Radiography detected up to 16% of cases of hip osteoarthritis among older patients with frequent hip pain in an analysis of participants in the Framingham Osteoarthritis Study and the Osteoarthritis Initiative.
“In older patients, inadequate recognition of osteoarthritis has consequences. Decreased functional status from osteoarthritis significantly increases morbidity from coronary heart disease, lung disease, diabetes, obesity, falls, frailty, and various other ailments,” said Dr. Chan Kim of Boston University and his associates. “Because many patients with hip pain do not have radiographic hip osteoarthritis, a health professional should continue with the evaluation and treatment of osteoarthritis, despite negative radiographic findings.”
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Radiographic pathology often is detected late in the course of knee OA and correlates poorly with knee pain, but few studies have examined these trends for the hip. The researchers analyzed pelvic radiographs and hip pain among 946 participants in the Framingham Osteoarthritis Study and 4,366 participants in the Osteoarthritis Initiative. They defined radiographic hip OA as a Kellgren-Lawrence grade of 2 or more – that is, definite superolateral or superomedial joint space narrowing and a definite osteophyte. They used various clinical symptoms of hip OA for comparison. Participants in both studies were older than 45 years, and tended to be in their early 60s (BMJ 2015 Dec 2. doi: 10.1136/bmj.h5983).
The most sensitive criterion in the study was groin pain, for which radiography was positive in 37% of hips in the Framingham Study and 17% of hips in the Osteoarthritis Initiative, the researchers said. Other clinical criteria were less sensitive, including anterior thigh pain, frequent hip pain, and painful internal rotation. Moreover, about 21%-24% of hips with radiographic OA were frequently painful.
The study did not evaluate MRI findings, the investigators noted. They suggested that such results would resemble those for the knee, in which MRI is “more sensitive than radiography, [but] it is far less specific for abnormalities suggestive of osteoarthritis in most middle-aged and older people.”
The National Institute of Arthritis and Musculoskeletal and Skin Diseases funded the study. The Osteoarthritis Initiative is funded by the National Institutes of Health, Merck Research Laboratories, Novartis, GlaxoSmithKline, and Pfizer. The researchers had no disclosures.