Short-term outcomes following dehydrated micronized allogenic cartilage versus isolated microfracture for treatment of medial talar osteochondral lesions

Background: Osteochondral lesions of the talus (OLTs) have been traditionally treated with bone marrow stimulation techniques such as microfracture. However, conventional microfracture results in a biomechanically weaker repair tissue of predominantly type I collagen. Acellular micronized cartilage matrix (MCM) serves as a bioactive scaffold to restore hyaline cartilage. The purpose was to compare short-term outcomes after microfracture with and without augmentation with MCM for medial-sided OLTs. Methods: A retrospective review was performed between 2010–2019 for medial-sided OLTs undergoing treatment with either microfracture augmented with MCM or isolated microfracture. The MCM was hydrated with either bone marrow aspirate concentrate (BMAC) or platelet-rich plasma (PRP). Outcomes included visual analogue scale (VAS) pain scores, Foot and Ankle Activity Measure (FAAM) scores, return-to-daily activities, and return-to-sport. Results: 48 patients (14 MCM with PRP, 6 MCM with BMAC; 28 isolated microfracture) with average age 35.5 years (range: 13.8–67.2 years) and mean follow-up 4.0 ± 3.4 years (range,.13–10.7) were included. There was no difference in average lesion size between MCM and microfracture groups (64.0 ± 49.4 mm² versus 57.3 ± 44.2 mm², P = .63) and a trend toward larger lesion size for BMAC compared to PRP (106.5 ± 59.2 versus 45.9 ± 32.1 mm², P = .056). There was no difference in time to return-to-activity (83.5 ± 18.8 versus 87.3 ± 49.1 days) or return-to-sports (151.9 ± 62.2 versus 165 ± 99.2 days) with MCM versus isolated microfracture. However, the MCM group had a significantly greater improvement in VAS pain score at final follow-up (4.9 ± 2.2 versus 2.7 ± 2.6, P = .0032) and significantly higher post-operative FAAM-Activities of Daily Living subscale scores (97.2 ± 8.2 versus 79.7 ± 32.8, P = .033). Conclusions: Augmenting microfracture with MCM hydrated with PRP or BMAC may result in beneficial changes in pain scores and activities of daily living, but similar return-to-activities and return-to-sport times compared to microfracture alone in management of medial OLT. Level of evidence: IV.