Comparative Study of Preoperative Sagittal Spinal Pelvic Alignment in Patients with Cervical Spondylotic Radiculopathy, Ossification of the Posterior Longitudinal Ligament, and Cervical Spondylotic Myelopathy.

Objectives: Cervical spondylosis may lead to changes in the sagittal parameters of the neck and trigger compensatory alterations in systemic sagittal parameters. However, there is currently a dearth of comparative research on the changes and compensatory alterations to sagittal parameters resulting from different types of cervical spondylosis. This study compared the preoperative sagittal alignment sequences among patients with cervical spondylotic radiculopathy (CSR), ossification of the posterior longitudinal ligament (OPLL), and cervical spondylotic myelopathy (CSM) caused by factors resulting from non-OPLL factors.

Materials And Methods: Full length lateral X-ray of the spine and cervical computed tomography (CT) of 256 patients (134 men, 122 women; mean age, 56.9 ± 9.5 years) were analyzed retrospectively. A total of 4096 radiomics features were measured through the lateral X-ray by two spinal surgeons with extensive experience. The clinical symptoms measures were the Japanese Orthopaedic Association (JOA) score, number of hand actions in 10 s, hand-grip strength, visual analog scale (VAS) score. Normally distributed data was compared using one-way analysis of variance (ANOVA) for parametric variables and χ test were used to analyze the categorical data.

Results: In the OPLL group, the C2-C7 Cobb angle was greater than in the CSR and CSM groups (19.8 ± 10.4°, 13.3 ± 10.3°, and 13.9 ± 9.9°, respectively, p < 0.001). Additionally, the C7-S1 SVA measure was found to be situated in the anterior portion with regards to the CSM and CSR groups (19.7 ± 58.4°, -6.3 ± 34.3° and -26.3 ± 32.9°, p < 0.001). Moreover, the number of individuals with C7-S1 SVA >50 mm was significantly larger than the CSM group (26/69, 11/83, p < 0.001). In the CSR group, the TPA demonstrated smaller values compared to the OPLL group (8.8 ± 8.5°, 12.7 ± 10.2°, p < 0.001). Furthermore, the SSA was comparatively smaller as opposed to both the OPLL and CSM groups (49.6 ± 11.2°, 54.2 ± 10.8° and 54.3 ± 9.3°, p < 0.05).

Conclusion: Patients with OPLL exhibit greater cervical lordosis than those with CSR and CSM. However, OPLL is more likely to result in spinal imbalance when compared to the CSM group. Furthermore, OPLL and CSM patients exhibit anterior trunk inclination and worse global spine sagittal parameters in comparison to CSR patients.