Table 3 Risk factors between the endplate injury and non-endplate injury groups

Age

70.68 ± 7.12

70.44 ± 7.20

0.828*

Sex (male/female)

17/57(23%/77%)

52/58(46%/54%)

0.002†

Osteoporosis diagnosis

< 0.001†

 Normal

14(19%)

31(28%)

 Osteopenia

20(27%)

52(47%)

 Osteoporosis

40(54%)

27(25%)

Surgery level

0.056†

 1 level

50(68%)

88(80%)

 2 levels

24(32%)

22(20%)

Disease type

N = 90

N = 145

0.235†

 Spinal stenosis only

28(31%)

37(26%)

 Degenerative spondylolisthesis

41(46%)

74(51%)

 Isthmic spondylolisthesis

5(6%)

12(8%)

 Degenerative retrolisthesis

9(10%)

15(10%)

 Degenerative segmental scoliosis

7(8%)

7(5%)

Cage type

N = 86

N = 144

0.481†

 PEEK

68(79%)

108(75%)

 3D printed titanium

18(21%)

36(25%)

Surgical factors

N = 86

N = 144

 Pre-operative disc height (mm)

8.82(7.27–9.31)

9.31(8.52–10.32)

< 0.001‡

 Post-operatvie disc height (mm)

10.88 ± 1.57

11.24 ± 1.82

0.093*

 Cage size (mm)

1(8)/11(9)/39(10)/24(11)/9(12)/2(13)

7(8)/20(9)/46(10)/57(11)/14(12)/0(13)

0.069†

 Discrepancy between preoperative disc height and cage size

1.92(1.03–2.97)

0.87(0.24–1.71)

< 0.001‡

DEXA

 Spine BMD (g/cm^2)

0.887(0.792–1.070)

1.014(0.891–1.169)

0.003‡

 Femur BMD (g/cm^2)

0.738(0.647–0.831)

0.795(0.732–0.924)

0.002‡

Endogenous factors

normal range

 sCa²⁺ (mg/dL)

8.8 ~ 10.5(mg/dL)

9.2(8.9–9.5)

9.3(9.0–9.53)

0.174‡

 sP⁻ (mg/dL)

2.5 ~ 4.5(mg/dL)

3.6(3.3–3.8)

3.5(3.2–3.9)

0.65‡

 Vitamine D (25-(OH) vit.D) (ng/mL)

30.1 ~ 100 (ng/mL)

28.2(16.1–36.1)

28.1(18–37.9)

0.693‡

 PTH (pg/ml)

10 ~ 65 (pg/ml)

31(17–45.5)

22(13–37.5)

0.056‡

Bone Turnover Marker

 sCTX (ng/mL)

0.025 ~ 0.573 (ng/mL)

0.389(0.239–0.602)

0.275(0.182–0.381)

< 0.001‡

N = 19

N = 23

 Osteocalcin (ng/mL)

male: 10.00 ~ 46.00 (ng/mL)

7.7(4.80–16.92)

13.3(6.70–15.52)

0.622‡

female: 10.00 ~ 46.00 (ng/mL)

N = 54

N = 85

 sP1NP (ng/mL)

male: 22.90 ~ 85.30 (ng/mL)

48.8(26.98–68.23)

35.9(26.86–62.00)

0.121‡

female: 16.27 ~ 73.87 (ng/mL)

N = 54

N = 85

 P1NP/CTX

107.59(83.57–180.46)

155.31(121.25–201.93)

0.001‡

Subtype (P1NP/CTX)

N = 54

N = 85

0.029†

 1

5(9%)

13(18%)

 2a

2(4%)

18(24%)

 2b

8(15%)

10(14%)

 3

6(11%)

7(9%)

 4a

16(30%)

24(32%)

 4b

17(31%)

13(18%)