Table 3.

The comparison of clinical and radiological characteristics between the subgroups LP and LN in the group PA

Clinical and radiological characteristics	Subgroup LP (laminoplasty) (n=5)	Subgroup LN (laminectomy) (n=11)
Age	61.00±3.54	62.36±8.77
Sex (M/F)	4/1	8/3
OPLL type
Continuous	1	3
Mixed	3	7
Segmental	0	1
Circumscribed	1	0
Interval between the initial and repeat surgeries (months)	56.60±74.61	62.64±26.69
Cobb’s angle on C2–7 (at the time of initial surgery) (°)	4.58±9.29	2.96±7.32
Cobb’s angle on C2–7 (at the time of repeat surgery) (°)	−3.32±13.03	−4.89±9.97
Changes of Cobb’s angle on C2–7 (between initial and repeat surgery) (°)	−7.90±5.61	−7.86±7.48
Segmental angle on the main OPLL lesion (at the time of initial surgery)* (°)	3.70±2.80	−0.10±4.02
Segmental angle on the main OPLL lesion (at the time of repeat surgery) (°)	−1.78±6.79	−3.85±6.22
Changes of segmental angle on the main OPLL lesion (between initial and repeat surgery) (°)	−5.48±5.69	−3.74±2.76

^*p<0.05.

subgroup LP: patients underwent laminoplasty as a posterior decompression at the initial surgery, subgroup LN: patients underwent laminectomy alone as a posterior decompression at the initial surgery, group PA: patients were approached posteriorly at the initial surgery and underwent anterior approach at the repeat surgery, M: male, F: female, OPLL: ossification of the posterior longitudinal ligament, negative angle: kyphotic curve, positive angle: lordotic curve