Spondylodiscitis: causes, symptoms, diagnosis, treatment

What types of diseases are there?

The classification of the disease is determined by the nature of the inflammatory process:

• Nonspecific (infectious) inflammation develops due to the penetration of bacteria into the internal contents of the disc (nucleus pulposus).
• Aseptic (non-bacterial) spondylodiscitis is associated with thinning of cartilage tissue against the background of chronic destructive-dystrophic processes in the spine.

The rarest type, postoperative inflammation, occurs as a result of incorrectly performed spinal surgeries. Simply put, infection during surgery.

Note: The most common cause of surgical infection is surgery to remove a herniated disc.

The course of the pathology depending on age

Taking into account the size of the localization of the pathology, spondylodiscitis can be single or multiple. In the first case, only one intervertebral disc is affected, the second case is more complex, negative processes spread over a large area of ​​the spine. Extensive spondylodiscitis is more common in children; during the period of intensive growth, the intervertebral discs cannot withstand the stress and are damaged.

The lumbar region of the spine suffers mainly. The cervical spine has the described pathologies very rarely. Risk groups include the following categories:

• minors during the period of active growth;
• men over 45 years of age who are actively involved in professional sports or have a job that involves lifting weights.

Men over 45 are at risk

In all cases, the doctor carefully examines the patient. If the pathology progresses at a high rate, powerful antibiotics may be prescribed for a short period of time. Drugs are selected only after special tests and analyzes are carried out.

Causes and mechanism of development

In most cases, the vertebral structures of the thoracic and lumbar regions are affected by pathology. Infectious pathogens penetrate the nucleus pulposus in two ways:

• through tiny cracks in the outer shell of the intervertebral disc (fibrous ring);
• through capillaries located in the hyaline layer of cartilage (endplates) adjacent to the nucleus pulposus.

In fact, any violation of the integrity of the vertebral structures becomes an entry point for infection. Bacteria trapped in the intervertebral disc secrete special protease enzymes that destroy the protein membrane of the cells. This allows pathogens to freely penetrate the semi-liquid contents of the core.

In the process of their reproduction, purulent masses are formed, consisting of the bacteria themselves, their decay products and dead blood cells. A capsule of pus (abscess) formed in the epidural space (between the periosteum and the dura mater) can cause infection of adjacent tissues. In addition, pus can break into the spinal canal and infect the spinal membranes.

When the purulent capsule is absorbed, the remnants of functional cartilage are replaced by connective tissue that does not bear a functional load. In an attempt to compensate for the problem, the body triggers the formation of excess bone tissue, from which osteophytes are formed - bone growths on the vertebrae. Their growth and fusion leads to blocking of the intervertebral space and complete immobility of the vertebrae.

With non-bacterial spondylodiscitis, the cartilage tissue becomes inflamed and dries out, the fibrous ring becomes thinner, and the intervertebral space is smaller. Due to the thinning of the disc, the vertebrae, having lost their shock-absorbing abilities, begin to rub against each other. The friction affects the nerve roots of the spine, which leads to severe pain.

Diagnosis of spondylosis

Because many people with spondylosis do not have any symptoms, imaging tests are required to make a diagnosis. If symptoms are present, it is necessary to differentiate clinical manifestations from other diseases such as spinal stenosis (cervical or lumbar).

The doctor begins with a physical examination of the patient, during which he will check range of motion, reflexes, muscle strength, and look for changes in gait.

Imaging techniques such as radiography, MRI, or computed tomography can provide a detailed morphological picture of the spinal tissue. Electromyography (EMG) may also be ordered to measure electrical activity and conduction from nerves to muscles.

What pathogens cause the infection?

Damage to the intervertebral discs, through which the infection enters the nucleus pulposus, causes direct injuries or chronic diseases of the spine (protrusions, hernias, etc.). In this case, the cause of nonspecific inflammation is most often staphylococcus and streptococcus bacteria.

Infection through the hematogenous route (through capillaries) occurs when bacteria are transferred from the primary source of infection. More than 50% of cases are caused by Koch bacilli, that is, the root cause of the disease is tuberculosis of the lungs or urogenital tract. When rods migrate from the organs of the genitourinary system, the intervertebral discs of the lumbosacral region are affected.

The most commonly affected disc is L5-S1, located between the sacrum and the lowest lumbar vertebra. Dissemination of bacteria from the lungs involves the thoracic vertebrae (mainly T2-T4). In addition to Koch's bacilli, the bacteria Treponema pallidum (syphilis), Proteus, Escherichia coli, etc. can penetrate the endplates through the blood.

Spinal tuberculosis (infographics)

Note: Tuberculous spondylitis (spondylodiscitis, as a type) is called Pott's disease. In everyday life – spinal tuberculosis.

Basic methods of spondylosis surgery:

Nerve decompression

Posterior Approach - The procedure is performed on the patient to remove bony spurs, enlarged ligaments, or scar tissue that is compressing the spinal cord and/or nerve roots. This procedure is commonly used to treat degenerative disc disease (degenerative disc disease) and/or facet joint arthritis. This technique can also be used to treat patients who have had previous surgeries, including spinal fusions.

Foraminotomy

This is a procedure in which the vertebral foramen—the canal through which the nerve root exits the spine—is widened through surgical manipulation. Narrowing of the foraminal canal is usually caused by osteochondrosis or spondyloarthrosis. Bone spurs, scar tissue or herniation (protrusion) of intervertebral discs, which are formed as a result of osteochondrosis or spondyloarthrosis, can narrow the anterior foraminal canal, causing various pathological conditions. A foraminectomy/foraminotomy widens the foraminal canal to its normal width.

Thermal ablation of facet joints

Thermal facet ablation is a laser eradication of the sensory nerves that cause pain. During thermal ablation, surgeons vaporize irritated and painful nerves around the facet joints.

Risk factors

Predisposing factors for the development of spondylodiscitis can be divided into two categories:

• chronic infectious and inflammatory diseases (outside the spine);
• triggers leading to deformation of the spinal column.

A combination of factors increases the chances of developing spondylodiscitis.

Risk factors by etiology

The risk of spondylodiscitis is higher in drug and alcohol addicts. With chronic intoxication of the body, the vertebral structures experience a deficiency of nutrients. Violation of trophism causes destruction of the spine.

Symptoms

During the formation and growth of osteophytes, pressure on the nerve roots increases. This causes dorsalgia (unbearable pain in the affected part of the spine). In addition, innervation is disrupted, which leads to decreased sensory sensitivity (paresthesia) up to numbness and paralysis.

If the infection occupies the lumbar vertebrae, the roots that transmit impulses from the spinal cord and brain are blocked. This causes weakness in the motor function of the legs. At the same time, there is a malfunction in the functioning of the digestive and urinary organs, the respiratory and cardiovascular systems.

Spinal tuberculosis in adults

With suppuration, signs of secondary infectious symptoms appear, namely:

• hyperthermia (up to 38.5℃);
• nausea, hyporexia (decreased appetite), resulting in weight loss;
• weakness, fatigue from usual activities;
• headaches and muscle pain;
• hyperhidrosis (excessive sweating).

The spread of the inflammatory process to soft tissue is externally expressed in redness and swelling of the area of ​​the back affected by spondylodiscitis. In some cases, the symptoms of infection are mild. The main manifestation of the disease is dorsalgia, similar to osteochondrosis.

Against the background of constant pain, irritability, insomnia, and nervousness appear. Often, patients mistake spondylodiscitis for an exacerbation of osteochondrosis, so they do not rush to see a doctor, but begin treatment on their own. This attitude towards back health can lead to serious complications.

In the chronic course of the infectious process, accumulation of purulent masses occurs. As a result, the abscess breaks through, and along with the bloodstream, the infection spreads throughout the body. Thus, a systemic inflammatory reaction develops with the development of toxemia and bacteremia, otherwise – sepsis. The neglected condition threatens the patient with death.

Symptoms of discitis

It is very difficult not to notice the signs of the disease. It develops quickly and acutely.

Characteristic symptoms of the pathology:

• Temperature increase.
• Fever.
• Acute pain in the spine, radiating to the abdomen, thigh, and lower leg. The pain intensifies with movement and does not go away within 3 weeks.
• Spasm of nearby muscles, limitation of back mobility.
• Weakness, increased sweating.

If spondylodiscitis has begun, then damage to the nerve endings is possible . In this case, the following symptoms develop:

• Numbness in the affected area.
• Weakening of reflexes.
• Urinary dysfunction.
• Muscle paresis.
• Deterioration in the functioning of internal organs.

How is spondylodiscitis diagnosed?

The diagnostic complex includes:

• Medical examination, history taking. Study of the patient's symptomatic complaints, medical history (presence of injuries and chronic diseases), palpation and visual examination of the skin of the back.
• Lab tests. The results of a clinical blood test indicate the development of an infectious process. First of all, this is leukocytosis, elevated ESR and C-reactive protein. To exclude (confirm) tuberculosis etiology, a Pirquet tuberculin test is performed.
• Hardware examination. The x-ray will show blurred contours of the vertebrae, which may indicate the formation of an abscess. More informative is a tomographic examination of the spine (CT, MRI).
• Needle biopsy. Taking a sample of biomaterial (exudate) with further microbiological examination allows you to accurately identify the causative agent of the infection.

Determining the type of pathogen helps to select the most effective drugs to destroy it.

Treatment

Complex conservative therapy includes medications, physiotherapy sessions, exercise therapy, and nutritional correction. Surgical intervention is performed in cases of massive accumulation of pus or large-scale destruction of vertebral structures.

Medicines

The action of medications is aimed at destroying pathogenic bacteria, relieving inflammation and pain. First of all, a course of antibiotic therapy is carried out. The choice of antibiotic depends on the type of infectious agent identified (drugs with broad antibacterial action can be used). In parallel, non-steroidal anti-inflammatory drugs (NSAIDs) and analgesics are prescribed to relieve pain.

After suppression of the infectious process, treatment is continued:

• chondroprotectors that restore cartilage tissue;
• muscle relaxants that reduce the tone of skeletal muscles;
• neurotropic B vitamins that improve tissue innervation.

Additionally, external anti-inflammatory agents (ointments, gels) are used.

Physiotherapy and exercise therapy

Physiotherapy sessions help improve blood circulation in the area of ​​the affected vertebra. Procedures such as electrophoresis, magnet, and laser therapy may be prescribed. Exercise therapy classes restore motor activity of the spine. The set of exercises is selected individually, taking into account the severity of the pathology, age and physical capabilities of the patient.

Surgery for spondylodiscitis

Surgical treatment accounts for approximately 25% of cases of spondylodiscitis. The simplest operation is pumping out purulent masses from the intervertebral space. More complex interventions include discectomy (removal of a damaged disc) and laminectomy (removal of bone plates).

Surgical treatment of spondylodiscitis is required in every fourth patient with this diagnosis

Diet therapy

Nutrition correction consists of enriching the diet with foods containing calcium, omega-3 polyunsaturated fatty acids, and collagen. The consumption of alcoholic beverages is strictly prohibited.