A biomechanical comparison of three fixation techniques in osteoporotic reverse oblique intertrochanteric femur fracture with fragmented lateral cortex.

Abstract

The treatment of the reverse oblique osteoporotic femur fractures is still problematic and can be complicated especially that are accompanied by a fragmented lateral cortex. The aim of this study was to compare three different internal fixation methods in the osteosynthesis of osteoporotic reverse oblique intertrochanteric femur fracture models with a fragmented lateral cortex. Biomechanical experiment study. A total of 24 osteoporotic femur models were obtained and divided into three groups [Group A: Proximal femoral nail(PFN), Group B: 95° angled blade plate (ABP), and Group C: proximal femoral anatomic locking plate (PFLP)] with each group which include eight bones. A standard fracture configuration was created as a reverse oblique intertrochanteric fracture and fixed with these implants. After fixation, all femur constructs were tested with an Instron 5800R tester (Instron, Canton, MA) in the biomechanics laboratory with axial loading and bending forces to assess axial and rotational stiffness and failure load. Displacement over 10mm and angulation greater than 10° in the fracture line were considered as failure. In all tests, ABP had statistically poorer results in comparison to the PFN and PFLP group. PFLP fixation had better biomechanical fixation results in comparison to the PFN group, although the results were not statistically significant. Orthopaedic surgeons should keep in mind that lateral cortex comminution brings further instability to these reverse oblique intertrochanteric osteoporotic fractures and high rates of failure may be encountered due to this instability. PFLP fixation may be an alternative fixation method biomechanically for these instable fractures.