Isolated Proximal Fibular Stress Fracture In Osteoarthritis Knee Presenting As L5 Radiculopathy

INTRODUCTION: Isolated proximal fibular stress fractures are rare and usually seen only in athletes and military recruits. Its occurrence with osteoarthritis of the knee is not documented. Diagnosis of stress fractures is not difficult, but they can mimic other pathologies at times. CASE REPORT: A 45-year-old male patient presented with pain and paresthesias in left lower thigh and leg. He was previously treated as L5 radiculopathy confirmed with lumbar spine magnetic resonance imaging (MRI). He received analgesics followed by nerve root blocks at another center. He was referred to our center for L4-5 root decompression. Due to atypical spine symptoms, leg radiographs and MRI was done, which showed isolated stress fracture of the left proximal fibula. CONCLUSION: We conclude that isolated stress fractures of the proximal fibula can present as L5 radiculopathy. A high level of suspicion is required for diagnosis. MRI is the investigation of choice when in doubt.