Comparison of Radiographic and Clinical Outcomes following Treatment of Talar Osteochondral Lesions with Micronized Cartilage Extracellular Matrix Mixed with Bone Marrow Aspirate Concentrate vs Microfracture

CATEGORY: Ankle, Arthroscopy, Sports INTRODUCTION/PURPOSE: Historically, microfracture has been the standard surgical treatment for talar osteochondral lesions (OLTs); however, it is associated with unsatisfactory long-term results due to the formation of biomechanically inferior reparative fibrocartilage as opposed to normal hyaline-like cartilage. Thus, the optimal treatment for OLTs remains contested. Application of micronized allogenic cartilage extracellular matrix (ECM) as an adjuvant therapy during the treatment of OLTs offers a promising option that could be administered arthroscopically to improve the quality of reparative tissue. The purpose of this study is to provide a case-control series comparing radiographic and functional outcomes following treatment of OLTs with an adjuvant mixture of micronized allogenic cartilage ECM and bone marrow aspirate concentrate (BMAC) to those achieved following standard microfracture with or without BMAC. METHODS: 194 patients (average age 37) with a minimum 1-year follow-up who were treated for an OLT by a fellowship-trained foot and ankle surgeon were screened for inclusion. 107 patients who received mixed micronized cartilage ECM and BMAC (Group I), 40 who were treated by microfracture augmented with BMAC (Group II), and 47 patients who were treated with traditional microfracture alone (Group III) were identified. Preoperative lesion size, lesion location, and concurrent injuries were recorded retrospectively. Foot and Ankle Outcome Scores (FAOS) were completed preoperatively and postoperatively through the prospective Registry database at the authors’ institution. Outcomes were assessed radiographically at a minimum of 6 months postoperatively by a trained radiologist using the MOCART scoring system. Linear regression modeling was used to assess differences in MOCART scores, post-operative FAOS scores, pre-to-postoperative change in FAOS, and the rate of revision surgery between groups I, II, and III. RESULTS: The average MOCART score for Group I was 62.39, (average follow-up 16.13 months; n = 46), 58.8 (26.82 months; n =25) for Group II and, 55.36 (43.12 months; n=14) for Group III patients (p=0.57). The rate of revision surgery for OLTs treated using adjuvant micronized cartilage ECM was 5% and was significantly lower when compared to a 22.7% rate of revision surgery following microfracture with or without BMAC (p<0.001). Finally, when controlling for lesion size, changes in pre-to-postoperative FAOS Pain and Sports Activities were significantly different amongst the 3 treatment groups (p=0.05). Group I had the greatest improvement in Pain. CONCLUSION: Micronized allogenic cartilage extracellular matrix serves as an adjunctive therapy that may help improve patients’ radiographic and functional outcomes following treatment of OLTs when compared to outcomes following traditional microfracture. Specifically, use of adjunctive ECM appears to have better postop FAOS Pain scores when controlled for lesion size when compared to microfracture. There is a lower rate of revision surgery with the use of allogenic cartilage ECM in the short to intermediate term when compared with microfracture.