Design and fabrication of two types of artificial tendons for evaluation of surgical techniques.

Double-loop tendons of fixed and adjustable lengths, and tendons with inner porous tapes both for anastomosis to tendon stumps have been made from readily available materials. By using stainless steel wire and polymer fibers, breakloads have been obtained that range from 20 to 100 lb and elongations have been reduced to less than 2%. Pore sizes up to 50 times 250 mu2 were achieved by using woven, knitted, and braided polyester tapes. For all tendons, Silastic was used to isolate inner fibers and to effect smooth gliding. Preliminary evaluation of these devices, after being implanted in the feet of chickens for 4 weeks, indicates that anastomotic strength of unions formed by use of loops is about 1000 g compared to more than 2000 for unions formed by tissue ingrowth.