Clinical and radiological outcomes of dynamic cervical implant arthroplasty: A 5-year follow-up

Table 3 Radiographic range of motion (°), alignment (°), and intervertebral height (mm) preoperatively and at five follow-up intervals

	Preop	1-mo	6-mo	12-mo	24-mo	60-mo
C2-C7 ROM	50.2 ± 14.6	44.8 ± 12.6a	48.2 ± 13.6	48.9 ± 13.8	49.4 ± 14.4	49.2 ± 13.7
FSU ROM	8.7 ± 3.1	6.2 ± 2.8a	8.0 ± 2.6	8.5 ± 2.7	8.3 ± 2.5	8.0 ± 2.5
Upper adjacent level ROM	9.3 ± 4.0	7.4 ± 3.8a	9.5 ± 3.4	9.4 ± 3.2	9.1 ± 3.0	9.0 ± 3.1
Lower adjacent level ROM	8.5 ± 3.2	7.1 ± 2.5a	7.9 ± 2.6	8.1 ± 2.7	8.4 ± 2.9	8.8 ± 2.7
C2-C7 left lateral bending	27.9 ± 9.6	21.4 ± 5.9a	27.3 ± 7.8	25.6 ± 8.1	26.7 ± 7.8	26.3 ± 8.1
C2-C7 right lateral bending	30.3 ± 10.2	22.6 ± 6.5a	28.8 ± 7.6	27.3 ± 8.5	27.5 ± 7.9	26.8 ± 7.7
FSU left lateral bending	3.5 ± 1.6	1.5 ± 0.4a	1.4 ± 0.4a	1.2 ± 0.3a	1.2 ± 0.5a	1.1 ± 0.3a
FSU right lateral bending	3.4 ± 1.6	1.6 ± 0.5a	1.6 ± 0.6a	1.3 ± 0.4a	1.2 ± 0.3a	1.0 ± 0.2a
C2-C7 alignment	10.3 ± 9.0	13.5 ± 7.6a	14.5 ± 8.9a	16.3 ± 9.4a	15.9 ± 7.8a	16.5 ± 7.9a
FSU angle	2.2 ± 1.6	3.4 ± 1.2a	4.5 ± 1.9a	5.4 ± 1.7a	5.3 ± 1.6a	5.5 ± 1.5a
Intervertebral height	4.2 ± 1.2	6.0 ± 1.3a	5.8 ± 1.6a	5.7 ± 1.4a	5.5 ± 1.3a	5.2 ± 1.1a

^aP < 0.05, compared with preoperative value. ROM: Range of motion; FSU: Functional spinal unit; FSU angle: The alignment of the operated segment.