Clohisy, John C.

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.

Background: Periacetabular osteotomy (PAO) remains the gold-standard treatment for acetabular dysplasia in skeletally mature patients with preserved cartilage. The purpose of this multicenter cohort study was to delineate the long-term radiographic natural history of the dysplastic hip following PAO based on the final position of the acetabular fragment. Methods: We evaluated patients who underwent PAO performed by 4 hip preservation surgeons to treat acetabular dysplasia with or without concomitant retroversion from 1996 to 2012 at 3 academic institutions. There were 288 patients with a mean clinical and radiographic follow-up of 9 years (range, 5 to 21 years). Postoperative radiographs made at the first clinical visit were used to determine if the acetabular fragment fell into a safe zone according to the absence of retroversion, a lateral center-edge angle (LCEA) of 25° to 40°, an anterior center-edge angle (ACEA) of 25° to 40°, and a Tönnis angle of 0° to 10°. Every available subsequent radiograph was assessed for degenerative changes by the Tönnis classification (grades 0 to 3). The time to progression was analyzed using Cox proportional hazards regression and multistate modeling. Results: Only the absence of retroversion was independently associated with a decreased risk of progressing at least 1 Tönnis grade during follow-up: hazard ratio (HR), 0.60 (95% confidence interval [CI], 0.38 to 0.94; p = 0.025). Achieving the ACEA safe zone yielded the greatest time increase for remaining in Tönnis grade 0 or 1 (43 years for having an ACEA in the safe zone compared with 28 years for not having an ACEA in the safe zone), followed by the absence of retroversion (34 years for the absence of retroversion compared with 24 years for the presence of retroversion). However, attaining the Tönnis angle or LCEA safe zones did not delay progression. The achievement of additional safe zones generally increased the length of time that patients spent in Tönnis grade 0 or 1: 25 years for 0 safe zones, 36 years for 1 safe zone, 29 years for 2 safe zones, 37 years for 3 safe zones, and 44 years for 4 safe zones. Conclusions: This study demonstrates the importance of achieving appropriate acetabular reorientation to enhance the longevity of the native hip following PAO. Although the LCEA and the Tönnis angle are the most common metrics used to assess appropriate acetabular correction, this study shows that adequately addressing retroversion and the ACEA has a greater impact on improving the natural history. Level of Evidence: Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.

Background: Periacetabular osteotomy (PAO) is the most common treatment for symptomatic acetabular dysplasia, or developmental dysplasia of the hip (DDH), in skeletally mature patients. The purpose of this multicenter cohort study was to delineate the long-term radiographic natural history of the dysplastic hip following PAO. Methods: We evaluated all patients undergoing PAO from 1996 to 2012 at 3 academic institutions in the United States. Inclusion criteria were PAO for DDH with a minimum 5-year radiographic follow-up. Exclusion criteria were PAO for isolated acetabular retroversion, neurogenic dysplasia, Legg-Calvé-Perthes disease, and prior hip surgery including osteotomies and arthroscopy. There were 288 patients, 83% of whom were women; the mean age and body mass index (BMI) were 29 years and 25 kg/m 2 , respectively. The mean clinical and radiographic follow-up was 9.2 years (range, 5.0 to 21.1 years). Every preoperative and postoperative hip radiograph was assessed to determine the degree of osteoarthritis according to the Tönnis classification. Survivorship was analyzed by multistate modeling, enabling assessment of progression through the Tönnis grades rather than just individual transitions as with Kaplan-Meier techniques. Results: At the time of final follow-up, 144 patients (50%) had progressed at least 1 Tönnis grade, with 42 patients (14.6%) undergoing total hip arthroplasty. The mean number of years spent in each Tönnis grade following PAO was 19 for Tönnis grade 1, 8 for Tönnis grade 2, and 4 for Tönnis grade 3. The probability of progression to total hip arthroplasty increased significantly on the basis of a higher initial Tönnis grade (p < 0.001). The most marked difference occurred between Tönnis grade 0 or 1 and Tönnis grade 2; for Tönnis grade 1, the probability of progression to total hip arthroplasty at 5 and 10 years was 2% and 11%, respectively, compared with 23% and 53%, respectively, for Tönnis grade 2. Conclusions: PAO effectively alters the natural history of DDH. Precise radiographic progression based on the Tönnis grade can now be used to ascribe prognosis for the native hip. Importantly, this investigation demonstrates a stark increase in progression to total hip arthroplasty within 10 years of PAO for patients with preoperative Tönnis grade-2 osteoarthritis compared with those with Tönnis grade-0 or 1 osteoarthritis. Level of Evidence: Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.

Background: Previous studies on periacetabular osteotomy (PAO) reported complication and reoperation rates of 5.9% and 10%, respectively. Hip arthroscopy is increasingly utilized as an adjunct procedure to PAO to precisely treat associated intra-articular pathology. The addition of this procedure has the potential of further increasing complication rates. Purpose: To determine the rates of complication and reoperation of combined hip arthroscopy and PAO for the treatment of acetabular deformities and associated intra-articular lesions. Study Design: Case series; Level of evidence, 4. Methods: Using a prospective database, the authors retrospectively reviewed 248 hips (240 patients) that underwent combined hip arthroscopy and PAO between 2007 and 2016. Data were collected at scheduled follow-up visits at approximately 1 month, 3 to 4 months, and 1 and 2 years after surgery. Mean follow-up from surgery was 3 years (range, 1-8 years). A total of 220 PAOs were done for symptomatic acetabular dysplasia, 18 for symptomatic acetabular retroversion, and 10 for combined acetabular dysplasia and acetabular retroversion. Central compartment arthroscopy was performed for treatment of intra-articular chondrolabral pathology in all cases. Select cases underwent femoral head-neck junction osteochondroplasty either arthroscopically before the PAO or through an open approach after it. Complications were graded according to the modified Dindo-Clavien complication scheme, which was validated for hip preservation procedures. Reoperations (excluding hardware removal) were recorded. Results: Grade III complications occurred among 7 patients (3%) while there were no grade IV complications. Grade III complications included deep infection (n = 3), wound dehiscence (n = 1), hematoma requiring exploration (n = 1), symptomatic heterotopic ossification requiring excision (n = 1), and deep venous thrombosis (n = 1). There were 13 reoperations (5%), and 3 were repeat hip arthroscopy. Univariate Cox hazard models were used to estimate the relative risk factors for complication and reoperation. Increased age (per decade) showed over twice the increased likelihood for complications (hazard ratio, 2.5; 95% CI, 1.67-3.74). Also, preoperative diagnosis of acetabular retroversion, not acetabular dysplasia, showed >3 times the increased risk of reoperation (hazard ratio, 3.05; 95% CI, 1.41-6.61). Conclusion: The rate of complications reported is comparable (3%) with previously published complication rates of PAO without hip arthroscopy. In this cohort, increasing age and diagnosis of acetabular retroversion were associated with higher complication and reoperation rates.

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]

Obesity is a risk factor for complications following many orthopaedic procedures. The purpose of this study was to investigate whether obesity was an independent risk factor increasing the rate of complications following periacetabular osteotomy (PAO) and to determine whether radiographic correction after PAO was affected by obesity.We retrospectively collected demographic, clinical and radiographic data on 280 patients (231 women; 82.5% and 49 men; 17.5%) who were followed for a mean of 48 months (12 to 60) after PAO. A total of 65 patients (23.2%) were obese (body mass index (BMI) > 30 kg/m2). Univariate and multivariate analysis demonstrated that BMI was an independent risk factor associated with the severity of the complications. The average probability of a patient developing a major complication was 22% (95% confidence interval (CI) 11.78 to 38.21) for an obese patient compared with 3% (95% CI 1.39 to 6.58) for a non-obese patient The odds of a patient developing a major complication were 11 times higher (95% CI 4.71 to 17.60, p < 0.0001) for an obese compared with a non-obese patient.Following PAO surgery, there was no difference in radiographic correction between obese and non-obese patients. PAO procedures in obese patients correct the deformity effectively but are associated with an increased rate of complications.Cite this article: Bone Joint J 2015;97-B:29–34.

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.

Background: The results of surgical treatment for femoroacetabular impingement have been increasingly reported, and more advanced intra-articular disease has been identified as an important predictive factor of outcome. Yet, the reliability of arthroscopic hip disease classification has not been well defined. Purpose/Hypothesis: To determine the intraobserver and interobserver reliability of the Beck classification of labral and articular cartilage disease (anterior-superior acetabular rim) encountered in hip arthroscopy. Secondly, we identified the sources of poor reliability that may be improved with future disease classification schemes. Our hypothesis was that the Beck classification of labral and chondral lesions would demonstrate substantial reliability, while the differentiation of early forms of disease would be a common source of disagreement. Study Design: Cohort study; Level of evidence, 3. Methods: Four experienced hip arthroscopists reviewed standardized arthroscopic videos of 40 cases. Arthroscopic findings at the anterior-superior acetabular rim were classified using the Beck classification of labral and articular cartilage disease. Repeat classification of videos was performed at least 2 weeks later. The reliability of arthroscopic classification was defined using the average weighted Cohen κ values and agreement rates. Results: Arthroscopic classification of labral disease using the Beck classification demonstrated moderate to substantial interobserver reliability (average κ = .62; range, .48-.78) and an overall agreement rate of 81.7%. Intraobserver reliability showed a similar level of reliability (average κ = .65; agreement rate, 80.6%). The differentiation between labral degeneration and labral detachment was a common source of disagreement. Similarly, the Beck classification of articular cartilage disease had moderate to substantial interobserver reliability (average κ = .65; range, .49-.78) and overall agreement rate of 57.5%. Intraobserver reliability showed a slightly better level of reliability (average κ = .80; agreement rate, 77.5%). The differentiation between articular cartilage malacia and debonding was a common source of disagreement. Conclusion: The arthroscopic classification of acetabular rim disease with the Beck classification has substantial interobserver reliability. This level of reliability is similar to previously reported arthroscopic disease classifications in the knee and shoulder and seems appropriate for future outcome reporting. Future classifications that eliminate common sources of disagreement may further improve the reliability.