Evaluation of 3 Needleless Grasping Suture Techniques for Soft-Tissue Graft Fixation: A Porcine Biomechanical Study

Abstract

Purpose: The purpose of this study was to evaluate the tendon graft holding strength of 3 needleless grasping suture techniques, namely the modified Prusik knot, Wittstein suture loop, and modified rolling hitch.

Methods: Thirty fresh-frozen porcine flexor profundus tendons were used and randomly divided into 3 groups of 10 specimens. The experimental procedure was designed to assess elongation of the suture-tendon construct across 3 different needleless tendon-grasping techniques. All suture configurations were completed with a multistranded nonabsorbable suture. Each tendon was pre-tensioned to 100 N for 3 cycles, cyclically loaded to 200 N for 200 cycles, and then finally loaded to failure. Elongation, load to failure, and mode of failure for each suture-tendon construct were measured.

Results: During cyclic loading, there were no significant differences in elongation for any of the tested suture-tendon constructs (modified rolling hitch, 21.2% ± 9.6%; modified Prusik knot, 21.4% ± 9.9%; and Wittstein suture loop, 26.2% ± 4.5%). Similarly, the failure load and cross-sectional area were not significantly different across all tested suture groups.

Conclusions: The modified Prusik knot, Wittstein suture loop, and modified rolling-hitch techniques had equal elongation after cyclic loading, as well as load to failure, in this in vitro biomechanical evaluation.

Clinical relevance: These needleless grasping suture techniques may be an attractive alternative to the commonly used whipstitch techniques for tendon graft fixation in ligament reconstruction.