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.