Background: In the military population the most common site of stress fracture is the tibia and bilateral lesions are common. Proximal fibular fractures produced without history of trauma are not
common. They can be either spontaneous or stress fractures but the distinction between these two categories is not clear.Case Report: A 18-year-old man, naval cadet, on his first day of basic training felt a bilateral cramp-like pain in the lateral aspect of the lower leg bilaterally, while doing a jumping exercise, the so called “kangaroo jumping”. The pain has gradually subsided over the next 5 weeks. On the 6th week of training he started to feel a deep pain in the middle of his shins bilaterally during and after running and marching. He asked for medical consultation by the end of the 8th week. Onexamination, there was only a mild tenderness to palpation over the middle of diaphysis of both tibiae bilaterally. The diagnosis of bilateral tibial shaft and bilateral proximal fibular fractures was confirmed with plain radiographs and bone scan. The patient was treated with rest.Conclusions: Although the obvious diagnosis is a bilateral tibial and fibular stress fracture, we believe that the nature of the bilateral proximal fibular fracture presented in this case is a spontaneous fracture due to jumping. Nevertheless the combination of bilateral stress tibial shaft fracture and bilateral stress or spontaneous proximal fibular fracture seems to be very rare, since we found no previous report in English literature.

Keywords: stress fracture, spontaneous fracture, tibial fracture, fibular fracture