Vascularized Composite Allotransplantation of the Elbow Joint: A Cadaveric Study
Mitchell A Pet, MD1; Angelo B Lipira, MD2; Yusha Liu, MD3; Dennis Kao, MD3; Jason H Ko, MD4
1Medstar Union Memorial Hospital, Baltimore, MD, 2Plastic Surgery, Oregon Health Sciences University, Portland, OR, 3University of Washington, Seattle, WA, 4Division of Plastic and Reconstructive Surgery, Northwestern University, Chicago, IL
Surgical options for the unreconstructable elbow are limited to arthrodesis, total arthroplasty (TEA), or osteoarticular allograft reconstruction. Fusion leads to severely restricted function, and TEA requires a lifetime lifting restriction of 5-10 pounds. For young, high-demand patients, non-vascularized osteoarticular allografts is a reasonable alternative, but such procedures are associated with an unacceptably high rates of non-union, bone resorption, instability, and need for serial replacement. Vascularized allotransplantation of the elbow joint has the potential to mitigate these complications. In this study, we aim to demonstrate the anatomic feasibility of elbow joint transplantation by designing such a flap, and demonstrating its vascularity using contrast angiography.
Existing anatomical studies were used to design and harvest a vascularized elbow joint flap pedicled on the brachial vessels in 10 cadaveric arms. Diaphyseal blood supply is provided by three nutrient arteries, and periarticular supply arises from the various collateral arteries of the arm and recurrent arteries of the forearm. The brachialis and supinator, and their respective nerves, were included as functional muscles because of their intimate association with critical vasculature. Tendinous insertions of the biceps and triceps, as well as the flexor/pronator and extensor origins were preserved for repair in the transplant recipient. Both lateral arm and radial forearm flaps were preserved to aid in soft tissue inset as well as vascular/immunologic monitoring (Figure 1-2). Contrast CT and X-ray angiography of each dissected specimen was performed to assess the location of the nutrient vessels and assess flap vascularity, as indicated by filling of the critical extraosseous and endosteal vessels.
Angiographic imaging 10 specimens demonstrated that this flap dissection preserves the nutrient endosteal supply to the humeral, radial and ulnar diaphysis (Figures 3-6), in addition to the critical extraosseous arterial structures perfusing the elbow joint and peri-articular tissues. From proximal to distal, these arteries are: the musculoperiosteal radial, posterior branch of the radial collateral, inferior ulnar collateral, recurrent interosseous, radial recurrent, and the anterior and the posterior ulnar recurrent.]
Vascularized composite allotransplantation of the elbow joint holds promise as a motion and function preserving option for young, high demand patients with a sensate and functional hand, who would otherwise be limited by the restrictions of total elbow arthroplasty or fusion. In this study we propose a flap design and technique for harvest, and also offered vascular-imaging based evidence that this flap is adequately vascularized.
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