MANAGEMENT OF PROXIMAL FEMUR FRACTURES

Abstract

Proximal femur fractures are usually low-energy injuries of elderly patients, but they can also occur after highenergy trauma in young adults and children. The proximal femur shows very special biomechanical (high load) and biological (blood supply) characteristics. These factors, the patient’s age, and the implant characteristics (weight bearing capacity and cut out risk) are determinants for the surgical management of proximal femur fractures.

There are two main fracture groups that require a different approach because of the difference in blood supply: 1) medial femoral neck fractures and 2) lateral femoral neck, trochanteric, and subtrochanteric fractures.

Medial femoral neck fractures occur in about 90% of dislocated adduction fractures. Because of the high risk of pseudarthrosis and head necrosis (~30 %) in older patients, a hip joint prosthesis should be used. A total hip prosthesis is used (mainly cementless) for patients in good biological condition; in elderly patients (> 80 Y.) a hemiarthroplasty is performed. Because prospective studies have not shown any benefit for bipolar hemiarthroplasty, we use a unipolar hemiarthroplasty.

In non-dislocated fractures of the elderly and in all medial femoral neck fractures in younger patients, a joint-preserving osteosynthesis is used. The most used therapy is three canulated screws. Because of implantrelated complications (dislocation, cut out) particularly in steep fracture lines, comminution zones, and noncompliant patients, a stabler fixation with an intramedullary device should be used. We prefer the gliding nail because of the rotation stability and minimal cut out risk of the I-beam profile femoral neck component.

Lateral femoral neck, trochanteric, and subtrochanteric fractures have a minimal risk of femoral head necrosis. Intramedullary locked nail systems such as the gliding nail and gamma nail have a much lower bending movement and therefore allow full weight bearing in all types of fractures. The gliding nail also gives rotation stability to the head and neck fragment in unstable fractures because of the I-beam-profile of the femoral neck component, and has an over 50% reduced cut out risk as compared to screw profiles.

Extramedullary implants like the DHS do not allow full weight bearing in unstable trochanteric fractures and are unsatisfactory in subtrochanteric fractures. They can be safely used only in stable fractures. Prostheses should not be used in primary management of trochanteric fractures because of the very low re-operation rate in modern intramedullary implants (< 4 %). The operation time, possible late complication, blood loss, and costs are higher for a hip prosthesis.