Calcification of the lateral collateral ligament of the knee: a rare cause of acute knee pain.

Calcification of the lateral collateral ligament is a rare phenomenon, which can cause acute knee pain. The management is usually conservative and there is subsequent resolution of the calcification seen on initial radiographs. It is important to exclude more sinister pathology such as septic arthritis as a cause of pain. We report the case of an elderly lady who presented with acute knee pain. Initial radiographs showed calcification at the lateral aspect of the knee joint. The pain settled with conservative management. Resorption of calcification was demonstrated on subsequent radiographs.