OCCULT OSSEOUS LESIONS ASSOCIATED WITH ANTERIOR CRUCIATE LIGAMENT TEARS

Occult osseous lesions occurring with anterior cruciate ligament tears have been described only recently. Twenty patients with complete ante rior cruciate ligament disruptions and evidence of occult osseous lesi ons on their preoperative magnetic resonance (MR) images were evaluate d retrospectively at 24- to 73-months' followup to document the natura l history and long-term effects of the lesions. Thirty-seven initial o sseous signal abnormalities were documented on the MR images of 20 pat ients. All 20 patients had lesions in the posterolateral tibial platea u, and 13 had additional lesions in the lateral femoral condyle. Twent y-four of the 37 osseous lesions appeared resolved on followup MR imag es, and 13 had become sclerotic. Lesions of the lateral tibial plateau were especially likely to be sclerotic at followup. This study reaffi rms the specificity of bone signal abnormalities of the posterolateral tibial plateau and lateral femoral condyle in association with comple te anterior cruciate ligament tears. The data indicate that a proporti on of anterior cruciate ligament patients will incur progressive artic ular cartilage abnormalities, although case-by-case predictions based on initial MR images would be unreliable.