TABLE 5.

Cox Regression Analyses of Postoperative Deformity Progression in SMA Patients After Adjusting for Age, Sex, SMA Type, and BMI

	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
Pedicle screw use (yes vs. no)	1.60 (0.367–7.016)	0.530	1.71 (0.359–8.159)	0.500	4.29 (0.753–24.414)	0.101
Triradiate cartilage (open vs. closed)	0.10 (0.006–1.712)	0.112	0.01 (0.00–0.866)	0.043	0.12 (0.013–1.126)	0.064
Initial follow-up
MCCA (deg.)	1.217 (1.051–1.410)	0.009	1.132 (1.017–1.261)	0.024	1.042 (0.988–1.099)	0.130
PO (deg.)	1.188 (1.031–1.370)	0.017	1.129 (0.888–1.436)	0.323	1.181 (1.007–1.384)	0.041
Concave-side FHCP (%)	0.982 (0.957–1.009)	0.193	0.972 (0.940–1.005)	0.094	0.980 (0.951–1.010)	0.185
Convex-side FHCP (%)	1.041 (0.969–1.118)	0.271	1.007 (0.948–1.070)	0.815	1.022 (0.971–1.076)	0.396
Cutoff points of postoperative MCCA at initial follow-up
MCCA ≥20 vs. <20 degrees	*	*	*	*	3.29 (0.378–28.623)	0.280
MCCA ≥25 vs. <25 degrees	*	*	6.12 (0.519–72.124)	0.150	4.98 (0.616–40.216)	0.132
MCCA ≥30 vs. <30 degrees	17.75 (1.539–204)	0.021	6.75 (0.947–48.184)	0.057	7.08 (1.224–40.920)	0.029
MCCA≥35 vs. <35 degrees	9.77 (1.161–82.151)	0.036	3.41 (0.612–18.979)	0.162	5.18 (1.128–23.785)	0.034

Bolded values denote statistical significance to P<0.05.

*Estimated cannot be computed.

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.