It is well documented that restricted weight bearing even for relatively short periods (12 weeks) associated with the surgical treatment of peri-articular injuries of the lower extremity (ie acetabulum, distal femur, tibial plateau, pilon, talus, calcaneus) can lead to a measurable decrease in bone density in the injured limb. Furthermore, this osteopenia can persist for extended periods of time - much longer than the original period of restricted weight bearing. This relative osteopenia can delay recovery from injury, lower fracture threshold for subsequent injury and potentially delay return to active duty in the case of a wounded warrior. There exists a significant body of research in the modulation of the osteopenia associated with restricted weight bearing as it pertains to long term space flight (microgravity).