Biomechanical study on the effect of five different lumbar reconstruction techniques on adjacent-level intradiscal pressure and lamina strain.

• Sudo, Hideki

• Oda, Itaru

• Abumi, Kuniyoshi

• Ito, Manabu

• Kotani, Yoshihisa

• Minami, Akio

Abstract

OBJECT: The objectives of this study were to compare the biomechanical effects of five lumbar reconstruction models on the adjacent segment and to analyze the effects of three factors: construct stiffness, sagittal alignment, and the number of fused segments. METHODS: Nondestructive flexion-extension tests were performed by applying pure moments to 10 calf spinal (L3-S1) specimens. One-segment (L5-6) or two-segment (L5-S1) posterior fusion methods were simulated: 1) one-segment posterolateral fusion (PLF); 2) one-segment PLF with interbody fusion cages (one-segment PLIF/PLF); 3) two-segment PLF; 4) two-segment PLIF/PLF; and 5) two-segment PLF in kyphosis (two-segment kyphotic PLF). The range of motion (ROM) of the reconstructed segments, intradiscal pressure (IDP), and lamina strain in the upper (L4-5) adjacent segment were analyzed. The ROM was significantly decreased in the PLIF/PLF models compared with that in the PLF alone models after both the one- and two-segment fusions. If the number of fused segments was increased, the pressure and strains were also increased in specimens subjected to the PLIF/PLF procedure, more so than the PLF-alone procedure. In the one-segment PLIF/PLF model the authors observed a reduced IDP and lamina strain compared with those in the kyphotic two-segment PLF model despite the latter's higher levels of initial stiffness. CONCLUSIONS: If the number of fused levels can be reduced by using PLIF to correct local kyphosis, then this procedure may be valuable for reducing adjacent-segment degenerative changes.

Journal

• Journal Of Neurosurgery:Spine

  Journal Of Neurosurgery:Spine 5 (2), 150-155, 2006-08

  American Association of Neurological Surgeons

Keywords

• biomechanical testing
• lumbar spine
• posterior lumbar interbody fusion
• intradiscal pressure
• lamina strain
• kyphosis

Details

• CRID: 1050001338979160448
• NII Article ID: 120000957289
• HANDLE: 2115/14612
• ISSN: 15475654
• Text Lang: en
• Article Type: journal article
• Data Source:
  • IRDB
  • CiNii Articles