# Biomechanical Evaluation of Novel Tendon Coaptation Technique: A Potential Application for Tendon Transfers

## TL;DR

This study compares different tendon repair techniques and finds that combining a traditional weave with a new device offers faster and equally strong results.

## Contribution

The study introduces a faster and equally effective combined tendon repair technique using a traditional weave and a new device.

## Key findings

- The CoNextions group had the fastest instrumentation time.
- The Pulvertaft and CoNextions combination showed similar strength to the traditional Pulvertaft weave.
- The Pulvertaft had the highest ultimate failure load at 67.5 N.

## Abstract

The purpose of this study was to evaluate the biomechanical performance and time to completion of the Pulvertaft weave technique, the CoNextions tendon repair system only, and a combination of single Pulvertaft weave with the CoNextions repair.

A total of 22 cadaveric hands were dissected, and the extensor pollicis longus tendons were harvested and divided into the following three groups: (1) Pulvertaft weave, (2) Pulvertaft weave + CoNextions, and (3) CoNextions. Each sample underwent axial loading in a cyclical fashion, followed by ramp to failure. Metrics of interest were suture time, displacement, stiffness, ultimate failure load, and failure mechanism were recorded.

Time required to instrument each configuration was significantly different across all groups; CoNextions group was the fastest. For cyclic loading, no significant differences in elongation were detected between the groups. The displacement at ultimate failure load, on average, for the Pulvertaft (10.6 mm) and the Pulvertaft and CoNextions combination (10.2 mm) were not significantly different compared with CoNextions (6.5 mm). The stiffness during cyclic loading was similar between the Pulvertaft (38.8 N/mm) and the Pulvertaft and CoNextions combination (36.7 N/mm), and both were found to be significantly stiffer compared with the CoNextions (28.0 N/mm). During the ramp to failure, no significant differences in stiffness were detected. The Pulvertaft had the largest ultimate failure load at 67.5 N.

The Pulvertaft weave and CoNextions tendon repair device demonstrated similar performance to traditional Pulvertaft tendon weave. The combination technique is faster than the traditional tendon weave and displayed improved performance compared with CoNextions repair alone.

The combined use of novel tendon repair with a single tendon weave allows for faster tendon coaptation and equivalent strength as a Pulvertaft weave.