To understand spinal injury, ailments and treatment, we must first understand our spine…

The spine is one of the most important structures in the human body, supporting much of your weight and protecting the spinal cord, the delicate nervous tissue which carries communication from the brain to the rest of the body. The spine is a strong but flexible column, allowing a wide range of movement.

All about vertebrae

The spine extends from the base of the skull to the tailbone and is made up of thirty-three bones known as the vertebrae. The first seven vertebrae (cervical vertebrae) are in the neck and are numbered ‘C’1 through ‘C’7. Nerve compression in this area can cause neck pain, which may radiate down the arms to the hands and fingers.


The next twelve vertebrae make up the thoracic region (’T’1 through ‘T’12); the ribs attach to these vertebrae and protect the heart and lungs. The lumbar region is the lower back, which contains five vertebrae (’L’1 through ‘L’5). It plays a significant role in motion and flexibility. It is the source of most motion and supports most of the body weight. Overload or taxing movements may strain the structure, compress the nerves and cause back pain, which may radiate down the legs to the feet. The regions beneath the lumbar spine are the sacrum (’S’1 through ‘S’5) and coccyx (a series of small bones often called the tailbone). These are fused they do not have discs between them.

Discs – Shock absorbers of the spine

The vertebrae in the cervical, thoracic and lumbar regions are separated by discs. A disc serves as a cushion and allows motion between the vertebrae. Thus an articulated spine is a column of individual vertebrae neatly piled like a stalk of coins held together by discs and ligament, protecting and allowing optimum function of spinal cord and nerve roots. If the vertebrae, disc or ligaments of the spine are damaged it renders the spine unstable and jeopardizes the function of the spinal cord and can cause paralysis and bladder and bowel incontinence.

Spinal instability

Instability of the spine is the inability of spinal column to sustain physiological loads without endangering the function of the spinal cord or nerve roots. There are a number of factors that can cause instability in spine.

Trauma

Trauma is the commonest cause of acute spinal instability due to injury to bone, disc and ligaments supporting the spine, risking spinal cord function (primary cord injury occurring at the time of trauma). If unrecognized or untreated, manipulation of unstable spine, can further damage the spinal cord (secondary cord injury) and a patient previously normal can be paralyzed later on. Prompt stabilization of the injured spine is essential not only to prevent secondary cord injury but also to provide an optimal stable environment for the primary cord damage to recover.

Tuberculosis

Though Tuberculosis is a medical disease, when it affects the spine it can cause enough destruction of vertebral body to render the spine unstable. Further pus and unhealthy tissue from infection may cause an abscess compressing the spinal cord and necessitating surgery.

Tumour

A bone affected by tumour is like a wooden log infested by white ants. Just as white ants infest and destroy wood in no time, similarly spinal tumors can cause enough destruction to cause instability and pathological fracture. Tumor mass itself may compress the spinal cord and cause paralysis necessitating surgery.

Disc degeneration

With age, discs between the vertebrae can dry out and can no longer cushion and absorb shock in the spine. Rapid degeneration may lead to instability.

Latrogenic instability

Over-enthusiastic spinal decompression can lead to damage to the facet joints (posterior joints in spine) leading to instability. Multiple level laminectomies can also lead to instability.

Spondylolisthesis


Congenital or acquired weakness in the pars (hook mechanism of the spine which prevents forward slip of vertebrae) causes shearing stresses at the disc which undergoes premature degeneration causing instability. Strong implants are required not only to neutralize the shearing stresses but also to reduce the slip and ensure sound fusion.

Spinal deformity

Spinal implants are required not only to correct spinal deformities but also to maintain correction till solid spinal fusion occurs.

Dr.C.S.Dhillon
Director, MIOT Centre for Spine Surgery

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