Development of intraoperative fluoroscopic protocols to avoid rotational malalignment during nailing of femoral fractures: a step-by-step guideline using the lesser trochanter profile or true lateral view.

Abstract

Rotational malalignment (≥ 15°) occurs in up to 35% of femoral fractures after intramedullary nailing, and standardized fluoroscopy protocols to prevent malrotation are lacking. We developed and evaluated two easy-to-use intraoperative fluoroscopy techniques to reduce malrotation. A human specimen study was performed to compare two standardized fluoroscopy protocols-the lesser trochanter profile and the true lateral view-with current clinical practice. A mid-shaft femoral fracture was created in a full-body cadaver, and an unlocked intramedullary nail was inserted. Random degrees of rotational malalignment were applied using a goniometer and reference wires at the fracture site. Ten physicians (consultants and residents) first estimated malrotation and then performed 150 rotational corrections: 50 according to (unstandardized) clinical practice, 50 using the lesser trochanter profile, and 50 using the true lateral view. The primary outcome was rotational malalignment, measured using reference wires at the fracture site. Clinicians' visual estimation deviated 15.5° [IQR 18.5-12.0] from actual malrotation. Corrections using unstandardized methods resulted in 12.5° [IQR 18.2-6.1] of malrotation. In contrast, the lesser trochanter and true lateral protocols reduced malrotation to 3.9° [6.8-2.1] and 3.6° [8.6-1.4], respectively. Both were significantly more accurate than current practice (p = 0.009 and p = 0.017). Surgeons favoured the lesser trochanter profile for its efficiency, ease-to-use, and minimal need for C-arm repositioning. This study introduces two step-by-step standardized fluoroscopy protocols to prevent rotational malalignment in femoral nailing. Both outperform traditional, unstandardized correction methods, with the lesser trochanter profile offering a more practical and time-efficient option for intraoperative use.