['The aim of the study was to assess the feasibility and clinical results of matrix-associated stem cell transplantation (MAST) and 2-year-follow-up in chondral defects of foot and ankle.', 'In a prospective, consecutive, non-controlled clinical follow-up study, all patients with chondral defects, that were treated with MAST from April 1st to November 30th, 2009 were analyzed. The size and location of the chondral defects, method-associated problems and the Visual Analogue Scale Foot and Ankle (VAS FA) before treatment and at follow-up were registered and analyzed.', 'Twenty-six chondral defects in 25 patients were included in the study. The mean age of the patients was 33 years (range, 16-48 years), 18 (72%) were male. The VAS FA before surgery was 49.2 on average (range, 24.3-68.4). The defects were located as follows: medial talar shoulder, n=9; lateral talar shoulder, n=13 (medial and lateral talar shoulder, n=1); distal tibia, n=1; posterior calcaneal facet, n=1; head of 1st metatarsal, n=2. The defect size was 1.1cm(2) on average (range, .5-6 cm(2)). All patients completed 2-year-followup. No complications or consecutive surgeries were registered. The mean VAS FA at follow-up was 94.5 (range, 73.4-100; t-test, p<.01).'] Is matrix-associated stem cell transplantation ( MAST ) in chondral defects of foot and ankle effective?