Outcomes for 2-Level TDR and ACDF.
| Study | Outcome | Treatment arm | Baseline | 7 Years | Mean Δ at 7 years* | P value† | Recovery Ratio |
|---|---|---|---|---|---|---|---|
| 2-Level | NDI | TDR | 53.8 ± 15.4 | 18.0 ± 19.1 | 35.6 ± 20.3 | 0.04 | 67% |
| ACDF | 55.7 ± 15.2 | 26.2 ± 22.4 | 28.2 ± 21.7 | 53% | |||
| VAS neck pain | TDR | 71.2 ± 20.5 | 19.0 ± 27.1 | 50.9 ± 30.6 | 0.21 | 72% | |
| ACDF | 75.1 ± 18.9 | 28.7 ± 30.4 | 44.1 ± 33.9 | 57% | |||
| VAS arm pain | TDR | 68.8 ± 25.0 | 15.9 ± 25.7 | 54.1 ± 32.8 | 0.99 | 74% | |
| ACDF | 73.1 ± 21.9 | 18.4 ± 27.0 | 55.1 ± 32.0 | 76% | |||
| SF-12 PCS | TDR | 33.4 ± 6.7 | 46.3 ± 11.1 | 12.7 ± 10.9 | 0.55 | 19% | |
| ACDF | 32.5 ± 7.7 | 43.7 ± 11.9 | 10.3 ± 11.4 | 15% | |||
| SF-12 MCS | TDR | 41.9 ± 11.3 | 52.0 ± 10.1 | 10.5 ± 12.7 | 0.30 | 16% | |
| ACDF | 42.0 ± 12.0 | 49.1 ± 12.7 | 7.2 ± 14.3 | 10% |
↵* Mean of differences in outcomes between 7 years and preoperative follow-up.
↵† Adjusted p-value for difference in change from baseline between TDR and ACDF at 7-year follow-up.Values given are mean ± SD unless otherwise indicated.NDI, neck disability index; VAS, visual analog scale; SF-12, Short Form 12-item Health Survey; MCS, Mental Composite Score; PCS, Physical Composite Score.