Age, morning stiffness, and certain kinds of pain can identify patients who are at risk for progression of hip osteoarthritis and who will need a total hip replacement, according to a report in Arthritis and Rheumatism. Age, morning stiffness, and certain kinds of pain can identify patients who are at risk for progression of hip osteoarthritis and who will need a total hip replacement, according to a report in the medical journal Arthritis & Rheumatism.

The course and risk factors associated with osteoarthritis of the hip have been reviewed, the authors explain, but few studies have examined the variables predicting progressive hip osteoarthritis.

Dr. Annet M. Lievense and colleagues from Erasmus Medical Center, Rotterdam, assessed the progression of hip osteoarthritis to total hip replacement and the factors associated with the progression in 224 patients attending general practices.

Twelve per cent of patients underwent total hip replacement during three years of follow-up because of severe pain or disability due to hip osteoarthritis, the authors report. By six years, the fraction had reached 22 per cent.

The patients' pain scores were higher than normal in 58 per cent of patients at the beginning of the study, the report indicates, and the percentage of patients with high pain scores increased to 68 per cent after three years and to 69 per cent after six years.

Factors that predicted total hip replacement included age of at least 60 years, morning stiffness, pain in the groin or thigh; decreased ability to extend the hip and painful passive internal rotation of the joint; and a Kellgren/Lawrence score of at least two on radiographic analysis.

"With information obtained from history taking, physical examination, and radiology, we are now better able to identify persons who are at high risk for progression of hip osteoarthritis," the investigators conclude. "This can be helpful not only to inform patients more precisely about the course of their hip pain, but also for future clinical trials.