The utility of hip arthroscopy for patients with painful borderline hip dysplasia

Purpose: We measured the width of the acetabular labra in, and the clinical outcomes of, patients with borderline hip dysplasia (HD) who underwent arthroscopy. Methods: A total of 1436 patients who underwent hip arthroscopy to treat symptomatic, acetabular labral tears were enrolled. From this cohort, we extracted a borderline HD group (162 cases). Lateral labral widths were evaluated using preoperative magnetic resonance imaging scans. Clinical data including the modified Harris hip score (mHHS), non-arthritic hip score (NAHS), hip outcome score-activity of daily living (HOS-ADL) score, visual analog scale (VAS) pain score, and Tonnis grade were collected. In addition, patient satisfaction with arthroscopy outcomes was rated. All complications and reoperations were noted. Results: The mean follow-up time was 87.4 months. The lateral labral width was 7.64 mm in those with normal hips and 7.73 mm in borderline HD patients, respectively (p = 0.870). The Tonnis grade progressed mildly from 0.46 to 0.76 (p = 0.227). At the last follow-up, clinical outcome scores (mHHS, NAHS, and HOS-ADL scores) and the VAS score were improved (p < 0.001). The mean patient satisfaction was scored at 8.2. The reoperation rate was higher in those who underwent labral debridement (25.6%) than labral repair (4.1%). Conclusions: The lateral labral width did not differ significantly between the borderline HD group and the nondysplastic control group. Arthroscopy relieved the symptoms of painful borderline HD and did not accelerate osteoarthritis. Therefore, if such patients do not respond to conservative treatment, hip arthroscopy can be considered for further treatment.