Intraoperative Measurement of Tibial Rotation With Lateral Axis Views Using C-arm for Tibial Fractures

Malrotation of tibial fractures after intramedullary nailing remains an unsolved problem. The incidence of malrotation >10(degrees) on computer tomography (CT) measurements has been high in cases of tibial shaft fractures. We aimed to assess the accuracy of a novel method for the measurement of tibial rotation using lateral axis views of the C-arm, to prevent postoperative malrotation. Consecutive patients with fresh tibial fractures treated by intramedullary nailing between January 2021 and December 2022 were included prospectively. Baseline tibial external rotation (TER) was measured preoperatively on the non-injured normal side with CT. After proximal or distal screw fixation, the C-arm TER was measured based on lateral axis views (tibial posterior condylar axis and bimalleolar axis views). The C-arm TER was compared with the normal-side CT TER; when the difference was <= 5(degrees), the procedure progressed, and screw fixation was carried out. The fractured-side CT TER was measured one week post-operatively. Twenty patients (13 males and seven females) were included. The mean age was 52.4 years. The Orthopaedic Trauma Association (OTA) classification was 42A in five patients, 42B in twelve patients, and 42C in three patients. The mean difference between C-arm TER and fractured-side CT TER was 2.3(degrees)+/- 1.7(degrees), with Pearson correlation coefficient r=0.968. The mean difference between normal-side CT TER and fractured-side CT TER was 4.8(degrees)+/- 2.8(degrees), and there was no incidence of malrotation >10(degrees). The C-arm method was highly accurate in estimating CT measurements and preventing tibial malrotation.