TABLE 2. Clinical and radiologic characteristics of the seven study patients.

Case	Sex	Age (years)	Diagnosis	Level	OPLL thickness at the most severe site (mm)	Operation modality	Preoperative JOA score	Postoperative JOA score	Preoperative C2–C7 lordotic angle
1	M	56	OPLL	C2–C4	3.8	Undercutting C2	10	3	3
2	M	64	OPLL	C2–C7	5.4	Undercutting C2	11	4	13
3	M	51	OPLL	C2–C6	6.2	Undercutting C2	10	3	14
4	M	51	OPLL	C2–C7	7.3	Undercutting C2	11	2	8
5	F	58	OPLL	C2–C4	5.6	Undercutting C2	11	3	18
6	M	58	OPLL	C2–C6	6.1	Undercutting C2	10	3	16
7	M	73	OPLL	C2–C5	5.9	Undercutting C2	10	3	12

OPLL: ossification of posterior longitudinal ligament, JOA: Japanese Orthopedic Association.