Long-Term Effects of Segmental Lumbar Spinal Fusion on Adjacent Healthy Discs: A Finite Element Study.
METHODS
Experimental study.


OBJECTIVE
The aim of the study was to develop a finite element (FE) model to study the long-term effects of various types of lumbar spinal interventions on the discs adjacent to the fused segment.


BACKGROUND
Earlier FE studies have been limited to one particular type of fusion and comparative quantification of the adjacent disc stresses for different types of surgical interventions has not been reported.


METHODS
A computer aided engineering (CAE) based approach using implicit FE analysis assessed the stresses in the lumbar discs adjacent to the fused segment following anterior and posterior lumbar spine fusions at one, two and three levels (with and without instrumentation).


RESULTS
It was found that instrumentation and length of fusion were the most significant factors in increasing adjacent level stresses in the lumbar discs.


CONCLUSIONS
In the present study, a calibrated FE model that examined spinal interventions under similar loading and boundary conditions was used to provide quantitative data which would be useful for clinicians to understand the probable long-term effect of their choice of surgical intervention.
Center for Product Design and Manufacturing, Indian Institute of Science, Bangalore, India.
Gunti Ranga
GR
Srinivas
Center for Product Design and Manufacturing, Indian Institute of Science, Bangalore, India.
Anindya
A
Deb
Department of Orthopaedics, HOSMAT Hospital, Bangalore, India.
Malhar N
MN
Kumar
Center for Product Design and Manufacturing, Indian Institute of Science, Bangalore, India.
Goutham
G
Kurnool
Intervertebral disc; Intervertebral disc degeneration; Lumbar vertebrae; Spinal fusion