Objective C2 slope (C2S), a cervical parameter mathematically approximated as T1 slope minus cervical lordosis (T1S–CL), predicts functional improvement in cervical deformity patients. Nonetheless, C2S is a positional parameter based only on the horizontal axis. The current study aims to introduce novel odontoid parameters and establish their relationships with patient-reported health-related quality of life (HRQoL).
Methods Lateral plain radiographs of 32 adults who underwent multilevel posterior cervical fusion were analyzed. The odontoid parameters included odontoid incidence (OI), C2S, odontoid tilt (OT), and gravity line-C2 distance (GL-C2), while the cervical parameters were the Cobb angle at C0–1, C1–2, C0–2, C2–7, C2–7 sagittal vertical axis (cSVA), T1 slope, and T1S–CL. The range of motion (ROM) of the occipito-atlantoaxial complex was measured in flexion and extension plain radiographs. Scores on the Neck Disability Index (NDI) and visual analogue scale (VAS) for axial neck (VASn) and arm pain were measured.
Results Compared to asymptomatic subjects, patients had larger C2S, cSVA, and T1S–CL, and smaller OT. Preoperatively, OI was significantly correlated with the ROM of C1–2 (r = 0.37, p < 0.05) and C0–2 (r = 0.46, p < 0.01). OT and C2S had significant correlations with the C0–1, C1–2, and C0–2 angles, GL-C2, and T1S–CL. Postoperative NDI scores were significantly correlated with OI (r = -0.40, p < 0.05) and OT (ρ = -0.37, p < 0.05). VASn was significantly correlated with GL-C2 (r = -0.35, p < 0.05).
Conclusion The odontoid parameters were significantly correlated with established cervical parameters and HRQoL measures. OI is a constant parameter representing the individual's compensatory reservoir at the upper cervical spine.
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Objective By using angulation of the axis itself, this study aims to define and analyze odontoid incidence (OI) and odontoid tilt (OT) as novel cervical alignment parameters and investigate their correlations with cervical alignment.
Methods Novel and existing parameters were measured with whole-spine lateral plain radiographs and EOS images of 42 adults without cervical symptoms. The correlations of OI, OT, C2 slope (C2S), and T1 slope (T1S) were calculated.
Results The OI, OT, and C2S showed significant correlations with C2–7 angle (r = 0.43, r = -0.42, r = 0.62, respectively) and C0–2 angle (r = -0.33, r = 0.48, r = -0.61, respectively). OI, OT, T1S were independent predictors of the C2–7 angle in univariate regression analysis (adjusted-R2 = 0.17, R2 = 0.15, R2 = 0.28, respectively). OI, OT, and T1S were independent predictors in the multivariable regression analysis with estimated standardized coefficients of 0.36, -0.67, -0.69, respectively (adjusted- R2 = 0.80, p < 0.001). Regarding the C0–2 angle, OI and OT were independent predictors in the univariate regression analysis (adjusted-R2 = 0.08, R2 = 0.21, respectively).
Conclusion OI, OT, and C2S had significant correlations with cervical alignment. As the pelvic incidence, the OI is the only anatomical and constant parameter that could be used as a reference point related to the cervical spine from the rostral end. The study results may serve as baseline data for further studies on the alignment and balance of the cervical spine.
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Correlation analysis between preoperative odontoid incidence and clinical outcomes 2 years after anterior cervical discectomy and fusion Yan Gong, Hao Liu, Yanchi Gan, Jiahui He, Zelin Zhou, Hang Zhuo, Yu Liu, De Liang, Hui Ren, Xiaobing Jiang, Zhaojun Cheng Journal of Orthopaedic Surgery and Research.2025;[Epub] CrossRef
The effect of cervical spine flexion-extension motion on odontoid parameters Longao Huang, Dun Liu, Hongyuan Xu, Junfei Feng, Tao Kang, Shengwang Wei, Hua Jiang Journal of Orthopaedic Surgery and Research.2025;[Epub] CrossRef
Odontoid parameters in subjects with and without degenerative cervical spondylosis Tao Kang, Weiyou Chen, Longao Huang, Hongyuan Xu, Hua Jiang BMC Musculoskeletal Disorders.2025;[Epub] CrossRef
Assessment of posterior odontoid tilt: Think scoliosis Neel Raja, Elias Petrou, Sonal Saran, Hasaam Uldin, Morgan Jones, Fahid Rasul, Kapil Shirodkar, Shashank Chapala, Rajesh Botchu Journal of Craniovertebral Junction and Spine.2025; 16(3): 278. CrossRef
The Significance of Odontoid Incidence in Patients With Cervical Spondylotic Myelopathy Hongyu Qin, Weiyou Chen, Longao Huang, Xin Xiao, Qinghua Yang, Hua Jiang Global Spine Journal.2024; 14(8): 2374. CrossRef
Variation of Odontoid Incidence According to Age in Asymptomatic Children Yuwang Du, Weiyou Chen, Hongyuan Xu, Xiao Liang, Chongyang Wang, Hongyu Qin, Hua Jiang World Neurosurgery.2024; 190: e496. CrossRef
Odontoid incidence: a constant cervical anatomical feature evident in standing plain radiographs and supine magnetic resonance images Longao Huang, Weiyou Chen, Hongyuan Xu, Hongyu Qin, Hua Jiang Journal of Orthopaedic Surgery and Research.2024;[Epub] CrossRef
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Surgical and Clinical Outcomes Associated With the Use of Barbed Sutures and Self-Adhering Mesh System and Polymeric Glue for Wound Closure in Multilevel or Revision Spinal Surgery: A Matched Cohort Comparative Study With Conventional Wound Closure Proced Junho Mun, Seung-Jae Hyun, Jae-Koo Lee, Sungjae An, Ki-Jeong Kim Neurospine.2023; 20(3): 981. CrossRef
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Objective Maintaining cervical lordosis (CL) after laminoplasty is important for indirect decompression of the spinal cord. This study aimed to identify preoperative dynamic radiographic predictors for the loss of CL after laminoplasty.
Methods We retrospectively analyzed 141 consecutive patients who underwent cervical laminoplasty for cervical myelopathy. The following radiographic parameters were measured before surgery and at 1 year of follow-up: CL, C7 slope, C2–7 sagittal vertical axis (SVA), C2–7 range of motion (ROM), CL in flexion, CL in extension, ROM of flexion (Flex ROM), and ROM of extension. The CL ratio (CLR) was defined as 100 × Flex ROM/ C2–7 ROM. ΔCL was defined as postoperative CL minus preoperative CL. Patients were classified into 2 groups: group K (kyphotic change group, ΔCL ≤ -10) and group C (control group, ΔCL > -10).
Results The patient population comprised 94 men and 47 women (mean age, 70.9 ± 9.4 years), with 24 patients (17.0%) classified into group K. CL, C7 slope, and CLR were significantly higher in group K than in group C. The groups did not significantly differ in age, sex, C2–7 SVA, and C2–7 ROM. On multivariable analysis, the CLR was significantly associated with postoperative kyphotic changes. On receiver-operating characteristic curve analysis (area under the curve = 0.717, p < 0.001), the cutoff value for CLR was 68.9%, with sensitivity and specificity of 87.5% and 57.3%, respectively.
Conclusion The CLR, reflecting the balance between flexion and extension mobility, was identified as a novel predictor for CL loss after laminoplasty, with a cutoff value of 68.9%.
Citations
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