It’s a good thing orthopaedists don’t rely solely on X-rays to diagnose hip osteoarthritis (OA), because an analysis of data from two large cohort studies casts doubt about the utility of radiographs in diagnosing hip OA in older patients.
Using pain localized to the groin or anterior hip or provoked by internal rotation as the clinical standard for diagnosing hip OA, the researchers compared participants’ reports of such pain with radiographic evidence. In the first cohort study (n=946), only 15.6% of hips in patients reporting frequent hip pain showed radiographic evidence of osteoarthritis. In the second study (n=4366), only 9.1% of hips in patients with frequent pain showed radiographic evidence of hip OA. Conversely, pain was not present in many hips with radiographic evidence of osteoarthritis.
These findings strongly indicate that many cases of hip arthritis would be missed if clinicians relied solely, or even largely, on radiographs. The findings also suggest that overdiagnosis of osteoarthritis would be likely if doctors relied on radiographs rather than examining patients and obtaining an appropriate history. The authors conclude that “health professionals should continue to evaluate and treat patients with hip pain suggestive of osteoarthritis despite negative radiographic findings.” This study is also a good reminder for physicians to treat patients, not imaging studies.