Evaluation and imaging of patellofemoral joint disorders.

Patellar instability is often challenging to diagnose. In addition, the diagnosis of associated soft tissue and chondral injuries that occur with patellar instability are challenging. Missed or failed diagnosis can lead to repeated episodes of instability and may increase the likelihood and grade of patellar and trochlear chondral injury. Radiographs, computed tomography scans, and magnetic resonance imaging studies can assist in the diagnosis of patellofemoral instability and associated injuries in the acute setting, but have been less helpful in the nonacute setting. Therefore, the diagnosis relies on suggestive history and confirmed with a physical examination with support of appropriate imaging studies. © 2010 Elsevier Inc. All rights reserved. [ABSTRACT FROM AUTHOR]