The clinical relevance of the presence of bridging syndesmophytes on kyphosis correction and maintenance following pedicle subtraction osteotomy for thoracolumbar kyphotic deformity in ankylosing spondylitis: a comparative cohort study

Table 2 Comparisons of patient demographic information, lordosing capability and correction loss per PSO segment between NBG and BG

Parameters	NBG	BG	t	p
Age	30.97 ± 8.28	40.31 ± 8.44	−4.687	0.000*
PI(°)	43.03 ± 10.60	49.36 ± 9.75	2.603	0.011*
LK(°)	19.59 ± 10.84	13.56 ± 8.50	−2.56	0.013*
Wedging index of OV	1.17 ± 0.16	1.09 ± 0.08	−2.635	0.011*
Instrumented segments	8.43 ± 1.25	8.06 ± 1.29	1.232	0.222
RCA(°)	20.03 ± 7.27	18.36 ± 8.28	−0.894	0.374
△PSA(°)	43.85 ± 8.71	40.22 ± 7.09	−1.895	0.062
△OVA(°)	35.74 ± 7.15	39.13 ± 6.99	2.003	0.049*
△ADWA(°)	8.10 ± 6.19	1.09 ± 2.88	−6.292	0.000*
Correction loss of △PSA(°)	2.62 ± 2.68	1.56 ± 2.11	−1.808	0.075
Correction loss of △OVA(°)	1.20 ± 2.14	1.34 ± 2.24	0.266	0.791
Correction loss of △ADWA(°)	1.41 ± 3.27	0.22 ± 1.49	−2.029	0.047*

*Indicates a statistically significant difference between the ossified and non-ossified groups (P < 0.05)
OVA indicates osteotomized vertebra angle, ADWA adjacent disc wedging angle, PSA pedicle subtraction angle, RCA rod contouring angle, OV osteotomized vertebra, PI pelvic index, LK local kyphosis

ISSN: 1471-2474