BACKGROUND AND SIGNIFICANCE. Musculoskeletal injuries are among the most common and disabling conditions affecting adults in the United States of America1, and our military population is no exception. Functional limitations may result from chronic pain, muscle weakness and nerve injuries leading to substantial direct and indirect healthcare costs6-8. The RTR clinical pathway was originally created at Brooke Army Medical Center in order to address the needs of the combat wounded limb salvage population9,10 . These highly motivated patients were frustrated by the slow pace of recovery and rehabilitation after severe limb threatening injury, and were further disheartened when witnessing their amputee peers progressing through their rehabilitation quickly and with apparently fewer setbacks. As a result, there were many requests for delayed amputation of a reconstructed limb in the hopes of improving functional performance. The RTR combines a custom, carbon fiber energy storage and return ankle foot orthosis, the IDEO, with a high-intensity, sports-medicine based rehabilitation program. After initiation of the RTR clinical pathway, improvements in overall physical function were readily apparent, with many patients returning to recreational sports and even running11. Preliminary research demonstrated significant improvements in functional performance in these limb salvage Soldiers after completion of the RTR clinical pathway, along with a decrease in the rate of requests for delayed amputation12. However, at this time the only evidence exists on military patients. This is the first attempt to explore the impact of the CUSTOMIZED EXOSKELETAL ORTHOSIS and the RTP in the civilian population.

The natural history of severe lower extremity injury is disheartening. In the largest study of such injuries to date (the Lower Extremity Assessment Project, LEAP), all patients were found to be severely disabled at 2 and 7 years after injury13,14. This was regardless of treatment with amputation or limb salvage. In both groups, only 50% of patients had been able to return to work at 2 years. Additionally, functional outcomes were found to have worsened at 7 years after injury. There was no standardized rehabilitation program, and the use of orthotics was not standardized in this research. Although many factors were similar between the groups, one major difference was found in the cost of treatment. When the price of prosthetics were included in the analysis, the lifetime costs of amputation were three times greater than those of limb reconstruction15. Although the LEAP study group did not include active duty military patients (this was a specific exclusion criteria), we can reasonably assume that: (1) these are severely disabling injuries, (2) in the absence of standardized rehabilitation they do not improve with time, and (3) the costs of amputation are substantial when compared to limb salvage.

Although physical therapy is frequently recommended after musculoskeletal injury and treatment, standardized protocols are lackingl10,16. There is currently no "gold standard" rehabilitation program for patients who have sustained lower extremity injuries as a whole, or for specific injury patterns. Consequently, there is no accepted protocol against which to compare our current program in a randomized fashion.

Validated measures of functional assessment, as well as patient-based outcomes have been developed for this patient population. The Short Form 12 (SF-12), and Short Musculoskeletal Function Assessment (SMFA) have been extensively validated for use in musculoskeletal research17,18. The functional measures tested in this protocol have also been validated on a healthy, uninjured active duty population.