Session II - Femur

Thurs., 10/5/06 Femur, Paper #8, 3:42 pm

Factors Affecting Postoperative Alignment of Subtrochanteric Femur Fractures

Thomas A. Russell, MD (e-Smith+Nephew); Hassan R. Mir, MD (n);
Jason Stoneback, BS (n); Brandon H. Downs, MD (n); Jose Cohen, MD (n);
Campbell Clinic/University of Tennessee Department of Orthopaedic Surgery, University of Tennessee College of Medicine, Memphis, Tennessee, USA

Purpose: Interlocking intramedullary nailing is the standard of care for treatment of many fractures of the proximal third of the femur. While the healing rates have been quite acceptable, higher rates of malalignment have been consistently reported for subtrochanteric fractures when compared with diaphyseal fractures. The purpose of this study was to determine the rate of malalignment in subtrochanteric femur fractures treated with intramedullary nails at out institution, and to determine differences based on several factors. The factors that we examined were use of the channel reamer, surgical position, entry portal, mechanism of injury (high- versus low-energy), Russell-Taylor classification, OTA classification, open versus closed fractures, open versus closed reduction, and type of implant used.

Methods: Between June 2003 and July 2005, 102 consecutive subtrochanteric femur fractures (99 patients) were treated with intramedullary nails. The Russell-Taylor and the OTA classification were used to identify fracture types. Fracture reduction was examined on the postoperative anteroposterior and lateral films with the use of a goniometer to determine angulation in the coronal and sagittal planes. Criteria for acceptable reduction were as previously reported in the literature, with angulation at the fracture of more than 5° degrees in any plane considered malalignment.

Results: The incidence of malalignment in our study was 9.8% for the 102 fractures. Malalignment of fractures treated without use of the channel reamer was 24%, decreasing to 5.2% when the channel reamer was used (P <0.01). There was not a statistically significant difference between the different Russell-Taylor fracture types, although there was a trend towards more malalignment in type 2A and 2B fractures (P = 0.13). None of the other factors studied had a statistically significant effect on malalignment. We also performed a whole model test on the factors that are surgeon-controlled (use of the channel reamer, surgical position, open versus closed reduction, type of implant used, and entry portal), and the only factor that had a statistically significant effect on malalignment was use of the channel reamer (P <0.01).

Conclusions/Significance: The incidence of malalignment in the overall study was significantly lower than that shown in any other study in the current literature. We feel that the concepts of trajectory control and entry portal protection help to provide this improvement in the rate of malalignment by preventing eccentric reaming and the resultant degradation of the integrity of the starting portal.

If noted, the author indicates something of value received. The codes are identified as a-research or institutional support; b-miscellaneous funding; c-royalties; d-stock options; e-consultant or employee; n-no conflicts disclosed, and *disclosure not available at time of printing.
· The FDA has not cleared this drug and/or medical device for the use described in this presentation (i.e., the drug or medical device is being discussed for an "off label" use). · · FDA information not available at time of printing.