Back Pain Overview

Introduction

The spine comprises vertebral bones which articulate with each other via posterior joints (the facets) and through the discs which separate the vertebrae (the motion segments). Ligaments and muscles support the bones. The disc is made up of tough ligaments, arranged around a common centre, on the outside (the annulus) and a soft centre on the inside (the nucleus pulposus), roughly comparable to a car tyre.

The disc thus acts as a shock-absorber. With repeated wear and tear – aggravated by occasional injury – the nucleus begins to lose water and becomes less elastic while the annulus weakens and bulges and eventually may rupture (slipped disc). This may lead to varying degrees of instability, where increased mobility results from loss of tensioning by the “deflated” disc.

While this process progresses, the facets are subjected to more stress and begin to degenerate (facet arthritis/arthrosis). Excessive bony growth (in the form of osteophytes) may occur around the joint which results in decreased movement.

With the loss of shock-absorbing capacity, the opposing vertebral body surfaces enlarge to diminish the pounding effect. This results in the development of large osteophytes. The osteophytes from the vertebrae, together with those from the facet joints, may combine with the disc and bulge to produce significant narrowing of the spinal canal (spinal stenosis) as well as the nerve canals (intervertebral foraminal stenosis). A bulging/ruptured disc may result in a similar problem.

Significant degeneration of supporting ligaments and joints can contribute to excessive movement of bone-on-bone which becomes unstable in certain postures/activities. The shifting bone may further compress the spinal canal and individual nerves. In this regard painful muscle spasm may occur, which is the body’s way of attempting to restore stability. (Muscle spasm however may also occur in response to any underlying spinal problem, including arthritis.)

A review of spinal symptoms

Source:Wikipedia

Spinal problems may occur in the cervical, thoracic and lumbar regions. Most commonly the problems occur in the more mobile areas of the spine, which are the cervical and lumbar regions.

Presenting symptoms may take the form of:

Local (neck or back) pain which may be aggravated by posture and/or activity.
Local pain with indistinct referral of symptoms to shoulder and arm or to buttock and leg.
Minimal pain in the neck or back with severe pain involving the limb. The pain may be associated with numbness or pins and needles as well as weakness.
Referred pain from the back into the buttocks, hips and legs which is aggravated by walking.

Symptoms requiring urgent attention:

Changes in bladder and bowel control, numbness in the private areas of the body.
Sudden or increasing gait disturbances.
Significant muscle weakness.

Approach to diagnosis

If symptoms are minimal and do not encroach upon daily life to any significant degree, then conservative treatment such as physiotherapy, chiropractic manipulation and analgesics (painkillers) may be all that is required. Should symptoms persist, deteriorate or progress to involve a limb, then a diagnosis would need to be made.

Investigative modalities which are used to establish a diagnosis include:

Straight X-rays with stress views – indicate the nature of bone structure, evidence of degeneration of structures and stability of bone-on-bone.
CAT scan – provide more detail of bone anatomy but should be used in conjunction with a myelogram, to outline details of neurological structure and discs.
Myelogram – the injection of a contrast agent into the spinal fluid via a lumbar puncture. This outlines all the neurological structures (spinal cord and nerves) and may be used in a dynamic fashion to show changes in different postural positions. This procedure requires an admission to hospital.
MRI scan – a comprehensive review of all structures in the spine and their three-dimensional relationships to each other.
Radioisotope bone scan – this assesses inflammatory activity in the bone or related joints.
Bone densitometry – provides information as to the presence of osteoporosis.
Discogram – the injection of contrast material into the disc. This provides information as to the appearance of the disc as well as simulates possible symptoms which may be arising from the disc.
Blood tests – to test for possible underlying active arthritis such as gout, rheumatoid etc.