Single-stage matrix-assisted bone marrow-derived cell concentrate implantation for osteochondral talar lesions: a 24-month clinical and MRI follow-up

Background The optimal surgical management of larger chronic osteochondral lesions of the talus (OLT) remains debated. This study describes 24-month clinical and MRI outcomes after a combined single-stage matrix-assisted procedure using debridement, bone-marrow stimulation, autologous bone marrow-derived cell concentrate, a type I collagen scaffold, and fibrin glue. Methods This exploratory retrospective case series screened consecutive patients treated between January 2016 and December 2020. Twenty-six patients were identified; 15 had sufficiently complete clinical and MRI data for the predefined 24-month complete-case analysis. Eligible lesions were classified as Giannini type II-IIA and Outerbridge grade III-IV. The principal clinical endpoint was the 24-month change in the American Orthopaedic Foot Ankle Society (AOFAS) Ankle-Hindfoot score. Secondary outcomes included Visual Analogue Scale (VAS) pain, 24-month MRI morphology assessed with the MOCART system, and reoperations. Six- and 12-month assessments were part of routine care but were not sufficiently complete for formal longitudinal analysis. Results The mean AOFAS score increased from 57.3 ± 12.0 at baseline to 92.4 ± 7.1 at 24 months, an absolute improvement of 35.1 points. The mean VAS score decreased from 4.7 ± 1.2 to 1.8 ± 0.8, an absolute reduction of 2.9 points. At 24 months, complete defect filling was observed in 12 of 15 patients (80.0%), hypertrophic filling in 2 (13.3%), and incomplete filling in 1 (6.7%). Complete integration with adjacent tissue was observed in 14 patients (93.3%); preserved surface morphology and uniform repair-tissue structure were each observed in 12 (80.0%). Mean MOCART score was 83.7 ± 14.4. Three patients (20.0%) underwent arthroscopic reoperation for symptomatic anterior impingement. Conclusion In this retrospective cohort, the combined single-stage procedure was associated with improved 24-month pain and functional scores and favorable MRI morphology of repair tissue. The uncontrolled design and multimodal procedure do not establish comparative efficacy, superiority, or an independent cell-specific treatment effect. Larger prospective controlled studies are needed.