Glossary

A – B

Allograft Bone – Bone derived from another human which is used for grafting procedures under appropriate sterile technique.

Anterior – The front portion of the body. It is often used to indicate the position of one structure relative to another.

Annulus Fibrosus – The outer, fibrous, ring-like portion of an intervertebral disc.

Anterolateral – Situated or occurring in front of and to the side.

Apical Vertebra – The most rotated vertebra in a curve; the most deviated vertebra from the patient’s vertical axis. Used in measuring curves in scoliosis.

Arthritis – Inflammation of a joint usually characterized by swelling, pain, and restriction of motion.

Arthrodesis – The fusion of bones across a joint space, thereby eliminating movement. It may occur spontaneously or as a result of a surgical procedure, such as fusion of the spine.

Arthropathy – Any disease or disorder involving a joint.

Arthroplasty – The surgical remodeling of a diseased or damaged joint.

Arthroscope – An instrument inserted into a joint cavity to view the interior of a joint and correct certain abnormalities. An arthroscope is an endoscope for use in a joint.

Arthroscopy – The procedure of visualizing the inside of a joint by means of an arthroscope.

Articular – Pertaining to a joint.

Autogenous Bone – Bone originating from the same individual; i.e. an individual’s own bone.

Autograft Bone – Bone transplanted from one part to another part of the body in the same individual.

Backbone – The flexible bone column extending from the base of the skull to the tailbone. It is made up of 33 bones, known as vertebrae. The first 24 vertebrae are separated by discs known as intervertebral discs, and bound together by ligaments and muscles. Five vertebrae are fused together to form the sacrum and 4 vertebrae are fused together to form the coccyx. The backbone is also referred to as the vertebral column, spinal column, or spine.

Bioabsorbable Polymer – A substance, such as some plastics, which the human body can break down and absorb.

Biocompatibility – A characteristic of some materials that when they are inserted into the body do not produce a significant rejection or immune response.

Biodegradation – The breakdown of organic materials into simple chemicals commonly found in the body.

Bone – The hard tissue that provides structural support to the body. It is primarily composed of hydroxyapatite crystals and collagen. Individual bones may be classed as long, short, or flat.

Bone Derivative – One of the substances extracted from bone, such as bone morphogenic proteins (BMP).

Bone Graft – Bone which is harvested from one location in an individual and placed in another individual (allograft bone) or in a different location in the same individual (autogenous bone).

Bone Marrow – The tissue contained within the internal cavities of the bones. A major function of this tissue is to produce red blood cells.

Bone Plate – Usually a relatively thin metal device which is affixed to bone via screws. Bone plates are used to immobilize bones or bone fragments such that healing can occur.

Bone Screw – A threaded metal device which is inserted into bone. The functions of bone screws are to immobilize bones or bone fragments or to affix other medical devices, such as metal bone plates to bones.

C – F

Cadaver – A term generally applied to a dead human body preserved for anatomical study.

Café Au Lait Spots – Light brown irregular areas of skin pigmentation. If sufficient in number and with smooth margins, they suggest neurofibromatosis.

Cancellous Bone – The spongy or honeycomb structure of some bone tissue typically found at the ends of long bones.

Cartilage – The hard, thin layer of white glossy tissue that covers the end of bone at a joint. This tissue allows a motion to take place with a minimum amount of friction.

Centrum – The body of a vertebra.

Cervical – The neck region of the spine containing the first seven vertebrae.

Chemonucleolysis – Chemical substance used in the treatment of an intervertebral disc that consists of an injection of chymopapain, a drug that dissolves part of the disc.

Clinical Studies – A process of strictly controlled evaluations involving patients. Some of these studies are required by the FDA prior to general release of a device or drug for use in humans.

Cobalt-Chrome – A mixture of metals used in many surgical implants.

Cobb Angle Measurement – Calculated by selecting the upper and lower end vertebrae in a curve. Erecting perpendiculars to their transverse axes. At their point of intersection, the angle is measured to indicate the curve’s angle.

Coccyx – The region of the spine below the sacrum. It is also known as the tailbone.

Collagen – A fibrous protein which is a major constituent of connective tissue, such as skin, tendons, ligaments, cartilage, and bones.

Comminuted Fracture – A fracture in which a bone is broken into more than two pieces. Often internal or external fixation devices are used to maintain proper alignment of the fragments.

Compensatory Curve – A curve, which can be structural, above or below a major curve that tends to maintain normal body alignment.

Compression – The act of pressing together. Refers to the loss of vertebral body height either anteriorly, posteriorly, or both.

Congenital – Present at and existing from the time of birth.

Coronal – Refers to a section that divides the body into anterior and posterior portions (front and back).

Cortical Bone – The dense bone that forms the outer surface of bone.

De-compress – To remove material to give more space for another structure.

De-mineralized Bone – Bone tissue which has been depleted of its minerals; e.g. calcium and phosphorous.

Disc (Intervertebral) – The tough, elastic structure that is between the bodies of spinal vertebrae. The disc consists of an outer annulus fibrosus enclosing an inner nucleus pulposus.

Disc Degeneration – The loss of the structural and functional integrity of the disc.

Discectomy – Surgical removal of part or all of an intervertebral disc.

Distal – Situated away from the center of the body.

Distraction – Excessive space between fracture fragments or vertebral segments due to interposed tissue or, most often, axial forces.

End Vertebra – (i)The most cephalad (i.e. toward the head) vertebra of a curve, whose superior surface tilts maximally toward the concavity of the curve. (ii)The most caudad (i.e. toward the coccyx) vertebra whose inferior surface tilts maximally toward the concavity of the curve.

Endogenous – Arising within or derived from the body.

Endoscope – A medical device for viewing internal portions of the body. It is usually comprised of fiber optic tubes and video display instruments.

Endoscopy – Inspection of internal body structures or cavities using an endoscope. Arthroscopy is an example of endoscopy in which the inside of a joint is visualized.

Epidural – Situated outside the thin, tough dural membrane that surrounds the brain and spinal cord.

Excision – Removal by cutting away material.

Exogenous – Originating outside the body.

Facet - A posterior structure of a vertebra which articulates (joins) with a facet of an adjacent vertebra to form a facet joint that allows motion in the spinal column. Each vertebra has two superior (upper) and two inferior (lower) facets.

Facetectomy – Excision of a facet.

Fatigue Fracture – A fracture that occurs in bone or in other materials, including metal, as a result of repeated stress as opposed to a single injury.

Fibrosis – The replacement of normal tissue with scar tissue.

Food and Drug Administration (FDA) – The Federal government agency that has regulatory authority over the manufacture, distribution, and labeling of drugs, medical devices, and foods.

Foramen – A natural opening or passage in bone.

Fracture – A disruption of the normal continuity of bone.

Fusion – The unification of bone as a whole; the act of bone fusing together. See Arthrodesis.

G – L

Gibbus – A sharply angular kyphos. A significant increase or marked hunched back.

Herniated Disc – Disruption of a normal disc such that the nucleus pulposus (the center part of the disc) material breaks through a defect in the annulus fibrosus (the peripheral part of the disc).

Heterotopic Bone Formation – The occurrence of bone growth in an abnormal location.

Hook – For spinal applications, a metallic device used to connect spinal structures to a rod.

Hydroxyapatite (HA) – The lattice-like structure of bone composed of calcium and phosphorous crystals which deposits on collagen to provide the rigid structure of bone.

Iatrogenic – Resulting from medical intervention; said of any adverse condition in a patient resulting from treatment by a physician or surgeon.

Idiopathic – Occurring without known cause. Self-originated.

Iliac Bone – A part of the pelvic bone that is above the hip joint and from which autogenous (produced by the body) bone grafts are frequently obtained.

Iliac Crest – Part of the iliac bone that is the prominent portion of the pelvic bone at the belt line of the body.

Immobilization – Limitation of motion or fixation of a body part usually to promote healing.

Implant – Any foreign material placed inside the body.

Intervertebral Disc – The tough, elastic structure that is between the bodies of spinal vertebrae. The disc consists of an outer annulus fibrosus enclosing an inner nucleus pulposus. Also referred as disc.

In vitro – Describing biological phenomena that are made to occur outside the living body (traditionally in a test tube). In vitro is Latin for in glass.

In vivo – Within a living body. In vivo is Latin for in life.

Inferior – Situated below or directed downward.

Informed Consent – Consent of the patient who has received sufficient information to have surgery, receive medication, or participate in a clinical study.

Institutional Review Board (IRB) – A committee designated by an institution, such as a hospital, to review and approve research projects; e.g. clinical studies in that institution.

Internal Fixation – The immobilization of bone fragments or joints with implants in order to promote healing or fusion.

Investigational Device Exemption (IDE) – A FDA regulatory status which permits the human use of an unapproved medical device for the purpose of collecting clinical data under strictly controlled conditions.

Joint – The junction or articulation of two or more bones that permits varying degrees of motion between the bones.

Kyphosis – An abnormal increase in the normal curvature of the thoracic spine. The thoracic spine has a normal kyphotic curve.

Lamina – An anatomical portion of a vertebra. For each vertebra, two lamina connect the pedicles to the spinous process as part of the neural arch.

Laminectomy – An operation for removal of part or all of the lamina of a vertebra, commonly performed in order to be able to remove an intervertebral disc protusion or to decompress a nerve root.

Laser – Light Amplification by Stimulated Emission of Radiation. The device that produces a focused beam of light at a defined wavelength that can vaporize tissue. In surgery, lasers can be used to operate on small areas without damaging delicate surrounding tissue.

Lateral – Situated away from the midline of the body.

Ligament – A band of flexible, fibrous connective tissue that is attached at the end of a bone near a joint. The main function of a ligament is to attach bones to one another, to provide stability of a joint, and to prevent or limit some joint motion.

Load Sharing – Structural support through grafts and/or implants.

Lordosis – An abnormal increase in the normal curvature of the lumbar spine. The lumbar spine has a normal lordotic curve.

Lumbago – A non-medical term signifying pain in the lumbar region.

Lumbar – The lower portion of the spine between the thoracic region and the sacrum. The lumbar spine consists of five vertebrae.

M – R

Medial – Situated closer to the midline of the body.

Medical Device Report (MDR) – The required reporting of medical device complaints involving a patient death, serious injury, or device malfunction.

Minimally Invasive Surgery – Surgery requiring small incision(s), usually performed with endoscopic visualization.

Neurosurgery – The surgical specialty involved in the treatment of disorders of the brain, spinal cord, and peripheral nerves.

Nerve Root – The portion of a spinal nerve in close proximity to its origin from the spinal cord.

Neural Arch – The bony arch of the posterior aspect of a vertebra that surrounds the spinal cord, also referred to as the vertebral arch.

Non-Union – Failure of fragments of a fractured bone to heal or to obtain bony fusion following an arthrodesis.

Nucleus Pulposus – The semi-gelatinous tissue in the center of an intervertebral disc. It is surrounded and contained by the annulus fibrosus which prevents this material from protruding outside the disc space.

Orthopaedics (also Orthopedics) – The medical specialty involved in the preservation and restoration of function of the musculoskeletal system that includes treatment of spinal disorders and peripheral nerve lesions.

Orthopaedic Implants – Medical devices used to replace or provide fixation of bone or to replace articulating surfaces of a joint.

Ossification – The process of forming bone in the body.

Osteoporosis – A disorder in which bone is abnormally brittle, less dense, and is the result of a number of different diseases and abnormalties.

Pathology – The study of disease states.

Pedicle – The part of each side of the neural arch of a vertebra. It connects the lamina with the vertebral body.

Pelvic Obliquity – Deviation of the pelvis from the horizontal in the frontal plane. Fixed pelvic obliquities can be attributed to contractures either above or below the pelvis.

Periosteum – A fibrous membrane that covers the surface of bone except at the end of the bones where it is covered with cartilage as part of a joint. In children, periosteum is involved in forming new bone and molding the configuration of bone; and in the adult, the periosteum forms new bone secondary to injury or infection.

Physical Therapy – The treatment consisting of exercising specific parts of the body such as the legs, arms, hands or neck, in an effort to strengthen, regain range of motion, relearn movement and/or rehabilitate the musculoskeletal system to improve function.

Physiology – The science of the functioning of living organisms, and their component systems or parts.

Posterior – Located behind a structure, such as relating to the back side of the human body.

Powered Surgical Instruments – Instruments which are powered by compressed air or electricity and are used in surgical procedures to cut, drill, or otherwise remove bone or cartilage, as well as to evacuate fluids.

Pre-Clinical Studies – Tests occurring prior to clinical studies, usually in vitro or in vivo involving animals. The purpose of these studies is to determine the safety and efficacy of the test material.

Premarket Notification [510(k)] – A regulatory method for gaining clearance from the FDA to market a device. The FDA is petitioned by a company to determine if a particular medical device is “substantially equivalent” to a device which was commercially available prior to May, 28, 1976. This method usually applies to Class I or II medical devices.

Premarket Approval (PMA) – A regulatory method for gaining a marketing clearance from the FDA for a Class III medical device. A company submits information to the FDA that documents the safety and effectiveness of the device.

Prosthesis – An artificial body part such as an artificial leg or arm. The term prothesis is also used to describe some of the implants used in the body such as a hip or knee replacement device.

Proximal – Nearest the center of the body.

Pseudoarthrosis (also Pseudarthrosis) – A form of a non-union in which there is the formation of a false joint with some cartilage covering the ends of the bones and a cavity containing fluid that resembles a normal joint.

Rotation – The movement of one vertebra to another about its normal or abnormal coronal axis.

Resection – The surgical removal of part of a structure, such as bone.

Resorption – The removal of bone tissue by normal physiological process or as part of a pathological process such as an infection.

Rhizotomy – Surgical transaction of a nerve root.

Rib Hump – The prominence of the ribs on the convexity of a spinal curvature, usually due to vertebral rotation best exhibited on forward bending. Seen most commonly in scoliosis.

Rod – In spinal applications, a slender, metal implant which is used to immobilize and align the spine.

Ruptured Disc – Disruption of a normal disc such that part of the nucleus pulposus (the center part of the disc) material breaks through a defect in the annulus fibrosus (the peripheral part of the disc). The same as a herniated disc.

S – Z

Sacrum – A part of the spine that is also part of the pelvis. It articulates with the ilia at the sacroiliac joints and articulates with the lumbar spine at the lumbosacral joint. The sacrum consists of five fused vertebrae that have no intervertebral discs.

Sagittal – Refers to a lengthwise cut that divides the body into right and left portions.

Sciatica – A lay term indicating pain along the course of a sciatic nerve, especially noted in the back of the thigh and below the knee.

Scoliosis – Lateral (sideways) curvature of the spine.

Sepsis – A state of infection of tissue due to disease-producing bacteria or toxins.

Skeleton – The rigid framework of bones that gives form to the body, protects and supports the soft organs and tissues, and provides attachments for muscles.

Spinal Canal – The bony channel that is formed by the intravertebral foramen of the vertebrae and in which contains the spinal cord and nerve roots.

Spinal Column – The flexible bone column extending from the base of the skull to the tailbone. It is made up of 33 bones, known as vertebrae. The first 24 vertebrae are separated by discs known as inter-vertebral discs, and bound together by ligaments and muscles. Five vertebrae are fused together to form the sacrum and 4 vertebrae are fused together to form the coccyx. The spinal column is also referred to as the vertebral column, spine, or backbone.

Spinal Cord – The longitudinal cord of nerve tissue that is enclosed in the spinal canal. It serves not only as a pathway for nervous impulses to and from the brain, but as a center for carrying out and coordinating many reflex actions independently of the brain.

Spinal Disc – The tough, elastic structure that is between the bodies of spinal vertebrae. The disc consists of an outer annulus fibrosus enclosing an inner nucleus pulposus. Also referred to as intervertebral disc.

Spinal Fusion – A surgical procedure to permanently join bone by interconnecting two or more vertebrae in order to prevent motion (see Arthrodesis).

Spinal Stenosis – Reduction in the diameter of the spinal canal due to new bone formation which may result in pressure on the spinal cord or nerve roots.

Spine – The flexible bone column extending from the base of the skull to the tailbone. It is made up of 33 bones, known as vertebrae. The first 24 vertebrae are separated by discs known as intervertebral discs, and bound together by ligaments and muscles. Five vertebrae are fused together to form the sacrum and 4 vertebrae are fused together to form the coccyx. The spine is also referred to as the vertebral column, spinal column, or backbone.

Spinous Process – The portion of the vertebrae that protrudes posteriorly from the spinal column. The spinous processes create the “bumps” felt on the midline of the back.

Spondylitis – Inflammation of vertebrae.

Spondylolisthesis – A defect in the construct of bone between the superior and inferior facets with varying degrees of displacement so the vertebra with the defect and the spine above that vertebra are displaced forward in relationship to the vertebrae below. It is usually due to a developmental defect or the result of a fracture. There are other more rare causes.

Spondylolysis – A defect in the neural arch between the superior and inferior facets of vertebrae without separation at the defect, and therefore no displacement of the vertebrae. It may be unilateral or bilateral, and is usually due to a development defect, but may be secondary to a fracture.

Stainless Steel – Iron-based metal containing chromium that is highly resistant to stain, rust, and corrosion. Certain grades of stainless steel are commonly used to make surgical implants and instruments.

Sterile – Free from living organisms.

Sterilization – The method used to render a material free from living organisms. Usual methods include steam under pressure, gas, and ionizing radiation.

Superior – Situated above or directed upward toward the head of an individual.
Tendon – The fibrous band of tissue that connects muscle to bone. It is mainly composed of collagen.

Third Party Payor – The source of reimbursement or payment of charges for medical services when the patient does not make direct payment; i.e. payments made by insurance companies, government agencies, or employers. The patient and the doctor represent the two other parties in third party pay arrangements.

Thoracic – The chest level region of the spine that is located between the cervical and lumbar vertebrae. It consists of 12 vertebrae which serve as attachment points for ribs.

Titanium – A metallic element used to make surgical implants.

Toxicology – The study of the toxic or harmful effects of substances on the body.

Translation – Vertebral body displacement; can describe lateral, anterior, or posterior displacement.

Transplant – The implantation of bone tissue, as in grafting, from one part of the body to another, or from one individual to another. Transplant also refers to the transfer of an organ such as a kidney or heart from one individual to another.

Transverse – Refers to a cut that divides the body into superior and inferior portions.

Vertebra – One of the 33 bones of the spinal column. A cervical, thoracic, or lumbar vertebra has a cylindrically-shaped body anteriorly and a neural arch posteriorly (composed primarily of the laminae and pedicles as well as the other structures in the posterior aspect of the vertebra) that protects the spinal cord. The plural of vertebra is vertebrae.

Vertebral End-Plates – The superior and inferior plates of cortical bone of the vertebral body adjacent to the intervertebral disc.

Wire – Metal thread available in various diameters and various degrees of stiffness and is generally used in surgery to transfix fractured bone.

Xenograft – A graft derived from one species for use in another species.

 

References:
Dorland’s Illustrated Medical Dictionary. Philadelphia, PA: W.B. Suanders Company, 1965.
Glossary of Spinal Terminology. Park Ridge, IL: American Academy of Orthopaedic Surgeons, 1985.
Human Anatomy, Eds. J.W. Hole, K.A. Koos, W.C. Brown, 1991.
Miller-Keane Encyclopedia & Dictionary of Medicine, Nursing & Allied Health, W.B. Saunders, New York, NY: 1992.
Scoliosis and Other Spinal Deformities, Eds. Moe, Winter, Bradford & Lonstein, 1978.
Webster’s Medical Desk Dictionary. Springfield, MA: Merriam Webster, Inc., 1986.
Viscogliosi, A. G. An Investor’s Guide to Orthopedic Terms. In M.R. Viscogliosi (Ed.), New York, NY: Martin Simpson & Company, Inc., 1992.
Code of Federal Regulations, Food and Drug, 21, Parts 800-1299. Washington: Office of the Federal Register, National Archives and Records Administration, 1990.