Microfracture for chondral defects of the talus: maintenance of early results at midterm follow-up.

We determined whether the early improvement in symptoms and function after microfracture in the management of articular cartilage defects of the talus is maintained at mid term follow-up. Factors influencing outcome and postoperative magnetic resonance imaging were also evaluated. We performed data collection prospectively using the Hannover Scoring System for the ankle (HSS) and a Visual Analog Scale (VAS) for pain and function preoperatively, at 1 +/- 0.1 year (45 ankles), 2 +/- 0.4 years (45 ankles), and at an average of 5.8 +/- 2.0 years (39 ankles) postoperatively. MRI was used to assess cartilage repair tissue based on the following variables: degree of defect repair and filling of the defect, integration to border zone, surface of the repair tissue, structure of the repair tissue and subchondral bone alterations. Comparing the outcome scores of the last follow-up to the previous follow-up points, the HSS and the VAS (pain, function and satisfaction) showed no deterioration. Four ankles, however, underwent further surgery to address the chondral defect and were regarded as failures. A body mass index greater than 25 kg/m(2) and having severe post-traumatic cartilage damage appeared to be negative prognostic factors. Results for patients older than 50 years were not inferior to those in younger patients. Microfracture arthroplasty induces repair of localized articular cartilage defects of the talus maintaining the encouraging early results at mid term follow-up.