Yogesh Kumaran, Anoli Shah, Akhil Katragadda, Adit Padgaonkar, Joseph Zavatsky, Robert McGuire, Hassan Serhan, Hossein Elgafy, Vijay K. Goel


July 2021, pp 1 - 9 Original Article Read Full Article 10.1007/s00586-021-06909-x

First Online: 14 July 2021

Purpose

Lumbar procedures for Transforaminal Lumbar Interbody Fusion (TLIF) range from open (OS) to minimally invasive surgeries (MIS) to preserve paraspinal musculature. We quantify the biomechanics of cross-sectional area (CSA) reduction of paraspinal muscles following TLIF on the adjacent segments.

Methods

ROM was acquired from a thoracolumbar ribcage finite element (FE) model across each FSU for flexion-extension. A L4-L5 TLIF model was created. The ROM in the TLIF model was used to predict muscle forces via OpenSim. Muscle fiber CSA at L4 and L5 were reduced from 4.8%, 20.7%, and 90% to simulate muscle damage. The predicted muscle forces and ROM were applied to the TLIF model for flexion-extension. Stresses were recorded for each model.

Results

Increased ROM was present at the cephalad (L3-L4) and L2-L3 level in the TLIF model compared to the intact model. Graded changes in paraspinal muscles were seen, the largest being in the quadratus lumborum and multifidus. Likewise, intradiscal pressures and annulus stresses at the cephalad level increased with increasing CSA reduction.

Conclusions

CSA reduction during the TLIF procedure can lead to adjacent segment alterations in the spinal element stresses and potential for continued back pain, postoperatively. Therefore, minimally invasive techniques may benefit the patient.


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