A Systematic Approach to Evaluating Knee Radiographs with a Focus on Osteoarthritis

Arthritis of the knee is commonly encountered in primary care and specialty settings. The initial work up and treatment of these patients requires a thorough evaluation and complete series of plain radiographs. Despite increased use of advanced imaging modalities, plain films remain the most instructive, available, and affordable diagnostic test. The evaluation of patients with arthritis can be challenging, by using a standardized approach one can perform a quick and adequately comprehensive evaluation. Here we outline an approach appropriate for the evaluation of these patients in any setting. Particularly, we advocate a complete history and physical exam augmented by a four view radiographic series: A weight bearing anterior-posterior (AP) of the knee, a 45 degree weight bearing posterior-anterior (PA) view of the knee, a standing lateral, and a Merchant view. Through our described systematic evaluation of these views, a great deal of information can be obtained often helping guide treatment plans created with the patient, and helping avoid a potential missed or delayed diagnosis.