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Parameters influencing the outcome after total disc replacement at the lumbosacral junction. Part 1: misalignment of the vertebrae adjacent to a total disc replacement affects the facet joint and facet capsule forces in a probabilistic finite element analysis.
- Source :
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European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society [Eur Spine J] 2013 Oct; Vol. 22 (10), pp. 2271-8. Date of Electronic Publication: 2013 Jul 20. - Publication Year :
- 2013
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Abstract
- Purpose: After total disc replacement with a ball-and-socket joint, reduced range of motion and progression of facet joint degeneration at the index level have been described. The aim of the study was to test the hypothesis that misalignment of the vertebrae adjacent to the implant reduces range of motion and increases facet joint or capsule tensile forces.<br />Methods: A probabilistic finite element analysis was performed using a lumbosacral spine model with an artificial disc at level L5/S1. Misalignment of the L5 vertebra, the gap size of the facet joints, the transection of the posterior longitudinal ligament, and the spinal shape were varied. The model was loaded with pure moments.<br />Results: Misalignment of the L5 vertebra reduced the range of motion up to 2°. A 2-mm displacement of the L5 vertebra in the anterior direction already led to facet joint forces of approximately 240 N. Extension, lateral bending, and axial rotation caused maximum facet joint forces between 280 and 380 N, while flexion caused maximum forces of approximately 200 N. A 2-mm displacement in the posterior direction led to capsule forces of approximately 80 N. Additional moments increased the maximum facet capsule forces to values between 120 and 230 N.<br />Conclusions: Misalignment of the vertebrae adjacent to an artificial disc strongly increases facet joint or capsule forces. It might, therefore, be an important reason for unsatisfactory clinical results. In an associated clinical study (Part 2), these findings are validated.
- Subjects :
- Biomechanical Phenomena physiology
Humans
Longitudinal Ligaments physiology
Longitudinal Ligaments surgery
Lumbar Vertebrae physiology
Lumbosacral Region physiology
Lumbosacral Region surgery
Range of Motion, Articular physiology
Rotation
Sacrum physiology
Tensile Strength physiology
Weight-Bearing physiology
Zygapophyseal Joint physiology
Zygapophyseal Joint surgery
Finite Element Analysis
Intervertebral Disc surgery
Lumbar Vertebrae surgery
Sacrum surgery
Total Disc Replacement adverse effects
Total Disc Replacement methods
Subjects
Details
- Language :
- English
- ISSN :
- 1432-0932
- Volume :
- 22
- Issue :
- 10
- Database :
- MEDLINE
- Journal :
- European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society
- Publication Type :
- Academic Journal
- Accession number :
- 23868223
- Full Text :
- https://doi.org/10.1007/s00586-013-2909-z