belstaff espana ldl ves gjaw jns

asbryobvrz · Wysłany: Wto 20:34, 08 Mar 2011

Deep-frozen allogeneic tendon graft histological and biomechanical study

Preservation methods with deep freezing method, freeze-drying method, chemical treatment method. Either save the method, the goal is to reduce antigenicity, to maintain the integrity of graft material to ensure sterility. Deep-freezing method is better to meet this standard. Domestic and foreign large number of experimental and clinical studies have shown that deep-freezing method does reduce the antigenicity of tendon J. Achilles tendon allograft in the experiment, histological examination after transplantation of autologous Achilles tendon with no significant difference, no obvious immune rejection, but also evidence of reduced antigenicity. Autologous tendon and tendon allograft, as in the transplant to go through a healing process,[link widoczny dla zalogowanych], including the anastomotic connection, tendon revascularization, new collagen production and decomposition of old collagen, stress and other steps in shaping J. After shaping period, the allograft tendon in histology and biomechanics of normal tendon will be no significant difference. Drez goats and other animal models also show the first 12 weeks of tendon allograft has revascularization can be achieved within 26 weeks prior to their replacement tissue function, and the self healing process of tendon similar. In this study, the transplant process, the allogeneic tendon and tendon tissue from the body compared to the performance of the cell response is a bit heavier, larger amount of new collagen, arranged in a little disorder, tendon bundles within a small area of focal necrosis. However, the period after transplantation, the activities of the posterior limbs of rabbits range, muscle strength, tendon continuity was no significant difference at 8 weeks the surface of the tendon allograft vascular network has been set with the self same arrangement of collagen fibers within the tendon bundles rules, and also the anastomosis as autologous tendon. So the authors believe that autologous tendon allograft tendon and experienced broadly similar healing process. Application to be considered when the tendon graft mechanical properties. This experiment was measured using a 75 ℃ treatment of deep frozen and fresh Achilles tendon allograft compared to no significant difference in the mechanical properties,[link widoczny dla zalogowanych], which defined the l886 Cryopreservation does not alter the mechanical properties of tendons. This study also shows 2,4,8 weeks after transplantation, allogeneic and autologous Achilles tendon remains the same mechanical strength, and further that the mechanical properties of tendon allograft can replace autologous tendon. For the conduct of clinical trials provide important theoretical basis. Deep-frozen tendon allograft after transplantation with the histologic changes in the mechanical properties to go through a process of dynamic change, and ultimately returned to normal mechanical properties. In this study, early transplantation (8 weeks), because of the ongoing vascularized tendon allograft, a large number of fibroblasts, collagen metabolism, catabolism strong and new collagen synthesis due to the alignment rules,[link widoczny dla zalogowanych], resulting in lower mechanical strength. Maximum load 2 weeks after transplantation, only 63.7% before transplantation, 4 weeks,[link widoczny dla zalogowanych], 70.9%, 73.9% at 8 weeks. Over time, the mechanical index may have a gradually increasing trend. Among them, the maximum tensile strength at 8 weeks, or even restored to the levels before transplantation. Mainly depend on the allograft tendon healing by exogenous,[link widoczny dla zalogowanych], so the most important early postoperative activities and to prevent adhesions, promote new collagen remodeling along the stress direction. At the same time as the mechanical strength of early postoperative tendon decreased significantly after the easily lead to over-stretch loose or broken in the early postoperative period must be given due protection, while avoiding the high-tension activity j.