Patient self-reported outcomes as per fusion outcomes within the static cage group.
| Static Cage Group | Changesa in ODI (%): Mean (Range, SD) | ||
| 3 mo | 6 mo | 12 mo | |
| Poor fusion | 3.2 (−4 to 16, 7.6) | −3.5 (−22 to 14, 15.3) | −15.64 (−46 to 16, 22.0) |
| Satisfactory fusion | −10.29 (−36 to 18, 15.6) | −18 (−44 to 14, 17.6) | −23.87 (−58 to 18, 19.6) |
| P value | 0.045 | 0.171 | 0.256 |
| Changesa in VAS—Back: Mean (Range, SD) | |||
| 3 mo | 6 mo | 12 mo | |
| Poor fusion | −2.2 (−9 to 1, 4.2) | −3.5 (−9 to 1, 4.8) | −3.7 (−9 to 5, 4.1) |
| Satisfactory fusion | −2.58 (−6 to 2, 2.5) | −3.5 (−7 to 0, 2.1) | −4.24 (−10 to 2, 3.2) |
| P value | 0.520 | 0.983 | 0.661 |
| Changesa in VAS—Both Legs Combined: Mean (Range, SD) | |||
| 3 mo | 6 mo | 12 mo | |
| Poor fusion | −4 (−7 to 0, 3.3) | −3.17 (−8 to 2, 3.9) | −1 (−14 to 9, 6.1) |
| Satisfactory fusion | −5.83 (−12 to 1, 4.0) | −6.28 (−15 to 9, 5.1) | −7.11 (−14 to 1, 4.7) |
| P value | 0.478 | 0.091 | 0.048 |
| Changesa in SF-12 (PCS): Mean (Range, SD) | |||
| 3 mo | 6 mo | 12 mo | |
| Poor fusion | 9.68 (5.4–16, 4.5) | 10.65 (5.7–16.1, 5.0) | 11.81 (−0.4 to 29, 10.3) |
| Satisfactory fusion | 7.44 (−2.7 to 21.2, 7.1) | 10.03 (−1 to 22, 6.6) | 14.53 (−2.8 to 37, 9.9) |
| P value | 0.535 | 0.790 | 0.439 |
| Changesa in SF-12 (MCS): Mean (Range, SD) | |||
| 3 mo | 6 mo | 12 mo | |
| Poor fusion | −7.2 (−26.1 to 0.7, 10.9) | −6.43 (−17.8 to 9.3, 12.9) | 1.97 (−22.9 to 38, 15.2) |
| Satisfactory fusion | 0.55 (−13.2 to 12.9, 8.8) | 3.21 (−10.8 to 20, 6.7) | 5.05 (−23 to 28.2, 12.7) |
| P value | 0.142 | 0.202 | 0.514 |
Note: Poor fusion is defined as fusion Bridwell grade 3 or 4, with or without subsidence. Satisfactory fusion is defined as Bridwell fusion grade 1 or 2, with no radiographic evidence of subsidence.
↵a The value of the change is the difference between the score at the targeted follow-up minus preoperative baseline score. It denotes statistical significance. ODI (a score of 0–100, with higher scores indicating worse disability); VAS (a score of 0–20 for both legs combined, with higher scores indicating more severe pain); PCS (range of 0–100, with higher scores indicating better physical health functioning); MCS (range of 0–100, with higher scores indicating better mental health functioning).
MCS, mental component score; ODI, Oswestry Disability Index; PCS, physical component score; SF-12, 12-item short form survey; VAS, visual analog scale.