Sagittal alignment of the cervical spine: radiographic analysis of 111 asymptomatic adolescents, a retrospective observational study

• Published in: BMC musculoskeletal disorders Vol. 23; no. 1; pp. 1 - 9
• Main Authors: Zhu, Yanjie, Zhang, Xinkun, Fan, Yunshan, Zhou, Zhi, Gu, Guangfei, Wang, Chuanfeng, Feng, Chaobo, Chen, Jia, He, Shisheng, Ni, Haijian
• Format: Journal Article
• Language: English
• Published: London BioMed Central 03.09.2022; BioMed Central Ltd; Springer Nature B.V; BMC
• Subjects: Adolescents; Adults; Asymptomatic; Asymptomatic adolescent; C2-7 Cobb; C2-7 plumb line; C7 Slope; Cervical morphology; Correlation analysis; Diagnosis, Radioscopic; Epidemiology; Internal Medicine; Medical examination; Medicine; Medicine & Public Health; Morphology; Musculoskeletal diseases; Observational studies; Orthopedics; Physiological aspects; Rehabilitation; Rheumatology; Sacrum; Sagittal alignment parameter; Spine; Spine (cervical); Sports Medicine; Statistical analysis; Surgical outcomes; Teenagers; Youth; China; Cervical morphology; C2-7 Cobb; C7 Slope; C2-7 plumb line; Sagittal alignment parameter; Asymptomatic adolescent
• ISSN: 1471-2474; 1471-2474
• DOI: 10.1186/s12891-022-05792-x

Purpose To describe the cervical spine morphology and explore its relationship to global sagittal alignment parameters in the asymptomatic adolescent population.  Methods A total of 111 adolescent subjects were included. Sagittal alignment parameters, including C7 Slope, C2-C7 Cobb, C2-7 plumb line (PL), C2-S1 Sagittal Vertical Axis (SVA), C7-S1 SVA, T5-12 Cobb, T10-L2 Cobb, L1-S1 Cobb, pelvic incidence (PI), pelvic tilt (PT) and sacral slope (SS), were obtained from lateral radiographs.  Results Forty-four males and sixty-seven females with a mean age of 16.12 ± 2.40 years were included in this study. The mean values of C7 Slope, C2-7 Cobb and C2-7PL were 20.45 ± 8.88°, -7.72 ± 12.10°, and 13.53 ± 11.63 mm, respectively. C2-7 Cobb, C7 Slope showed significant differences between the male and female groups. Correlation analysis showed that C7 slope was significantly correlated with C2-7 Cobb ( r  = -0.544, P  < 0.001), C2-S1 SVA ( r  = 0.335, P  < 0.001), and C7-S1 SVA ( r  = 0.310, P  = 0.001), but not lumbosacral parameters(L5-S1 Cobb, PI, PT, SS). Using a modified method of Toyama to describe the cervical spine morphology, there were 37 cases (33.3%) in the Lordotic group, and C7 slope, C2-7 Cobb and C2-7PL showed significant differences between groups. According to C2-C7 Cobb, there were 80 Lordotic cases (72.1%). C7 slope and C2-7PL were significantly different between the two groups. Conclusion The cervical spine morphology of asymptomatic adolescents varies widely, from lordotic to kyphotic. Combining different classification methods provides a better understanding of the morphology of the cervical spine. C7 slope is an important predictor of global sagittal balance and C2-7PL is a key parameter for restoring cervical lordosis, which should be considered pre-operatively and for conservative treatment. Cervical regional sagittal alignment parameters are not correlated with lumbosacral parameters, and C2-7 Cobb, C7 Slope showed significant differences between males and females.