Clinical Impact and Correlations of Odontoid Parameters Following Multilevel Posterior Cervical Fusion Surgery

Abstract

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.

Optimizing Surgical Strategy for Cervical Spinal Deformity: Global Alignment and Surgical Targets

“…Functionally, a substantial T1S necessitates a corresponding CL to achieve harmonious alignment and facilitate horizontal gaze. Insufficient CL in this context results in a high T1S–CL, adversely impacting disability scores [ 49 ]. Oe et al [ 50 ] conducted a study on 656 volunteers aged 50 to 89 years and found that cSVA> 40 mm or more, T1S> 40°, and T1S–CL> 20° had worse EuroQoL-5 dimension health status scores.…”

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 Procedure

“…Studies on the parameters for determining the level of operation segment are being investigated due to the increase in long level of segments spinal surgery, including adult spinal deformity [ 5 - 7 ]. Additionally, there is a growing interest on the complications of long level of segment spinal surgery, and the research of which materials used for wound closure might significantly reduce the length of an operation [ 8 - 10 ].…”

Significance of Atlantoaxial and Subaxial Spinal Instability in Cervical Spinal Spondylosis: Commentary on “Clinical Impact and Correlations of Odontoid Parameters Following Multilevel Posterior Cervical Fusion Surgery”

“…The authors of this article have identified alterations in the angulation of the odontoid process and in the C2 slope in cases with multisegmental cervical spondylotic myelopathy. 16 These parameters indicate alterations in alignment and spinal balance and are additional evidences that indicate atlantoaxial instability. The authors have performed spinal stabilization from C3 below.…”

“…Craniovertebral junction has been essentially ignored in the management of degenerative spinal disease. The authors of this article have identified alterations in the angulation of the odontoid process and in the C2 slope in cases with multisegmental cervical spondylotic myelopathy [ 16 ]. These parameters indicate alterations in alignment and spinal balance and are additional evidences that indicate atlantoaxial instability.…”