RESORBABLE AND NON-RESORBABLE AUGMENTATION DEVICES FOR TENORRHAPHY OFXENOGRAFTS IN EXTENSOR TENDON DEFICITS - 12 WEEK STUDY

Resorbable (poly-L-lactide) and non-resorbable (polyethylene terephath alate) tendon augmentation devices (TAD) in conjunction with a pericar dial adhesion barrier, were designed to strengthen tenorrhaphies and w ere evaluated in an ovine extensor tendon deficit model in a short ter m study. Fifteen centimetres of tendon were resected and replaced with kangaroo tail tendon xenografts that had been cross-linked with 0.075 % glutaraldehyde (GA) at 4 degrees C for one or seven days. Compared w ith tenorrhaphies performed with Kessler sutures alone, both types of TAD were more effective at preventing tenorrhaphy dehiscence, and thus maintaining tendon function. Furthermore, tensile strength of TAD ten orrhaphies increased significantly between zero and twelve weeks. For xenografts cross-linked in GA for one day, the tensile strength of ten orrhaphies with the resorbable TAD rose from 38 +/- 9 N at time zero, to 116 +/- 46 N at twelve weeks, while non-resorbable TAD tenorrhaphy strength at time zero was 42 +/- 16 N and 99 +/- 27 N at twelve weeks. For xenografts cross-linked with GA for seven days, similar increases in tensile strength of tenorrhaphies, with the two types of TAD were found. As there was no significant difference in mechanical performanc e or tissue response between the two TAD types in the first 12 weeks, use of the resorbable poly-L-lactide device may be advantageous clinic ally. Tensile strengths of midsections of the tendon xenograft cross-l inked for 7 days was not significantly diminished 12 weeks after impla ntation and these xenografts were partially remodelled around the peri phery. However, the tensile strength of xenografts cross-linked for on e day declined significantly between time zero (319 +/- 80 N) and twel ve weeks (239 +/- 92 N), suggesting that this degree of crosslinking w as inadequate for maintenance of mechanical strength. Evaluation of th e performance of tenorrhaphy augmentation devices with xenografts, ove r a longer implantation period, is required to further understand thei r usefulness for reconstruction of traumatic tendon injuries. (C) 1997 Elsevier Science Limited.