Hip Arthroscopy for Femoroacetabular Impingement Syndrome Shows Good Outcomes and Low Revision Rates, With Young Age and Low Postoperative Pain Score Predicting Excellent 5-Year Outcomes.

PURPOSE: To evaluate the clinical outcomes of hip arthroscopy for femoroacetabular impingement syndrome (FAIS) and their predictors at a minimum 5 years' follow-up. METHODS: We retrospectively analyzed patients with FAIS after first-time unilateral hip arthroscopy between January 2010 and July 2016. Patient-reported outcomes (PROs) included the validated modified Harries Hip Score (mHHS) and Visual Analog Scale for Pain (Pain VAS). We included patients with Tönnis grade 0 or 1 and reported PROs, and excluded patients with previous hip diseases or bilateral symptoms. Bivariate and multivariate analyses were used for data analysis. RESULTS: We included 159 patients with a mean follow-up of 6.4 years, aged 36.18 ± 8.61 years, 41.5% female, and a mean body mass index of 23.61 ± 3.45. The mean postoperative mHHS was 88.82 ± 11.60, and the mean Pain VAS was 1.93 ± 1.89, significantly better than before surgery (P < .001). Postoperative alpha angle (P = .003) and lateral center edge angle (P < .001) were significantly decreased. Most patients (83.7%) achieved clinically important improvement based on patient-acceptable symptom state and minimal clinically important difference (MCID). The overall revision surgery rate was 2.5%. There were no conversions to total hip arthroplasty. Bivariate analysis indicated that age (P < .001), preoperative mHHS (P = .002), and postoperative Pain VAS (P <.001) correlated with postoperative mHHS at a minimum 5 years' follow-up. Multivariate regression analysis of MCID showed that age (P <.001), preoperative PROs (P < .01 for both), and postoperative Pain VAS (P < .001) were significant outcome predictors. CONCLUSION: Patients with FAIS after first-time unilateral hip arthroscopy showed significant improvement in PROs at mid-term follow-up, with a low revision surgery rate. Young patients and those with low postoperative Pain VAS showed excellent outcomes at a minimum 5 years' follow-up. LEVEL OF EVIDENCE: Level IV, retrospective case series.

The Presence of Central Acetabular Osteophytes May Negatively Affect the Outcome After Primary Arthroscopic Therapy of Femoroacetabular Impingement Syndrome.

PURPOSE: To compare short-term follow-up outcomes after primary arthroscopy in femoroacetabular impingement syndrome (FAIS) patients with untreated central acetabular osteophytes (CAO) to a control group without CAO. METHODS: A retrospective analysis was performed using data from FAIS patients who had primary arthroscopy between 2017 and 2018. The presence of CAO was confirmed arthroscopically, and there were 2 groups created. The CAO group was 1:1 propensity-score matched to a control group (without CAO) based on age, gender, body mass index (BMI), TÓ§nnis grade, symptom duration before surgery, and follow-up time. Patient-reported outcomes (PROs), such as the Hip Outcome Score-Activities of Daily Living (HOS-ADL), International Hip Outcome Tool 12-component form (iHOT-12)，modified Harris Hip Score (mHHS), and visual analog scale (VAS) scores were used to evaluate the level of function included. The minimal clinically important difference (MCID) and patient acceptable symptomatic state (PASS) were also calculated to determine meaningful outcome improvement. Radiographic measures, performed procedures, complications, and revision surgery were also compared and analyzed for both groups. P values less than .05 were considered statistically significant. RESULTS: A total of 46 hips with CAO and 46 hips without CAO were propensity matched. At the minimum final follow-up of 2 years, the CAO group had significantly lower HOS-ADL (78.8 vs 85.5; P = .008), iHOT-12 (74.8 vs 79.3; P = .019), and mHHS (78.9 vs 87.2; P = .002) scores, as compared to the CAO group. Furthermore, patients in the CAO group were significantly less likely to achieve the MCID and PASS for the mHHS score (78.3% vs 93.5%; P = .036, 58.7% vs 78.2%; P = .043, respectively). There was no change in the rate of complications (4.3% vs 0%) and revision hip arthroscopy (4.3% vs 2.2%) between the two groups at the final follow-up. CONCLUSIONS: This study demonstrated that surgically treated FAIS patients with CAO might experience worse short-term, patient-reported outcomes, as compared with propensity-matched patients without CAO. LEVEL OF EVIDENCE: III, case-control study.

Hip Gluteus Medius Tears Are Associated With Lower Femoral Neck-Shaft Angles and Higher Acetabular Center-Edge Angles.

PURPOSE: 1) To assess the possible relationship between the morphology of femur or acetabulum and the gluteus medius pathology. 2) To analyze the outcome of isolated arthroscopic treatment of femoroacetabular impingement (FAI) for patients with radiographic gluteus medius tear. METHODS: We performed a retrospective study of FAI patients who underwent arthroscopy between January 2016 to December 2019. Demographic data, such as sex, age, body mass index (BMI), symptom duration, were collected. Radiographic parameters, including alpha angle, lateral center-edge angle (LCEa), femur neck-shaft angle (NSa), gluteus medius pathology, were also collected. Exclusion criteria were previous hip conditions, such as osteoarthritis (Tönnis grade > 1), rheumatoid arthritis, ankylosing spondylitis, snapping hip, previous surgery on the ipsilateral hip, or incomplete data. We followed up these patients with radiographic gluteus medius tear. No surgical procedure for gluteus medius was performed. The minimum follow-up period was 13 months. Patient-reported outcomes, such as modified Harris Hip score (mHHS), visual analog scale (VAS), and patient acceptable symptom state (PASS), as well as physical examination data, including tenderness at the greater trochanter, abductor weakness, limping gait, and positive Trendelenburg sign or test, were gathered preoperatively and postoperatively. RESULTS: A total of 569 hips (314, 55.2% male) were collected eventually, with a mean age of 36.5 ± 10.4 years (range: 13.0 to ∼65.0). Gluteus medius pathology was found in 209 (36.7%) hips, including 41 (7.2%) partial-thickness tears and 10 (1.8%) complete tears. The NSa of the normal, tendinosis, partial tear, and complete tear groups was 133.8 ± 4.7°, 130.6 ± 3.8°, 129.4 ± 3.9°, and 129.6 ± 3.4°, respectively (P < .001). The LCEa of each group was 31.7 ± 35.7°, 33.3 ± 6.5°, 34.9 ± 6.8°, and 33.7 ± 8.1°, respectively (P = .004). On multivariable logistic regression analysis, lower NSa and higher LCEa were identified as risk factors for developing gluteus medius pathology (P < .001). For patients with gluteus medius tear, two cases were lost to follow-up and two cases had incomplete data. The mean follow-up period of the remaining 47 hips was 29.5 ± 12.9 (range: 13 to 59) months. The mHHS improved from 54.8 ± 19.1 to 90.1 ± 6.7 points (P < .001), and VAS decreased from 6.8 ± 1.6 to 3.0 ± 1.6 points (P < .001). Forty-two cases met the threshold of PASS, with a rate of 89%. The abductor strength increased from 4.1 ± 1.00 to 4.6 ± .7 grades (P = .002). However, for patients with a completely torn gluteus medius, improvement of abductor strength was not significant statistically (3.4 ± .9 to 3.9 ± .9, P = .234). CONCLUSION: There was a correlation between lower NSa/higher LCEa and gluteus medius pathology. Isolated arthroscopic treatment of FAI for patients with radiographic gluteus medius tear can gain satisfactory patient-reported outcomes. LEVEL OF EVIDENCE: Therapeutic case series, IV.

Volume of Gluteus Maximus and Minimus Increases After Hip Arthroscopy for Femoroacetabular Impingement Syndrome.

PURPOSE: To investigate the change in muscle volume around the hip in patients with femoroacetabular impingement (FAI) after arthroscopy and evaluate other factors related to muscle change. METHODS: We performed a retrospective review of magnetic resonance imaging data of patients with FAI who underwent hip arthroscopy. Magnetic resonance imaging was obtained pre- and postoperatively. The cross-sectional area (CSA) of muscles were determined on axial images. The Wilcoxon signed-rank test was used to determine the differences between pre- and postoperative hip muscle CSA. The correlations of change in muscle CSA with age, sex, body mass index, pain level, preoperative symptom duration, follow-up time, and multiple validated patient-reported outcomes were also analyzed with a Spearman rank correlation test. RESULTS: Fifty-one patients with a mean age of 36.5 ± 5.6 years were included and analyzed. The follow-up was 26.6 ± 0.5 months (range, 24-40 months), and 27 (52.9%) were women. Patients with FAI showed increased hip muscle CSA of gluteus maximus (P = .002) and gluteus minimus (P = .001). Post- compared with preoperative, the value for the change in medius CSA was underpowered, and no differences in other hip muscle CSAs were observed. The increased muscle CSA of the gluteus maximus was significantly correlated with the improvement of modified Harris Hip Score (ρ = 0.404; P = .003). The increased muscle CSA of the gluteus minimus was significantly correlated with the improvement of pain Visual Analog Scale (ρ = 0.452; P = .001). Age, body mass index, sex, symptom duration, and follow-up time were not significantly correlated with change in muscle CSA. CONCLUSIONS: Patients with FAI have a significantly increased postoperative muscle CSA of the gluteus maximus (7.8%) and the gluteus minimus (11.6%) compared with preoperative values. The increased muscle CSA of the gluteus maximus and gluteus minimus was significantly correlated with improvement in modified Harris Hip Score and pain Visual Analog Scale, respectively. The increase of muscle volume may be associated with the improvement of subjective function and pain relief. LEVELS OF EVIDENCE: Level IV, therapeutic case series.