Intact Ligamentum Teres Predicts Superior Prognosis in Borderline Dysplastic Patients: A Matched Pair Controlled Study with Minimum Five-Year Outcomes Following Hip Arthroscopy

OBJECTIVES: (1) To report minimum five-year patient reported outcomes (PROs) in borderline dysplastic patients with ligamentum teres (LT) tears who underwent hip arthroscopy and (2) to compare these PROs to a pair-matched control group of borderline dysplastic hips without LT tears. METHODS: Data was prospectively collected for patients who underwent hip arthroscopy during September 2008 and August 2013. Patients were included if had a preoperative diagnosis of borderline dysplasia [lateral center-edge angle (LCEA) of 18°- 25°] and had preoperative and minimum five-year postoperative modified Harris Hip Scores (mHHS), Non-Arthritic Hip Scores (NAHS), and Visual Analogue Scale for pain (VAS) scores. Exclusion criteria were Tönnis grade osteoarthritis >1, previous hip conditions, any prior ipsilateral hip surgery, or workers’ compensation status. Two borderline dysplastic groups were created. An LT tear group was matched 1:1 to a control group (no LT tear) with similar age, sex, body mass index (BMI), and laterality via propensity score matching. Significance was set at P < 0.05. RESULTS: 24 LT tear patients (24 hips) were matched 24 patients (24 hips) without an LT tear. There was no significant difference in age, sex, BMI, or laterality between groups. Mean age was 36.2 ± 17.2 and 34.9 ± 15.9 years for the control and LT tear group, respectively (P = 0.783). There were 17 (70.8%) and 16 (66.7%) females in the control and LT tear group, respectively and the mean preoperative LCEA was 23.3° and 22.2° in the control and LT tear group, respectively. No differences were observed between groups in baseline PROs, intraoperative findings, or surgical procedures, except for LT treatment. Five-year postoperative PROs were comparable in both groups, with the control group exhibiting superior Veterans RAND 12-Item Health Survey Mental Component (VR-12M) (P = 0.041) and Short Format 12 Mental Health (SF-12M) (P = 0.042). The control group exhibited less pain and higher satisfaction with surgery; however, this trend was not significant. Finally, the LT tear group was significantly less likely to achieve the patient acceptable symptomatic state (PASS) for mHHS (P = 0.022). CONCLUSION: Following hip arthroscopy, patients with borderline dysplasia and LT tears demonstrated favorable PROs at minimum five-year follow-up. Outcomes were similar to a pair-matched control group without LT tears, with the control group showing higher VR-12M and SF-12M scores. Furthermore, borderline dysplastic patients with LT tears were significantly less likely to achieve the PASS for mHHS.