Millis, Michael B.

Background: Long-term outcomes of femoroacetabular impingement (FAI) surgery, particularly survivorship, are critical to guide treatment decision-making and patient counseling, yet only a limited number of studies have reported mid- to long-term survivorship. The purpose of this study was to report survivorship rates at a mean 10-year follow-up in a large, multicenter FAI surgery cohort and to identify clinical predictors of survivorship. Methods: A prospective, multicenter cohort study assessed patients treated for FAI with hip arthroscopy or surgical dislocation from 2008 to 2012. At a minimum of 8 years, 362 hips (80.1%) had follow-up that permitted assessment of total hip arthroplasty (THA)-free survivorship. A Cox proportional-hazards model was developed to identify risk factors for THA. Results: tThe cohort included 362 hips with a mean patient age of 32.1 years; 53% were in females, and 95.6% were in Caucasian patients. The THA-free survivorship of the cohort was 90.6% at a mean of 10.4 ± 1.6 years postoperatively. Risk factors for THA were older age at surgery (p = 0.01), male sex (p = 0.02), body mass index of ≥30 kg/m 2 (p = 0.009), and femoral head chondromalacia (p < 0.001). Conclusions: This study demonstrates that FAI surgery yielded durable 10-year THA-free survivorship of 90.6%. Older age at surgery, obesity, male sex, and femoral head chondromalacia were key predictors of conversion to THA. Level of Evidence: Therapeutic Level II . See Instructions for Authors for a complete description of levels of evidence.

Abstract Introduction: Labral injury at the time of open and arthroscopic hip preservation surgery for symptomatic femoroacetabular impingement (FAI) is managed with debridement versus refixation by the treating surgeon based on tear pattern, tissue quality, and hip morphology. While refixation has been favored based on mid-term outcomes in some series, differences in the long-term patient reported outcomes (PROMS) have not been defined in well-designed and matched prospective series. Methods: This study consisted of a prospective, multi-center cohort that underwent primary surgical treatment for symptomatic FAI. Patients were included if they underwent corrective osteoplasty and a labral refixation or a labral debridement procedure. Using a ratio of 1:1, hips with labral refixation and labral debridement were matched by age, sex, and surgical approach. Postoperative assessments were conducted at a minimum 8 years after surgery using PROMS and assessment of reoperations. Results: A total of 237 hips (n=188 labral refixation, n=49 labral debridement) met the inclusion criteria for the current study. 48 hips from the labral refixation and 48 hips from debridement groups with mean follow-up of 10.3±1.7 years and 10.6±2.1 years respectively were included. No significant differences were observed in the femoral head, acetabular cartilage grade, or labral grade between the groups. The mHHS improved 19.8±19.6 and 23.4±16.8 from baseline to the final follow-up in the labral refixation and debridement groups, respectively (p=0.43). There were no significant differences in PROMS between the labral refixation and debridement groups. Overall, 66% and 76% of the labral refixation and debridement groups achieved the MCID for the mHHS respectively (p=0.30). There were more revision surgeries with labral refixation than with debridement (10.4% vs. 2.1%, p=0.09), but more conversions to total hip replacement in the labral debridement group (8.3% vs. 4.2%, p=0.38), but neither of these differences were statistically significant. Discussion: Both labral refixation and debridement are effective with durable improvement in PROMS at a mean of 10 years in a prospective cohort of patients treated surgically for symptomatic FAI. No significant differences in baseline or final PROMS were observed, and similar rates of revision and conversion to hip replacement were observed in the debridement and refixation groups.

Abstract The understanding and treatment of prearthritic hip disease has evolved remarkably over the past 20 years. The principal investigator and the multicenter Academic Network of Conservational Hip Outcomes Research (ANCHOR) group have had a key role in improving the quality of care for these patients suffering from the three most common prearthritic conditions: femoroacetabular impingement, developmental dysplasia of the hip, and residual Legg‐Calve‐Perthes Disease. We aim to demonstrate that based on the six quality of care dimensions as defined by Donabedian, our 20‐year academic journey has markedly improved the quality of care for young patients with prearthritic hip disease.

Background: Full-thickness acetabular cartilage lesions are common findings during primary surgical treatment of femoroacetabular impingement (FAI). Purpose: To evaluate clinical outcomes after acetabular microfracture performed during FAI surgery in a prospective, multicenter cohort. Study Design: Cohort Study; Level of evidence, 3. Methods: Patients with FAI who had failed nonoperative management were prospectively enrolled in a multicenter cohort. Preoperative and postoperative (mean follow-up, 4.3 years) patient-reported outcome measures were obtained with a follow-up rate of 81.6% (621/761 hips), including 54 patients who underwent acetabular microfracture. Patient characteristics, radiographic parameters, intraoperative disease severity, and operative procedures were analyzed. Propensity matching using linear regression was used to match 54 hips with microfracture to 162 control hips (1:3) to control for confounding variables. Subanalyses of hips ≤35 and >35 years of age with propensity matching were also performed. Results: Patients who underwent acetabular microfracture were more likely to be male (81.8% vs 40.9%; P < .001), be older in age (35.0 vs 29.9 years; P = .001), have a higher body mass index (27.2 vs 25.0; P = .001), and have a greater alpha angle (69.6° vs 62.3°; P < .001) compared with the nonmicrofracture cohort (n = 533). After propensity matching to control for covariates, patients treated with microfracture displayed no differences in the modified Harris Hip Score or Hip Disability and Osteoarthritis Outcome Score ( P = .22-.95) but were more likely to undergo total hip arthroplasty (THA) (13% [7/54] compared with 4% [6/162] in the control group; P = .002), and age >35 years was associated with conversion to THA after microfracture. Microfracture performed at or before 35 years of age portended good outcomes with no significant risk of conversion to THA at the most recent follow-up. Conclusion: Microfracture of acetabular cartilage defects appears to be safe and associated with reliably improved short- to mid-term results in younger patients; modified expectations should be realized when full-thickness chondral lesions are identified in patients >35 years of age.

Background: Surgical treatment of femoroacetabular impingement (FAI) continues to evolve and is most commonly approached with either hip arthroscopy (HA) or surgical dislocation (SD) of the hip. The purpose of this study was to compare the outcomes of similar patients undergoing surgical treatment of FAI with either HA or SD. Methods: A prospective multicenter cohort study of patients undergoing primary surgical treatment of FAI was performed. Follow-up at a minimum of 1 year (mean, 4.3 years) was available for 621 hips (81.7%), including 399 procedures with HA and 222 procedures with SD. Propensity scores were calculated and reflect the likelihood of surgical treatment with HA versus SD for a given set of covariates. Propensity scores allowed 1:1 matching to identify similar patients at baseline. After propensity matching, 128 matched pairs of patients who underwent HA and 128 matched pairs of those who underwent SD were included in the study. The primary outcome was the postoperative modified Harris hip score (mHHS); secondary outcomes included the Hip disability and Osteoarthritis Outcome Score (HOOS), the University of California Los Angeles (UCLA) activity score, and the Short Form-12 (SF-12) physical and mental subscores, as well as the rate of persistent symptoms, revision surgery, and total hip arthroplasty (THA). Results: After propensity matching, the 2 groups exhibited similar distributions of all of the covariates that were included in the model. Both groups demonstrated significant improvements in all patient-reported outcomes (PROs). The final mHHS was not significantly different between the 2 matched groups (81.3 for the HA group versus 80.2 for the SD group, p = 0.67). Likewise, the HOOS pain subscale was similar at the time of final follow-up (77.6 versus 80.5, respectively, p = 0.32). No difference between the HA group and the SD group was identified in the rate of THA (0% and 3.1%, respectively, p = 0.41) and revision surgery (7.8% and 10.9%, respectively, p = 0.35); overall rates of persistent symptoms were 21.9% for the HA group and 24.4% for the SD group (p = 0.55). Conclusions: In a propensity-matched analysis of patients who were treated with either approach, patients undergoing HA or SD demonstrated similar outcomes at a mean of 4 years postoperatively. Level of Evidence: Therapeutic Level II . See Instructions for Authors for a complete description of levels of evidence.

Objectives: The Bernese periacetabular osteotomy (PAO) is becoming a widely utilized procedure. Patients are younger, highly active, and may desire to return to sport activity. Counseling and managing expectations in these patients is challenging as there is limited information regarding activity level after PAO. The purpose of this study was to analyze physical activity levels after PAO in a large, prospective multicenter cohort. Methods: Assessment of prospectively collected data from a multicenter group included 456 hips treated by PAO for hip dysplasia. After exclusions, 359 hips (80 male, 279 female) remained with a mean age of 25.9 years and mean BMI of 25. Demographics, radiographic measures, and clinical outcomes were evaluated preoperatively, at 1 year follow-up, and at minimum 2 years postoperatively (mean 44.9 months). Activity level was assessed with the University of California-Los Angeles (UCLA) activity score, patients were stratified into low, moderate, and high activity groups based on preoperative function. Descriptive statistics and linear regressions were performed for the primary outcome of change in UCLA. Results: UCLA scores were improved on average 0.6 points at final follow up (p = 0.001). When stratified, the low activity and moderate activity groups had significant improvement in UCLA scores (p<.0001 and p=0007) while the high activity group saw a decrease in UCLA scores (p<.0001). mHHS, HOOS Pain, and HOOS Sports and Recreation scores were significantly improved across all activity levels. Univariable linear regression analysis identified prior ipsilateral surgery, arthroscopy at time of PAO, and preoperative ACEA to be predictors of the change in UCLA score (p<0.05). With the multivariable model, the effect of prior ispilateral surgery was maintained (p = 0.002). Conclusion: The data suggests that improvements in activity level and function can be expected following PAO surgery, with greater gains experienced by patients with lower preoperative level of activity. [Figure: see text][Figure: see text]

Background: Current literature describing the periacetabular osteotomy (PAO) is mostly limited to retrospective case series. Larger, prospective cohort studies are needed to provide better clinical evidence regarding this procedure. The goals of the current study were to (1) report minimum 2-year patient-reported outcomes (pain, hip function, activity, overall health, and quality of life), (2) investigate preoperative clinical and disease characteristics as predictors of clinical outcomes, and (3) report the rate of early failures and reoperations in patients undergoing contemporary PAO surgery. Methods: A large, prospective, multicenter cohort of PAO procedures was established, and outcomes at a minimum of 2 years were analyzed. A total of 391 hips were included for analysis (79% of the patients were female, and the average patient age was 25.4 years). Patient-reported outcomes, conversion to total hip replacement, reoperations, and major complications were documented. Variables with a p value of ≤0.10 in the univariate linear regressions were included in the multivariate linear regression. The backward stepwise selection method was used to determine the final risk factors of clinical outcomes. Results: Clinical outcome analysis demonstrated major clinically important improvements in pain, function, quality of life, overall health, and activity level. Increasing age and a body mass index status of overweight or obese were predictive of improved results for certain outcome metrics. Male sex and mild acetabular dysplasia were predictive of lesser improvements in certain outcome measures. Three (0.8%) of the hips underwent early conversion to total hip arthroplasty, 12 (3%) required reoperation, and 26 (7%) experienced a major complication. Conclusions: This large, prospective cohort study demonstrated the clinical success of contemporary PAO surgery for the treatment of symptomatic acetabular dysplasia. Patient and disease characteristics demonstrated predictive value that should be considered in surgical decision-making. Level of Evidence: Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.

Background: The morphologic characteristics of the labrum in patients with symptomatic acetabular dysplasia have been described to some extent in smaller retrospective series, but the need remains to further define these disease characteristics and their importance as a diagnostic feature of hip instability. Purpose: To (1) characterize the morphologic characteristics of the labrum in patients with symptomatic acetabular dysplasia and (2) test the relationships between specific labral variants, severity of dysplasia, and duration of symptoms. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Thirteen surgeons from 10 centers enrolled patients undergoing periacetabular osteotomy (PAO) for symptomatic acetabular dysplasia from 2008 to 2014. Patient demographics, presenting characteristics, preoperative radiographic data, operative data, and intraoperative findings were prospectively collected and retrospectively reviewed. Results: A total of 942 patients (972 hips) met the initial inclusion criteria, with a mean age of 25.2 years (range, 9-51 years; 84% female, 16% male). In addition to having PAO, 52.6% of hips had an anterior arthrotomy and 19.8% had a hip arthroscopy either to perform an osteochondroplasty of the femoral head-neck junction or to address labral pathologic changes. Of these 553 hips in which the labrum was visualized, labral morphologic status was graded as hypertrophic in 50%, normal in 45%, hypoplastic in 4%, and ossified in less than 1%. Decreased lateral center-edge angle and anterior center-edge angle and increased acetabular inclination were associated with labral hypertrophy, but chronicity of symptoms was not. Of the 553 hips, 64% had tears of the labrum, with the majority being degenerative-type tears. Conclusion: Labral pathologic changes are common in patients with symptomatic acetabular dysplasia. Labral hypertrophy, however, is not a universal finding, particularly in hips with mild dysplasia, and therefore should not be considered a reliable diagnostic criterion for instability.

Background: Symptomatic femoroacetabular impingement (FAI) is associated with hip pain, functional limitations, and secondary osteoarthritis. There is limited information from large patient cohorts defining the specific population affected by FAI. Establishing a large cohort will facilitate the identification of “at-risk” patients and will provide a population for ongoing clinical research initiatives. The authors have therefore established a multicenter, prospective, longitudinal cohort of patients undergoing surgery for symptomatic FAI. Purpose: To report the clinical epidemiology, disease characteristics, and contemporary surgical treatment trends in North America for patients with symptomatic FAI. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Upon approval of the institutional review boards at 8 institutions, 12 surgeons enrolled consecutive patients undergoing surgical intervention for symptomatic FAI. Patient demographics, physical examination data, radiographic data, diagnoses, operative data, and standardized patient-reported outcome measures were collected. The first 1130 cases are summarized in this study. Results: A total of 1076 consecutive patients (1130 hips) were enrolled; 55% (n = 622) were female, and 45% (n = 508) were male, with an average age of 28.4 years and average body mass index (BMI) of 25.1. Demographics revealed that 88% of patients who were predominantly treated for FAI were white, 19% reported a family history of hip surgery, 47.6% of hips had a diagnosis of cam FAI, 44.5% had combined cam/pincer FAI, and 7.9% had pincer FAI. Preoperative clinical scores (pain, function, activity level, and overall health) indicated a major dysfunction related to the hip. Surgical interventions were arthroscopic surgery (50.4%), surgical dislocation (34.4%), reverse periacetabular osteotomy (9.4%), limited open osteochondroplasty with arthroscopic surgery (5.8%), and limited open by itself (1.5%). More than 90% of the hips were noted to have labral and articular cartilage abnormalities at surgery; femoral head-neck osteochondroplasty was performed in 91.6% of the surgical procedures, acetabular rim osteoplasty in 36.7%, labral repair in 47.8%, labral debridement in 16.3%, and acetabular chondroplasty in 40.1%. Conclusion: This multicenter, prospective, longitudinal cohort is one of the largest FAI cohorts to date. In this cohort, FAI occurred predominantly in young, white patients with a normal BMI, and there were more female than male patients. The disease pattern of cam FAI was most common. Contemporary treatment was predominantly arthroscopic followed by surgical hip dislocation.