The diagnosis of “spinal canal stenosis” can be determined by spondylometry on routine radiographs, computed tomography (CT), magnetic resonance imaging (MRI) of the spine, on myelograms. The main designation is given to the value of the anteroposterior sagittal diameter of the spinal canal or dural SAC. The reduced distance from the posterior surface of the vertebral body to the nearest opposite zone on the arch at the base of the spinous process in any part of the spine up to 12 mm is characterized as stenosis of the spinal canal. A similar condition may result from soft tissue changes in the canal and epidural space (disc herniation, ossification of ligaments, epiduritis, lipoma), in such cases, stenosis is diagnosed by the degree of deformation of the dural SAC (MG, MRI). The root canal is considered to be narrowed when its minimum diameter at any level is equal to or less than 3 mm or when the root pocket does not contrast.
In conditions of stenosis of the vertebral or radicular canal, there is no correspondence of the capacity of the bone-fibrous case of the spine to the neurovascular formations enclosed in it. It creates a chronic pathogenetic situation with dynamic and permanent disorders of blood and liquor circulation, mechanical effects on nerve structures with a peculiar clinical picture that requires an appropriate therapeutic approach.
The most common cause of spinal canal narrowing is a combination of progressive dystrophic process in the discs, joints, ligaments of the spine with a pre-existing relatively small capacity of the canal as a result of congenital or constitutional features of the structure of the vertebral column (bodies, vertebral arches).
Osteochondrosis, complicated by protrusion or herniated disc, leads as it progresses to the development of segmental stenosis of the vertebral and radicular canals. At the stage of instability, stenosis is dynamic if the initial depth of the canal is sufficient, and then the restabilization of the vertebral segment eliminates clinical manifestations. Multiple lesions of the discs, joints and ligaments in primary osteoarthritis in the elderly causes polysegmental stenosis. Spondylarthrosis, lateral herniated discs cause selective stenosis of the root canal. In spondylarthrosis, primary osteoarthritis, the lesion usually occurs at several levels.
For a better understanding of the problem, we present the systematization of spinal canal stenosis, which reflects the etiology, nature of stenosis, clinical syndromes, severity and course of the disease.
- Stenosis of the spinal canal in disorders of development and formation of the skeleton.
1.1. Developmental abnormalities of the spine: complete or partial ankylosis of the vertebrae; side and rear wedge-shaped design and a butterfly vertebrae; abnormalities of the arches and articular processes of the vertebrae (hyperplasia, hypoplasia, asymmetry, impaired orientation and tropism); clefts of the vertebrae; anomalies lumbosacral transition (asymmetrical sacralization of the hyperplastic transverse processes of the transitional vertebra, hyperplasia of the spinous process of L—V with a cleft sacrum); multiple malformations of the vertebrae.
1.2. Dysplasia of the spine: achondroplasia, hypochondroplasia, spondyloepiphyseal dysplasia (disease Morquio), spondilolistesis disease (Chairman— May), osteopathy deformans (Paget’s disease), fibrous dysplasia, ectstasy chondrodysplasia, generalized hyperostosis, marble disease.
1.3. Constitutional stenosis of the spinal canal.
- Degenerative spinal stenosis: low back pain stage 3-4 with a pronounced osteophytosis bodies, articular processes; massive protrusion or the median disc herniation, lateral or foraminal herniated disc; subglottic sequestration of disc reactive cases; deforming spondiloarthrosis, the primary deforming osteoarthritis of the spine; ligamentous ossificans of the spine (hypertrophy, ossification of the posterior longitudinal and yellow ligaments); degenerative spondylolisthesis.
- Degeneratively acquired spinal stenosis: spondylolisthesis with spondylolysis; late complications of spinal cord injury; late complications of laminectomy; late complications of spinal fusion; late complications chemonucleolysis disk; late complications of spondylitis, epiduritis; complicated by idiopathic, neuromuscular or other spinal deformity (hyperlordosis, kyphosis, scoliosis); fluorosis; hormonal spondylopathy; the lipomatosis epidural space.
- Combined spinal stenosis (any combination of congenital, constitutional, acquired stenosis, protrusion or herniated disc).
- Characteristics of spinal canal stenosis.
5.1. Type of stenosis: spinal canal stenosis; radicular canal stenosis; combined spinal and radicular canal stenosis.
5.2. Localization and prevalence of spinal canal stenosis: along the axis of the spine (cervical, thoracic, lumbar and sacral canal stenosis); monosegmental, polysegmental, total, asymmetric, unilateral, intermittent with the presence of normal segments between the zones of stenosis.
5.3. Stage of development of stenosis: dynamic, fixed stenosis.
- Clinical syndromes of spinal canal stenosis.
6.1. Paroxysmal syndromes: neurogenic intermittent claudication (radicular, ponytail, spinal cord); paroxysmal convulsive syndrome; paroxysmal paresis of hands, feet; paroxysmal sensitivity disorders (paresthesia, thermal dysesthesia, hypesthesia); paroxysmal pelvic disorders; transient neurological deficit after mild spinal injury.
6.2. Permanent syndromes: reflex pain with muscle-dystonic, autonomic-vascular and neurodystrophic manifestations (cervicalgia, cervicobrachialgia, cervicobrachialgia, thoracalgia, lumbalgia, sciatica, sacralgia, coccygodynia); radicular (monoarticular, polyradicular, cauda equina syndrome); radicular-vascular (radiculomyeloischemia, infarction of the spinal cord, myelopathy).
- The nature and severity of clinical manifestations of spinal stenosis:
I degree-mild manifestations of intermittent claudication, mild pain, walking is not disturbed;
Grade II — moderately pronounced symptoms of intermittent claudication, moderate pain, walking moderately disturbed, the movement without assistance;
III degree-pronounced manifestations of intermittent claudication, severe pain, walking with help;
IV degree-severe manifestations of intermittent claudication, pronounced pain, the patient does not walk.
- The nature of the disease: progressive (fast or slow); recurrent (stage of exacerbation, remission, regression); stationary disease.