Spinal stenosis means the space available for the spinal cord and nerves within the bony canal of the back bone, becomes narrow and causes undue pressure on the spinal cord and nerves. This narrowing causes a restriction to the functioning of spinal cord and nerves, resulting in weakness and numbness of the legs. Major symptoms include pain, numbness, tingling in legs and loss of muscle control. The location of the stenosis determines which area of the body is affected.
There are several types of spinal stenosis, with lumbar stenosis and cervical stenosis being the most frequent. While lumbar spinal stenosis is more common, cervical spinal stenosis is more dangerous because it involves compression of the spinal cord that controls upper and lower limbs. On the other hand, lumbar stenosis usually affects the functioning lower limbs only.
Making the diagnosis of spinal stenosis involves a complete evaluation of the spine. The process always begins with a medical history and physical examination. Imaging studies (x-ray, MRI, etc.) are often used to determine the extent and location of the nerve compression.
The medical history will tell the physician about subjective symptoms, possible causes for spinal stenosis, and other possible causes of back pain.
The physical examination of a patient will give the information about possible area of nerve pinching/compression. Some important factors that should be investigated are any areas of sensory abnormalities, numbness, and any muscular weakness.
The MRI has become the most frequently used study to diagnose spinal stenosis. The MRI uses magnetic signals (instead of x-rays) to produce images of the spine. MRIs are helpful because they show more structures, including nerves, muscles, and ligaments, than seen on x-rays or CT scans. MRIs are helpful at showing exactly what is causing spinal nerve compression.
A CT myelogram is used as a substitute investigation in patients with pacemakers where MRI can not be done.
There is no outright cure for ankylosing spondylitis, but there are treatments that can reduce discomfort and improve function. The goals of treatment are to reduce pain and stiffness, maintain a good posture, prevent deformity, and preserve the ability to perform normal activities. When properly treated, people with ankylosing spondylitis may lead fairly normal lives. Under ideal circumstances, a team approach to treat spondylitis is recommended. Members of the treatment team typically include the patient, doctor, physical therapist, and occupational therapist. In patients with severe deformities, surgery (osteotomy and fusion) can be done.
Non – Surgical / Conservative
- Education about the course of the condition and how to relieve symptoms
- Medicines to relieve pain and inflammation, under the guidance of a spine physician
- Exercise, to maintain or achieve overall good health,aerobic exercise, such as riding a stationary bicycle, which allows for a forward lean, walking, or swimming can relieve symptoms
- Weight loss, to reduce symptoms and slow down the progression of the stenosis.
- Physical therapy, to provide education, instruction, and support for self-care; physical therapy instructs on stretching and strength exercises that may lead to a decrease in pain and other symptoms.
Epidural steroid injection, though not of much long term benefit, but may help some patients to tide over difficult clinical situation when other definitive treatment is not available or the patient needs to make up his/her mind to get a definitive treatment done.
Lumbar Stenosis :
- Lumbar decompressive laminectomy – Removing the roof of bone overlying the spinal canal and thickened ligaments in order to decompress the nerves and spinal sac of nerves. 70-90% of people have good results.
- Lumbar Microdecompression under Microscope – when the number of spinal levels affected by stenosis are limited, then a microsurgical decompression can be employed to avoid the scars of big open surgery and still provide a reasonably good relief to the patient suffering from spinal compression.
- Lumbar decompression with spinal instrumentation – in certain cases of lumbar stenosis, the narrowing of the space in vertebral canal is also associated with some component of spinal instability or spinal deformity. In such cases, it is usually better to remove the pressure from spinal cord by decompression as well as to stabilize the instable spine and correct the spinal deformity as much as safely possible. This is accomplished by using high grade titanium screws and rods that are fixed to the deformed spine.
- Minimally Invasive Spinal instrumentation and decompression – Certain cases of spinal stenosis can be effectively managed using the minimally invasive spinal decompression and stabilization. The advantage in such cases is : less muscle damage in the back related to the surgical procedure, quicker rehabilitation and recovery of the patient, early return to function.
Cervical Stenosis & Its Treatment
Cervical Laminectomy – this is the simplest of the cervical spine decompression method to remove the roof of the bony spinal canal and relieve the pressure building upon the cervical spinal cord.
Cervical Laminectomy and screw instrumentation – In certain cases of cervical stenosis, it is important to stabilize the cervical spine along with removal of the pressure. This is again accomplished by using high grade medical titanium screws and rods that are fixed to the spinal column and used to provide stability.
Cervical Laminoplasty – this technique is very popular to remove pressure from multiple levels in the cervical spine without actually removing too much of the stabilizing bones. Certain cases of cervical stenosis can be managed very well using this technique.
Anterior Cervical Corpectomy and Fusion – in this surgical technique, the spinal canal is opened from the front of the neck and thickened ligaments and vertebrae are removed. The gap created by such removal of bone and discs is replaced by using either a bone graft from the patient’s body or artificial titanium cage/spacer. Spine is subsequently stabilized by using titanium plates and screws.
In certain comples cases of cervical spinal stenosis, a front and back surgery of the neck may be required to relieve the patients fully of their symptoms.
All the factors below may cause the spaces in the spine to narrow,
- Body’sligaments can thicken (ligamentum flavum)
- Bone spurs develop on the bone and into the spinal canal
- Intervertebral discsmay bulge or herniate into the canal
- Facet joints degenerate and become thick encroaching the space for nerves
- Compression fractures of the spine, which are common in osteoporosi
- Cysts form on the facet joints causing compression of the spinal nerves (thecal sac)
Spinal canal is too small at birth
Structural deformities of the vertebrae may cause narrowing of the spinal canal
3. Instability of the spine or spondylolisthesis
A vertebra slips forward on another
Accidents and injuries may dislocate the spine and the spinal canal or cause burst fractures that yield fragments of bone that go through the canal.
5. Tumors of the Spine:
Irregular growths of soft tissue will cause inflammation
Growth of tissue into the canal pressing on nerves, the sac of nerves, or the spinal cord.
- Standing discomfort
- Walking restriction beyong a few minutes
- Discomfort/pain, in shoulder, arm and hand
- Buttock / Thigh only
- Below the knee
- Pinched nerve,causing numbness
- Significant difficulty in walking beyond a few minutes. Patients usually walk for a short distance and their legs become painful, heavy and numb. Then they have to find a chair to sit to relieve themselves of these symptoms. This is called Intermittent neurogenic claudication characterized by lower limb numbness, weakness, diffuse or radicular leg pain associated with tingling/paresthesis in the legs, weakness heaviness in buttocks radiating into lower extremities with walking or prolonged standing. Minimal to zero symptoms when seated or lying down.
Radiculopathy – nerve dysfunction causes objective signs such as weakness, loss of sensation, etc.
Cauda equina syndrome: Lower extremity pain, weakness, numbness that may involve area around anus and buttocks, associated with bladder and bowel dysfunction (loss of control over urination and stool).
- Gait disturbance
- Structural deformity in the back
- Lethargy and inability to perfrom day to day tasks
- Presence of severe or progressive neurologic deficit
- Lower back paindue to degenerative disc or joint changes