Atraumatic Insufficiency Fractures of the Tarsal Bones - An Unusual Cause of Recurrent Heel Pain in a Patient with Rheumatoid Arthritis: A Case Report.

The incidence of insufficiency fractures is approximately 1% in rheumatoid arthritis patients. The predisposing factors are chronic inflammation, skeletal deformities, biomechanical stresses and osteoporosis. The medications used in the treatment of rheumatoid arthritis such as Glucocorticosteroids and Methotrexate also contribute to the development of osteoporosis and insufficiency fractures. A 68-year old lady who was suffering from rheumatoid arthritis and on long term Methotrexate was seen in the outpatient clinic with recurrent episodes of heel pain. Examination revealed diffuse tenderness around the heel with full range of ankle movements but painful limitation of subtalar joint movements. Radiographic examination of the ankle showed a highly suspicious fracture of the calcaneus and confirmed on MRI as an insufficiency fracture. She was treated successfully with oral bisphosphonates and moon boot brace. She presented after two years with recurrent episodes of heel pain. The plain radiograph and MRI scan confirmed an insufficiency fracture of the talus. She was treated non-operatively with intravenous Zolendronic acid and bracing. In chronic rheumatoid arthritis patients especially on Methotrexate and Glucocorticoids a high index of suspicion of insufficiency fractures should be considered if they present with bone pain. MRI scan is the investigation of choice and is conclusive.