Multifocal stress fractures in a patient with rheumatoid arthritis.

Stress fractures are often associated to activities that requires repetitive stress such as running. However, insufficiency-type stress fractures can also occur in patients with risk factors such as rheumatoid arthritis. Diagnosis of stress fracture would require a thorough clinical evaluation along with radiological imaging. However, this may be difficult due to how it mimics other musculoskeletal problems. The case of a woman in her 60s presenting with 2 months of severe ipsilateral right knee and ankle pain is used as an example. Based on initial clinical assessment and plain radiograph, her provisional diagnosis was osteoarthritis or inflammatory arthritis secondary to rheumatoid disease. However, MRI scan revealed that she had multifocal stress fractures in her knee, ankle and foot. Hence, we hope that this case study can allow clinicians to consider multifocal stress fracture as a possible diagnosis in patients with risk factors and to have lower threshold in performing MRI scans.