Long-term prognosis of nonoperatively treated acute knee distortions having primary hemarthrosis without clinical instability.

The purpose of the study was to examine the long-term prognosis of nonoperatively treated acute knee distortions having primary hemarthrosis without clinical instability. A multidimensional follow-up analysis was performed on 84 patients an average 8 years after injury. The analysis included four standardized knee scoring scales for subjective, objective, functional, and radiological evaluations, as well as isokinetic and isometric strength measurements. In the great majority of the patients (86%) the long-term results were excellent or good. The main reason for failure was ACL insufficiency, an obvious outcome of overlooked rupture of that ligament in the primary situation. If the injured knee is indeed stable, if there is no suspicion of ACL injury or patella luxation in the patient's history or clinical findings, and if routine radiographs are negative, primary arthroscopy is not needed. However, a close followup with repeated clinical examinations and a well-planned rehabilitation program is obligatory.