Patients Undergoing Microfracture With Allograft Cartilage and Autologous Platelet-Rich Plasma Augmentation for Chondromalacia in the Hip Achieving High Rates of Meaningful Outcomes at 2-Year Follow-Up

Abstract

Purpose

To evaluate rates of achieving meaningful outcomes and clinical failure at 2 years after undergoing microfracture augmented with allograft cartilage with autologous platelet-rich plasma and to identify predictors of conversion to total hip arthroplasty (THA).

Methods

Data from a prospective series of consecutive patients with Outerbridge grade 4 chondromalacia of the acetabulum or femoral head who underwent hip microfracture augmented with allograft cartilage between January 2017 and June 2022 were analyzed. Patient-reported outcomes were collected preoperatively and at a minimum of 2 years postoperatively. The Hip Outcome Score–Activities of Daily Living Subscale, Hip Outcome Score–Sports-Specific Subscale, modified Harris Hip Score, and Non-arthritic Hip Score thresholds for achieving the minimal clinically important difference, patient acceptable symptomatic state, and substantial clinical benefit at 2 years after surgery were calculated. Logistic regression analysis was performed to identify any association between nonmodifiable variables and clinical failure.

Results

A total of 108 hips (80.6% follow-up) among 106 patients had 2-year follow-up and were included in the final analysis. The mean age and body mass index (BMI) were 37.9 ± 10.1 years and 26.8 ± 4.7, respectively, with a mean follow-up time of 31.9 ± 8.4 months (range, 24-53 months). There was a statistically significant improvement in all functional score averages over the 2-year period (P < .05). A total of 84.7%, 75.5%, and 70.4% of patients reached at least 1 threshold for achieving the minimal clinically important difference, patient acceptable symptomatic state, and substantial clinical benefit, respectively. There were 11 patients (10.2%) who underwent conversion to THA, with increased age, BMI, and preoperative pain duration increasing the likelihood of requiring THA (P < .05 for all). Finally, chondromalacia size or chondromalacia index (e.g., Outerbridge grade × surface area) was not associated with clinical failure or achievement of meaningful outcomes (P > .05 for all).

Conclusions

Patients undergoing microfracture with allograft cartilage and autologous platelet-rich plasma augmentation for acetabular or femoral head chondromalacia showed a statistically significant improvement in outcome scores and high rates of achieving meaningful outcomes at 2-year follow-up regardless of chondromalacia defect size. The rate of conversion to THA was 10.2%, with increased age, BMI, and preoperative pain duration increasing the likelihood of requiring THA.

Level of Evidence

Level IV, therapeutic study.