Radiological outcome and intraoperative evaluation of a computer-navigation system for femoral nailing: A retrospective cohort study

Aim: Intraoperative determinations of femoral antetorsion and leg length during fixation of femoral shaft fractures present a challenge. In femoral shaft fracture fixations, a computer-navigation system has shown promise in determining antetorsion and leg length discrepancies. This retrospective cohort study aimed to determine whether the use of computer navigation during femoral nailing procedures reduced postoperative femoral malrotation and leg length discrepancy, as well as the number of revision cases. We also sought to determine whether radiation exposure time was reduced when computer navigation was used. Materials and methods: Of 246 patients treated for femoral shaft fractures between 2004 and 2012, we selected those that received postoperative computed tomography for rotation and leg length control. We included 24 patients who received navigation-assisted treatments and 48 who received unassisted treatments, matched for age, sex, and fracture type. All patients were treated by femoral nailing. Results: The groups showed significant differences in the mean (standard deviation (SD) delay before surgery (navigation-assisted vs. unassisted groups: 8.5 +/- 3.2 vs. 5.2 +/- 5.8 days; P < 0.05) and surgery times (163.7 +/- 43.94 vs. 98.3 +/- 28.13 min; P < 0.001). The groups were significantly different in the mean (SD) radiation exposure time (4.43 +/- 1.35 vs. 3.73 +/- 1.5 min; P = 0.042), and were not significantly different in the postoperative femoral antetorsion difference (8.83 +/- 5.52 degrees vs. 12.4 +/- 9.2 degrees; P = 0.056), or in the postoperative length discrepancy (0.92 +/- 0.75 vs. 0.95 +/- 0.94 cm; P = 0.453). Four (16.7%) navigation-assisted and 15 (31.25%) unassisted surgeries got revision for torsion and/or length corrections. Conclusion: Our results showed that, compared to unassisted femoral surgery, the computer-navigation system did not improve postoperative results or reduce radiation exposure. In the future, improvements in handling and application could facilitate the workflow and may provide better postoperative results. Currently, computer navigation may provide advantages for complicated or sophisticated cases, such as complex three-dimensional deformity corrections. (C) 2014 Elsevier Ltd. All rights reserved.