Efficacy of an aiming device for the placement of distal interlocking screws in trochanteric fixation nailing

Locked intramedullary nailing continues to be the surgical treatment of choice for most long bone fractures. Performing distal interlocks can be a technical challenge. Free hand (FH) technique remains to be most popular. Radiation exposure, particularly to the surgeon still remains a concern with this technique.

A prospective randomized analysis of 20 patients undergoing operative fixation with long trochanteric fixation nailing for intertrochanteric or subtrochanteric fractures was performed. The groups were randomized into (1) aiming arm group (AA) and (2) FH group by computer generated randomization technique. Two distal interlocking screws were placed in every case. Various parameters were analyzed including total operating time, distal interlocking time, total fluoroscopy time, distal fluoroscopy time and nail dimensions. The variables in two groups were compared to each other using Fischer's exact test.

The mean distal interlock time was 7.1 +/- 2.4 and 12.1 +/- 3.2 min for AA and FH techniques respectively. There was a 41.3% decrease in the distal interlock time with the device, which was statistically significant (P < 0.001). The distal interlock fluoroscopy time was 9.2 +/- 4.9 and 28.9 +/- 16.4 s with AA technique and the FH technique respectively. This 68.2% reduction in time taken for distal fluoroscopy was statistically significant (P < 0.001). However, the reduction in the total fluoroscopy time was statistically not significant.

The AA is very efficient and user friendly and also reduces the radiation exposure.