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

Abstract

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.

Achieving Successful Outcomes in High-Level Athletes With Borderline Hip Dysplasia Undergoing Hip Arthroscopy With Capsular Plication and Labral Preservation: A Propensity-Matched Controlled Study

“…While they identified that moderate to severe dysplasia (LCEA, <15°) was a predictor of clinical failure, patients with BD (LCEA, 15°-25°) demonstrated good long-term survival rates. Furthermore, Beck et al 6 evaluated outcomes of patients with BD undergoing hip arthroscopic surgery for femoroacetabular impingement against a matched control group with normal acetabular coverage at minimum 5-year follow-up and found that rates of achieving clinical success were not statistically significantly different between the groups. This study is among the first to investigate this topic in the athletic population.…”

“…Some studies have demonstrated high failure rates, while others have shown favorable outcomes with clinical success rates not significantly different from those in patients with normal acetabular coverage in the general population. 3,6,18,57 In the setting of frank dysplasia (LCEA, <18°), periacetabular osteotomy (PAO) is the preferred treatment; however, a consensus has not been established for the management of patients with BD, who often have a wide spectrum of instability. 43…”

“…Some studies have demonstrated high failure rates, while others have shown favorable outcomes with clinical success rates not significantly different from those in patients with normal acetabular coverage in the general population. 3,6,18,57 In the setting of frank dysplasia (LCEA, \18°), periacetabular osteotomy (PAO) is the preferred treatment; however, a consensus has not been established for the management of patients with BD, who often have a wide spectrum of instability. 43 While the literature has recently supported good outcomes in patients with BD undergoing hip arthroscopy, there are few, if any, studies to date that have compared the outcomes between high-level athletes with BD and those with normal coverage.…”

One Bony Morphology, Two Pathologic Entities: Sex-Based Differences in Patients With Borderline Hip Dysplasia Undergoing Hip Arthroscopy

“…43 There is increasing evidence that this population of patients may also achieve satisfactory clinical outcomes with arthroscopic treatment. 3,6,7,17,28,43 Increased attention is being paid toward studying hip arthroscopy outcomes in specific patient populations, predominately stratified by age 8,27,62 and sex, 9,47 recognizing that certain demographic subsets of patients have unique pathology and may require differing treatments. In patients with BHD, cohort studies have identified sex-based differences in patient-reported outcome (PRO) measures, with females achieving greater relative improvement of PRO scores after surgery.…”

Hip Arthroscopy for Femoroacetabular Impingement: Minimal Clinically Important Difference Rates Decline From 1- to 5-Year Outcomes

“…2 Current mid-term data suggest an index surgery failure rate (of revision arthroscopy or conversion to THA) ranging from 0% to 86%, suggesting that indications for surgery need further optimization. [12][13][14][15] Also, this range of failure rates suggests there is significant variability in the published cohorts to date. 2,[6][7][8][9][10][11][12] Furthermore, only 2 mid-term studies have evaluated minimal clinically important difference (MCID) and patient acceptable symptomatic state (PASS) rates, albeit in an elderly patient cohort older than age 50 years and a strictly microfracture cohort, respectively.…”