ABSTRACT: Knee pain is a common complaint in older patients, and osteoarthritis is the leading cause. We prospectively evaluated the diagnostic patterns of nonorthopedic physicians in 100 consecutive patients older than 60 years who had knee pain. Our study shows that there is a lack of consensus about the use radiographic studies for diagnosis of knee pain in older patients. Weight-bearing radiographs are ideal for evaluating knee pain. MRI frequently is overly sensitive in detecting pathology and often underestimates joint-space narrowing and arthrosis. MRI also represents a much larger cost and burden on the health care system. MRI is indicated when the cause of knee pain is not readily apparent after careful physical and radiographic evaluation. (J Musculoskel Med. 2008;25:500-504)
Knee pain is one of the most common musculoskeletal complaints in patients older than 50 years.1-3 Up to 30% of these patients report persistent knee pain lasting more than 3 months.1 As the population ages and patients continue to be active, the proportion of patients with knee symptoms and pathology probably will increase. Although osteoarthritis (OA) overwhelmingly is the most common cause of knee pain in this patient population, "acute on chronic" events (eg, degenerative meniscal tears and ligament injuries) may add to patients' pain and disability.
The ease, availability, and sensitivity of MRI as an initial diagnostic tool create a misconception that this is the test of choice for patients presenting with knee pain. In our opinion, there is a tendency to overuse expensive and often unnecessary imaging of older patients with knee pain, resulting in delays in diagnosis and treatment, inconveniences to patients, and increased health care costs.
In this article, we present findings from our study that evaluated the diagnostic patterns of nonorthopedic physicians in the evaluation and treatment of older patients with knee pain. We also offer a diagnostic and radiographic algorithm.
MATERIALS AND METHODS
We prospectively evaluated the diagnostic patterns of nonorthopedic physicians in 100 consecutive patients older than 60 years who had knee pain. There were 68 women and 32 men (mean age, 78 years; range, 60 to 99 years). Demographic information recorded for each patient included referring physician specialty, types of radiographic studies, and dates. A group of board-certified orthopedic surgeons who had a subspecialty in hip and knee reconstruction examined all patients. The diagnosis, treatment, outcome, and any required additional testing were recorded.
The radiographic studies available for each patient at the time of initial evaluation are outlined in Figure 1. Of the 100 new patients, 13 presented to the office with no x-ray films, 26 had had only MRI scans of their knees, 22 had been evaluated with both MRI scans and x-ray films, and 29 presented with non–weight-bearing radiographs of their knees; 32 patients in this series had been evaluated previously with standing anteroposterior (AP) and lateral x-ray films of their knees.