Study design: Retrospective analyses of prospectively collected data regarding 180 patients with cervical spondylotic myelopathy (CSM).
Objective: To detect the characteristics of C3-4 level CSM in elderly patients (C3-4CSM) (main analysis) and to validate the postoperative outcomes of anterior cervical discectomy and fusion (ACDF) and of laminoplasty (LAMP) (subgroup analysis).
Summary of background data: It remains unclear which surgical technique offers the best outcomes for CSM.
Methods: The main analysis included 180 patients with CSM, divided into two groups (C3-4CSM group, n = 46; conventional CSM group, n = 134) according to the findings of the preoperative physical examination and magnetic resonance imaging. The subgroup analysis included 46 patients with C3-4CSM, divided into two groups (ACDF group, n = 21; LAMP group, n = 25) according to surgical technique. Preoperative demographics and postoperative outcomes were compared.
Results: The age at surgery was higher, disease duration was shorter, and preoperative Japanese Orthopaedic Association (JOA) score was lower in the C3-4CSM group than in the conventional CSM group. Although the C3-4 range of motion was significantly higher, that of other levels was significantly lower in the C3-4CSM group. The anteroposterior diameter for levels C3-C7 was significantly larger in the C3-4CSM group. In the subgroup analysis using the repeated-measures analysis of variance, the postoperative JOA scores, and visual analog scale of neck pain were significantly better in the ACDF group.
Conclusion: Higher age, shorter disease duration, and worse JOA scores appear to be characteristic of C3-4CSM. In the management of C3-4CSM, ACDF provided better surgical outcomes than did LAMP; hypermobility at the C3-4 level, a radiological characteristic of C3-4CSM, may be one of key factors affecting surgical outcome. The chance to diagnose C3-4CSM is increasing with the increasing healthy life expectancy. To enable effective resolution of symptoms, C3-4CSM must be distinguished from conventional CSM.
Level of evidence: 4.