Strength retention of chromic gut and monofilament synthetic absorbable suture materials in joint tissues

The rate at which absorbable sutures lose their mechanical strength in vivo is particularly important in orthopedic applications where high physical loads, often increased by early mobilization, severely test the strength of sutures. The failure load and maximum tensile strength of chromic catgut and two monofilament absorbable synthetic suture materials (polydioxanone and polytrimethylene carbonate) were measured up to six weeks after implantation in sheep as: (1) a suture securing a synovial incision and (2) coils located either within the synovial cavity of the knee or intramuscularly. Although all synovial wounds healed satisfactorily, the performances of the different materials varied. The strength of chromic gut was largely lost within a week and fragmentation occurred at Week 4. The synthetic materials lost their strength relatively slowly. Polytrimethylene carbonate degraded in a linear manner, remaining intact but with little strength by Week 6. Polydioxanone, though losing strength at a slower rate, tended to fragment early, which may be of clinical importance in situations of delayed wound healing.