ISAKOS: 2023 Congress in Boston, MA USA

2023 ISAKOS Biennial Congress In-Person Poster

 

Biodegradable Magnesium Bone Staples Show Comparable Primary Stability In Comparison to Bone Staples Made Of Steel - A Biomechanical Comparison.

Adrian Deichsel, MD, Münster, NRW GERMANY
Johannes Glasbrenner, MD, Münster GERMANY
Michael J. Raschke, MD, Prof., Münster GERMANY
Jens Wermers, MD, Münster GERMANY
Matthias Klimek, M. Sc., Muenster GERMANY
Christian Peez, MD, Münster, NRW GERMANY
Thorben Briese, MD, Münster GERMANY
Elmar Herbst, MD, PhD, Muenster GERMANY
Christoph Kittl, MD, MD(res), Muenster GERMANY

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

The FDA has not cleared the following pharmaceuticals and/or medical device for the use described in this presentation. The following pharmaceuticals and/or medical device are being discussed for an off-label use: Medical Magnesium GmbH, Magnesium Staple

Summary

This study investigated whether biodegradable bone staples made of magnesium display similar biomechanical primary stability in comparison to typically utilized metal staples.

Abstract

Background

Bone staples (BS) have been previously shown to be a viable modality for peripheral tendon graft fixation in knee surgery. However, soft tissue reactions might make implant removal necessary. Magnesium is a promising material for biodegradable orthopedic implants, with mechanical properties closely resembling human bone. The. purpose of the present study was to assess the primary stability of cortical fixation of tendon grafts in knee surgery comparing BS made of metal to a novel BS made of magnesium.

Methods

Primary stability of peripheral tendon graft fixation was assessed in a porcine model of MCL reconstruction (each n = 10), utilizing 8 mm wide Richards fixation staples (group Me1, Smith and Nephew, London, UK), 8 mm wide spiked ligament staples (group Me2, Arthrex, Naples, Florida), or magnesium staples (group Mg1, Medical Magnesium GmbH, Aachen, Germany). Primary stability was assessed using a uniaxial material testing machine (Instron, Norwood, MA). Cyclic loading at 50 N and 100 N was apllied for 500 cycles each, followed by a load to failure test. Statistical comparison was performed using the Kruskall-Wallis test.

Results

After 500 cycles at 50 N, elongation was 1.5 mm ±0.5 in the Me1 group, 1.9 mm ±0.5 in the Me2 group, and 1.8 mm ±0.4 in the Mg1 group. After 1000 cycles of loading (500 cycles at 50 and 500 cycles at 100 N), elongation was 3.6 mm ±0.9 in the Me1 group, 3.5 mm ±0.6 in the Me2 group, and 4.1 mm ±1.0 in the Mg1 group. No significant differences regarding elongation were found between the groups (p > 0.05).
Load to failure of the staples was 352 mm ±115 in the Me1 group, 373 mm ±77 in the Me2 group, and 449 mm ±92 in the Mg1 group. No significant differences regarding load to failure were found between the groups (p > 0.05). There was no significant difference observable between stiffness of the different fixation constructs.

Conclusion

BS made of magnesium display comparable biomechanical primary stability and may therefore be a possible alternative to classic metal BS.