Bilateral stress fractures of femoral neck in non-athletes: a report of four cases / 中华创伤杂志(英文版)

Femoral neck stress fractures (FNSFs) are rare, constituting only 5% of all stress fractures in young adults. These fractures are usually seen in athletes, military recruits and patients with underlying metabolic diseases. The treatment of FNSFs is still controversial because of the inherent complications associated with the treatment procedure. We came across 4 cases of bilateral FNSFs in non-athletic individuals who were manual labourers without underlying bony disorders. Two patients with FNSFs and coxa vara deformity on both sides were managed by subtrochanteric valgus osteotomy and dynamic hip screw fixation. One of the remaining two patients was treated by cannulated cancellous screw fixation on one side and subtrochanteric valgus osteotomy on the other side. The fourth patient received subtrochanteric valgus osteotomy on one side and bipolar hemiarthroplasty on the other side after failed cannulated screw fixation. All the fractures healed without any complications. No evidence of avascular necrosis or arthritis was noted in our series. Subtrochanteric valgus osteotomy restores normal neck-shaft angle in patients suffering from FNSFs combined with coxa vara deformity. Moreover, it helps to bring the forces acting around the hip to normal biomechanical levels, leading to fracture union and better results. Replacement arthroplasty is recommended to patients who fail to achieve bony union after fixation.

Multicentric osteosarcoma

Multicentric osteosarcoma is a rare type of osteosarcoma with a poor prognosis. It is usually described as the occurrence of tumorous lesions in more than one bone, but without pulmonary metastasis. It may be of a synchronous or metachronous variety. We report the case of a 12-year-old boy with a synchronous variety of multicentric osteosarcoma, although he did not have any risk factors for the disease. We also discuss the current debate on whether multicentric osteosarcoma represents multiple primary tumours or metastatic disease.