Far Cortical Locking Versus Standard Constructs for Distal Femur Fractures

To determine if Far Cortical Locking screws increase fracture healing rates at 3 months in Closed Distal Femur Fractures in adults when compared to Standard screw constructs. Fracture healing at 3 months will be assessed via radiographic and clinical assessment of the fracture. Null Hypothesis: There will be no difference in fracture healing at 3 months post-fixation between subjects treated with far cortical locking screw or standard screw fixation.

A multicentre randomized controlled trial with a sample size of 138 subjects. Primary Outcome is fracture healing at 3 months via radiographic and and clinical assessment. Radiographic healing will be defined as bridging of one or more cortices as seen on x-ray. Radiographic assessment will be centrally adjudicated by a committee of three study investigators. Clinical healing will be assessed using the Function Index for Trauma (FIX-IT). Secondary outcome measurements will include patient-reported quality of life and CT quantification of fracture callus volume. Quality of life will be measured with the Short-Form 36 Version 2 (SF-36) instrument at all follow-up intervals. A CT scan of the fracture site will be performed at the 3 month follow-up. Using a quantitative protocol the volume of callus will be measured and the extent of cortical bridging will be assessed. Additional secondary outcomes include radiographic and clinical healing, as well as patient-important complications. These will include adverse events, delayed union (\>6 months), non union (failure for fracture healing to progress on serial x-rays between 6 and 9 months), malalignment (\>5 degrees), hardware failure, infection, and reoperation. Information surrounding the type of complication, duration, management and/or treatment of all complications will be recorded A Data Safety Monitoring Board will be established to independently monitor trial data. Specific inclusion criteria: * Men or women ages 18 years or older * Displaced distal femur fracture (OTA 33A or 33C) as seen in radiographs * Planned treatment using a distal femur locking plate * Ability to read and speak English or availability of translator willing to assist with completion of study forms * Fractures \< 14 days post injury * Provision of informed consent Specific exclusion criteria: * Open distal femur fracture requiring flap or vascular repair (grade 3b or 3c) * Planned fixation strategy includes interfragmentary lag fixation of non-articular fractures * Active local infection * Limited life expectancy due to significant medical co-morbidity or medical contraindication to surgery * Inability to comply with rehabilitation or form completion * Likely problems, in the judgment of the investigators, with maintaining follow-up (i.e. patients with no fixed address, patients not mentally competent to give consent, etc.) * Non-ambulatory patients * Lack of bone substance or poor bone quality which, in the surgeon's judgment, makes locked plate fixation impossible * Periprosthetic fractures * Any concomitant lower-extremity injury that requires non-weight-bearing beyond 6 weeks post-operative * Addition of bone graft, bone graft substitute or BMP * Pregnant women