Extramedullary skeletal traction for intramedullary femoral nailing

Summary: The through-and-through forms of femoral skeletal traction that are often used during intramedullary nailing for femur fractures can present two problems: (a) impingement with the intramedullary nail, requiring repositioning of the traction pin intraoperatively under radiographic control, to a position that may not optimally control the fracture; and (b) the risk of contaminating the intramedullary canal that will soon contain the metallic fixation device, especially when placed in the emergency room or at the bedside. Two new forms of extramedullary skeletal femoral traction are presented. The pullout strength and optimal positioning of these devices on the distal femur were evaluated. The first form of extramedullary traction evaluated was the large AO/ASIF pinless clamp. The second form of extramedullary traction, the extramedullary skeletal clamp, was based on a modification of the Gardner-Wells tong. These two forms of skeletal traction were compared with standard ten-sioned Kirschner wire (K-wire) through-and-through traction. Six fresh-frozen distal femora from donors (average age 29 years) were used to test the three femoral traction devices. Five of these specimens were skeletally mature. A total of 38 pullout tests were conducted. The pullout strength of the tested devices was in the following descending order: (a) tensioned K-wire; (b) extramedullary skeletal clamp (in the optimal metadiaphyseal position, 77% the strength of the K-wire); and (c) large ASIF pinless clamp (in the optimal metaphyseal position, 46% the strength of the K-wire). The mode of failure for each device was cut-out through or from the bone. The latter two values were significantly less (p 0.05) than were those with the K-wire. A surgeon may find these extramedullary traction devices helpful, to prevent impingement with the intramedullary nail, which can occur with a through-and-through traction device. Another potential clinical application of these extramedullary devices is in cases where distal femoral traction is favorable to proximal tibial traction, but there is fear of inoculating the femoral canal. Other examples include fractures where more direct control of the distal fragment is needed or where ligamentous damage to the knee has occurred. However, clinical trials testing the efficacy of these extramedullary devices are required before recommending their use.