Summary

Within this carefully selected group, our analysis revealed that increased age was the main risk factor for failure in the management of borderline hip dysplasia with isolated primary arthroscopic hip surgery with capsular plication.

Abstract

Purpose

To evaluate the current indications for arthroscopic capsular plication in patients with borderline hip dysplasia and to report on the potential risk factors for failure with this approach.

Hypothesis

Borderline dysplastic patients with lower lateral center-edge angle (LCEA) and greater age will be at a higher risk of failure after arthroscopic capsular plication.

Methods

Data were retrospectively reviewed for all patients between 15 and 40 years of age who underwent hip arthroscopy from November 2008 to January 2015. Inclusion criteria were an LCEA between 18 - 25 degrees, Tonnis grade =1, primary cases with capsular plication, and minimum 2-year follow-up. Patients were excluded if had any history of previous ipsilateral hip procedure, conditions, or Tonnis grade =2. Age, sex, and body mass index (BMI) was retrieved for each patient. Patient-reported outcomes (PROs), including modified Harris Hip Score (mHHS), Non-Arthritic Hip Score (NAHS), Hip Outcome Score – Sports Specific Subscale (HOS-SSS), and pain scored on a 0-10 visual analog scale (VAS) were obtained preoperatively and at a minimum of 2-year postoperatively, in addition to the postoperative International Hip Outcome Tool 12 (iHOT-12) measure. The “Success” group consisted of all patients who achieved the patient acceptable symptomatic state (PASS) of mHHS = 74 and had no ipsilateral hip surgeries subsequent to their index arthroscopy. The “Failure” group was comprised of patients who were below the PASS at latest follow-up, required secondary arthroscopy, or conversion to total hip arthroplasty (THA). Patient satisfaction and minimal clinically important difference (MCID) were also calculated. Mean age for the “failure” group was applied as a cut-off age for sub analysis, and relative risk (RR) for failure was determined.

Results

Ninety patients with a total of 97 hips (79.5%) met criteria for the “Success” group and 25 patients with 25 hips met criteria for the “Failure” group. No significant differences in preoperative baseline scores or VAS were found. However, there did appear to be a trend that the “Failure” group had a lower mean preoperative score for all PROs measures and a higher VAS score. The differences in mHHS and NAHS closely approached significance (P = 0.053). Postoperative PROs, VAS, and patient satisfaction of the “Success” group were significantly higher than the “Failure” group. Risk factor analysis revealed that the “Failure” group was older than the “Success” group (P = 0.005). Patients over 35 years were 2.25 times more likely to fail according to RR (P = 0.0266). LCEA did not differ between the groups and no other risk factors for failure were identified.

Conclusions

Stringent criteria for patient selection and meticulous repair or augmentation of the static stabilizers of the hip yielded favorable clinical outcomes in this study cohort with borderline dysplasia. Within this carefully selected group, our analysis revealed that increased age was the main risk factor for failure in the management of borderline hip dysplasia with isolated primary arthroscopic hip surgery with capsular plication. Patients over 35 years were 2.25 times more likely to fail.

Study Design: Case Series; Level of Evidence, 4