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 PRP, and to identify predictors of conversion to total hip arthroplasty.

Methods: Data from a prospective series of consecutive patients with Outerbridge grade IV chondromalacia of the acetabulum or femoral head who underwent hip microfracture augmented with allograft cartilage between January 2017 and June 2022 was analyzed. Patient-reported outcomes were collected preoperatively and at minimum 2 years postoperatively. The Hip Outcome Score- Activity of Daily Living (HOS-ADL), -Sports Subscale (HOS-SS), modified Hip Harris Score (mHHS), and Non-Arthritic Hip Score (NAHS) thresholds for achieving the minimal clinically important difference (MCID), patient acceptable symptomatic state (PASS), and substantial clinical benefit (SCB) at 2-year after surgery were calculated. Logistic regression analysis was performed to identify any association between non-modifiable variables and clinical failure.

Results: A total of 108 hips (80.6%) among 106 patients had 2-year follow up and were included in the final analysis. The combined mean age and 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 years (p<0.05). A total of 84.7%, 75.5%, and 70.4% reached at least one threshold for achieving MCID, PASS, and SCB, respectively. There were 11(10.2%) patients that underwent conversion to THA (Total Hip Arthroplasty), with increased age, BMI, and preoperative pain duration increasing the likelihood of requiring THA (p<0.05 for all). Lastly, chondromalacia size or chondromalacia index (e.g., Outerbridge grade x surface area) was not associated with clinical failure or achieving meaningful outcomes (p>0.05 for all).

Conclusion: Patients undergoing microfracture with allograft cartilage and autologous PRP augmentation for acetabular or femoral head chondromalacia demonstrated statistically improved outcome scores and high rates of achieving meaningful outcomes at 2-year follow-up regardless of chondromalacia defect size. Conversion to THA was 10.2%, with increased age, BMI, and preoperative pain duration increasing the likelihood of requiring THA.

Study design: Level 2, prospective cohort.