Corneas are usually transplanted within five days of donation, since they cannot be preserved much longer than that. However, sclera can be stored up to five years. As a neuro- surgeon who also performs spinal surgery, I am quite aware of the use of musculoskeletal tissue in transplantation, needed by more than 450,000 patients annually. Right here in our Ambulatory Treatment Center and the main operating rooms, our orthopaedic surgeons performed approximately 250 anterior cruciate ligament reconstructions last year. We are told that the number could be doubled or increased even more than that if only tissues were available.
Bone tissue is rendered acellular by freezing and processing, thus reducing immunogenicity.
Like sclera, these tissues can be stored up to five years. Bone grafts are used for total hip revision surgery, limb salvage and spinal fusions. Ligament repairs are done with donor tendons and ligaments. Neurosurgeons use fascia lata, pericardium and dura for dura repair. Cardiac surgeons need aortic and pulmonary homografts for repair of various disorders from congenital anomalies to valvular disease and aortic stenosis.