Measurement of Paradoxical and Coupled Motions Following Lumbar Total Disc Replacement

Article Figures & Data

Table 1

Average Range of Motion Over Time for Lumbar Total Disc Replacement and Lumbar Discectomy

Procedure	Movement	SRot	SRot Rotation (°) cRot	aRot
LTDR	Flexion	1.8 ± 3.3	-0.4 ± 0.8	0.2 ± 0.9
	Extension	-0.6 ± 1.1	-0.2 ± 0.7	-0.1 ± 0.8
	Total Sagittal	3.5 ± 2.4	0.8 ± 0.7	1.0 ± 0.7

LD	Flexion	2.8 ± 2.6	0.0 ± 0.2	-0.2±1.0
	Extension	-2.2 ± 1.6	0.1 ± 0.9	0.0 ± 0.3
	Total Sagittal	4.7 ± 2.2	0.7 ± 1.4	1.5 ± 2.6

Table 2

Nonparametric Binomial Tests for the Proportion of Paradoxical Motions in LTDR

LTDR	N	Proportion of Paradoxical Motion Mean (SD)	Test w/	Test Proportion
Total	53	0.264 (0.445)^*	LD Total	0.067

Flexion	26	0.269 (0.452)	LTDR Extension	0.259
Extension	27	0.259 (0.447)

L4-5	26	0.192 (0.402)
L2-3	11	0.364 (0.505)^*	LTDR L4-5	0.192
L5-S1	16	0.313 (0.479)^*	LTDR L4-5	0.192

1Mo	10	0.400 (0.516)
1Yr	19	0.211 (0.419)^*	LTDR 1Mo	0.4
2Yr	24	0.250 (0.442)^*	LTDR 1Mo	0.4

Mono-segmental	34	0.265 (0.448)
Bi-segmental	19	0.263 (0.452)	LTDR 1-level	0.265

Comparison of total cases between LTDR and LD and comparison of LTDR cases between each motion, level, post-operative time-point and number-of-operation.
↵* Significantly different with changes in testing proportion