Summary

Arthroscopic suprapectoral biceps tenodesis performed with an interference screw or a suture anchor provides a similar fixation strength.

Abstract

Purpose

Studies covering biomechanical properties of arthroscopic suprapectoral biceps tenodesis using interference screw or suture anchor are published in the literature but they are limited to a small sample sizes. The purpose of this study was to assess and compare the biomechanical properties and load-to-failure (LTF) of 2 arthroscopic suprapectoral biceps tenodesis fixation techniques, interference screw (IS) fixation and double-loaded suture anchor (SA) fixation.

Materials And Methods

39 human cadaveric shoulders were randomized into two treatment groups. 20 shoulders received an IS and 19 SA. A biceps tenodesis was performed according to the techniques listed above. Cyclic loading tests on a dynamic-loading testing device were used to measure and compare the resistance to failure pull-out between the two groups. Hartley's Fmax test and Tukey's Honest Significant Difference method were used for statistical analysis.

Results

In IS group the minimal LTF was six cycles at 100 N and maximum LTF 20 cycles at 200 N while in SA group the minimal LTF was nine cycles at 100 N and maximum LTF 77 cycles at 200 N. SA showed increasing (though not significant) resistance, comparing to screws (diff=7.04, lwr=-2.35, upr=16.43, p=0.1768), where eight of them reached 200 N load before failure whereas in IS fixation only three reached it. The IS group failed due to a complete tendon tearing at the bone-tendon-screw interface while the SA group failed at the suture-tendon interface due to slippage of lasso loop.

Conclusions

Based on these results, a biceps tenodesis using an IS or a SA technique will provide a similar fixation strength. The surgeon treating biceps tenodesis should expect similar initial strength using an IS or double-loaded SA.