Summary
Predictors of 2-year outcomes after biocartilage use in the hip
Abstract
Introduction
Recently, a biologic scaffold combining allograft cartilage and autologous platelet-rich plasma (BioCartilage®) has been introduced to augment microfracture treatment of symptomatic chondral defects of the hip.
Purpose
To evaluate rates of achieving meaningful outcomes and clinical failure at 2-year after undergoing microfracture augmented with BioCartilage, and determine whether chondral defect size influences functional outcomes.
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 BioCartilage between October 2016 and April 2020 was analyzed. Patient-reported outcomes were collected preoperatively and at minimum one-year 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 baseline 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. 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 was not associated with clinical failure or achieving meaningful outcomes (p>0.05 for all).
Conclusion
Patients undergoing microfracture with BioCartilage augmentation for acetabular or femoral head chondromalacia demonstrated 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.