Femoral malrotation after unreamed intramedullary nailing: an evaluation of influencing operative factors.

OBJECTIVE

The objective of this study was to determine which clinical factors influence the presence and extent of femoral malrotation during unreamed nail insertion performed without a fracture table.

DESIGN

Retrospective chart review.

SETTING

Academic trauma center.

INTERVENTION

Patients were treated statically locked femoral nails inserted without reaming in either a retrograde or antegrade manner without the use of a fracture table between April 1, 2000, and December 31, 2005. All patients received postoperative computed tomography scans. Institutional radiographic threshold for revision surgery was 15° of either internal or external rotation.

MAIN OUTCOME MEASUREMENTS

Postoperative computed tomography measurements of rotation were compared with the opposite side. Patients were grouped by 1) Orthopaedic Trauma Association fracture classification; 2) closed versus mini open reduction; 3) surgeon experience; 4) antegrade versus retrograde femoral nail; and 5) time of day surgery performed (day shift versus night shift). The following parameters were measured from the chart and x-ray: rotational malalignment, x-ray time, and duration of surgery.

RESULTS

There were 82 femurs in 82 patients, 59 men and 23 women, with a mean age of 32 years (range, 17-83 years). Eighteen femurs (22%) showed a malrotation of greater than 15°. Seven were internally malrotated (mean, 23°; range 16°-32°), whereas 11 were externally malrotated (mean, 24.2°; range, 16°-39.7°). After clinical examination, only 11 of the 18 patients (61%) underwent revision surgery, six patients for external malrotation (mean, 27.47°; range, 21.9°-39.7°) and five for internal malrotation (mean, 23.6°; range, 16°-32°). Malrotation varied significantly with fracture severity with Type C averaging 19.4° (24 patients), Type B 9° (26 patients), and Type A 6.6° (32 patients). No difference was found between an open and closed technique nor the experience of surgeon or the type of implant. There was a significant difference depending on the time of surgery in which an average malrotation of 15.2° (14 patients) was found on the night shift and an average malrotation of 10.3° (68 patients) was found during the day.

CONCLUSION

Rotational malalignment greater than 15° was found in 22% of femurs treated in this study. Fracture comminution and time of day the surgery was performed had the greatest effect on the severity of malrotation.