This study follows the Pilot Investigation of Ewing Amputation for Veterans with PAD Undergoing a Below Knee Amputation. The 2 year pilot feasibility phase has concluded recruitment and enrollment.

The current phase is a 5 year randomized study of Ewing Below Knee Amputation vs. Standard Below Knee Amputation. If Veterans participate, they will be randomized to either Ewing Amputation or Standard Below Knee Amputation.

The scientific premise motivating this proposal is that Ewing Amputation is a promising surgical technique that may improve walking metrics in dysvascular Veterans by providing a better residual limb and improving pain and balance.

In preparation of this proposal, we have formed multi-disciplinary surgical teams at each site, and we have been supported by a clinical trial planning meeting to garner the considerable expertise in rehabilitation and amputee assessment from VA and DOD experts to assist in the design of this proposal, testing the overall hypothesis that: Ewing Amputation can help Veterans walk.

Major amputations lead to significant challenges for Veterans and their loved ones. Thus, amputations and the care of amputees are a major focus of the VHA. Hence, the tripartite goals of the VHA Amputation System of Care (ASoC) are to: provide state of the art care, maximize health and independence, and to be the provider of choice for amputated Veterans. Veterans undergo ~1000 transtibial amputations (TTA) annually, making TTA a commonly performed operation in the VA. Almost all Veterans requiring TTA are dysvascular with peripheral artery disease (PAD) and/or diabetes. TTA is a safe operation with a low 30-day mortality rate, and ambulation with prosthesis rates are much better for TTA versus transfemoral amputations (TFA). Since ~50% of Veterans are satisfied with their ambulation after major amputation, improving ambulation is an important benchmark forward in the care of Veterans. Importantly, the lower ambulation rates in Veterans are attributed to modifiable sequelae of major amputation, including: slower wound healing9,10; chronic pain, imbalance, and falls. Excitingly, new techniques can improve pain and balance and may improve wound healing/prevent falls. Ewing amputation (EA) recreates the agonist-antagonist myoneural interface (AMI) maintaining muscle tension, proprioception and limiting fibrofatty muscle degeneration of muscle flaps. EA also creates regenerative peripheral neural interfaces (RPNI) to improve pain control. Thus, EA may have a significant benefit to Veterans undergoing TTA.

Inclusion Criteria:

• Veterans who have reasonable blood flow to heal a TTA (defined as palpable popliteal pulse or palpable femoral pulse with popliteal artery signal)
• Veterans with an expectation of participating in rehabilitation and resuming ambulation after amputation (defined by the Veteran interest, recent ambulation by the Veteran, ability to participate in physical therapy as deemed by the investigators' physical therapy team)
• Veterans who will be undergoing below knee amputation for reasons other than infection (uninfected patients) or Veterans who have had foot infection localized below the ankle (retinaculum uninfected) that has been adequately debrided and treated with appropriate antibiotic course.

Exclusion Criteria:

• Veterans with end-stage renal disease (ESRD)
• Veterans requiring major amputation due to infection that includes the ankle retinaculum
• Veterans deemed to have inadequate blood flow to heal a TTA
• Veterans who cannot participate in rehabilitation or are not expected to be able to ambulate with a prosthesis for any reason
• Veterans who were randomized for their other limb (to prevent Veteran from the possibility of having 2 different amputations)