A clinical and radiological study of back pain in rheumatoid arthritis.

Five hundred and three patients with RA were questioned about the symptom of back pain. Chronic back pain, lasting more than 3 months, occurred in 33 per cent of the group. A group of 100 back pain patients were studied in more detail using a structured questionnaire, clinical examination and radiology. Ninety-four of these patients had low back pain. Particular clinical patterns (such as that of the facet syndrome) were sought but no clear characteristics were found. Fifty-two lumbar spine X-rays were available from the RA population and these were compared to 52 age and sex matched X-rays from outpatients with chronic mechanical low back pain. Significant differences between these groups radiologically were a higher frequency of osteoporosis and a higher frequency of disc narrowing without associated osteophytes in the RA population. This study differs from previous reports which found other characteristic radiological features of RA of the lumbar spine (spondylolisthesis, facet erosions, and vertebral fracture), a discrepancy possibly resulting from the use of a control group having low back pain.