Determination of the effect on the proximal femoral load distribution of diaphyseal cement support in femoral intertrochanteric fractures with calcar defect by finite element analysis

Abstract

Objectives: This study aims to investigate biomechanically positive and negative aspects of arthroplasties in combination with diaphyseal cement support as an alternative to calcar supported prosthesis on the proximal femoral load distribution, using finite element analysis method in a virtual environment in intertrochanteric fractures with calcar femoral defect. Materials and methods: Three femur models were created using the ANSYS method. These were named as a intertrochanteric fracture model without calcar defect, an intertrochanteric fracture model with thick cement mantle and calcar defect, and an intertrochanteric fracture model with thin cement mantle and calcar defect. In the finite element analysis setting, two regions were analyzed for load distributions. The first one was the whole femur, while the other one was the region starting from trochanter minor and extending distally to the 5 cm area.
Results: In the trochanteric fracture model without calcar defect, the stress value in the whole femur was found to be 22.9 MPa; whereas it was 29.2 MPa in the 5 cm long section starting at the trochanter minor. The stress values were 23.6-29.9 MPa in the intertrochanteric fracture model with thick cement mantle and 24.2-32.1 MPa in the intertrochanteric fracture model with thin cement mantle and calcar defect. The statistical analysis was performed using t-test and a p value of >0.005 was found in all.
Conclusion: Our study results showed that forming a type of calcar to be used in a hemiarthroplasty surgery and shaping of this region with bone cement does not produce further stress on the cement/bone intersection in intertrochanteric fractures with defected calcar region.