Table 5. Re-operation incidence and cumulative failure estimatesa at 4 years after lumbar spinal fusion surgery patients by BMI (kg/m2).
| BMI category | Aseptic re-operationb | Re-operation due to ASD | |||
|---|---|---|---|---|---|
| Incidence, n (%) | Cumulative failure, % (95% CI) | Incidence, n (%) | Cumulative failure, % (95% CI) | ||
| Overall | 750 (9.3) | 14.4 (13.3–15.6) | 222 (2.8) | 6.0 (5.2–7.0) | |
| <25 | 164 (8.7) | 13.8 (11.6–16.3) | 52 (2.8) | 6.2 (4.6–8.4) | |
| 25–30 | 285 (9.1) | 14.4 (12.7–16.4) | 79 (2.5) | 5.8 (4.5–7.5) | |
| 30–35 | 199 (10.0) | 14.8 (12.7–17.2) | 56 (2.8) | 5.6 (4.1–7.5) | |
| 35–40 | 73 (9.3) | 13.7 (10.7–17.4) | 28 (3.6) | 7.4 (4.9–11.0) | |
| 40+ | 29 (10.8) | 18.0 (11.0–28.7) | 7 (2.6) | 5.7 (2.4–13.4) | |
a, Cumulative failure estimates defined as one minus the Kaplan-Meier survival estimates; b, re-operations for infection or non-union excluded. ASD, adjacent segment disease; CI, confidence interval; BMI, body mass index.