To analyze factors influencing clinical results after microfracture surgery in patients with osteoarthritic knee.

After microfracture surgery, in sixty-six patients with sixty-eight knees having full thickness chondral defect by arthroscopic evaluation, clinical results were evaluated with Baumgartner's nine-point scale during the follow-up of 1 year 4 months (range, 1-2 years 5 months). Results were analyzed according to age, the degree of preoperative varus and the existence of flexion contracture.

Sixty-three knees showed excellent or good results at clinical evaluation. According to age, a significant difference was observed about 65 years old (p<0.05). The patients without flexion contracture and with less varus change had better clinical results, as did patients whose medial deviation of mechanical axis was less than 75% (p<0.05).

Better clinical results, after microfracture surgery, were obtained in patients who were under the age of 65, with less than 75% of medial deviation of the mechanical axis on standing AP radiogram and no flexion contracture.