Resident- Small Animal Surgery University of Melbourne, Western Australia, Australia
Biomechanical Comparison of a 3-Loop Pulley and a 4-Loop Pulley Suture for Tenorrhaphy in the Canine Gastrocnemius Tendon. O'Byrne K1, Sugiyama T2, Robinson D1, Wooward A1, Ryan S1. 1Melbourne University, Melbourne, Australia; 2Animalius Vet, 6 Focal Way, Bayswater, WA, Australia.
Gap formation impedes tendon healing and reduces the tensile strength following tenorrhaphy. A suture pattern that provides greater resistance to gap formation than the 3-loop pulley, will provide a basis for choice in clinical cases. The objective of this study was to compare a 3-loop pulley (3LP) suture pattern with a 4-loop pulley (4LP) suture pattern, for the tenorrhaphy of canine gastrocnemius tendon repair. This was a randomized, cadaveric, biomechanical study. Thirty gastrocnemius tendons were transected and repaired with either 3LP or 4LP suture pattern. A tensile load was applied at 25 mm/min until construct failure. The load required to form a 1 mm gap, 3 mm gap, and maximum load at failure was recorded and compared between groups. The 4LP mean load to form a 1 mm gap was 16.8 N (95% CI = 11.3–22.4 N) greater than the 3LP. The estimated mean load to form a 3 mm gap for the 3LP and 4LP was 39.3 N (95% CI = 34.5–44.5 N) and 53.7 N (95% CI = 48.4–58.9 N), respectively. The mean load to form a 3 mm gap was 14.6 N (95% CI = 8.0–21.5 N) greater in the 4LP than the 3LP. The estimated mean load for failure in the 3LP and 4LP was 40.8 N (95% CI = 35.9–45.5 N) and 53.6 N (95% CI = 48.5–58.6 N) respectively. Limitations of this study are related to the cadaveric biomechanical testing model, with no ability to assess the effects of tendon healing. In conclusion, a 4LP suture pattern better resists gap formation and requires greater load before failure than a 3LP.