Stress fractures of the pubic rami in rheumatoid arthritis

To draw attention to and detail the features of stress fractures of the pubic rami in patients with rheumatoid arthritis (RA).

Twenty two cases were collected prospectively over a four year period from patients undergoing active rheumatological surveillance in Leeds. Both old and new fractures were included. Information was obtained from the patients, clinical notes, and radiological investigations.

All patients were women (mean age 68.1 years) with longstanding (mean disease duration 24.2 years) seropositive RA. Nineteen (86%) were receiving regular prednisolone treatment and all patients had radiological evidence of osteoporosis, with vertebral crush fractures in 10 (63%) of the 16 who had vertebral x ray examination. There was no biochemical evidence of osteomalacia. Nineteen (86%) presented with pain in the low back, groin, or hip and three were asymptomatic. Pain developed gradually in seven with an acute onset in the remainder. Six gave a history of a fall but only seven were x rayed at the onset of symptoms and initial radiographs were negative in five of these. In eighteen the fracture had either minimal or no effect on their mobility. Fractures affected all four pubic rami and in four all four were fractured. All but one patient (who had multiple fractures) made an uneventful recovery over two to four weeks with conservative management.

Stress fractures of the pubic rami in RA appear to be more common than had been recognised. The low grade nature of symptoms, the minimal effect on mobility, and the absence of significant trauma are typical features and suggest that many more stress fractures may go unrecognised.