Biomechanical testing of posterior lumbar stabilization systems

B. K. Dhillon, K. Fraysur, K. Sedacki, M. Ammerman, B. P. Kelly, Denis Diangelo

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Study Design- A biomechanical testing protocol was used to compare three different posterior stabilization devices in a human cadaveric spine model. Objective- To compare the range of motion and load sharing properties of two dynamic posterior stabilization devices and one rigid posterior stabilization device. Background- Rigid rod pedicle screw fixation systems are used for lumbar interbody fusion. Risks of degenerating adjacent levels and stress-shielding have led surgeons to advocate the use of dynamic pedicle screw fixation devices. Methods- Three different rod constructs were used with the bilateral Click'X pedicle screw fixation system (Synthes Spine). Six lumbo-sacral spine segments were tested in flexion and extension in the (1) Harvested condition. Following instrumentation with a rigid anterior interbody load sensing graft the specimens were sequentially tested in: (2) L4-L5 discectomy (No Rod), (3) Rigid rod, (4) PEEK rod, and (5) NHance rod (Synthes Spine) conditions. An actuator off-set from the spine applied a global bending moment. A motion tracking system monitored individual MSU rotations and the force sensing graft measured load sharing. Results- Flexibility of the instrumented spine conditions was significantly greater than the Harvested condition in extension, but was significantly less in flexion. During flexion a significant decrease in motion occurred at the operative level in all three spine conditions relative to the Harvested condition. In extension, a significant increase in motion compensation occurred in the adjacent levels of all three spine conditions relative to the Harvested condition. Rigid and PEEK rods were significantly less than the NHance rod with respect to the initial graft load after instrumentation. Conclusions- The NHance rod did provide sufficient stability to treat fusion or segmental instabilities by reducing motion at the instrumented level. While the dynamic capacity of the device did show functionality at low loads, at higher loads it behaved as a traditional rigid rod.

Original languageEnglish (US)
Title of host publication25th Southern Biomedical Engineering Conference 2009
Pages213-218
Number of pages6
Volume24
DOIs
StatePublished - Nov 6 2009
Event25th Southern Biomedical Engineering Conference 2009 - Miami, FL, United States
Duration: May 15 2009May 17 2009

Other

Other25th Southern Biomedical Engineering Conference 2009
CountryUnited States
CityMiami, FL
Period5/15/095/17/09

Fingerprint

Grafts
Polyether ether ketones
Stabilization
Testing
Fusion reactions
Motion compensation
Bending moments
Shielding
Actuators
polyetheretherketone

All Science Journal Classification (ASJC) codes

  • Bioengineering
  • Biomedical Engineering

Cite this

Dhillon, B. K., Fraysur, K., Sedacki, K., Ammerman, M., Kelly, B. P., & Diangelo, D. (2009). Biomechanical testing of posterior lumbar stabilization systems. In 25th Southern Biomedical Engineering Conference 2009 (Vol. 24, pp. 213-218) https://doi.org/10.1007/978-3-642-01697-4_77

Biomechanical testing of posterior lumbar stabilization systems. / Dhillon, B. K.; Fraysur, K.; Sedacki, K.; Ammerman, M.; Kelly, B. P.; Diangelo, Denis.

25th Southern Biomedical Engineering Conference 2009. Vol. 24 2009. p. 213-218.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Dhillon, BK, Fraysur, K, Sedacki, K, Ammerman, M, Kelly, BP & Diangelo, D 2009, Biomechanical testing of posterior lumbar stabilization systems. in 25th Southern Biomedical Engineering Conference 2009. vol. 24, pp. 213-218, 25th Southern Biomedical Engineering Conference 2009, Miami, FL, United States, 5/15/09. https://doi.org/10.1007/978-3-642-01697-4_77
Dhillon BK, Fraysur K, Sedacki K, Ammerman M, Kelly BP, Diangelo D. Biomechanical testing of posterior lumbar stabilization systems. In 25th Southern Biomedical Engineering Conference 2009. Vol. 24. 2009. p. 213-218 https://doi.org/10.1007/978-3-642-01697-4_77
Dhillon, B. K. ; Fraysur, K. ; Sedacki, K. ; Ammerman, M. ; Kelly, B. P. ; Diangelo, Denis. / Biomechanical testing of posterior lumbar stabilization systems. 25th Southern Biomedical Engineering Conference 2009. Vol. 24 2009. pp. 213-218
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