Finite Element Analysis of Proximal Femoral Nail Anti-Rotation Blade Combined with Cerclage Wire Fixation for Osteoporotic Subtrochanteric Fracture

Osteoporosis is a type of systemic bone disease wherein the patient is highly vulnerable to bone fracture because of the decrease in bone density and quality, destruction of the bone microstructure, and an increase in the bone fragility. Most of the osteoporotic subtrochanteric fractures are unstable in nature, requiring the conservative treatment of a long-duration bed rest and traction; this condition is prone to complications resultant from extended bed rest, often leading to death. Presently, the preferred treatment is internal fixation, such as sliding hip screws, blade plates, locking compression plates, and femoral intramedullary nails [1-8]. Owing to its valuable biological properties, intramedullary nail can be used for the optimal fixation of subtrochanteric fractures [9-11]. Unless any contraindication exist, immediate tolerable weight-bearing activities may be allowed to patients with subtrochanteric femur fractures who have been treated with statically locked intramedullary nails [12]. Considering that the proximal femoral fracture occurs under the traction of the surrounding muscles, it is extremely challenging to perform precision reduction and fixation in the surgery. Inappropriate reduction and selection of internal fixation can easily lead to failure of internal fixation, resulting in complications such as lower limb shortening deformity, hip varus deformity, and nonunion of fracture. Presently, good outcomes have been reported with the use of PFNA combined with cerclage wire for the treatment of subtrochanteric fracture of the femur [13-15]. There are few studies to help decide whether PFNA should be combined with cerclage wire or used alone according the Seinsheimer classification of subtrochanteric fractures.