Reverse distal femoral locking compression plate (DF-LCP), does it fit and how to fit on Asian's proximal femurs? A cadaveric study.

Abstract

Reverse distal femoral locking compression plates (DF-LCP) have been used as an alternative treatment in complex proximal femur fractures. The purpose of this study was to assess the compatibility of reverse DF-LCP with Asian proximal femurs, to determine the matching patterns and integrate information to establish guidelines for correct application. Twenty-eight adult cadaveric femurs were obtained from 5 males and 9 females with an average age of 69.27years (range 59-85). A contralateral 13-hole DF-LCP was applied with MIPO technique using the vastus ridge as a landmark for Hole A. The first locking screw was inserted through Hole A under fluoroscopic guidance just above the femoral head-neck junction in AP view and centered of the neck in lateral view, followed by three proximal locking screws. The number of screws successfully inserted through the femoral neck, including any penetration of femoral neck, the gap between anterior and posterior borders between plate and bone, the anatomical parameters of proximal femur, and any mismatches between the plate and the bone were recorded. Most of the screws (82.1%) in Holes A, D, E, and F were put into the femoral neck without breaking through. The average distance from the entry point at the vastus ridge to the anterior cortex of the femur was 17.3 ± 2.3mm and from the posterior cortex was 19.46 ± 2.55mm. The anterior gap was 4.93 ± 1.01mm, and the posterior gap was 13.48 ± 1.44mm. The mismatch where the distal part of the plate started to lift off from the bone > 2mm at the 8th hole with an average distance of 2.78 ± 2.01 mm. That distance gradually increased distally to an average of 9.38 ± 6.03mm at the 13th hole. Reverse DF-LCP can fit most proximal femurs in the Asian population and can be used as an alternative implant when performed using an appropriate technique. However, as a relatively consistent mismatch was found at the distal part starting at the 8th hole, so if a plate is longer than 9 holes, the plate contouring should be considered.