Early Advanced Weight Bearing for Peri-articular Knee and Pilon Injuries

Inclusion Criteria: * Ages 18-55 * Closed or Open (Gustilo Type I, II or IIIA) fractures: Distal femur (AO/OTA 33B, 33C), tibial plateau (AO/OTA 41B, 41C), or Distal tibia/pilon (AO/OTA 43B, 43C) * Definitively treated with a plate * Ambulatory prior to injury * Able to participate in rehab starting 28 days after definitive fixation * Meets AlterG requirements (4'8- 6'4; 85-400lbs) Exclusion Criteria: * Medical or psychological disease that would preclude safe functional testing (e.g., severe traumatic brain injury, stroke, heart disease, etc.) * Prior joint trauma or disease of the operative extremity that resulted in pain, stiffness, or other limitation to mobility * Injury to the contra-lateral limb, upper extremities or axial skeleton that would influence single limb weight-bearing or use of an assistive device * Pregnancy * Unable to speak English * Severe problems with maintaining follow-up (e.g. patients who are prisoners, homeless at the time of injury, who are intellectually challenged without adequate family support, or have documented psychiatric disorders). * Unable to provide informed consent.