Abstract:

BACKGROUND: Cervical disc replacement is widely used for cervical spondylosis as it can maintain cervical motion of the target segments and reduce the degeneration of adjacent segments. But few studies have focused on the influence of intra-operative cervical posture in the cervical disc replacement to the post-operative cervical motion.
OBJECTIVE: To check the correlation between intra-operative cervical posture and post-operative cervical motion in cervical disc replacement.
METHODS: Forty-nine patients that underwent single segmental PRESTIGE LP cervical disc replacement surgery from January 2008 to July 2010 in West China Hospital, Sichuan University were enrolled in this retrospective study. X-ray film of the C-arm fluoroscopy as well as the cervical sagittal neutral position and dynamic position (hyperextension, flexion) before and after replacement were collected, and the target intervertebral disc Cobb angle was measured. Linear correlation and regression were preformed to analyze the relation between angle difference before and during replacement and motion improvement before and after replacement.
RESULTS AND CONCLUSION: There was no significant difference of the lordotic angle of the aimed disc during cervical disc replacement before and after replacement (P > 0.05); after replacement, the angle of the artificial disc was improved in neutral position, hyperextension and flexion (P < 0.01), and there was no significant difference of the overall range of motion after replacement; the overall range of motion was increased in flexion direction (P < 0.01), and there was no significant difference of the overall range of motion in extension direction (P > 0.05). There was a linear correlation between the angle and range of motion and angle difference before and during replacement (P < 0.01). A moderate lordotic intra-operative cervical posture is vital to range of motion artificial disc after cervical disc replacement, especially in the flexion direction.