1. Teaching File Case: Osteonecrosis/Osteochondrosis Diagnosis: Spontaneous Osteonecrosis of the Medial Femoral Condyle Findings: Essentially normal initial study (05/08/01). Pathology: Subsequent MR & radiograph demonstrates clinical suspicion. Slide 1 of 3 Clinical History: Acute onset, pain in knee.

2. Teaching File Case: Osteonecrosis/Osteochondrosis Diagnosis: Spontaneous Osteonecrosis of the Medial Femoral Condyle Findings: Osteochondral abnormality of the medial femoral condyle. Pathology: Finding not evident with loss of overlying cartilage on initial radiograph (05/08/01). Osteochondral defect more evident on follow up radiograph (08/08/01) (arrowhead). Slide 2 of 3 Clinical History: Acute onset of pain in knee.

3. Teaching File Case: Osteonecrosis/Osteochondrosis Diagnosis: Spontaneous Osteonecrosis of the Medial Femoral Condyle Findings: Osteochondral abnormality of the medial femoral condyle clearly. Pathology: Evident on follow up radiograph (08/08/01) (arrowhead). Slide 3 of 3 Clinical History: Acute knee pain 3 months prior to this radiograph.