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 Newcastle-Ottawa 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° to 25° 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° 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.
LEVEL OF EVIDENCE: Level IV, systematic review of Level III to IV studies.