Prevalence and distribution of thoracic and lumbar compressive lesions in cervical spondylotic myelopathy

Abstract

Study design: Retrospective cross-sectional study.

Purpose: This study analyzed the prevalence and distribution of horacic and lumbar compressive lesions in cervical spondylotic myelopathy as well as their relationships with cervical developmental spinal canal stenosis (DCS) by using whole-spine postmyelographic computed tomography.

Overview of literature: There are few studies on missed compressive lesions of the spinal cord or cauda equina at the thoracolumbar level in cervical spondylotic myelopathy. Furthermore, the relationships between DCS, and the prevalence and distribution of thoracic and lumbar compressive lesions are unknown.

Methods: Eighty patients with symptomatic cervical spondylotic myelopathy were evaluated. Preoperative image data were obtained. Patients were classified as DCS or non-DCS (n=40 each) if their spinal canal longitudinal diameter was <12 mm at any level or ≥12 mm at all levels, respectively. Compressive lesions in the anterior and anteroposterior parts, ligamentum flavum ossification, posterior longitudinal ligament ossification, and spinal cord tumors at the thoracolumbar levels were analyzed.

Results: Compressive lesions in the anterior and anteroposterior parts were observed in 13 (16.3%) and 45 (56.3%) patients, respectively. Ligamentum flavum and posterior longitudinal ligament ossification were observed in 19 (23.8%) and 3 (3.8%) patients, respectively. No spinal cord tumors were observed. Thoracic and lumbar compressive lesions of various causes tended to be more common in DCS patients than non-DCS patients, although the difference was statistically insignificant.

Conclusions: Surveying compressive lesions and considering the thoracic and lumbar level in cervical spondylotic myelopathy in DCS patients are important for preventing unexpected neurological deterioration and predicting accurate neurological condition after cervical surgery.

Keywords: Cervical surgery; Lumbar spine; Tandem spinal stenosis; Thoracic spine.

Fig. 1. (A) Compressive lesions in the anterior parts (i.e., disc herniation or osteophytes). (B) Compressive lesions in the anteroposterior parts (i.e., ligamentum flavum hypertrophy). (C) Ligamentum flavum ossification. (D) Posterior longitudinal ligament ossification.

Fig. 2. Distribution of compressive lesions in the anterior parts. DCS, developmental spinal canal stenosis; NDCS, non-developmental spinal canal stenosis.

Fig. 3. Distribution of compressive lesions in the anteroposterior parts. DCS, developmental spinal canal stenosis; NDCS, non-developmental spinal canal stenosis.

Fig. 4. Distribution of ligamentum flavum ossification. DCS, developmental spinal canal stenosis; NDCS, non-developmental spinal canal stenosis.

Fig. 5. Distribution of posterior longitudinal ligament ossification. DCS, developmental spinal canal stenosis; NDCS, non-developmental spinal canal stenosis.

Fig. 6. Computed tomography myelography of the cervical and lumbar spine. (A) Sagittal reconstruction image of the cervical spine showing degenerative spinal canal stenosis at the C3-4 level. (B) Sagittal reconstruction image of the lumbar spine showing degenerative spinal canal stenosis at the L3-4 and L4-5 levels. (C) Axial image of the lumbar spine showing severe degenerative spinal canal stenosis at the L4-5 level.