ABSTRACT
Objective:To explore the correlation between cervical curve and ossification of ligaments in cranio-cervical junction and cervical spine in patients with cervical degenerative diseases.Methods:A retrospective study was conducted among 458 patients with cervical degenerative disease who underwent cervical spine X-ray and CT examinations at the Orthopedics Department of Beijing Tiantan Hospital, Capital Medical University between January 2016 and July 2020. There were 265 males and 193 females, with an average age of 57.02±10.41 years (range, 22-87 years). Patients were divided into 5 types (lordosis, straight, S-type degenerative kyphosis, R-type degenerative kyphosis and C-type degenerative kyphosis). Cervical lordosis was defined as C 2-C 7 curve <-4°, cervical kyphosis was defined as >4°, cervical straight was defined as -4° to 4°. C 2-C 7 curve, C 0-C 2 curve were measured respectively, and correlations among these imaging parameters were analyzed. CT images were used to assess the presence of ossification of ligaments in cranio-cervical and cervical spine, including ossification of the posterior longitudinal ligament, nuchal ligament, ligamentum flavum, transverse ligament, apical ligament, diffuse idiopathic skeletal hyperostosis (DISH), as well as capped dens sign (CDS), and correlations between these cervical curve and presence of ossification of ligaments were analyzed. The different grades were based on the length of the ossification of interest with respect to the distance from the posterosuperior rim of the anterior arch of the atlas to the inferior margin of the foramen magnum on mid-sagittal cervical spine CT images, Grade 3 CDS was determined when the length was more than two-thirds. Results:There were 245 patients with cervical lordosis, 114 patients with straight, 53 patients with S-type degenerative cervical kyphosis, 36 patients with R-type degenerative cervical kyphosis and 10 patients with C-type degenerative cervical kyphosis. C 0-C 2 curve showed a negative correlation with C 2-C 7 curve in all enrolled patients ( r=-0.45, P<0.001) and R-type degenerative kyphosis group ( r=-0.58, P<0.001); C 0-C 2 curve showed no correlation with C 2-C 7 curve in lordosis ( r=-0.10, P=0.124), straight ( r=-0.11, P=0.233), S-type degenerative kyphosis ( r=-0.01, P=0.943) or C-type degenerative kyphosis groups ( r=0.03, P=0.946). CDS was detected in 38.4% (176/458) of patients, and Grade 3 was detected in 17.9% (82/458) of patients. The prevalence of CDS was correlated with R-type degenerative cervical kyphosis ( r=0.10, P=0.030). Cervical kyphosis, S-type degenerative kyphosis, C-type degenerative kyphosis, C 2-C 7 curve and C 0-C 2 curve showed no correlation with ossification of the posterior longitudinal ligament, nuchal ligament, ligamentum flavum, transverse ligament, apical ligament, diffuse idiopathic skeletal hyperostosis (DISH) or different grades CDS ( P>0.05). Conclusion:R-type degenerative cervical kyphosis are more likely to correlate with the cranio-cervical curve and CDS, which is an ossification of ligament in cranio-cervical junction.
ABSTRACT
Objective:To explore sagittal parameters change of upper cervical spine after anterior cervical decompression and fusion (ACDF) and analyze the influential factors by comparison between single-, double- and multi-level surgery.Methods:In this retrospective study, 126 patients (include 60 patients with radiculopathy, 41 patients with myelopathy and 25 patients with myeloradiculopathy) who underwent ACDF between December 2016 and December 2018, were followed up at least 1year ranged from14 to 38 months, with the average of 25.6±7.2 months. 20 patients were operated by single-level ACDF, 45 patients were operated by double-level ACDF and 61 patients were operated by 3- or 4-level ACDF. Standing radiographs of cervical spine and the flexion and extension cervical X-rays were obtained in all patients at 1week before, 3 months after and 1year after operation. The Japanese Orthopaedic Association (JOA) Scores, visual analogue scale (VAS) and neck disability index (NDI) were used to evaluate the clinical effectiveness. Cervical sagittal parameters were assessed with the following parameters: the platform angle of axis (C2Slope), the cobb angle and the range of motion (ROM) of C2-7, C0-1 and C1-2.Results:All the patients obtained satisfactory clinical effects. The mean operative time of single-, double- and multi-level group were 86.4±15.5 min, 117.6±15.6 min and 170.2±28.7 min, respectively. The intraoperative blood loss of 3 groups were 16.5±5.2 ml, 37.2±30.5 ml and 63.4±41.5 ml, respectively. There was statistically significant difference between the 3 groups ( P<0.05). In the single- and double-level groups, the changes of the cobb angle and ROM of upper cervical spine between 1 week before operation and 1 year after operation was no significant difference ( P>0.05). In the multi-level group, the ROM of atlantooccipital joint (C0-1) increased significantly from 11.5°±6.1° before operation to 16.1°±13.9° 3 months and 15.3°±4.8° 1 year after operation ( P<0.05). The cobb angle of upper cervical spine and C2Slpoe was decreased significantly from 21.0°±7.6°, 6.1°±6.7° before operation to 18.6°±7.7°, 4.3°±6.9° 3 months and 19.7°±7.2°, 5.6°±6.3° 1 year after operation respectively ( P<0.05). However, there was no significant difference of cobb angle ofatlantooccipital joint between 1 week before operation and 1 year after operation ( P>0.05). Conclusion:Single- and double-level surgery makes a better ability of preserving the restoration of cervical lordosis, with little impact on the upper cervical spine, meanwhile multi-level fusion shows a negative influence on the restoration and limits the range of motion, also increases risk of surgical operation and degeneration of the atlantooccipital joint, with the increased stress distribution and range of motion.