TABLE 4.
Cox Regression Analyses of Postoperative Deformity Progression in SMA Patients
| Scoliosis | PO | Concave-side Hip | ||||
|---|---|---|---|---|---|---|
| Progression (n=10) vs. Stable (n=19) | Progression (n=10) vs. Stable (n=14) | Progression (n=11) vs. Stable (n=15) | ||||
| Variables | HR (95% CI) | P | HR (95% CI) | P | HR (95% CI) | P |
| Age at surgery (y) | 1.03 (0.858–1.229) | 0.776 | 1.23 (1.036–1.448) | 0.017 | 0.89 (0.718–1.100) | 0.277 |
| Sex (male vs. female) | 0.24 (0.054–1.080) | 0.063 | 0.53 (0.130–2.183) | 0.382 | 0.41 (0.115–1.462) | 0.169 |
| BMI (kg/m2) | 0.98 (0.851–1.118) | 0.724 | 0.85 (0.707–1.025) | 0.089 | 0.97 (0.851–1.098) | 0.602 |
| SMA type (III vs. II) | 1.38 (0.285–6.709) | 0.687 | 4.73 (0.665–33.560) | 0.120 | 2.90 (0.692–12.180) | 0.145 |
| Pedicle screw use (yes vs. no) | 1.73 (0.428–7.017) | 0.441 | 1.78 (0.432–7.301) | 0.426 | 1.52 (0.444–5.228) | 0.503 |
| Triradiate cartilage (open vs. closed) | 1.32 (0.263–6.580) | 0.738 | 0.36 (0.044–2.996) | 0.348 | 0.98 (0.257–3.704) | 0.972 |
| Initial follow-up | ||||||
| MCCA (deg.) | 1.107 (1.039–1.178) | 0.002 | 1.083 (1.022–1.148) | 0.007 | 1.045 (0.999–1.093) | 0.053 |
| PO (deg.) | 1.177 (1.054–1.314) | 0.004 | 1.099 (0.908–1.329) | 0.332 | 1.213 (1.027–1.432) | 0.023 |
| Concave-side FHCP (%) | 0.982 (0.958–1.006) | 0.145 | 0.982 (0.956–1.008) | 0.178 | 0.986 (0.963–1.010) | 0.248 |
| Convex-side FHCP (%) | 1.046 (0.980–1.116) | 0.174 | 1.036 (0.971–1.106) | 0.280 | 1.021 (0.975–1.068) | 0.383 |
| Cutoff points of postoperative MCCA at initial follow-up | ||||||
| MCCA ≥20 vs. <20 degrees | 32.91 (0.023–46801) | 0.346 | 35.13 (0.055–22304) | 0.280 | 2.51 (0.317–19.817) | 0.384 |
| MCCA ≥25 vs. <25 degrees | 46.15 (0.133–16043) | 0.199 | 1.99 (0.417–9.516) | 0.388 | 5.21 (0.665–40.841) | 0.116 |
| MCCA ≥30 vs. <30 degrees | 12.02 (1.448–99.727) | 0.021 | 5.20 (1.070–25.232) | 0.041 | 6.42 (1.356–30.381) | 0.019 |
| MCCA≥35 vs. <35 degrees | 6.67 (1.330–33.460) | 0.021 | 3.90 (0.963–15.765) | 0.057 | 4.59 (1.187–17.709) | 0.027 |
Bolded values denote statistical significance to P<0.05.
BMI indicates body mass index; CI, confidence interval; FHCP, femoral head coverage percentage; HR, hazard ratio; MCCA, major curve of Cobb angle; PO, pelvic obliquity; SMA, spinal muscular atrophy.