Atypical Subtrochanteric Fracture Through a Cephalomedullary Implant: A Case Report.

Abstract

Intramedullary nails are the standard of care for treating diaphyseal femoral shaft fractures1. Advantages over plate osteosynthesis include less invasive application and earlier weight-bearing2. Cephalomedullary nails have expanded the application of intramedullary nails to include peritrochanteric fractures3, and they have been useful for prophylactic fixation of impending pathologic fractures4-8 and concomitant ipsilateral femoral neck and shaft fractures9. There is burgeoning interest in the use of cephalomedullary nails to treat diaphyseal femoral fractures in osteopenic patients prone to peritrochanteric fractures10 and for patients with atypical subtrochanteric fractures secondary to bisphosphonate use. Proponents of these applications theorize that cephalomedullary fixation treats undetected femoral neck fractures and may protect the femoral neck11 and peritrochanteric region from fracture7,8,12. Here, we report a case of an atypical subtrochanteric femoral fracture that presented months after a midshaft fracture had been treated with a cephalomedullary nail in the ipsilateral femur. Although the femoral fracture had healed, the implant and bone failed at the location of the subtrochanteric fracture after a low-energy fall. While implant failure in the presence of mal-reduction or osseous nonunion is a well-recognized phenomenon13, to our knowledge, subtrochanteric fracture and cephalomedullary implant failure after a low-energy fall have not been reported to occur proximal to the site of a healed diaphyseal fracture. The patient was informed that data concerning the case would be submitted for publication, and she provided consent. An eighty-one-year-old Southeast Asian woman (height, 157.5 cm; weight, 59.8 kg) sustained a right diaphyseal femoral fracture (AO/OTA classification, 32-A2) after a ground-level fall (Figs. 1-A and 1-B). Past medical history included coronary artery disease, hyperlipidemia, hypertension secondary to renal artery stenosis, and osteopenia verified by a bone density scan (spine T-score of …