Biomechanical assessment of suture techniques used for tendon repair

Objective: The aim of this study was to assess different tendon suture techniques from the perspectives of both tensile strength and early active mobilization. Methods: In this study, we implemented repairs on 40 flexor digitorum profundus (FDP) tendons, acquired from fresh frozen cadavers. The tendons were divided into 5 groups of 8 tendons each. We applied the 2-strand modified Kessler suture technique in the first group, the 4-strand Strickland suture technique in the second group, the 4-strand modified Kessler (without epitenon suture) suture technique in the third group, and the 4-strand modified Kessler (with epitenon sutures) suture technique in the fourth group. The remaining 8 intact tendons were set aside as the control group. The strength of the different tendon suture techniques were measured using the Instron® device. Results: The average tolerance strength of the first group was determined as 39.89±9.65 Newtons (N), the average tolerance strength of the second group was 39.64±9.14 N, the average tolerance strength of the third group was 50.29±11.24 N, the average tolerance strength of the fourth group was 54.47±6.83 N, and the average tolerance strength of the control group was 119±17.59 N. The tensile strength of the fourth group was significantly higher (p 0.05) than the first group, and the tensile strength of the third group was also significantly higher (p 0.05) than the first group. No significant difference was observed between the tensile strengths of the second and first groups (p 0.05). Conclusion: According to our findings, the tensile strength of 4-strand sutures, with or without epitenon sutures, are significantly higher than the tensile strength of 2-strand sutures. All suture techniques applied had sufficient tensile strength to promote early mobilization.