Table 2.

Average change of spinal parameter.

	Pre-op	Post-op 1 m	Post op 3 yrs	P value
O group
LL, °	36 ± 14	37 ± 14	37 ± 17	NS
PT, °	22 ± 10	20 ± 10	21 ± 9	NS
SS, °	29 ± 11	31 ± 10	30 ± 10	NS
PI-LL, °	15 ± 14	14 ± 13	13 ± 15	NS
T group
LL, °	40 ± 14	41 ± 13	41 ± 15	NS
PT, °	22 ± 7	23 ± 8	22 ± 8	NS
SS, °	30 ± 8	30 ± 8	30 ± 9	NS
PI-LL, °	13 ± 13	12 ± 13	11 ± 14	NS

Pre-op indicates preoperative; Post-op1m, postoperative 1 month; Post-op 3yrs, postoperative 3 years.