Comparing Weight Bearing After Intramedullary Fixation Devices for the Proximal Femur Fracture

Prospective Randomized Trial Comparing the Weight Bearing After Fixation of Proximal Femur Fractures With Two Different Proximal Intramedullary Devices

The purpose of the study is to Compare the stability of the fracture and pain after surgery by measuring the stride length and weight bearing on the operated leg. This study will compare these parameters between two different proximal femur nails used for fixing hip fractures.

Fractures of the proximal femur and hip are relatively common injuries in adults.

According to the Evans and the AO Classification systems, the fracture can be described as stable after reduction or not according to the direction of the fracture lines and the comminution of the medial cortex or the lateral wall of the proximal femur.

Biomechanically, nails allow for stable anatomical fixation of more comminuted fractures without shortening the abductor moment arm or changing the proximal femoral anatomy. These devices provide fracture stability by virtue of allowing the lateral aspect of the head and neck to come to rest against the nail in the medullary canal.

For fractures with comminuted medial cortex or involvement of the lateral cortex (AO 2.2 - AO 3.3) it is advisable to fixate with a more stable fixation device such as intramedullary proximal femur nail Several intramedullary devices are currently in use for the treatment of the intertrochanteric fractures. In our institution, for the unstable fracture we use either one of the intramedullary devices manufactured by Synthes (Proximal femoral nail - anti-rotation = PFNA) or by Smith&Nephew (Trochanteric Antegrade Nail = InterTan).

Each of these nails allow compression over the Nail\Blade with the intramedullary stability.

There are 3 main complications in the treatment of intramedullary devices : (1) varus collapse of the head/neck, (2) uncontrolled shortening of the neck, and (3)femoral shaft fractures at the tip of the nail The InterTan, unlike other devices, allows for immediate intraoperative compression of the principal fracture fragments through linear compression combined with rotational stability secondary to its unique geometry and mechanism of action.

The mechanical stability of the fracture after the fixation is reflected by the weight bearing the patient can hold . In order to find weather there is a mechanical difference between the two devices we would like to perform a test measuring the weight bearing after fixation of intertrochanteric fractures comparing the pain and impression of mechanical stability in the two devices.

The method to test the amount of weight bearing would be using the "SmartStep gait system" TM (Andante Medical Devices Ltd), an innovative biofeedback and monitoring system that records and analyzes key gait parameters and provides instantaneous and accurate audio and visual feedback.

Inclusion Criteria:

• pertrochanteric fracture ao 2.2 and above
• ambulatory patient, without support prior to the fall
• minor trauma mechanism
• without other injuries
• operated 3 days from the injury

Exclusion Criteria:

• dementia
• s/p hip or knee arthroplasty
• known osteoarthritis