Biomechanical Study Comparing Pulvertaft, Double Side-to-Side, and Locking Side-to-Side Tendon Suture Techniques

Purpose: In this study, we present a single-sided locking side-to-side (STS) suture technique as a possible alternative for the Pulvertaft weave in tendon transfers. The aim of the study was to compare the biomechanical characteristics of the single-sided locking STS reconstruction with Pulvertaft and double-sided nonlocking STS reconstructions. Methods: Twenty-four human cadaveric extensor digitorum communis tendons and 24 flexor digitorum superficialis tendons were randomly assigned to 1 of 3 groups, resulting in a total of 8 flexor tendons and 8 extensor tendons per group: Pulvertaft, double-sided nonlocking STS, and single-sided locking STS reconstructions. Load to failure was measured with a tensile testing machine. Increase in cross-sectional area was used as a measure of bulkiness at the reconstruction site. Results: In extensor tendons, single-sided locking STS reconstructions showed a higher load to failure than Pulvertaft reconstructions, whereas no difference was found in load to failure between single-sided locking and double-sided nonlocking STS reconstructions. In flexor tendons, single-sided locking STS reconstructions showed a higher load to failure than Pulvertaft reconstructions. However, load to failure of single-sided locking STS reconstructions was less than double-sided nonlocking STS reconstructions. In both extensor and flexor tendons, the percent increase in cross-sectional area at the reconstruction site was higher in Pulvertaft reconstructions than single-sided locking STS reconstructions, whereas no difference was found between single-sided locking STS and double-sided nonlocking STS reconstructions. Conclusions: Single-sided locking and double-sided nonlocking STS reconstructions are suitable alternatives to the Pulvertaft technique for tendon transfers owing to a higher strength and less bulkiness. Because load to failure of both STS reconstructions did not differ in extensor tendon transfers, the single-sided locking STS reconstruction seems especially suitable for extensor tendon transfers. Clinical relevance: This study provides anatomical evidence that the single-sided locking STS reconstruction yields a higher strength and is less bulky than the Pulvertaft reconstruction in tendon transfers.