Mechanical performance of polyglycolic acid and polyglactin 910 synthetic absorbable sutures

The mechanical performance of polyglycolic acid and polyglactin 910 sutures has been assessed using standardized reproducible tests. The results of these studies demonstrated distinct differences in their performance that can be related, in part, to their structural configuration. The size of the 4-0 polyglactin suture was significantly larger than that of the 4-0 polyglycolic acid suture. Since the strength of any suture is proportional to its cross sectional area, the strength of unknotted and knotted polyglactin 910 sutures was signficantly greater than that of the polyglycolic acid sutures. The strength of both sutures was similarly diminished by the formation of the knot. When these sutures were added to tissue, the breaking strength was even further reduced. The rate of decline in breaking strength of the two absorbable sutures in healing skin wounds was comparable. These absorbable sutures displayed knot security with a two throw square knot, 1 = 1. The ability of these sutures to reach knot break with this knot configuration is characteristic of sutures in which the surface exhibits a high coefficient of friction. Their rough surface also caused them to drag through tissue, making difficult to adjust tension on a continuous running suture.