René Hartensuer, Oliver Riesenbeck, Martin Schulze, Dominic Gehweiler, Michael J. Raschke, Paul W. Pavlov, Thomas Vordemvenne


October 2014, Volume 23, Issue 11, pp 2321 - 2329 Original Article Read Full Article 10.1007/s00586-014-3533-2

First Online: 26 August 2014

Purpose

Purpose of this paper is to evaluate the primary stability of a new approach for facet fixation the so-called Facet Wedge (FW) in comparison with established posterior fixation techniques like pedicle screws (PS) and translaminar facet screws (TLS) with and without anterior cage interposition.

Methods

Twenty-four monosegmental fresh frozen non-osteoporotic human motion segments (L2–L3 and L4–L5) were tested in a two-arm biomechanical study using a robot-based spine tester. Facet Wedge was compared with pedicle screws and translaminar screws as a stand-alone device and in combination with an anterior fusion cage.

Results

Pedicle screws, FW and translaminar screws could stabilize an intact motion segment effectively. Facet Wedge was comparable to PS for lateral bending, extension and flexion and slightly superior for axial rotation. Facet Wedge showed a superior kinematic capacity compared to translaminar screws.

Conclusions

Facet Wedge offers a novel posterior approach in achieving primary stability in lumbar spinal fixation. The results of the present study showed that the Facet Wedge has a comparable primary stability to pedicle screws and potential advantages over translaminar screws.


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