(a)  

ODI		TDR (n = 25)	PTDS (n = 25)	a P
Preop ODI	Min–Max	40–100	46–98	0.847
	Mean ± SD	67.20 ± 20.79	66.16 ± 16.82
ODI (3 months)	Min–Max	12–56	12–38	0.069
	Mean ± SD	32.32 ± 10.87‡	27.16 ± 8.63‡
ODI (12 months)	Min–Max	4–34	2–26	0.010*
	Mean ± SD	18.00 ± 7.64‡	12.88 ± 5.75‡
ODI (24 months)	Min–Max	2–20	2–18	0.408
	Mean ± SD	9.12 ± 4.28‡	8.04 ± 4.53‡
	b P	0.001**	0.001**

^aStudent's t-test, ^brepeated measures test.

^‡Adjustment for multiple comparisons: Bonferroni P < 0.01.

*P < 0.05, **P < 0.01.