purpose:To identify patient characteristics and preoperative factors associated with an increased risk of early revision surgery and/or extended postoperative medical care after index hip arthroscopic surgery.Study Design:Case-control study; Level of evidence, 3.Methods:Utah’s All Payer Claims Database, a state-mandated registry containing data from all payers, including private insurance, Medicare Advantage, and Medicaid, was queried to identify patients who underwent hip arthroscopic surgery during a 3-year period (January 1, 2013, to December 31, 2015). Demographics, comorbidities, nonoperative care modalities, pain medications, and revision procedures were collected using claims data at 6 months preoperatively and 12 months postoperatively.Results:A total of 1283 patients who underwent primary hip arthroscopic surgery were analyzed, of whom 57.6% (n = 739) were female. Within 1 year of index surgery, 7.8% and 2.1% of patients underwent revision hip arthroscopic surgery and conversion to total hip arthroplasty (THA), respectively. Patients older than 60 years and male patients were more likely to undergo revision arthroscopic surgery (odds ratio [OR], 0.89; P < .001 and OR, 1.59; P = .04, respectively) and convert to THA (OR, 1.03; P = .01 and OR, 2.25; P = .05, respectively). Preoperative opioid use was significantly associated with increased odds of revision surgery (OR, 1.64; P = .05) and THA (OR, 2.70; P = .03). No significant relationship existed between preoperative physical therapy or intra-articular hip injections and revision hip arthroscopic surgery (OR, 1.20; P = .45 and OR, 1.18; P = .52, respectively) or conversion to THA (OR, 0.89; P = .79 and OR, 0.71; P = .46, respectively).Conclusion:This study showed that predictable patient factors can effectively guide preoperative decision making and may improve prognosis. Certain patient pools require optimization preoperatively, and a subset of patients appears to require additional surgical indications.

Influence of Cigarette Smoking at the Time of Surgery on Postoperative Outcomes in Patients With Femoroacetabular Impingement: A Matched-Pair Cohort Analysis

Background: There is literature on the association between smoking in patients undergoing orthopaedic procedures and poor short-term outcomes. However, there are few data on smoking as an independent predictor of midterm outcomes in patients undergoing hip arthroscopic surgery for femoroacetabular impingement (FAI). Purpose: To evaluate 2-year postoperative outcomes in patients undergoing hip arthroscopic surgery for FAI in current smokers compared with an age- and body mass index (BMI)–matched group with no smoking history. Study Design: Cohort study; Level of evidence, 3. Methods: Consecutive patients undergoing primary hip arthroscopic surgery for FAI between June 2012 and January 2016 were screened for smoking habits. Exclusion criteria included revision or bilateral surgery, dysplasia, and less than 2-year follow-up. Forty current smokers at the time of surgery were matched 1:2 by age and BMI to patients with no smoking history. Outcome measures included the Hip Outcome Score (HOS)–Activities of Daily Living (ADL), HOS–Sports-Specific Subscale (SSS), modified Harris Hip Score (mHHS), and visual analog scale (VAS) for pain and satisfaction. Minimal clinically important difference (MCID) and patient acceptable symptom state rates were calculated for all patients. Results: All patients demonstrated significant improvements in all outcome measures (P < .001). Current smokers experienced inferior postoperative HOS-ADL (80.4 vs 89.1, respectively; P = .013) and HOS-SSS (65.8 vs 75.6, respectively; P = .046) scores and greater VAS pain scores (3.2 vs 1.8, respectively; P = .011) than nonsmokers. Current smoking was correlated with inferior HOS-ADL (r = –0.27, P = .003) and HOS-SSS (r = –0.18, P = .046) scores and greater VAS pain scores (r = 0.26, P = .005). Controlling for age, sex, and BMI, smoking was a significant independent predictor of postoperative HOS-ADL (β = –8.7 [95% CI, –14.3 to –3.0]; P = .003), HOS-SSS (β = –9.8 [95% CI, –19.5 to –0.2]; P = .046), and VAS pain (β = 14.6 [95% CI, 4.4 to 23.7]; P = .005) scores. Current smokers had lower odds of achieving the MCID for the HOS-ADL (odds ratio, 0.31 [95% CI, 0.12-0.83]; P = .019) and mHHS (odds ratio, 0.31 [95% CI, 0.10-0.88]; P = .028). Conclusion: Current smokers had inferior postoperative HOS-ADL and HOS-SSS scores, increased pain, and lower odds of achieving the MCID for the HOS-ADL and mHHS at 2 years postoperatively than patients without any smoking history.

Computer tomography acquired hip angles and patient reported outcomes in patients with femoroacetabular impingement syndrome

Purpose: Patients with femoroacetabular impingement syndrome (FAIS) experience pain, decreased function and quality of life. Patients present with cam and/or pincer morphology in their hip joint. FAIS is diagnosed via imaging, clinical signs and symptoms. In large cohorts using radiological measures, cam morphology has been associated with later development of osteoarthritis (OA) of the hip while it is less certain how pincer morphology is related to development of OA. In the cohort studies, pincer morphology was quantified using the lateral center edge angle (CE) and the anterior CE angle. Pincer, defined this way, was not associated with development of OA. However, quantifying pincer only by these two angles may not give the full picture of pincer impingement and its relation to hip OA. Hence, further description of abnormal values in patients with FAIS could help investigate the pathogenesis of FAIS. Furthermore, associations between patient reported outcomes and the specific angles might highlight which radiological parameters affect outcomes experienced by the patients. Hence, the aims of the study were 1) to describe computer tomography (CT) acquired angles in patients with FAIS compared with reference values from the literature 2) to investigate the association between hip angles in patients with FAIS and the Copenhagen Hip and Groin Outcome Score (HAGOS) and if HAGOS scores differ between patients with hip angles above/below mean reference values. Methods: Patients were eligible for inclusion if they were scheduled for primary hip arthroscopic surgery for FAIS. The study was approved by the Central Denmark Region Committee on Biomedical Research Ethics (1-10-72-239-14) and the Danish Data Protection Agency (1-16-02-499-14). The CT images of the hip were acquired on a Philips Brilliance 64 (Philips Medical Systems, Best, the Netherlands) scanner with low-dose radiation. Furthermore, a single image through the femoral condyles was obtained to measure the femoral anteversion (FeAV). Data were transferred to a Philips Mx view station (Philips Medical Systems, Best, the Netherlands). On the reformatted images the alpha angle, the CE angle, the acetabular index (AI), the posterior acetabular sector angle (PASA), the anterior acetabular sector angle (AASA), the horizontal acetabular sector angle (HASA) and the acetabular anteversion (AcAV) was measured by an experienced musculoskeletal radiologist. All patients completed the HAGOS. Associations between patient reported outcomes and hip angles was tested with linear regression. Comparisons between HAGOS data above/below mean reference values of hip angles were performed with the Wilcoxons test for unpaired data. Results: Sixty patients aged 36 ±9, 63% females were included in the study. Hip angles (55 patients) and HAGOS scores (60 patients) are tabulated in Table 1. Hip angles were not associated with any of the HAGOS scores. Those patients with a higher FeAV, PASA and HASA than reference mean values had worse HAGOS scores compared to those with lower hip angles than reference mean values. Conclusions: Patients presented with a high FeAV angle and many patients had a low AI angle. There was no overall association between HAGOS scores and hip angles, but patients with a high FeAV, PASA and/or HASA had worse HAGOS scores. These angles should be further investigated in order to investigate the pathogenesis of FAIS and to investigate whether the angles are related to later development of hip OA. Table details: ∼ Healthy reference values from Valera et al. 2018 Arch Orthop Trauma Surg, Lepage-Saucier et al. 2014 Eur Radiol and Kierkegaard et al. 2017 Journal of Science and Medicine in Sport. ∗ For the acetabular index angle, it is %patients below the reference meanTable 1Hip angles and HAGOS scores.Patients (mean±standard deviation)Healthy reference values (mean±standard deviation) ∼%patients with scores higher than reference mean (number of pt.)Affected legAlpha51.7 ±9.653.3 ±13.138% (21)FeAV27.5 ±10.517 ±391% (50)CE33.1 ±5.635 ±640% (22)AI2.8 ±6.06 ±569% (38)*AASA59.2 ±6.663 ±631% (17)PASA94.9 ±6.8103 ±911% (6)HASA154.1 ±9.3165 ±942% (23)AcAV18.0 ±4.724 ±547% (26)HAGOSPain51 ±20100Symptoms47 ±17100Activities of daily living53 ±24100Sport34 ±18100Physical activities21 ±23100Quality of life31 ±15100 Open table in a new tab