Spinal Stenosis

Introduction

The spinal canal is a space surrounded by the front of the vertebrae, the vertebral body, the intervertebral disc, and the back of the vertebrae, the lamina arcus vertebrae. The spinal canal connects from the lower part of the skull to the cervical, thoracic, lumbar and sacral vertebrae, and within the spinal canal there is a spinal cord extending from the soft water to the upper lumbar spine, and at the bottom there is a cauda equine, a bundle of nerve roots connected to the spinal cord. Spinal stenosis is the narrowing of the spinal canal, the passage through which nerves pass. The term spinal stenosis is used mainly in the lumbar region. In spinal stenosis, magnetic resonance imaging (MRI) shows that the cerebrospinal fluid that does not look normal inside the dural lining of the nerves in the spinal canal does not pass through the cerebrospinal fluid.

Many researchers have reported on spinal stenosis, and in 1976 more than 20 orthopedic and neurosurgeons gathered to define spinal stenosis as a type of narrowing of the central spinal canal, lateral recess, or intervertebral foramen. It may be local, segmental, or general, and the cause of this narrowing is due to bone or soft tissue. Recently, many scholars have used this to develop lumbar spinal stenosis, including various intermittent claudications by compressing the umbilical cord or nerve roots due to spinal canal or intervertebral cavity narrowing. It is defined as a disease causing.

Studies on the incidence and prevalence of spinal stenosis are insignificant and not exactly known. Radiography may show pressure on the hips in about 20% of elderly people over 60 years of age, and in about 10% of men over 75 and 25% of women, degenerative spondylolisthesis can be observed. Surgical treatment includes 1 spinal decompression every 1,000 people in North America aged 65 and older. The frequency of spinal stenosis by age has increased 19 times in 1990 compared to 1979. Is the increase of surgical treatment for spinal stenosis is due to an increase in the actual incidence of spinal stenosis due to an increase in the elderly population, or more spinal stenosis has been diagnosed due to the development of radiological diagnostic techniques, or for spinal stenosis It is not clear whether there are a lot of active treatments.

Cause and Classification

Because the definition of spinal stenosis can be so broad and arbitrary, supplementation to it has required classification by the nature of the disease. Arnoldi et al. Classified congenital or developmental and acquired spinal stenosis and classified them according to pathological findings that caused anatomical location and stenosis.¹ This classification is the most widely used to date, with some modifications and supplements, according to many authors, as follows:

1. Congenital, developmental spinal stenosis

• Idiopathic
• Cartilage aplasia

2. Acquired spinal stenosis

1) Degenerative

• Center of spinal canal
• Around the spinal canal
• Lateral recesses, neuromuscular canals
• Intervertebral cavity
• Degenerative anterior dislocation

2) Mixed (congenital, degenerative, or mixed disc herniation)

3) Spinal Anterior Spondylolisthesis

4) Nosocomial

• After plaque disc resection
• After spinal fixation

5) Traumatic

6) Other

• Paget’s disease
• Fluorosis

Congenital, developmental spinal stenosis appears as a characteristic form in which the distance between the pedicle narrows toward the distal lumbar region, as in dwarfism in cartilage aplasia, or in normal-height people with short pedicles. These congenital spinal stenosis is a normal vertebral canal due to the short pedicle, but has a trilobal spinal canal and causes central stenosis due to the reduction of front and rear pedicle. Congenital and developmental spinal stenosis often occurs in the early 30s, the age at which degenerative changes begin because there is no free space in the spinal canal.

The most common degenerative spinal stenosis begins in its fifties and sixties, and lateral cavities and intervertebral stenosis are common, in addition to central stenosis. It occurs most often in the 4-5 lumbar intervertebral column, and also occurs in the 3-4 lumbar intervertebral and the fifth lumbar-first lumbar intervertebral column.

In the past, many were reported in men, but recent reports tend to be more prevalent in women. Especially in the case of degenerative spondylolisthesis, it occurs four to six times in women, which is explained by the relaxation of the ligaments under the influence of hormones. Many diseases or syndromes may be involved in the development of spinal stenosis, but most rarely contribute directly to the occurrence of spinal stenosis, and spinal stenosis caused by these diseases is accompanied by degenerative changes at an earlier age than normal stenosis. Will appear.

Pathology

The absolute criterion for central spinal stenosis is defined as the case in which the anterior and posterior lengths of the spinal canal are less than 10 mm on a computed tomography (CT) scan and the relative stenosis is less than 13 mm.

According to Kirkaldy-Willis and Farfan, one segment of the lumbar spine consists of three joint complexes, two posterior joints and one intervertebral disc.² First, the degenerative change of the intervertebral disc occurs, which narrows the intervertebral disc space, which changes the load characteristics applied to the posterior joint. After the degeneration of the posterior joint, abnormal movement occurs, which leads to degenerative changes in the joint, thickening and thickening of the yellow ligaments. This series of degenerative changes reduces the volume of the spinal canal.

Central spinal stenosis develops from yellow ligament thickening, intervertebral disc protrusion, anterior spondylolisthesis, thickening of the facet joints, and degenerative hip joint cysts. Usually, central spinal stenosis is caused by a thickening of the posterior joint in the intervertebral disc into the spinal canal, mainly due to the thickening of the lower spine of the upper spine. Spinal stenosis, due to soft tissue thickening, accounts for 40% of central spinal stenosis, due to the narrowing of the intervertebral discs and the subluxation of the posterior joint resulting in a decrease in the upper and lower lengths of the spinal canal. That is, soft tissues, such as yellow ligaments, posterior joints, and posterior ligaments, occupy a significant portion of the cross section of the spinal canal, causing spinal stenosis. In patients with spinal stenosis caused by the soft tissues described above, the symptom worsens when the back is stretched because the yellow ligament is inserted into the spinal canal and the stenosis becomes severe.

Lateral lumbar spinal stenosis accounts for 8-11% of all lumbar neuromyopathy, and lateral lumbar stenosis can be divided into three parts:

• Stenosis of the entrance zone (lateral recess, lateral recess)
• Stenosis of the mid zone
• Stenosis of the exit zone

The lateral recess is a space surrounded by coronary projections on the back, the dura on the inside, the pedicle on the outside, and the vertebral and intervertebral discs on the front, where nerve roots begin to surround the cerebrospinal fluid and nerve fascia. Normal lateral recesses are at least 5 mm high and lateral stenosis at 3-4 mm.

The middle part is a space consisting of the pars interarticularis in the rear, the pedicle in the upper part, the vertebrae in the front, and the spinal canal in the inner part. In this area, the compression of the nerve roots occurs due to fibrocartilage tissue thickened by a defect in the isthmus, by pedicle in the presence of rotational deformation of the vertebrae, or asymmetrically in the intervertebral disc spacing.

The outlet intervertebral cavity is surrounded by upper and lower pedicles, anterior vertebrae, intervertebral discs, posterior joints and yellow ligaments. The normal intervertebral cavity is 20-30 mm high, 8-10 mm wide and 40-160 mm2 wide. If the height of the intervertebral cavity is less than 15 mm or the height of the posterior intervertebral disc is less than 4 mm, nerve root compression in the intervertebral cavity occurs.

The causes of intervertebral stenosis can be both static and dynamic. The static cause is degenerative spondylosis, which is caused by a decrease in the intervertebral disc spacing and dislocation of the lower posterior joint in the anterior and upward direction. Also, in the anterior region, intervertebral stenosis may occur by intervertebral disc protruding or by the formation of a bony pole (bones that grow like spines due to degenerative changes) of the vertebral cartilage endplate. In general, the volume of the intervertebral cavity increases by 12% when the waist is bent, but the volume of the intervertebral cavity decreases by 15% when the waist is unfolded. I can explain.

Intervertebral stenosis is a major cause of spinal failure syndrome, and 60% of those who have symptoms after surgery do not know that the nerve roots are compressed in the intervertebral cavity during surgery, and thus they cannot decompress (relax) the compressed nerve roots in the intervertebral cavity. Because

Symptoms

Since spinal stenosis is mostly caused by degenerative, the initial symptoms are similar to degenerative spondylitis and begin slowly. Vague lukewarm pain and stiffness appear on the lower back, which is alleviated by exacerbation and warming in a humid and cold climate. In addition, it is typical to improve when the activity worsens and stabilizes.

Depending on their cultural background, customs, personal experience, or sensitivity to pain, they may not stay in the hospital for many years, and they may see a doctor when their symptoms worsen. I accept it. In general, when symptoms occur frequently and become worse, especially when daily activities such as walking or going to the market are disturbed, the doctor visits the doctor. Symptoms are neurotic intermittent lameness (a pain when walking and less pain when stopping). Getting closer to you, pain, numbness, cramps, numbness, muscle weakness, etc. 85% of patients feel dull pain, 57% have paresthesia, 47% have weakness in the lower extremity muscles, and 15% have a feeling of cramping. Symptoms begin in the back and buttocks and gradually spread toward the knee, often inconsistent with the appearance of the skin nerve distribution. Symptoms of the lower extremities usually appear asymmetrically on one leg, but may also appear on both legs. Symptoms of one skin nerve distribution are typical neuromuscular lesions that are common in severe intervertebral or lateral stenosis. Sudden appearance or worsening sciatica symptoms may indicate the presence of nucleus prolapse in existing spinal stenosis.

Since the size of the spinal canal depends on the posture, symptoms usually worsen when the waist is extended and improve when bent. In patients who develop symptoms in a standing or back position, 80% of people sit down and bend their backs and only 75% or more experience relief of the symptoms. Most patients do not clearly explain their symptoms, but they know that they can be alleviated if they are bent or sitting, bent on a chair or pole, or bent on a wall. Many patients experience a gradual decrease in walking distance over many months. Even if you can’t walk much, you’re not going to bend your bike. It is common to bend like an ape in older stenosis patients.

Diagnoses

The most important in the diagnosis of spinal stenosis is listening to medical history. In other words, you should determine what your main symptoms are and whether you have neurogenic claudication, the most important symptom of spinal stenosis. Neuropathy lameness causes pain in the lower limbs when walking, first, how far you can walk, second, what are the direct symptoms that prevent you from walking, and third, what are the symptoms and how they relate to symptoms when you are not moving The patient’s symptoms should be described and analyzed in detail by asking questions such as whether they are able to walk again after taking a rest, whether they can walk again after a break, and how long they should rest.

A physical examination should check your nerve function, including your lower limbs, muscle strength, and reflexes.

Radiological examinations can confirm the presence of degenerative lesions in the lumbar spine, narrow intervertebral disc spacing, reduction of the anteroposterior distance of the spinal canal, scoliosis, scoliosis, spondylolisthesis, and intersegmental instability. Spinal angiography is a useful test to check if the contrast passes through the spinal cavity by injecting the contrast medium into the dura mater, but it is an invasive test and has side effects such as headache, nausea and seizures.

Computed tomography (CT) not only accurately informs the shape and size of the central spinal canal, but also directly reveals the condition of the lateral recesses and intervertebral cavities. It allows you to immediately identify the pathology that causes it.

Magnetic resonance imaging (MRI) is a radiation-free and noninvasive method that allows morphological and pathophysiological determinations of the intervertebral disc (disc) and bone marrow, as well as anatomical forms of various soft tissues, including intradural and extradural structures. I will.

Treatments

1. Conservative (non-surgical) treatment

Patients with spinal stenosis often undergo conservative treatment first, as a sudden worsening of symptoms or deterioration of function is rare. Conservative treatment options include changes in daily activities, proper exercise, physical therapy, lumbar braces, nonsteroidal anti-inflammatory drugs, antidepressants, nasal spray calcitonin, various drug treatments, point injections, intradural steroid injections, manual therapy, acupuncture, ultrasound, Various methods are used, including electrical stimulation therapy, heat therapy.

Very little research has been conducted on the results of various nonsurgical treatments. O’neil et al reported that in 145 patients, non-surgical treatment improved symptoms in 70% of patients and mild improvement in 23% of patients.³ Johnsson et al. Reported conservative treatment in 32 patients for an average of 49 months.⁴ 70% had no symptoms, 15% had improved symptoms, and 15% had worsened symptoms. Atlas et al. Performed better prospective cohort studies in patients with spinal stenosis and in the non-surgical group.⁵ The results were better in the non-surgical group. In 15% of the groups, leg pain worsened after 1 year, and in 20%, back pain worsened.

2. Indications for Surgical Treatment

Surgery does not need to be done urgently in patients with spinal stenosis, unless the nerves worsen, such as a sudden weakening of the leg and impaired stool function.

Surgery may be necessary if your neurological symptoms worsen, if conservative treatment does not relieve pain, or if you have persistent disability or limited daily life. Low back pain by itself is not an indication of surgery. However, there are many difficulties in the correct application of these indications. Larequi-Lauber et al analyzed whether the surgical indications of 328 patients who underwent vertebral discectomy for spinal stenosis were appropriate.⁶ 38% reported that the surgical indications were inappropriate. But there is no absolute contraindication to surgical treatment. Accompanied by medical illness affects the outcome of surgical treatment, but old age itself is not a contraindication to surgery. However, non-surgical treatment should be given to patients without a history of spinal stenosis, physical examination, or radiological findings.

3. Principles of Surgical Treatment

The goal of surgery is to improve function, reduce pain and prevent neurological symptoms from worsening. To achieve this goal, the pressured nerve must be decompressed. The extent of decompression should be determined by the anatomical site of the patient’s lesion. For example, even if the symptoms are on one side only, if the spinal stenosis is on both sides, the radiograph should not depress only one side. If you depress only one side, you will soon see the other side. In addition, the segment to be decompressed should never be underestimated and, if possible, all decomposed segments should be sufficiently decompressed. It is not easy to limit yourself to any one segment of your physical exam.

Most importantly, preserving the stability of the spine with sufficient decompression will prevent late surgical failure. To this end, firstly, the lower part of the posterior joint should be preserved using an angled tool, and secondly, the parotid should be preserved to prevent back pain and instability due to postoperative fractures. If you encounter an unexpected problem during decompression, you may need to perform additional fusion to connect the spinal segments.

4. Surgical Treatment

Laminectomy is the standard for surgical treatment of lumbar spinal stenosis. In addition, laminotomy can be performed on one or both sides, and there is also a method of vertebral plaque surgery that reaches to one side and decompresses on both sides.

In patients with spinal stenosis without preoperative instability or deformity, decompression is performed without sacrificing stability, and there is no need for additional spinal fusion or instrumentation.

However, in patients with spinal stenosis with deformity or instability preoperatively, it is often reported that postoperative decompression adds better postoperative results. Even in patients with spinal stenosis without preoperative deformation or instability, extensive decompression and arthroscopic resections may require additional fusion or pedicle screw fixation.

Frequently Asked Questions

1. What is the difference between the herniated disc and spinal stenosis?

Spinal stenosis is a common disease after middle age, a condition in which the spinal canal is narrowed, which is the space where the nerve passes. When the spinal canal of the neck is narrowed, it is called cervical spinal stenosis. When the spinal canal of the waist is narrowed, it is called lumbar spinal stenosis. The symptoms of lumbar discs and spinal stenosis may be similar in that the lumbar nerve descends from the waist down to the legs, causing numbness and difficulty in walking. Hard tissues, mainly bones and joints, press on the nerves. In terms of pain, the lumbar discs often progress quickly, and spinal stenosis often develops over time. Also a characteristic symptom of spinal stenosis is intermittent claudication. This is distinguished from the symptoms of the herniated disc, which is fine when you are sitting, but with a slight walk, your legs are numb and your pain hurts so you can sit and rest and walk again.

2. Do all patients diagnosed with spinal stenosis need treatment or surgery?

As you get older, your spinal canal narrows a little. Spinal stenosis does not happen suddenly at any moment. If you are diagnosed with spinal stenosis, the disease is unfamiliar and difficult to worry about. However, like the herniated disc, spinal stenosis does not require surgery unless it interferes with daily life.

3. When do patients with spinal stenosis need treatment?

If the pain is so severe that you can’t stretch your back properly or have trouble walking, you should treat it. Even in this case, it is common to start treatment with physiotherapy, medication, and exercise prescription rather than performing surgery immediately. In about 50% of patients, their symptoms improve without surgery. However, improving symptoms does not always widen the narrowed spinal canal so there is always a chance of relapse.

4. When do patients with spinal stenosis need surgical treatment?

Surgical treatment is when daily back pain and leg pains make life difficult and ineffective for non-surgical treatment for 2-3 months. In addition, if the symptoms of paraplegia progress rapidly or stool dysfunction is present, surgical treatment can be considered from the beginning.

5. I have been diagnosed with spinal stenosis, and I’m curious about what to look out for, good food, bad food, good posture, and exercise.

In spinal stenosis, food does not need to be specially screened. However, tobacco is known to be bad for back pain. Exercises that are good for back pain may include back strength training, stretching, or swimming. There are no special postures to avoid, but it is not good to stay in one position for a long time.

6. I need surgery for spinal stenosis and I am worried about having diabetes. Can diabetics have surgery?

Diabetes is a disease that requires careful attention to any surgery, not just spinal surgery. This is because the likelihood of inflammation after surgery is high. However, diabetes does not mean that you will not have the necessary surgery. Therefore, if you take special care before and after surgery, you do not have to worry too much because you can safely undergo surgery without any side effects.

7. Spinal fusion is a surgery to harden the spine. Can I move my back when I harden my spine?

Spinal fusion is a procedure in which two bones are joined together by a bone graft between the upper and lower vertebrae. However, with the compensation of the other segments of the lumbar spine and the pelvis, it is possible to move the lower back even with one or two knots of the spine.

8. In the treatment of spinal stenosis, spinal fusion is a combination of metal fixation and bone graft. Should I remove the metal later?

If you do not have symptoms such as back pain, you do not need to have a surgery to remove the metal. Sometimes a screw breaks in your body. In about 10% of patients who have an internal fixation machine, this kind of screw breakage occurs. If there are no symptoms, it is not necessary to remove the metal. However, recent studies have reported a lot of evidence that even in the absence of screw breakage or loosening, fine metal particles are generated around the metal-fixing machine, and low back pain is caused by a series of immune responses. Therefore, if there are symptoms, removing the metal fixation machine can be a treatment.

9. I had surgery for spinal stenosis ten days ago. However, from the time of surgery until now, the big toe part is numb, and the calf seems to burst a few days ago. It is very painful from the thigh to the outside of the leg, with more pain than before. Is it common for these symptoms to appear after surgery?

Some time may be required to recover from numbness after spinal stenosis surgery. This may be more likely if the condition is severe before surgery. In this case, rehabilitation is also necessary while treating with drugs. However, if the pain worsens or if there are paralysis symptoms, magnetic resonance imaging (MRI) may be necessary to check for abnormalities.