An Intact Ligamentum Teres Predicts a Superior Prognosis in Patients with Borderline Dysplasia: A Matched-Pair Controlled Study With Minimum 5-Year Outcomes After Hip Arthroscopic Surgery
Background: Hip arthroscopic surgery in patients with borderline dysplasia continues to be controversial. In addition, it has been suggested that ligamentum teres (LT) tears may lead to inferior short-term patient-reported outcomes (PROs) when compared with a match-controlled group.
Purposes: (1) To report minimum 5-year PROs in patients with borderline dysplasia and LT tears who underwent hip arthroscopic surgery and (2) to compare these PROs to those of a matched-pair control group of patients with borderline dysplastic hips without LT tears.
Study design: Cohort study; Level of evidence, 3.
Methods: Data were prospectively collected for patients who underwent hip arthroscopic surgery between September 2008 and August 2013. Patients were included if they had a preoperative diagnosis of borderline dysplasia (lateral center-edge angle [LCEA], 18°-25°) and had preoperative and minimum 5-year postoperative modified Harris Hip Score (mHHS), Nonarthritic Hip Score (NAHS), and visual analog scale (VAS) for pain scores. Exclusion criteria were osteoarthritis of Tönnis grade >1, previous hip conditions, any previous ipsilateral hip surgery, or workers' compensation status. There were 2 borderline dysplastic groups 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 < .05.
Results: A total of 24 patients with an LT tear (24 hips) were matched to 24 patients without an LT tear (24 hips). There was no significant difference in age, sex, BMI, or laterality between groups. The mean age was 36.2 ± 17.2 and 34.9 ± 15.9 years for the control and LT tear groups, respectively (P = .783). There were 17 (70.8%) and 16 (66.7%) female patients in the control and LT tear groups, respectively, and the mean preoperative LCEA was 23.3° and 22.2° in the control and LT tear groups, respectively. No differences were observed between groups in baseline PROs, intraoperative findings, or surgical procedures. LT debridement was performed in 17 (70.8%) patients in the LT tear group compared with 0 (0.0%) in the control group. Also, 5-year postoperative PROs were comparable in both groups, with the control group exhibiting superior Veterans RAND 12-Item Health Survey (VR-12) mental (P = .041) and Short Form-12 (SF-12) mental (P = .042) scores. Finally, hips with an intact LT were significantly more likely (P = .022) to achieve the patient acceptable symptomatic state (PASS) for the mHHS (100.0% and 75.0%, respectively). No significant differences were present between the groups for the minimal clinically important difference (MCID) of the mHHS (P = .140), MCID of the Hip Outcome Score-Sport-Specific Subscale (HOS-SSS) (P = .550), or PASS of the HOS-SSS (P = .390).
Conclusions: After hip arthroscopic surgery, patients with borderline dysplasia and LT tears demonstrated favorable PROs at a minimum 5-year follow-up. Outcomes were similar to a matched-pair control group without LT tears, with the group with intact LTs showing higher VR-12 mental and SF-12 mental scores. Furthermore, patients with borderline dysplasia and intact LTs were significantly more likely to achieve the PASS for the mHHS.