The biomechanical influence of anterior vertebral body osteophytes on the lumbar spine: A finite element study.

BACKGROUND CONTEXT: Anterior vertebral body osteophytes are common with degeneration but their biomechanical influence on the whole lumbar spine remains unclear.

PURPOSE: To investigate the biomechanical influence of anterior vertebral body osteophytes on the whole lumbar spine.

STUDY DESIGN/

SETTING

This is a study using finite element analysis.

OUTCOME MEASURES: Intersegmental rotation, maximum Mises stress, and intradiscal pressure on the intervertebral discs of different lumbar levels were calculated.

METHODS

A finite element model of an intact lumbar spine was constructed and validated against in vitro studies. The modified models, which had different degrees of anterior vertebral body osteophyte formation (OF) in combination with disc space narrowing, were applied with physiological loadings.

RESULTS

The lumbar levels with various degrees of OF altered the kinematics of these levels, which also affected the whole lumbar spine. In flexion and lateral bending, the segment that was one level inferior to the vertebra with OF showed a trend towards increased range of motion. On the intervertebral discs that were one level inferior to the OF level, a trend towards increase in the maximum von Mises stress was found on the annulus.

CONCLUSIONS

Segments adjacent to levels with anterior vertebral body osteophytes showed increased intersegmental rotation and maximum stress. Further clinical observation should be performed to verify the results in vivo.