Demographic data of radiological analysis.
| Demographic | L2/3 | L3/4 | L4/5/6 | All Disc Levels | P |
| No. of cages | 35 | 72 | 108 (106: L4/5; 2: L5/6) | 215 | |
| AC/AP, mean ± SD (range) | 41.1% ± 8.3% (24%–63%) | 42.2% ± 7.8% (24%–62%) | 41.2% ± 7.7% (21%–63%) | 41.5% | NS among 3 levels |
| ≥50% | 14.3% | 16.7% | 10.2% | 13% | NS among 3 levels |
| ≥60% | 2.9% | 2.8% | 0.9% | 1.9% | |
| ARA, mean ± SD (range), ° | 1.7 ± 6.6(−14 to 14) | 1-.9 ± 5.8(−16 to 14) | -4 ± 4.7*(−16 to 5) | −2.9° | <0.05 for L4/5/6 vs L2/3, L3/4 |
| ≤−10° | 11.4% | 11.1% | 13.9% | 12.6% | NS among 3 levels |
| Cages installed in PCA,a b n/N (%) | 1/35 (2.9%) | 6/72 (8.3%) | 6/108 (5.6%) | 13/215 (6%) | |
| contact (−) ○ | 0/1 | 1/6 | 0/6 | 1/13 | |
| p/o contact ▲ | 0/1 | 5/6 | 4/6 | 9/13 | |
| contact (＋) ● | 1/1 | 0/6 | 2/6 | 3/13 | |
| Symptomatic radiculopathy (+) | 0/1 | 0/6 | 2/6 | 2/13 | |
| RC/RL value | 48.4% ± 3.1% (42.2%–52.4%) | ||||
| R-cage tip, mm | −0.5 ± 3.1 (−5 to 7) | ||||
| CW/RL value | 93.8% ± 6.1% (78.8%–100%) |
Abbreviations: AC/AP value, (anterior endplate edge–cage center/anterior–posterior endplate edge) x100 %; ARA, axial rotation angle (°); CW/RL value, cage width/right-left endplate edge x100 %; NS, not significant; PCA, potential contact area; p/o, possibility of; R-cage, right endplate edge-cage; RC/RL, right endplate edge-cage center/right-left endplate edge.
↵a Definitions of PCA: (1) AC/AP value ≥50% and ARA ≤ –10° (area A). (2) AC/AP value ≥60% and ARA ≤ –0° (area B). (3) Transition area between areas A and B,
↵b Contact (–): no chance of contact between the cage and the nerve; p/o contact: the possibility of contact between the cage/tools and the nerve; contact (+): direct contact between the cage and the nerve,
c Analysis of 13 cages in PCA.