Finite element analysis of a novel modular support system for lumbar reconstruction following vertebral column resection

Table 1 Simplified lumbar morphometric parameters used for implant design and finite element construct modelling

Parameter	Mean value (mm)	Design relevance	Application in FEA model
ABVH	28.97	Reference for anterior body height	Used to define anterior support height
PBVH	29.24	Reference for posterior body height	Used to adjust posterior construct profile
VW	41.13	Reference for vertebral width	Used to determine implant footprint width
VD	30.57	Reference for vertebral depth	Used to determine implant anteroposterior depth
PL	48.96	Reference for pedicle length	Used to guide pedicle screw length selection
PW	10.56	Reference for pedicle width	Used to guide pedicle screw diameter selection

FEA: Finite element analysis; ABVH: Anterior vertebral body height; PBVH: Posterior vertebral body height; VW: Vertebral width; VD: Vertebral depth; PL: Pedicle length; PW: Pedicle width.

Table 2 Material properties

Component	Material	Young’s modulus (MPa)	Poisson’s ratio	Yield strength (MPa)	Model context
Polyethylene block	Polyethylene	690	0.46	20	ASTM-based model
Cortical bone	Bone	17000	0.30	50	Vertebra-based model
Cancellous bone	Bone	100	0.20	1.67	Vertebra-based model
Conventional mesh cage	Titanium	110000	0.36	793	Vertebra-based and ASTM-based models
Pedicle screws	Titanium	110000	0.36	793	Vertebra-based and ASTM-based models
Rods	Titanium	110000	0.36	793	Vertebra-based and ASTM-based models
VCR-MSS components	Titanium alloy	110000	0.36	793	Vertebra-based and ASTM-based models

VCR-MSS: Vertebral column resection modular support system.