Table 2.
Comparison of radiological outcome according to surgical levels
| Variable | 1-Level ACDF (n = 78) | 2-Level ACDF (n = 49) | 3-Level ACDF (n = 38) | p-value |
|---|---|---|---|---|
| C2–7 Cobb angle (°) | ||||
| Preoperative | 10.85 ± 10.28 | 8.70 ± 7.95 | 13.24 ± 7.99 | 0.074 |
| Postoperative 6 mo | 14.53 ± 9.24 | 15.25 ± 9.37 | 14.21 ± 7.35 | 0.849 |
| Postoperative 6-mo change (Δ) | 3.68 ± 9.62 | 6.92 ± 10.02 | 0.97 ± 5.68 | 0.010* |
| Postoperative 12 mo | 13.15 ± 9.79 | 13.95 ± 7.14 | 13.53 ± 7.42 | 0.875 |
| Postoperative 12-mo change (Δ) | 2.30 ± 7.78 | 5.26 ± 6.93 | 0.29 ± 6.56 | 0.006* |
| Postoperative 24 mo | 13.01 ± 9.05 | 14.32 ± 7.09 | 13.52 ± 7.42 | 0.678 |
| Postoperative 24-mo change (Δ) | 2.16 ± 7.80 | 5.62 ± 7.38 | 0.28 ± 6.50 | 0.003* |
| C2–7 ROM (°) | ||||
| Preoperative | 46.36 ± 13.55 | 45.16 ± 11.19 | 42.39 ± 10.40 | 0.260 |
| Postoperative 6 mo | 39.96 ± 11.38 | 33.11 ± 11.44 | 26.42 ± 13.69 | < 0.001* |
| Postoperative 6-mo change (Δ) | -6.41 ± 13.77 | -12.05 ± 15.19 | -15.97 ± 12.98 | 0.002* |
| Postoperative 12 mo | 44.08 ± 10.56 | 36.93 ± 9.79 | 26.02 ± 11.67 | < 0.001* |
| Postoperative 12-mo change (Δ) | -2.29 ± 13.74 | -8.22 ± 12.52 | -16.36 ± 13.40 | < 0.001* |
| Postoperative 24 mo | 43.60 ± 10.55 | 36.49 ± 9.20 | 24.76 ± 9.45 | < 0.001* |
| Postoperative 24-mo change (Δ) | -2.76 ± 14.15 | -8.67 ± 12.18 | -17.63 ± 13.26 | < 0.001* |
| Segmental angle (°) | ||||
| Preoperative | 1.45 ± 4.51 | 3.29 ± 6.66 | 8.32 ± 5.88 | < 0.001* |
| Postoperative 6 mo | 5.33 ± 3.84 | 7.38 ± 5.85 | 10.66 ± 6.34 | < 0.001* |
| Postoperative 6-mo change (Δ) | 3.89 ± 6.21 | 4.09 ± 8.52 | 2.33 ± 5.33 | 0.428 |
| Postoperative 12 mo | 3.41 ± 2.79 | 5.91 ± 5.93 | 9.38 ± 6.27 | < 0.001* |
| Postoperative 12-mo change (Δ) | 1.96 ± 4.16 | 2.62 ± 5.68 | 1.06 ± 4.81 | 0.325 |
| Postoperative 24 mo | 3.26 ± 2.78 | 6.17 ± 5.37 | 9.42 ± 6.11 | < 0.001* |
| Postoperative 24-mo change (Δ) | 1.76 ± 4.17 | 2.42 ± 5.67 | 0.86 ± 4.82 | 0.325 |
| Segmental height (mm) | ||||
| Preoperative | 37.25 ± 10.28 | 55.13 ± 5.66 | 75.59 ± 8.31 | < 0.001* |
| Postoperative 6 mo | 34.58 ± 6.12 | 54.23 ± 5.28 | 79.48 ± 9.32 | < 0.001* |
| Postoperative 6-mo change (Δ) | -2.67 ± 5.18 | -0.90 ± 2.54 | 3.89 ± 3.93 | < 0.001* |
| Postoperative 12 mo | 37.63 ± 4.56 | 56.34 ± 5.54 | 77.25 ± 7.98 | < 0.001* |
| Postoperative 12-mo change (Δ) | 0.38 ± 1.75 | 1.21 ± 2.47 | 1.66 ± 3.47 | 0.020* |
| Postoperative 24 mo | 36.93 ± 4.36 | 55.64 ± 5.23 | 76.55 ± 7.61 | < 0.001* |
| Postoperative 24-mo change (Δ) | -0.32 ± 1.75 | 0.51 ± 2.47 | 0.96 ± 3.47 | 0.020* |
| UDH (mm) | ||||
| Preoperative | 6.46 ± 1.02 | 6.50 ± 0.89 | 6.37 ± 0.71 | 0.809 |
| Postoperative 6 mo | 5.77 ± 0.88 | 5.80 ± 0.90 | 5.96 ± 0.93 | 0.545 |
| Postoperative 6-mo change (Δ) | -0.69 ± 0.63 | -0.70 ± 0.77 | -0.41 ± 0.62 | 0.077 |
| Postoperative 12 mo | 5.84 ± 0.91 | 5.81 ± 0.83 | 5.57 ± 0.91 | 0.281 |
| Postoperative 12-mo change (Δ) | -0.69 ± 1.04 | -0.69 ± 0.56 | -0.80 ± 0.87 | 0.786 |
| Postoperative 24 mo | 5.59 ± 0.82 | 5.57 ± 0.84 | 5.17 ± 0.87 | 0.032* |
| Postoperative 24-mo change (Δ) | -0.86 ± 0.67 | -0.93 ± 0.73 | -1.20 ± 0.89 | 0.070 |
| LDH (mm) | ||||
| Preoperative | 6.28 ± 0.96 | 6.25 ± 1.05 | 5.84 ± 1.19 | 0.089 |
| Postoperative 6 mo | 5.74 ± 0.97 | 5.74 ± 0.94 | 5.45 ± 1.12 | 0.305 |
| Postoperative 6-mo change (Δ) | -0.55 ± 0.72 | -0.51 ± 0.57 | -0.39 ± 0.43 | 0.435 |
| Postoperative 12 mo | 5.77 ± 0.84 | 5.47 ± 0.94 | 5.09 ± 1.09 | 0.001* |
| Postoperative 12-mo change (Δ) | -0.58 ± 0.99 | -0.78 ± 0.84 | -0.75 ± 0.44 | 0.392 |
| Postoperative 24 mo | 5.64 ± 0.74 | 5.44 ± 0.80 | 5.07 ± 1.06 | 0.004* |
| Postoperative 24-mo change (Δ) | -0.64 ± 0.54 | -0.81 ± 0.71 | -0.77 ± 0.51 | 0.251 |
| USROM (°) | ||||
| Preoperative | 13.56 ± 6.93 | 12.79 ± 6.06 | 10.77 ± 3.71 | 0.069 |
| Postoperative 6 mo | 17.11 ± 6.35 | 15.72 ± 6.53 | 13.19 ± 4.26 | 0.005* |
| Postoperative 6-mo change (Δ) | 3.56 ± 9.04 | 2.93 ± 9.45 | 2.43 ± 3.45 | 0.773 |
| Postoperative 12 mo | 16.54 ± 6.79 | 16.31 ± 5.87 | 17.71 ± 4.29 | 0.515 |
| Postoperative 12-mo change (Δ) | 2.98 ± 9.72 | 3.52 ± 7.25 | 6.95 ± 3.88 | 0.039* |
| Postoperative 24 mo | 16.91 ± 6.78 | 17.08 ± 5.62 | 19.37 ± 4.37 | 0.098 |
| Postoperative 24-mo change (Δ) | 3.36 ± 9.61 | 4.29 ± 7.46 | 8.60 ± 4.11 | 0.004* |
| LSROM (°) | ||||
| Preoperative | 13.37 ± 7.00 | 11.35 ± 6.86 | 11.70 ± 7.19 | 0.228 |
| Postoperative 6 mo | 14.07 ± 8.01 | 12.46 ± 6.67 | 11.03 ± 4.40 | 0.142 |
| Postoperative 6-mo change (Δ) | 0.69 ± 10.45 | 1.11 ± 9.82 | -0.67 ± 4.49 | 0.650 |
| Postoperative 12 mo | 13.95 ± 6.70 | 15.12 ± 6.73 | 13.96 ± 4.41 | 0.550 |
| Postoperative 12-mo change (Δ) | 0.58 ± 8.70 | 3.77 ± 8.29 | 2.26 ± 5.21 | 0.085 |
| Postoperative 24 mo | 14.29 ± 6.78 | 15.22 ± 6.11 | 14.24 ± 4.33 | 0.678 |
| Postoperative 24-mo change (Δ) | 0.92 ± 8.75 | 3.87 ± 8.29 | 2.54 ± 5.23 | 0.122 |
Values are presented as mean±standard deviation.
ACDF, anterior cervical discectomy and fusion; C2–7 SVA, C2–7 sagittal vertical axis; ROM, range of motion; UDH, upper segmental disc height; LDH, lower segmental disc height; USROM, upper segmental range of motion; LSROM, lower segmental range of motion.
*
p<0.05, statistically significant differences.