EXTRAMEDULLARY SKELETAL TRACTION FOR INTRAMEDULLARY FEMORAL NAILING

The through-and-through forms of femoral skeletal traction that are of ten 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; a nd (b) the risk of contaminating the intramedullary canal that will so on contain the metallic fixation device, especially when placed in the emergency room or at the bedside. Two new forms of extramedullary ske letal 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 extrame dullary skeletal clamp, was based on a modification of the Gardner-Wel ls tong. These two forms of skeletal traction were compared with stand ard tensioned Kirschner wire (K-wire) through-and-through traction. Si x fresh-frozen distal femora from donors (average age 29 years) were u sed to test the three femoral traction devices. Five of these specimen s were skeletally mature. A total of 38 pullout tests were conducted. The pullout strength of the tested devices was in the following descen ding order: (a) tensioned K-wire; (b) extramedullary skeletal clamp (i n the optimal metadiaphyseal position, 77% the strength of the K-wire) : and (c) large ASIF pinless clamp (in the optimal metaphyseal positio n, 46% the strength of the K-wire). The mode of failure for each devic e was cut-out through or from the bone. The latter two values were sig nificantly less (p < 0.05) than were those with the K-wire. A surgeon may find these extramedullary traction devices helpful to prevent impi ngement with the intramedullary nail, which can occur with a through-a nd-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 inocul ating the femoral canal. Other examples include fractures where more d irect control of the distal fragment is needed or where ligamentous da mage to the knee has occur-red. However, clinical trials testing the e fficacy of these extramedullary devices are required before recommendi ng their use.