First Metatarsal Bilateral Stress Fracture: A Case Report

INTRODUCTION: Metatarsal stress fractures typically occur in the second and third metatarsus metaphysis, with only rare cases in the fourth and first. The main factors influencing its onset are repetitive stress from prolonged training, biomechanical factors and bone weakness. There is only a paucity of literature documenting first metatarsal stress fractures; the authors present a rare bilateral first metatarsal stress fracture. CASE REPORT: A Caucasian 52-years-old amateur female runner with no other risk factors or medical condition was admitted in our institute with complaints of severe bilateral forefoot pain for 2 weeks arisen after a 20 km run of an amateur race. The patient presented bilateral hallux valgus (HVA) and advanced osteoarthritis of the first metatarsal-phalangeal joint, which is not usually considered a biomechanical risk factor for metatarsal stress fractures. Radiographs of both feet showed linear sclerosis, perpendicular to the diaphysis of the first metatarsal, approximatively in the half of the bone. Signs of osteoarthritis of the first metatarsal-phalangeal were also detected bilaterally. The patient was treated with rest, bilateral post-operative rocker sole shoes that she has worn for 6 weeks, cryotherapy, analgesics as needed and pulsed electromagnetic fields for 8 h per day for 40 days with a complete resolution of symptoms and the previous radiological findings. CONCLUSION: The authors believed that the bilateral HVA condition could be considered an indirect sign of overuse, and it may be investigated and eventually treated as a responsible for this pathologic condition.