Effects of single-level dynamic cervical implantation on the cervical alignment and range of motion
LI Zhong-hai
HOU Shu-xun
WU wen-wen
YU Shun-zhi
HOU Tie-sheng
Abstract：Objective To observe the changes of the cervical alignment and range of motion ( ROM ) after single-level dynamic cervical implant ( DCI ) implantation for patients with cervical spondylosis, and to evaluate its safety and efifciency. Methods From August 2009 to January 2012, 17 patients with cervical spondylosis were received and treated according to the indications of DCI implantation, including 4 cases of cervical spondylotic myelopathy and 13 cases of cervical spondylotic radiculopathy. There were 7 males and 10 females, with a mean age of 43.4 years old ( range;36-53 years ). The affected segments included C3~4 in 1 case, C4~5 in 6 cases, C5~6 in 6 cases and C6~7 in 4 cases. Anterior cervical discectomy and DCI implantation after spinal canal decompression were performed on 17 patients. The ROM of DCI implantation segments and adjacent segments preoperatively and in the latest follow-up was measured, as well as the Cobb’s angle of DCI implantation segments at functional spinal unit ( FSU ) and the overall cervical alignment Cobb’s angle from C2~7. The adjacent segment degeneration was evaluated according to Miyazaki classiifcation of cervical disc degeneration. Results All patients were followed up for a mean period of 19.4 months ( range;12-41 months ). The ROM of DCI implantation segments was ( 7.8±2.2 ) ° preoperatively and ( 8.4±2.5 ) ° in the latest follow-up respectively, without statistically signiifcant difference ( P>0.05 ). The ROM at adjacent segment level was ( 8.3±1.9 ) ° and ( 8.7±2.1 ) ° preoperatively and ( 8.5±2.1 ) ° and ( 8.8±2.4 ) ° in the latest follow-up respectively, without statistically signiifcant difference ( P>0.05 ). The Cobb’s angle of DCI implantation segments at FSU was ( 0.4±5.1 ) ° preoperatively and ( 3.7±5.5 ) ° in the latest follow-up respectively, with statistically signiifcant <br> differences ( P<0.05 ). The overall cervical alignment Cobb’s angle was ( 7.8±11.2 ) ° preoperatively and ( 8.6± 10.7 ) ° in the latest follow-up respectively, without statistically signiifcant difference ( P>0.05 ). All patients gained MRI follow-up. Disc degeneration up to 1 grade occurred to 3 of 34 ( 9%) adjacent segments, and no relative clinical symptom appeared. Conclusions DCI in the treatment of single-level cervical spondylosis can effectively improve FSU kyphosis and recover cervical local lordosis, as well as preserve the kinematics characteristics of operation segments, adjacent segments and the whole cervical spine. Theoretically, DCI is conducive to the prevention of adjacent intervertebral disc degeneration, which still should be further assessed after a long-term follow-up.
Keywords：Cervical spondylosisFollow-up studiesIntervertebral disc degenerationSpinal fusionOrthopedic procedures
Publication Date：2013-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：6( 574-579 )