Artikel
Biomechanical effect of different lumbar interspinous implants on flexibility and intradiscal pressure
Das biomechanische Verhalten verschiedener lumbaler interspinöser Implantate betreffend Flexibilität und intradiskalem Druck
Suche in Medline nach
Autoren
-
J. Drumm
- Klinik für Neurochirurgie, Universitätsklinikum Homburg/Saar
-
A. Kettler
- Institut für Unfallchirurgische Forschung und Biomechanik, Universität Ulm
-
K. Häussler
- Institut für Unfallchirurgische Forschung und Biomechanik, Universität Ulm
-
C. Mack
- Institut für Unfallchirurgische Forschung und Biomechanik, Universität Ulm
-
W. I. Steudel
- Klinik für Neurochirurgie, Universitätsklinikum Homburg/Saar
-
L. Claes
- Institut für Unfallchirurgische Forschung und Biomechanik, Universität Ulm
-
H.-J. Wilke
- Institut für Unfallchirurgische Forschung und Biomechanik, Universität Ulm
| Veröffentlicht: | 11. April 2007 |
|---|
Gliederung
Text
Objective: The aim of this in vitro study was to compare four different interspinous implants: Colfex, Wallis, Diam and X-Stop - in terms of its effect on the three-dimensional flexibility and the intradiscal pressure of lumbar spine specimens.
Methods: 24 human lumbar spine specimens were divided into four equal groups. For the flexibility testing the specimens were mounted in a spine tester and loaded with pure moments in flexion/extension, lateral bending and axial rotation. The following states were tested: (1) intact, (2) defect, (3) directly after implantation. Range of motion and the intradiscal pressure were determined from the flexibility tests.
Results: In each implant group the defect caused an increase in range of motion by about 8% in lateral bending to 18% in axial rotation. Coflex crimped, Wallis, Diam, and X-Stop compensated a destabilizing effect in extension. In this loading direction they allowed about 50% of the range of motion of the intact state, whereas in lateral bending and axial rotation the values of the range of motion stayed about the values of the defect state. Similarly the intradiscal pressure after implantation was similar to that of the intact specimens in flexion, lateral bending and axial rotation but much smaller during extension.
Conclusions: In conclusion, Coflex crimped, Wallis, Diam and X-Stop had a similar effect on the three-dimensional flexibility of the treated segments: they significantly stabilized in extension, but had almost no effect in flexion, lateral bending and axial rotation.
