Fatigue fractures suggesting clinical monarthritis

To examine etiologic factors, clinical features, and outcome in a series of consecutive patients with fatigue fractures diagnosed at a rheumatology division for a defined population over a 14-month period.

A prospective study of the patients diagnosed with fatigue fracture at the rheumatology division of the Hospital Xeral-Calde (Lugo, Spain) between July 2000 and August 2001 was conducted. Hormonal status, body mass index, lifestyle, job, underlying diseases, and drug intake, which might be attributable risk factors for the stress fracture, were assessed. In all the patients a followup of at least 6 months was required.

Six consecutive patients (4 women) fulfilled the inclusion criteria. All of them were younger than 65 years (median 45 years; range 36-64 years) and had a body mass index lower than 25. In this series no distinctive occupation was found. The delay to diagnosis since the onset of symptoms ranged from 0.5 to 6 months (median 1.5). All patients but 1 were sent to the rheumatology division because of a clinical diagnosis of monarthritis. Pain and swelling were the presenting symptoms. Conventional radiographs were normal and fine needle aspiration of the joints yielded negative results for microcrystals and organisms. Magnetic resonance imaging disclosed the presence and site of fracture in all the cases. Sequelae of mechanical pain and subsequent osteoarthritis were observed in the 3 cases with longer delay to diagnosis.

Fatigue fractures are not exceptional in unselected adults. Rheumatologists should consider this diagnosis in patients presenting with monarthritis. Physician awareness is required to prevent the development of sequelae.