Hip Arthroscopy and Borderline Developmental Dysplasia of the Hip: A Systematic Review

Purpose: To provide an up-to-date evidence-based review of hip arthroscopy for patients with borderline developmental dysplasia of the hip (BDDH). Methods: Literature describing hip arthroscopy in patients with BDDH was systematically identified from PubMed, EMBASE, and Cochrane Library using the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. All studies that involved BDDH and not just those reporting their clinical outcomes were included. Methodological Index for Non Randomized Studies criteria and NewcastleeOttawa Scale were used to assess the quality of studies. The definition of BDDH, operative technique, correlation with labrum and/or cartilage lesions, outcome, and factors associated with poor outcome were collected and analyzed. Results: Assessment of the articles yielded 28 studies involving 1502 hips that were included for final analysis. There were no studies with a high risk of bias. BDDH was defined as lateral center-edge angle of 20 degrees to 25 degrees in most studies. Hip arthroscopy for BDDH showed an improvement in the weighted mean postoperative modified Harris Hip Score, from 60.2 to 81.7, a relatively high rate of acquisition of minimal clinically important difference of 79.5% to 87%, and had 1.0% rate of complications. Eleven studies reported on all the patients undergoing a capsular plication. Four studies reported that BDDH was associated with cartilage damage on the femoral head. Age older than 35 or 42 years and >= 20 degrees of femoral anteversion were reported as risk factors for poor outcomes. Conclusions: Hip arthroscopy for BDDH with capsular plication provides improvement in patient-reported outcome measures and a relatively high rate of acquisition of minimal clinically important difference with a low rate of complications in the shorter term. BDDH may be associated with cartilage damage on the femoral head. Female sex is a factor related to good outcomes, whereas older age, excessive femoral anteversion, and anterior undercoverage of acetabulum are risk factors related to poorer outcomes.