Subchondral microfracture of the knee without osteonecrosis after arthroscopic medial meniscectomy.

We report a case of an osteonecrosis-like lesion of the knee that developed shortly after an arthroscopic medial meniscectomy. Clinical presentation, physical findings, and imaging of the knee including magnetic resonance imaging were similar to those of the cases that have been reported as osteonecrosis after meniscectomy. However, histologic analysis of the lesion revealed that there was no osteonecrosis but rather a subchondral microfracture with active callus formation.