Comparative study to measure femoral malrotation in inter-trochanteric femur fracture done by conventional and fluoroscopic method

Abstract

: Rotational malalignment following intramedullary nailing in intertrochanteric femur fractures is an under recognized complication. The incidence is varied from 17 to 35% as per literature. In this study we used intraoperative fluoroscopic method to assess anteversion angle, incidence of malalignment and to check whether intraoperative fluoroscopy is useful to reduce incidence of rotational malalignment or not. Twenty patients of intertrochanteric femur fracture who presented to hospital between 1 October 2019 to 30 September 2020 were divided in two groups of 10 patients each. Group 1 was operated with intraoperative fluoroscopic method and group 2 operated by conventional method of intramedullary nailing. Alignment measured as angle of anteversion by post-operative CT scan and comparison between two groups was done.: The incidence of rotational malalignment was 15%. Three patients had significant difference of 15° in anteversion angle compared to opposite normal femur. All these three malalignments were seen in the fluoroscopic group 1 and had unstable fracture patterns. Unstable fracture patterns are at increased risk of rotational malalignment. In intra operative fluoroscopic method distal femur posterior condylar axis is taken in to consideration. Most of the elderly people have some degree of fixed flexion deformity of the knee due to arthritic changes. This requires more internal rotation to achieve straight posterior condylar axis. This may be the reason for internal rotation malalignment in the fluoroscopic method.