MR arthroscopy not recommended for older patients with hip pain

The gold standard examination for diagnosing and localizing an acetabular tear is magnetic resonance arthrography, an MRI technique that involves injecting contrast dye into the joint. However, it may be clinically inappropriate and a waste of healthcare resources for older patients with hip pain, according to an article published in the August issue of Skeletal Radiology.

Musculoskeletal radiologists and orthopedic specialists at the David Geffen School of Medicine at the University of California - Los Angeles do not believe that MR arthrography offers any clinical benefit of the majority of patients over age 50 presenting with hip pain, especially if they have been diagnosed with arthritis or osteoarthritis. These individuals are unlikely candidates for successful labral debridement or repair, and a hip radiograph or standard MRI scan may provide the clinical information needed.

Published clinical studies have produced some conflicting results on the benefit of performing hip arthroscopy for labral tears in patients over age 50, but the consensus suggest that surgery often does not relieve patients of their pain, especially if a patient has osteoarthritis. Additionally, labral tearing in an older asymptomatic patient may not be the reason for the source of pain. A hip X-ray, or if necessary, a standard MRI, may provide the clinical information needed.

For these reasons, and because of the additional cost and possible risk to a patient having MR arthrography, lead author Rohit Jayakar of the Department of Orthopedic Surgery and colleagues do not recommend that MR arthrography be routinely ordered or used to evaluate labral pathology without justification. They advise that physicians needs to clinically evaluate if labral pathology is the primary pain generator in the hip and to rule out other potential causes of hip pain. They recommend that both standard MRI and MR arthrography should generally be reserved to confirm a diagnosis that would warrant further intervention or a change in treatment plans. Examples the authors cite include patients with minimal arthritis seen on a radiograph and who might benefit from surgery.

Because the authors question the utility of using MR arthrography to diagnose hip pain in older patients, they conducted a study to assess the frequency of acetabular labral tears in symptomatic patients and correlate the likelihood of a labral tear with age, gender, hip alpha angle, and the severity of arthritis. They retrospectively reviewed 208 hip MRI arthrograms and corresponding radiographs of patients treated at UCLA between 2004 and 2013. They identified and measured lateral tears and alpha angles on MR arthrograms and Tönnis grade and joint space width on hip radiographs.

93.3% of all patients showed some degree of labral pathology, including 100% of patients with moderate to severe arthritis. 73% had true labral tearing. The authors did not discover any statistically significant correlations between labral tear grade and Tönnis grade or joint space width. They believe that the high rates of labral pathology in all groups suggest routine ordering of MR arthrography for older patients may be clinically inappropriate.

“In this specific set of patients over 50 years old with hip pain, the use of MR arthrography is a misuse of healthcare funds. The cost of the procedure, as well as the unnecessary risks of the exam, can be avoided. This imaging technique should be reserved for patients with minimal arthritis on X-ray who stand to benefit from a surgical procedure,” lead author Jayakar commented to Applied Radiology.

REFERENCE

1. Jayakar R, Merz A, Plotkin B, et al. Magnetic resonance arthrography and the prevalence of acetabular labral tears in patients 50 years of age and older. Skeletal Radiol. 2016 45;8: 1061-1067.