Operative strategies for ankylosing spondylitis-related thoracolumbar kyphosis: focus on the cervical stiffness, coronal imbalance and hip involvement

Table 1 The descriptions of the types and surgical strategies

Type	Subtype	Total number	Cervical stiffness	Coronal imbalance	Hip involvement	Strategies
Type	Subtype	25	8	6	10	Strategies
I	-	10	-	-	-	HP method
II	IIa	8	3	-	-	Modified CBVA method with or without HP method
	IIb		-	2	-	HP method and APSO
	IIc		-	-	3	HP method, Evaluating the state of hips, THA
III	-	7	5	4	7	All the above

HP Hilus pulmonis, CBVA Chin-brow vertical angle, APSO Asymmetric pedicle subtraction osteotomy, THA Total hip arthroplasty.

ISSN: 1471-2474