Risk factors for proximal junctional kyphosis after posterior long-segment internal fixation for chronic symptomatic osteoporotic thoracolumbar fractures with kyphosis

Table 1 Demographic data

Groups	Sex		Age	BMD T value	Injury		Level				Time from injury to surgery
Groups	Male	Female	(years)	(SD)	sprain	fall	T₁₁	T₁₂	L₁	L₂	(years)
PJK Group (n = 30)	12	18	73.6 ± 5.3	− 4.5 ± 0.4	6	24	5	12	10	3	5.8 ± 2.2
Non-PJK Group (n = 65)	20	45	64.5 ± 5.2	− 3.5 ± 0.4	25	40	12	25	20	8	6.1 ± 2.8
χ²/t value	0.783		7.858	12.164	0.038		0.187				0.396
P value	0.376		0.000	0.000	0.845		0.980				0.652

ISSN: 1471-2482