Session V - Femur
The Success of Exchanged Reamed Intramedullary Nailing for Femoral Shaft Nonunions
David J. Hak, MD; Stanley S. Lee, MD, James A. Goulet, MD; University of Michigan, Ann Arbor, MI
Purpose: Success rates greater than 90% have been reported for treatment of femoral nonunions by exchange reamed nailing. In contrast, a recent study reported a 47% failure rate of exchange reamed femoral nailing.1 The current study attempts to investigate the recent discrepancy in the union rate and to analyze factors that may contribute to failure of exchange reamed femoral nailing.
Methods: We conducted a retrospective study of 23 consecutive patients with femoral diaphyseal nonunions treated with exchange reamed femoral nailing from 1989 to 1997. Factors reviewed for each patient were age, gender, smoking history, mechanism of injury, associated injuries, closed versus open fracture, classification of femur fracture, type of nonunion, increase in intramedullary nail diameter, use of proximal and distal interlock screws, and intraoperative culture results. The average age was 33 years (range 17-68). Six injuries were open fractures. Fourteen of the patients smoked cigarettes. The average number of procedures before nail exchange was 1.25. The average increase in diameter from the original nail to the exchange nail was 2.0 mm. Both proximal and distal interlocking screws were placed in 15 patients. In seven patients the nonunion was dynamically interlocked using only proximal or distal interlocking screws. One patient was not interlocked.
Results: Eighteen of the 23 patients (78 %) healed their femoral nonunions without additional procedures. Two patients achieved union with additional procedures (one following a bone graft and one following repeat exchange reamed nailing). Of the five patients that failed to unite following exchange nailing, all were cigarette smokers and all had atrophic nonunions. Each of the failures had an injury that predisposed the fracture site to significant devascularization. An infection was documented by positive intraoperative cultures in three cases, and all successfully healed following exchange reamed nailing.
Discussion: The incidence of nonunions following intramedullary nailing of diaphyseal femoral fractures is low. Historically many of these nonunions may have been due to technical errors and implant limitations. Nonunions occurring today using contemporary intramedullary nailing techniques may be more challenging to successfully treat. Nonunion patterns which are rotationally unstable likely benefit from locking both proximally and distally. Compression should be applied to the nonunion site prior to static interlocking or by using a dynamic interlocking nail.
Conclusions: Exchange reamed nailing remains the preferred method of treatment for nonunions following femoral nailing, resulting in successful union in 18 of 23 patients in this series.
1. Weresh MJ, Hakanson R, Stover M, Sims SH, Kellam JF, and Bosse MJ. The Failure of Reamed Intramedullary Nailing for Aseptic Ununited Femoral Shaft Fractures. Presented at Orthopaedic Trauma Association, Louisville, Kentucky, October 19, 1997.