Comparison of Intraoperative Endplate Injury between Mini-Open Lateral Lumbar Interbody Fusion (LLIF) and Transforaminal Lumbar Interbody Fusion (TLIF) and Analysis of Risk Factors: A Retrospective Study

Figures & data

Figure 1. CT value measured from pre-operative CT scan. (a,b) lumbar lordosis (LL), (c,d) segmental lumbar lordosis (SLL), (e) Anterior height of the intervertebral space, (f) Posterior height of the intervertebral space, SLL: segment lumbar lordosis, LL: lumbar lordosis.

Figure 2. Cage position. The endplate was divided into 4 regions. (a) anterior-inferior edge of the cage falls on zone I. (b) anterior-inferior edge of the cage falls behind zone I.

Table 1. Characteristics And intraoperative endplate injury of patients received LLIF or TLIF surgery.

Variables	LLIF	TLIF	T/c	P-value
NO.	106	93
Age	61.76 ± 8.55	59.61 ± 9.91	1.64	0.102
Gender			1.16	0.281
Female	65	50
Male	41	43
BMI	24.05 ± 3.51	24.23 ± 3.65	−0.36	0.72
Diagnosis			0.051	0.822
Spondylolisthesis	70	60
Spinal Stenosis	36	33
Surgical Segment			0.316	0.854
L2-3	3	4
L3-4	7	6
L4-5	96	83
Pfimann Classification			3.146	0.37
II	0	1
III	6	3
IV	50	37
V	50	52
L1CT Value	135.8 ± 40.6	142.03 ± 51.02	−1.02	0.309
LL	46.94 ± 12.15	44.36 ± 11.51	1.53	0.127
SLL	14.35 ± 7.16	15.68 ± 6.8	−1.347	0.18
IH	8.01 ± 2.33	8.4 ± 2.82	−1.059	0.291
Endplate Damage			3	0.083
Injury	64	67
Uninjured	42	26

Note: LLIF, lateral lumbar interbody fusion; TLIF, transforaminal lumbar interbody fusion; BMI, body mass index; LL, lumbar lordosis; SLL, segment lumbar lordosis; IH, intervertebral space height.

Table 2. Univariate Analysis for endplate injury in LLIF group.

Variables	Without Endplate Injury	With Endplate Injury	T/c	P-value
Gender			4.574	0.032
Female	34	31
Male	30	11
Age	60.41 ± 9.14	63.83 ± 7.17	−2.05	0.043
BMI	24.03 ± 3.19	24.08 ± 3.98	−0.068	0.946
Diagnosis			3.197	0.074
Spondylolisthesis	38	32
Spinal Stenosis	26	10
Surgical Segment			2.04	0.361
L2-3	3	0
L3-4	4	3
L4-5	57	39
Pfimann Classification			0.0272	0.873
II	4	2
III	31	19
IV	29	21
V			0.0272	0.873
Cage Position
Anterior Located	31	10	6.485	0.011
Posterior Located	33	32
Cage Length			3.493	0.062
45 cm	15	17
50 cm	49	25
Cage Height(mm)
10	4	4	2.575	0.462
12	10	11
14	44	23
15	6	4
L1 CT Value	145.5 ± 41.8	119.95 ± 34.72	3.285	0.001
LL	46.08 ± 12.55	48.24 ± 11.53	−0.896	0.372
SLL	14.8 ± 7.06	13.66 ± 7.33	0.804	0.423
IH	8.51 ± 2.27	7.25 ± 2.24	2.826	0.006
Height Variance	5.02 ± 2.17	5.94 ± 2.3	−2.101	0.038

Note: LLIF, lateral lumbar interbody fusion; BMI, body mass index; LL, lumbar lordosis; SLL, segment lumbar lordosis; IH, intervertebral space height.

Table 3. Binary logistic regression analysis for endplate injury in LLIF group.

Variables	OR	P value	95% CI
Gender	0.433	0.085	0.167	1.123
L1CT Value	0.985	0.028	0.972	0.998
Age	1.058	0.126	0.984	1.136
Height Variance	1.263	0.038	1.013	1.575
Cage Position	3.881	0.009	1.398	10.771

Note: LLIF, lateral lumbar interbody fusion; CI, confidence interval.

Figure 3. The patterns of intraoperative endplate injury during LLIF procedures. (a) Endplate abrasion, without cage settling. (b) one edge of the cage settles into the vertebral body. (c) two diagonal edges of the cage settle into the vertebral bodies. (d) the upper or lower surface of the cage settles into the vertebral body. (e) Fracture of the superior or inferior vertebral body, the fracture line is distributed along the coronal plane.

Figure 4. (a)–(b) The anterior-inferior edge of the cage falls on the anterior part of the epiphyseal ring and the cage footprint area on the endplate. (c)–(d): the anterior-inferior edge of the cage falls behind the anterior part of the epiphyseal ring and the cage footprint area on the endplate.

Figure 5. (a)–(d) Severe endplate damage or even coronal vertebral fractures accompanied by facet joint degeneration.