Intervertebral Disc Herniation

What is intervertebral disc herniation?

The intervertebral disc is a cartilaginous structure that possesses a gel-like consistency and is positioned amidst vertebrae. Its central function primarily lies in jointing the vertebrae, which, in turn, serves to maintain the flexibility and elasticity of the spine. Additionally, the intervertebral disc functions as a cushion, serving to absorb external loads generated on the vertebrae during movements.  The nucleus pulposus, a gelatinous material, constitutes the central part of the intervertebral disc and is surrounded by a fibrous ring of dense-elastic nature.

Intervertebral disc herniation is a pathology characterized by the extrusion of the nucleus pulposus or a portion thereof beyond the confines of the fibrous ring. Typically, a fragment of a herniated intervertebral disc gets into the spinal canal, where the roots of the spinal cord and the spinal cord are located. The space of the vertebral canal is delimited by the osseous and ligamentous apparatus.  Consequently, an increase in the volume of the spinal canal, in the form of an intervertebral disc fragment, can potentially exert compression on both the spinal cord roots and the spinal cord itself.  

Intervertebral disc herniation may be manifest in any segment of the spine, with the highest incidence noted in the lumbar region. It has also been identified within the cervical region. Infrequently, it is possible for a herniated disc to manifest in the thoracic region.

Reasons

Intense pressure exerted on the spinal column (such as physical injury, lifting a heavy object, or rotating whilst heaving heavy objects), may result in a prolapse of the intervertebral disc. The intervertebral disc tissues and their associated ligaments experience degeneration and atrophy over the course of aging. In this setting, the occurrence of a hernia can be provoked by even low-intensity physical activity or awkward movement.

Risk factors

• Excessive weight, imposes additional strain on the intervertebral discs, particularly within the lumbar region of the spine.
• Regular physical activity, which may include weight lifting, pulling, lying down, rotational movement, etc., is associated with an increased risk of formation of a hernia.
• The genetic factors. Some people have a genetic predisposition to herniated discs.  It is common for several members of a family to exhibit the presence of a hernia.
• Smoking of tobacco. It is believed that tobacco smoking has a detrimental effect on the oxygenation of the intervertebral disc tissues, resulting in an aggravation of the degenerative processes.
• Driving a vehicle for a long time. The extended periods of sitting and exposure to vibrations from the vehicle’s engine are known to elicit unfavorable effects on the spinal column.
• A sedentary lifestyle. In this case, it has been observed that a reduction in the strength of the dorsal muscles occurs and more pressure is exerted on the intervertebral discs.

Pain   

The primary complaint expressed by individuals experiencing a herniated disc is pain. Pain has the ability to exhibit localization within specific regions of the spine or spread to the upper or lower limb. Localized pain results from injury to the ligamentous system surrounding the spinal column, while spreading pain arises from irritation to the root of the spinal cord due to pressure exerted by the herniated intervertebral disc (radiculopathy). The pain localization is determined by the location of the hernia. Lumbar disc herniation commonly begins with pain in the lumbar region, which is concomitant with spreading pain extending towards the leg. Rarely, a hernia may manifest exclusively with a spreading pain that emanates outwardly without any pain in the lumbar region. In the majority of instances, the spreading pain occurs on one side. Regarding an intervertebral disc located within the cervical spine, the pain in the cervical region is transmitted to the hand, rarely to the shoulder.

Numbness, weakness in the limb 

The clinical indicators of radiculopathy are not restricted solely to the occurrence of radiating pain. The pressure of the hernia on the root of the spinal cord can result in a disruption of blood circulation and harm to the nerve fibers, which can initially present as numbness or pin sensation in any region of the limb. Subsequent to the impairment of the motor fibers, a diminution of strength of the associated muscles within the limb occurs. For instance, in the case of a herniated fifth lumbar disc, damage to a motor fiber results in weakness when stretching the foot.   

Urination and bowel dysfunction 

Anatomically, the spinal cord ends at the level of the first lumbar vertebra. Below the level of the first lumbar intervertebral plate, within the spinal canal there is only the bundle of the roots coming out of the spinal cord, the so called “cauda equine”. In cases of large lumbar hernia, the pressure exerted not only affects a single root but also impacts the cauda equina nerve bundle. In this case, in addition to the indications described above (pain, numbness, weakness), urinary and bowel dysfunction may be observed.         

Indications of spinal cord injury 

Intervertebral disc herniation may, in addition to nerve root damage, have detrimental effects on the spinal cord, leading to myelopathy. Intervertebral herniations in the cervical or thoracic areas can result in injury to the spinal cord. The injury of spinal cord is commonly followed by a range of   symptoms such as limb weakness progressing to total immobility, loss of sensation progressing to complete impairment and urinary and bowel dysfunction.

Diagnosing

Magnetic resonance imaging of the spine is considered the most optimal method of diagnosing intervertebral disc herniation. Magnetic resonance imaging (MRI) offers a comprehensive visualization of the spinal cord, nerve roots, intervertebral discs, and the associated ligamentous apparatus.

Computer tomography is also used for diagnostic purposes as it provides clear visualization of osseous structures, facilitating assessments of dimensions and configurations of the spinal canal, and the intervertebral discs. Electroneuromyography is additionally conducted in certain cases. The present test determines the extent of nerve root damage.

Treatment
Non-surgical treatment

• Medical treatment
• Physiotherapy
• Manual therapy

Surgical treatment
In which cases is the surgical operation perfumed?

• In the instances of severe radiating (radicular) pain, where conventional medical treatment proves ineffective or difficult to adhere to. As a consequence of this, the patient experiences limitations in physical and/or mental activity, resulting in a decline in their overall well-being and quality of life.
• In the event that non-surgical treatment proves to be ineffective.
• Symptoms indicating root damage (such as numbness, decreased sensitivity, and weakness) are 
• In the presence of clinical and/or radiological signs of spinal cord damage (myelopathy).
• For urgently developed cases of “cauda equine” or indications of spinal cord injury, urgent surgical intervention is required  

Surgery of lumbar intervertebral disc herniation

A small skin incision (measuring up to 3. 5 cm) is made in the region of the waist, specifically in the central line, corresponding to the level of the affected intervertebral disc. Following the lateral displacement of the back muscles, the dorsal part of the spinal column becomes discernible to the surgeon. Under microscopic observation, a surgical procedure involves the careful extraction of a small section of bone in order to access both the nerve root and the herniated disc located between the vertebrae. The latter is then excised, and the nerve root is released from the surrounding tissue. 

A small (4-5 cm) incision is commonly executed on the anterior region of the neck, predominantly on the right side. Under microscopic observation, one maneuver involves accessing the larynx and esophagus while another involves accessing the area between the muscular and vascular structures, for the purposes of accessing the anterior aspect of the spinal column at the level where the disc has been damaged. Consequently, the intervertebral disc is entirely excised, along with the hernia. To achieve spinal stabilization, an alternative implant may be inserted at the site of the excised disc within the intervertebral space. 

Post-operative period  

After the surgical procedure, a significant majority of patients do not experience radicular (radiating) pain. Additional indicators of root damage (such as numbness, reduced sensitivity, and weakness) typically exhibit a reversed pattern of restoration. However, the extent to which these symptoms can recover largely depends on the duration of their manifestation preceding the surgery. The activation of patients (including such as getting up, and walking) occurs shortly after the operation. It has been observed that the average duration of a patient’s stay in a hospital is approximately 2 days.

• The enhancement of the muscles in the dorsal region. The most optimal way to achieve this objective is to engage in physical activity such as swimming.
• In instances involving prolonged periods of sitting, maintaining the spine in the proper  position
• It is advisable to abstain from lifting weights. However, if such activities are necessary, it is crucial to correctly lift weights to minimize undue strain on the spine. This can be achieved by ensuring that the weight load is evenly distributed on the limbs and not on the spine.
• Losing weight.

• Tobacco smoking cessation