Thoracolumbar Spine - An Overview

Introduction:

The central supporting system of the body is the human spine consisting of 33 small vertebral bones stacked together. This comprises seven cervical vertebrae of the neck region, twelve thoracic vertebrae of the upper back area, five lumbar vertebrae in the lower back region, and sacral and coccyx vertebrae. Each vertebra has unique features and performs different functions in the body.

The thoracolumbar spine is the transitional vertebrae of the more rigid thoracic upper back vertebrae and the lower back lumbar vertebrae. Since this region is a transitional vertebra, this region is prone to injury. This article discusses the thoracolumbar spine, anatomical considerations, and associated pathologic conditions.

What Are the Anatomical Considerations of the Thoracolumbar Spine?

The thoracolumbar spine generally comprises twelve bones of the thoracic spine and five bones of the lumbar spine.

• The thoracic vertebrae (T1-T12) are connected to firm rib cages on both sides. They are essential for protecting the internal organs and providing support and structure to the body's trunk. Generally, there is some degree of curvature along the spine. The normal curvature of the thoracic spine is bent in a backward C shape called the kyphotic curve.

• The lumbar spine consists of L1 to L5 of the lower back region. It connects to the pelvic bone and helps in supporting the upper part of the spine. The lumbar spine curves in an inward C-curvature called the scoliotic curve.

• The thoracolumbar spine is where the thoracic spine meets the lumbar spine. It is a transition part of the spine since it connects the more rigid and flexible parts. This intervertebral region, referred to as the thoracolumbar junction, is more prone to injury and especially the area between T11 to L2.

• Injury to the thoracolumbar junction often results in permanent neurological deficits (abnormal, weak nervous system functioning).

What Are the Associated Conditions of the Thoracolumbar Spine?

This region of the spine is more prone to trauma and other conditions.

Thoracolumbar Fractures: Thoracolumbar fractures occur due to trauma from road traffic accidents, work-related injuries, falls from height, or recreational injuries. They occur mostly due to high-impact injuries often associated with other injuries, especially cervical spine fractures. They occur more commonly in individuals around the age of 15 to 29 years of age.

• The thoracic spine T11 and T12 are not articulated with the sternum (vertical bones on the anterior part of the chest) and are called the floating ribs.

• The anatomical set-up of this transitional part of the spine makes them vulnerable to injuries from high-impact forces and degenerative diseases.

Clinical Features: Patients often present with back and radicular pain (radiating pain from the back to the hip in the spine region). Patients may have neurological deficits depending on the level of spinal cord involvement. Thorough neurological examinations are required in these patients.

Diagnosis: Firstly, when suspected of a thoracolumbar fracture, these patients are advised for a radiological examination such as an X-ray (anteroposterior view) in patients with no signs of neurological problems.

• When there are any abnormalities in the X-ray, these patients are advised for a CT (computed tomography).

• MRI (magnetic resonance imaging) is also used in assessing the soft-tissue structures of the spine, such as the intervertebral discs, nerve roots, spinal cord, and posterior ligaments.

Treatment: Patients with thoracolumbar fractures are managed based on the guidance of ATLS (advanced trauma life support) with appropriate immobilization. Restricting further movements of the backbone is advised to prevent further damage to the spinal cord.

• Based on the patient’s stability and neurological involvement, they may require immediate surgical intervention.

• Restricting spine movements in patients with unstable fractures can prevent further neurological deficits, and they are handled with extreme precautions.

• Non-operative management options, such as extension bracing and lumbar corsets, are recommended in patients with stable fractures. They provide lower back muscular support and help in restricting back movements.

• Surgical management of these patients involves decompression and instrumented spinal fusion or posterior instrumented fusion without decompression.

Thoracolumbar Syndrome: When the rotational forces (torque) from the spine's middle section pass through the spine's lower back region, often occurring during twisting and turning motions, the surrounding tissues absorb this force to protect the spine. When this motion happens repeatedly under excessive load, the surrounding tissues are at high risk of inflammation and irritation, eventually leading to mild degenerative changes in the intervertebral structures.

Other names: Thoracolumbar spine syndrome is also referred to as posterior ramus syndrome, Maigne syndrome, or dorsal ramus syndrome.

Clinical manifestations: The condition causes pain along the region innervated by the cluneal nerve (cutaneous nerves of the buttocks) extending outside the T12, L1, and L2 regions. Patients often complain of lower back pain which is frequently present only on one side of the spine and rarely on both sides. Twisting rotational movements are often accompanied by severe lower back pain and pain increases with extension.

Diagnosis: Diagnosis of this condition is made based on the clinical manifestations, and the clinician performs a thorough clinical evaluation of the patient. The clinician generally diagnoses this condition by provoking the facet joints of the thoracolumbar spine (joints connecting the spine's bones) with palpation. Presence of tenderness on the crest of the ilium (curved part of the hipbone).

Treatment: Management of the condition involves manual therapy, exercises, and local injection applications.

• Cold and electric stimulation, Non-steroidal anti-inflammatory drugs, and myofascial therapy manage the pain and inflammation.

• Simple stabilization, dissociative movement therapy, and manual medical applications improve the range of motion.

• Muscle strength and muscle strength balance are gained through intermediate and advanced stabilization exercises, proprioceptive exercises, plyometric exercises, intermediate and advanced dissociative movement therapy, and resistance exercises.

• Local corticosteroid injection therapy is effective in treating pain in the early stages.

Conclusion:

The thoracolumbar spine is the transition segment (T11 to L2) connecting the more rigid and less mobile thoracic spine and the more flexible and weight-bearing lumbar spine. Due to their anatomical arrangement, they are more vulnerable and are at higher risk of traumatic injury, intervertebral disc diseases, and various other pathological conditions. Fractures in this region devastate the patient's quality of life and loss of productive years. Early management of neurologic deficits in these patients results in a better prognosis.