Introduction: Cervical stenosis is a defining feature of CSM. Matsunaga et al proposed that elements of stenosis are both static and dynamic, where the dynamic elements magnify the canal deformation of the static state. We hypothesize that dynamic motion may be associated with myelopathy severity and neck disability and present novel methods of dynamic motion analysis in CSM.
Methods: Post-hoc analysis of a prospective, multicenter database of patients with (CSM). 110 patients (34%) met inclusion criteria: symptomatic CSM, age over 18, baseline flexion/extension radiographs, and HRQOLs (mJOA, NDI, SF-36, and Nurick grade). The mean age was 57+12 years with 41% female (n=46). Correlations with HRQOLs were analyzed for regional and focal parameters in flexion and extension. Baseline dynamic parameters (F/E cone relative to a fixed C7, center of rotation, range of motion arc relative to the COR) were also analyzed for correlations to HRQOLs.
Results: At baseline, the mean HRQOLs demonstrated disability and the mean radiographic parameters demonstrated sagittal malalignment. Among regional parameters, there was a significant correlation between increased C2-C7 angle in flexion and Nurick grade (R=0.189, p 0.048) with no significant correlations in extension (Fig 1). Focal parameters including C7 slip were significantly correlated with disability (Flex R=-0.377, p 0.003; Ext R=-0.261, p 0.027). Reduced flexion/extension motion cones, a more posterior center of rotation, and smaller range of motion correlated with worse HRQOLs (Fig 1).
Conclusions: Dynamic motion analysis may play an important role in understanding CSM. Focal parameters demonstrated a significant correlation with worse HRQOLs especially C7 slip in flexion and extension. Novel methods of motion analysis demonstrated reduced motion cones correlated with worse myelopathy grades. More posterior center of rotation and smaller range of motion were both correlated with worse general health scores (PCS & Nurick).
Patient Care: The results of this study improves patient care by demonstrating that dynamic motion plays a role in development of cervical myelopathy.
Learning Objectives: By the conclusion of this session, participants should be able to:
1) Understand that dynamic motion analysis may play an important role in understanding CSM, 2) appreciate that novel methods of motion analysis demonstrated reduced motion cones correlated with worse myelopathy grades and 3) realize that more posterior center of rotation and smaller range of motion were both correlated with worse general health scores (PCS & Nurick).