Case Report Subchondral Microfracture of the Knee Without Osteonecrosis

Abstract: 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. Key Words: Meniscectomy—Osteonecrosis—Magnetic resonance imaging—Arthroscopy. Osteonecrosis of the knee developing after arthro-scopic meniscectomy has been previously re-ported.1-4 In these studies, the diagnosis of the lesions has been based mostly on clinical findings and imag-ing studies of the knee. Specifically, the usefulness of magnetic resonance imaging (MRI) has been shown for the diagnosis.4,5 On the other hand, few studies have reported a histologic analysis of the lesion. We present a case of a patient who developed an osteo-necrosis-like lesion in the medial femoral condyl