Assistant Professor Small Animal Orthopedics North Carolina State University, North Carolina
Effect of Two-, Four-, Six-, and Eight-Strand Repairs on the Biomechanical Properties of Experimental Canine Tendons. Chang Y1, Duffy DJ1, Moore G2. 1North Carolina State University, Raleigh, NC; 2Purdue University, West Lafayette, IN.
Various factors affect the biomechanical properties of the tenorrhaphy and repair site strength. Our objective was to determine the effect of two-, four-, six-, and eight-strand sutured repairs on the biomechanical properties of experimental canine tendons. Twenty-eight cadaveric gastrocnemius tendons were randomly assigned to four groups (n = 14/group). Tendons were repaired using a simple interrupted suture technique using a two-, four-, six-, and eight-strand technique using 2-0USP polypropylene suture. Biomechanical testing was performed with evaluation of yield, peak, and failure loads, gap formation between tendon ends and failure mode. Statistical significance was set at P < 0.05. Increasing the number of strands significantly increased repair site strength (P < 0.001). Use of an eight-strand repair demonstrated significantly higher tensile strength among groups (P < 0.001), followed by six-, four-, and two- strand. There was a significant positive correlation regarding resistance to 1 mm and 3 mm gap formation (P < 0.001) as number of strands used for the construct repair increased. All sutured constructs failed by mode of suture pull-through. Increasing the number of suture strands crossing the repair site significantly increases the tensile strength and the resistance to gap formation of repaired canine gastrocnemius constructs. Suture patterns using multiple strands traversing the repair site should be recommended for canine tenorrhaphy. This information will be important to guide suture pattern refinement, repair methodology and implementation in clinical cases. Future studies are needed to assess the effect of multi-strand suture patterns in vivo to assess their effect on glide function, tendinous healing and long-term clinical function and outcome.