3D CT map of the femoral intertrochanteric fracture involving the posteromedial wall / 中华创伤骨科杂志

ABSTRACT

Objective@#To investigate the distribution characteristics of the fracture lines on the posteromedial wall by mapping the femoral intertrochanteric fractures involving the posteromedial wall on 3D CT.@*Methods@#A retrospective study was conducted of the 136 patients with femoral intertrochanteric fracture who had been treated at Department of Orthopaedics, Affiliated Hospital to Chengdu University from January 2009 to October 2018. They were 57 men and 79 women with an average age of 64 years (from 48 to 81 years). By the AO classification, 101 cases were type 31-A2 and 35 type 31-A3. Their CT data were collected for 3D reconstruction. By comparing the specific markers on the femoral shaft and lesser trochanter, the 3D CT reconstruction images were superimposed and orientated to the standard models of intertrochanteric posteromedial wall to create a map of the fracture. The width, height, area, and fracture deviation angle of the fracture of posteromedial wall were measured to characterize the distribution of the fracture lines.@*Results@#In the 136 femoral intertrochanteric fractures involving the posteromedial wall, the height of the posteromedial wall fracture was 48.76±4.11 mm, the width 29.78±3.29 mm, the area 1,468.47±75.26 mm2, and the fracture deviation angle 49.93°±13.05°. The fracture area ratio (fracture area/posteromedial wall area) was 38.34%±16.58%. On the map of the posteromedial wall fracture, the fracture lines were densely distributed in the lesser trochanter and in front of it. In the fractures of type 31-A2, the lines of the posteromedial wall fracture were mostly distributed in the lesser trochanter and below it, going obliquely from anterosuperior to posteroinferior to affect the lower calcar femorale. In the fractures of type 31-A3, the lines of the posteromedial wall fracture were mostly distributed in the lesser trochanter and above it, going obliquely from anteroinferior to posterosuperior to affect the upper calcar femorale.@*Conclusion@#The fracture map can help visual understanding of the intertrochanteric fracture involving the posteromedial wall, and provide further characterization of the posteromedial wall fracture in the fractures of AO types 31-A2 and 31-A3.