Matrix-associated stem cell transplantation (MAST) in chondral defects of the ankle is safe and effective - 2-year-followup in 130 patients.

Background: The aim of the study was to assess the 2-year-follow-up of matrix-associated stem cell transplantation (MAST) in chondral defects of the ankle.

Methods: In a prospective consecutive non-controlled clinical follow-up study, all patients with chondral defect that were treated with MAST from October 1, 2011 to July 31, 2013 were analyzed. 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 analyzed. 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). The matrix was fixed into the chondral defect with fibrin glue.

Results: One hundred and forty-four patients with 150 chondral defects were included in the study. The age of the patients was 35 years on average (range, 12-68 years), 85 (59%) were male. The VAS FA before surgery was 48.5 on average (range, 16.5-78.8). The defects were located as follows, medial talar shoulder, n=62; lateral talar shoulder, n=66 (medial and lateral talar shoulder, n=6), tibia, n=22. The defect size was 1.6cm on average (range, .6-6cm). 130 patients (90%) completed 2-year-follow-up. The VAS FA improved to an average of 87.5 (range, 62.1-100; t-test (comparison with preoperative scores), p=.01).

Conclusions: MAST led to improved and high validated outcome scores. No method related complications were registered. Even though a control group is missing, we conclude that MAST is a safe and effective method for the treatment of chondral defects of the ankle.