ISAKOS Congress 2021

2021 ISAKOS Biennial Congress ePoster

 

Bone Staples for Cortical Fixation of Tendon Grafts in Knee Surgery: A Biomechanical Study

Johannes Glasbrenner, MD, Münster GERMANY
Adrian Deichsel, MD, Münster, NRW GERMANY
Michael J. Raschke, MD, Prof., Münster GERMANY
Andre Frank, MSc, Muenster GERMANY
Thorben Briese, MD, Münster GERMANY
Mirco Herbort, MD, Prof., Munich GERMANY
Elmar Herbst, MD, PhD, Muenster GERMANY
Christoph Kittl, MD, MD(res), Muenster GERMANY

University Hospital Münster, Department of Trauma, Hand and Reconstructive Surgery, Münster, GERMANY

FDA Status Not Applicable

Summary

Bone staples provided comparable primary stability in relation to interference screw fixation in cortical fixation of tendon grafts in knee surgery in a porcine knee model.

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Abstract

Background

The use of interference screws for cortical fixation of tendon grafts in knee ligament reconstruction may lead to converging tunnels in the multiligament reconstruction setting. The purpose of the present study was to assess the primary stability of cortical fixation of tendon grafts in knee surgery using modern suture anchors and bone staples in comparison to interference screw fixation. The hypothesis was, that bone staples and modern suture anchors would provide comparable primary stability in relation to interference screw fixation.

Study Design: Controlled laboratory study.

Methods

Cortical tendon graft fixation was performed in a porcine knee model at the tibial insertion area of the medial collateral ligament using three different techniques: interference screw (n=10), suture anchor (n=10) and bone staple (n=10) fixation. Specimens were mounted in a materials-testing machine and cyclic loading for 1000 cycles with up to 100 N was applied to the tendon graft followed by load to failure testing. One-way ANOVA was performed for statistical analysis (p < .05).

Results

There were no statistical differences (p=n.s.) in elongation during cyclic loading or peak failure load during load-to-failure testing between bone staple (3.4 mm ±1.0 and 376 N ±120) and interference screw fixation (3.9 mm ±1.2 and 312 N ±99.5). Suture anchor fixation was found to have statistically more elongation (6.4 mm ±0.9; p<0.01) during cyclic loading and lower peak failure load (228 N ±49.0; p<0.0001) during ultimate failure testing in comparison to bone staple and interference screw fixation.

Conclusion

Bone staples provide comparable primary stability in relation to interference screw fixation in cortical fixation of tendon grafts in knee surgery. Primary stability of tendon graft fixation using a single suture anchor was significantly inferior in comparison to bone staple and interference screw fixation. The use of bone staples in cortical fixation of tendon grafts can help to avoid the conflict of converging tunnels.