BackgroundThe aim of the study was to assess the 5-year-follow-up after matrix-associated stem cell transplantation (MAST) in chondral lesions at the ankle as part of a complex surgical approach. MethodsIn a prospective consecutive non-controlled clinical follow-up study, all patients with chondral lesion at the ankle that were treated with MAST from April 1, 2009 to May 31, 2012 were included. Size and location of the chondral lesions, method-associated problems and the Visual-Analogue-Scale Foot and Ankle (VAS FA) before treatment and at follow-up were analysed. Stem cell-rich blood was harvested from the ipsilateral pelvic bone marrow and centrifuged (10min, 1500RPM). The supernatant was used to impregnate a collagen I/III matrix (Chondro-Gide) that was fixed into the chondral lesion with fibrin glue. ResultsOne hundred and twenty patients with 124 chondral lesions were included in the study. Age at the time of surgery was 35 years on average (range, 12–65 years), 74 (62%) were male. VAS FA before surgery was 45.2 on average (range, 16.4–73.5). Lesions were located at medial talar shoulder, n=55; lateral talar shoulder, n=58 (medial and lateral, n=4); tibia, n=11. Lesion size was 1.7cm2 on average (range, .8–6cm2). One hundred patients (83%) completed 5-year-follow-up after. VAS FA improved to 84.4 (range, 54.1–100; t-test, p<0.01). ConclusionsMAST as part of a complex surgical approach led to improved and high validated outcome scores in the mid-term-follow-up. No method related complications were registered. Even though a control group is missing, we conclude that MAST as part of a complex surgical approach is an effective method for the treatment of chondral lesions of the ankle for at least five years.