Strength retention of chromic gut and synthetic absorbable sutures in a nonhealing synovial wound

The rate at which absorbable sutures lose their mechanical strength in a slow healing wound is clinically important, particularly because the factors inhibiting normal healing are not always apparent at the time of closure. Sutures of chromic catgut and two monofilament absorbable synthetic suture materials (polydioxanone and polyglyconate) were used to close a synovial incision in the knees of sheep. A corticosteroid was applied around the wound resulting in minimal tissue healing when the sutures were retrieved up to six weeks later. The failure load and maximum tensile strength of the retrieved sutures were measured. The mechanical degradation of the materials followed a pattern similar to that in normally healing wounds except that the early fragmentation of chromic gut and polydioxanone occurred far less frequently and neither weakened further after three weeks. Polyglyconate was significantly the strongest material up to three weeks but thereafter continued to weaken. The strength of absorbable sutures was retained longer than in a healing lesion probably because of the absence of the phagocytic cells of an inflammatory tissue.