Table 3.

Correlation of surgical ligamentum flavum thickness and fibrosis

	Right LF r-value	p-value	95 % CI	Left LF r-value	p-value	95 % CI
(a) Correlation of Surgical LF Thickness and Fibrotic Grades
Group 1	-0.29	0.028	0.24–3.26	-0.42	0.069	-0.14–3.06
Group 2	-0.32	<0.001*	1.04–2.44	-0.22	<0.001*	0.84–2.21
Group 3	0.49	0.18	-0.42–1.46	0.72	0.059	-0.88–2.49
(b) Correlation of Surgical LF Thickness and Area of Fibrosis (%)
Group 1	-0.42	<0.001*	-59.11–-23.73	-0.31	<0.001*	-65.37–-41.31
Group 2	-0.41	<0.001*	-47.88–-34.39	-0.29	<0.001*	-53.87–-38.27
Group 3	0.65	0.008	-89.55–-29.46	0.50	0.019	-88.48–-16.41

LF: ligamentum flavum, CI: confidence onterval, %: percentage, r: correlation coefficient, * significant p-value; Group 1: critical developmental spinal stenosis (DSS), Group 2: relative DSS, Group 3: Non-DSS