Glossary of Terms

Bilateral Having to do with or relating to both sides of the body (opposite of unilateral).

Bone scan A technique where a small amount of radioactive material is injected into the bloodstream. This material then collects in the bones and becomes visible to a radiation detector such as an x-ray firm. Increased bone uptake suggests increase bone formation, for example in healing after a fracture or in response to an infection. The radioactive material rapidly becomes inert and poses no medical threat.

Brachial plexus The complex of nerves emerging from the lower levels in the neck to form three main nerve trunks supplying motor and sensory function to the upper limbs.

Bursitis Inflammation of the bursa, a small fluid filled sac that functions as a gliding surface to reduce friction between tissues moving in opposite directions. A bursa can become inflamed for a variety of reasons, from injury, infection, an underlying rheumatic condition or simple wear and tear.

Cauda equina Latin for the 'tail of the horse'; refers to the nerves that hang down from the end of the spinal cord and fill the spinal canal in the lower back. The nerves leave the canal in a regular sequence, one to the right and one to the left at each disc level.

Cerebrospinal fluid (CSF) A clear fluid surrounding the brain spinal cord and spinal nerves and contained within the dura and arachnoid membranes.

. Cervical spine That part of the spine that forms the neck, consisting of seven separate vertebrae.

Chronic Refers to the duration of pain but not its intensity. Typically, chronic back pain means symptoms present for longer than three months.

Claudication Intermittent pain in the leg brought on by activity, usually walking, and relieved by rest. There are two common types: 1) intermittent or peripheral vascular - caused by poor circulation to the muscles of the legs 2) neurogenic - caused by poor circulation to the nerve roots within the spine.

Congenital Refers to conditions caused by a genetic inheritance. They may be evident at birth or develop later in life.

Coccyx The final small vertebrae at the lower end of the spine below the sacrum. It is a vestigial tail and has a variable number of mobile segments (3 to 5).

Codeine A narcotic pain-reliever and cough suppressant.

CT scan (CAT scan) Computerized Axial Tomography is a series of X-ray “slices” that are interpreted by a computer able to detect slight variations invisible to the human eye. The separate layers are then reconstructed into a full picture – sometimes in 3D.

Decompression The term refers to reducing pressure and when applied to the back it refers to any procedure (usually surgical) that shifts or removes physical structures that are applying pressure on the neural elements (spinal cord and nerve roots) within the spine.

Dexa-scan An technique used for assessing bone density.

Disc The soft tissue structure between two vertebrae. It is made up of an outer fibrous shell, an inner nucleus of water containing proteins and two cartilaginous end plates that attach it to the bones above and below. The disc at birth contains a high proportion of water but loses its water content throughout life becoming thinner and less flexible.

Discogram An x-ray technique where a radio-opaque dye is injected into a disc and the pattern of the dye viewed on x-ray to outline the disc’s internal structure. Pain reproduced during the test is considered by some to be diagnostic of a symptomatic disc.

Discotomy A surgical procedure in which a small portion of an intervertebral disc is removed. Also called a partial discectomy.

Disc degeneration A natural aging process of gradual dehydration and narrowing of a disc.

Disc protrusion The bulging of a portion of the outer shell of the disc. The amount of bulge is further described as a prolapse, herniation or sequestration. The term “slipped disc” is also incorrectly used since, although the wall of the disc may bulge the disc itself remains firmly anchored between the vertebrae

Dura The outermost, toughest, and most fibrous of the adjacent membranes covering the brain, spinal cord and spinal nerves. It lines the spinal canal and contains the cerebrospinal fluid.

Epidural steroid injection A procedure used to treat spinal nerve irritation. An anti-inflammatory agent, usually mixed with a local anaesthetic, is injected into the space between the wall of the spinal canal and the dura (“epi” means ‘upon or adjacent to). The purpose is typically to reduce the leg dominant pain (sciatica) caused by an inflamed nerve root.

Facet joints A pair of small joints linking every pair of vertebrae in the spine. They are mobile joints similar in structure to the other joints in the body such as the joints in the fingers. They are designed to guide and limit movement of the spinal motion segment; two adjacent vertebrae and the intervening disc.

Foramen The bony channel on either side of the spine passing between adjacent vertebrae through which the nerve roots exit from the spinal canal.

Fusion An operation, generally using screws and rods or plates, to temporarily stop movement between the vertebrae so that bone can grow across the gap. The adjacent surfaces of the vertebrae are roughened to simulate a fracture which triggers the body’s normal healing response. Fusion can mean the operation to create the bony bridge but it also refers to the permanent joining together of the vertebrae by that bone.

Grafting Applies to the surgical application of extra material, usually bone, to stimulate new bone formation between two bony surfaces. It may employ the patient’s own bone, bone from another person or a synthetic substitute. It is a component of fusion surgery.

Instability Used to describe abnormal or excessive movement between vertebra. It can be defined in radiographic terms on x-ray, in biomechanical terms in the laboratory or in clinical terms with respect to the patient’s symptoms. Unfortunately there is no correlation between the three methods of instability measurement.

Kyphosis A forward bend to the spine. (opposite of lordosis).

Lamina The laminae are two broad plates, extending outward from the mid-line spinous process of the vertebra to the facet joints. They form the roof of the spinal canal.

Laminectomy Refers to the operation in which the lamina is removed. Partial removal is termed a partial laminectomy or a laminotomy.

Lateral Toward the outside (opposite of medial)

Ligaments Bands of collagen and protein that link bones together.

Lordosis A backward bend to the spine. (opposite of kyphosis)

Lumbar The spine between the rib cage and the pelvis. There are usually five mobile lumbar vertebrae but occasionally the number of movable segments increases to six or decreases to four. The change is mirrored in the number of segments in the sacrum.

Medial Towards the mid-line (opposite of lateral).

MRI scan Magnetic resonance imaging surrounds the body with a magnetic field and uses radio frequency impulses to alter the signals produced by hydrogen molecules in the body. The signal changes are captured and displayed on a computer, which uses them to determine the location of the molecules. Hydrogen is found in the body’s water and that makes MRI particularly good at detecting problems with the soft tissues

Multidisciplinary rehabilitation A treatment involving a variety of different medical disciplines and knowledge bases.

Myelogram A radiographic examination where a radio-opaque dye is injected into the cerebrospinal fluid to outline the contents of the dural sac. It also outlines any structure, like a bulging disc or bony outgrowth that is deforming the sac from the outside.

Nerve root These arise from the spinal cord and travel down inside the spinal canal. At each level a nerve root emerges through a tunnel on either side of the spine between the vertebrae. The roots combine to form larger nerve trunks and eventually the nerves that travel down the legs.

Non-steroidal anti-inflammatory Drugs (NSAIDs) Anti-inflammatory medication used to reduce irritation from a variety of conditions that create an inflammatory reaction in the body. They have less effect than steroid preparations. They do have an additional analgesic effect but also have significant side effects particularly in the gut or cardiovascular system.

Nucleus pulposus The center of the intervertebral disc, it is formed of water containing proteins that function under compressive loads as a hydraulic shock absorber to distribute pressure evenly throughout the disc. As the nucleus dries out with age, this equalizing ability is lost and this can lead to disc problems.

Osteoarthritis A form of joint deterioration that leads to thinning of the cartilage surfaces. It has a less aggressive inflammatory component than most other forms of generalized arthritis. It can result from injury or appear as the result of normal aging and there is a variety with a typical joint distribution that involves mainly women.

Osteophytes Also known as bone spurs, osteophytes are bony projections around the margins of joints, often associated with osteoarthritis.

Osteoporosis A condition where thinning of the internal structure of the bones makes them weak. It usually affects older women. Osteoporosis itself is not painful but because the structure of the bone becomes fragile it can lead to painful spinal compression fractures.

Pain Pain is an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage.

Paraplegia Refers to the loss of function, movement and sensation, in the lower limbs.

Pedicles Two short bony projections running between the body of the vertebra and the laminae on both sides of the spinal canal. They are the sidewalls of the canal.

Pelvis The bony funnel-shaped structure formed by the hip bones (ilium) and the sacrum, the solid lower portion of the spine.

Posterior The back surface of something (opposite of anterior)

Quadriplegia Refers to the loss of function, movement and sensation in all four limbs.

Radicular pain Refers to pain produced by direct nerve root involvement and felt along the course of the nerve in the leg (or arm).

Referred pain Refers to pain arising from a structure (other than a nerve) but which is felt most intensely at a site distant from the origin, typically along the spine or in the buttocks. The distribution is based on embryological development.

Sacrum The curved triangular bone at the base of the spine. It usually contains five fused vertebrae although the number can vary in relation to the number of mobile segments in the lumbar spine.

Scoliosis An abnormal side-to-side curvature of the spine, typically combined with an abnormal rotation. Scoliosis can result from a number of causes including congenital spinal abnormalities, paralysis and age-related spinal degeneration. One commonly recognized variety is the scoliosis of adolescents that occurs around puberty and can progress through the teen-age years.

Sciatica Constant leg dominant pain resulting from irritation of the roots of the sciatic nerve within the spinal canal.

Spinal cord The main nerve trunk of the body, which runs inside the spinal canal from the base of the skull down to behind the second lumbar vertebra.

Spinal stenosis A narrow spinal canal. This can be present at birth or more commonly develop in older people as a result of the bony overgrowth that accompanies spinal degeneration. It may or may not be symptomatic.

Spondylitis A term describing any inflammatory condition of the spine.

Spondylosis A term describing an abnormal condition of the spine. Because the term can apply to anything about the spine that is not considered normal it has little practical value. It is most often used in conjunction with degenerative conditions.

Syndrome A constellation of signs and symptoms that appear reliably together and respond predictably to treatment

Ultrasound An imaging technique used to visualize subcutaneous body structures including tendons, muscles, joints, and internal organs.

Unilateral Having to do with or relating to one side of the body (opposite of bilateral).

Vertebra An individual bone in the spine. The spine consists of seven neck vertebrae, twelve vertebrae behind the rib cage, five vertebrae in the lower back, five fused vertebra in the sacrum and a variable number of vertebra in the coccyx.