Hip Arthroscopic Surgery in Borderline Developmental Dysplastic Hips: A Systematic Review

Background: It remains controversial whether hip arthroscopic surgery should be applied to patients with a borderline developmental dysplastic hip (BDDH). Purpose: To review the outcomes of hip arthroscopic surgery for a BDDH and which factors influence these outcomes. Study Design: Systematic review. Methods: PubMed, Embase, and the Cochrane Library were searched through March 2018 for studies reporting the outcomes of primary hip arthroscopic surgery in patients with a BDDH. Inclusion in the review was based on the definition of a BDDH, patient-reported outcomes, and duration of follow-up. The primary outcome was the modified Harris Hip Score (mHHS). The failure rate, visual analog scale, satisfaction score, and patient-reported outcomes such as the Hip disability and Osteoarthritis Outcome Score were defined as secondary outcomes. Results: Nine studies with 425 patients who underwent hip arthroscopic surgery were included in this review. The mean follow-up times ranged from 25.4 to 28.8 months across the studies. A significant improvement was obtained in the mHHS, with a mean score of 61.8 preoperatively to 82.8 postoperatively; all other patient-reported outcomes also improved significantly, except the 12-Item Short Form Health Survey mental component summary. The overall failure rate was 14.1%, and the mean reoperation rate was 8.5%. The rate of conversion to total hip arthroplasty ranged from 4.4% to 26.0%, and the rate of conversion to periacetabular osteotomy was 4.0%. Combined defects such as cartilage damage, hip osteoarthritis, ligamentum teres tears, and femoroacetabular impingement could influence the outcomes after arthroscopic surgery in BDDHs. Conclusion: Hip arthroscopic surgery was demonstrated to be a promising approach for BDDHs, but the outcomes could be influenced by multiple risk factors. A higher level of evidence is still needed to support current findings.