Canadian Orhopaedic Foundation


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Acetabulum: The cup-shaped socket of the hip joint. In fact, in Latin an "acetabulum" is cup, a vinegar cup. The acetabulum is a feature of the pelvis. The head (upper end) of the femur (the thighbone) fits into the acetabulum and articulates with it, forming a ball-and-socket joint.

Achilles tendon: A tough sinew that attaches the calf muscle to the back of the heel bone. It is one of the longest tendons in the body.

Acromegaly: overgrowth of the bones of the hands, feet, and face.

Ankylosing spondylitis: Arthritis of the spine, resembling rheumatoid arthritis.

Anterior cruciate ligament: A ligament in the knee that crosses from the underside of the femur (the thigh bone) to the top of the tibia (the bigger bone in the lower leg). Abbreviated ACL.

Arthritis: Inflammation of a joint, usually accompanied by pain, swelling, and sometimes change in structure.

Arthrodesis: surgical fusion of a joint. The procedure removes any remaining articular cartilage and positions the adjacent bones to promote bone growth across a joint. A successful fusion eliminates the joint and stops motion. The usual purpose is pain relief or stabilization of an undependable joint.

Arthroplasty: is a surgical procedure in which an artificial joint replaces a damaged joint, usually a hip, knee, shoulder or ankle.

Arthroscopy: A surgical technique whereby a tube-like instrument is inserted into a joint to inspect, diagnose and repair tissues. It is most commonly performed in patients with diseases of the knees or shoulders.

Articular cartilage: Cartilage which covers surface of bones forming a synovial joint; also called hyaline cartilage.

Articulations: Another word for joints; places of union between two or more bones.

Aspirate or Aspiration: to remove fluids from a body cavity by suction; usually done to obtain specimens for analysis.

Atrophy: A wasting away of tissue, frequently related to decreased use or decreased blood supply.

Avascular necrosis: (AVN) A condition in which the poor blood supply to an area of bone leads to bone death. The head of the femur is often the site of AVN. Also called avascular necrosis and osteonecrosis.

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Bilateral: occurring on both sides of a midline point or pertaining to both sides of the body (example, bilateral knee replacement means having both knees replaced).

Bone cement: A plastic grouting material used to hold joint replacement prosthesis to the natural bone.

Bone Mineral Density (BMD): tests and the technology that they use is known as bone densitometry. These tests are safe, painless and accurately measure the density of your bones. A BMD test can tell you whether or not you have osteoporosis and how likely you are to develop it in the future, and can help you to make decisions that may prevent fractures or further bone loss.

Bone scan: A procedure in which the doctor injects a small amount of a radiotracer (radioactive material) into a vein, typically in the patient's arm. Then, a special scanning camera passes over the patient's body, recording the distribution of radiotracer throughout the skeleton. A computer then translates this information into two-dimensional images recorded on film. Upon examining the bone scan, a doctor examines how the body absorbed the radiotracer. Healthy bone is characterized by uniform absorption throughout the body; areas of increased uptake appear as "hot spots" on the scan, and are associated with various abnormalities.

Bouchard's nodes: Nodes formed on the hand in osteoarthritis.

Brachial: pertaining to the arm.

Bunion: A bunion is a localized painful swelling at the base of the big toe (the great toe). The joint is enlarged (due to new bone formation) and the toe is often misaligned. It is frequently associated with inflammation. It can be related to inflammation of the nearby bursa (bursitis) or degenerative joint disease (osteoarthritis).

Bursae: Sacs containing a thin film of synovial fluid in synovial joints.

Bursectomy: The surgical removal of a bursa. The bursa is a sac formed by two layers of synovial tissue that is located where there is friction between tendon and bone or skin and bone.

Bursitis: Bursitis is inflammation of a bursa. A bursa is a tiny fluid-filled sac that functions as a gliding surface to reduce friction between tissues of the body. The major bursae are located adjacent to the tendons near the large joints, such as the shoulders, elbows, hips, and knees.

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CT (computed tomography): sometimes called CAT scan, uses special x-ray equipment to obtain image data from different angles around the body, and then uses computer processing of the information to show a cross-section of body tissues and organs. CT imaging is particularly useful because it can show several types of tissue -- lung, bone, soft tissue, and blood vessels -- with great clarity. Using specialized equipment and expertise to create and interpret CT scans of the body, radiologists can more easily diagnose problems such as cancers, cardiovascular disease, infectious disease, trauma, and musculoskeletal disorders. (CT of the body is a patient-friendly exam that involves little radiation exposure).

Calcification: Deposition of calcium salts.

Calcaneus: heel bone.

Carpal or carpus: pertaining to the wrist.

Carpal tunnel syndrome: median nerve compression at the wrist that is characterized by pain, numbness, and weakness in the median nerve distribution of the hand.

Cartilage: Connective tissue that covers joint surfaces.

Cerebral Palsy: describes a group of disorders affecting body movement and muscle coordination. The medical definition of cerebral palsy is a "non-progressive" but not unchanging disorder of movement and/or posture, due to an insult to or anomaly of the developing brain.

Cervical: having to do with any kind of neck.

Clavicle: collar bone.

Clubfoot: complex foot disorder that affects the muscles, ligaments, bones and joints of the foot and ankle.

Coccygeal: referring to the coccyx or tailbone.

Coccyx: The small tail-like bone at the bottom of the spine very near to the anus. The coccyx is made up of 3-5 rudimentary vertebrae. It is the lowest part of the spinal column.

Coccygectomy: excision of the coccyx, the tail bone of the vertebral column.

Collagen: A protein which gives strength and resilience to connective tissue such as bone and cartilage.

Compact bone: Hard, dense bone, found in main shaft of long bones and outer layer of other bones.

Compartment syndrome: condition in which there is swelling and an increase in pressure within a limited space (a compartment) that presses on and compromises blood vessels, nerves, and tendons that run through that compartment; usually involves the leg, but can also occur in the forearm, arm, thigh, shoulder and buttock.

Condyle: The rounded surface of a bone that allows movement of a joint.

Congenital: present at birth.

Congenital hip dysplasia: abnormal formation of the hip joint in which the ball at the top of the thighbone (the femoral head) is not stable within the socket (the acetabulum). The ligaments of the hip joint may also be loose and stretched.

Connective tissue: tissue that connects and supports the structures of the body

Contractility: Capacity of a muscle fiber to undergo shortening.

Crepitus: Crackling sound on joint movement.

Curettage: The removal of growths from within cavity walls; in the treatment of musculoskeletal tumors, the scraping of tumour out of bone.

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Deep vein thrombosis (DVT): venous blood clot formation caused by immobilization, hypercoagulation, obstructed venous flow, or endothelial injury, among others.

Degeneration: Breakdown of the natural tissue.

Degenerative joint disease (DJD): deterioration of the articular cartilage that lines a joint, which results in narrowing of the joint space and pain; osteoarthritis.

Diaphysis: Shaft of a long bone.

Diarthrosis: Freely moveable joint; synovial joint.

Diskectomy: surgical procedure in which an intervertebral disk is removed.

Dislocation: The condition of the components of a joint not lining up correctly. May also refer to bones that are not lined up correctly.

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Ectomy: word termination to indicate excision of the structure or organ designated by the root to which it is affixed, for example, tonsillectomy, diskectomy.

Edema: Excessive accumulation of fluid in the body tissues (e.g. swollen ankles).

Epiphysis: End of a long bone.

Ethmoid bone: an irregularly shaped, spongy bone that provides the floor of the front part of the skull and the roof of the nose. Consists of two masses of thin plates enclosing air cells and looks like a sieve.

Excision: removal by cutting.

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Fascia: sheet or band of tough fibrous connective tissue; lies deep under the skin and forms an outer layer for the muscles.

Fasciotomy: surgical incision of the fascia.

Femur: The femur is the bone in the leg that extends from the hip to the knee.

Fibula: The lateral (outside) and smaller of the two long bones in the lower leg between the knee and ankle. (The other bone in the lower leg is the tibia.)

Frontal bone: The large bone that makes up the forehead and supplies the upper edge and roof of the orbit (eye socket).

Fracture: A break in the continuity of bone.

Fusion or arthrodesis: The joining of two bones into a single unit, thereby obliterating motion between the two. May be congenital, traumatic, or surgical.

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Gout: An inherited disorder characterized by a raised blood uric acid level and deposits of crystals in and around joints.

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Hammertoes: A hammertoe is a toe that is bent because of a weakened muscle. The weakened muscle makes the tendons (tissues that connect muscles to bone) shorter, causing the toes to curl under the feet.

Hamstrings: three muscles in the posterior region of the buttock and thigh.

Heberden's nodes: Nodes formed on the hand in osteoarthritis.

Herniated disk: Rupturing of the tissue that separates the vertebral bones of the spinal column.

Humerus: upper arm bone.

Hyaline cartilage: Cartilage which covers surface of bones forming synovial joint; also called articular cartilage.

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Ischium: bone making up the lower down back part of the pelvis.

Ilium: The upper part of the bony pelvis which forms the receptacle for the head of the femur at the hip joint. The word "ilium" is the Medieval Latin term for the hip bone. The adjective is iliac.

Incision: a surgical cut.

Inflammation: occurs when tissue is crushed, stretched, or torn.

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Joint: A joint is the area where two bones are attached for the purpose of motion of body parts. A joint is usually formed of fibrous connective tissue and cartilage. An articulation or an arthrosis is the same as a joint.

Joint manipulation or joint mobilization: skilled, passive movement of a joint either within or beyond its active range of motion.

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Kyphosis: A deformity of the spine characterized by extensive flexion.

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Laminotomy: Removal of part of the lamina (bony arch) above and below an affected nerve in order to decompress the corresponding spinal cord and/or spinal nerve root. Removal of the Ligamentum Flavum from between the Lamina.

Ligaments: Fibrous bands of dense collagen bundles attached to the end of bones; connect one bone to another bone.

Lumbar: Referring to the 5 lumbar vertebrae which are situated below the thoracic vertebrae and above the sacral vertebrae in the spinal column. The 5 lumbar vertebrae are represented by the symbols L1 through L5.

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Magnetic Resonance Imaging (MRI): Is a non-invasive procedure that uses powerful magnets and radio waves to construct pictures of the body. Any imaging plane (or "slice") can be projected, stored in a computer, or printed on film. MRI can easily be performed through clothing and bones. However, certain types of metal in the area of interest can cause significant errors in the reconstructed images.

Mandible: lower jaw bone.

Marrow: soft blood-forming tissue that fills the cavities of bones or the central part of a bone.

Medullary cavity: Marrow cavity; central cavity in long bone.

Meniscus: The word "meniscus" comes from the Greek and refers to a crescent-shaped structure. Today a meniscus is something that is shaped like a crescent moon or a croissant pastry. The meniscus acts as a smooth surface for the joint to move on.

Meniscectomy: removal of meniscus cartilage of the knee.

Metacarpals: five bones of the hand that extend from the wrist to the fingers.

Metatarsals: five cylindrical bones extending from the heel, tarsus, to the toes. The metatarsals are numbered from the inside out, so the first metatarsal extends to the big toe.

Metatarsus: part of the foot between the tarsus and the toes; consists of five long bones termed the metatarsals that extend from the tarsus to the phalanges.

Myotomy: Surgery in which the muscle or muscular tissue is cut or dissected.

Muscles: connective tissue that affects movement; a component of nearly all organs and body systems.

Muscular Dystrophy: is the name of a group of muscle disorders that are characterized by progressive weakness and wasting of the voluntary muscles that control body movement.

Musculoskeletal system: The complex system that includes: bones, joints, ligaments, tendons, muscles, and nerves.

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Occipital bone: forms the rear and rear bottom of the skull. The occipital bone encloses a large oval hole called the foramen magnum that allows passage of the spinal cord. The occipital bone articulates (joins) with the parietal and temporal bones of the skull, the sphenoid bone in front of it, and the first cervical vertebra (the atlas) beneath it.

Open Surgery: A procedure where the surgeon cuts skin and tissues so that he/she has a direct access to the structures or organs involved.

Orthopaedic surgeon (or orthopaedist): The physician who diagnoses, treats, manages the rehabilitation process, and provides prevention protocols for patients who suffer from injury or disease in any of the components of the musculoskeletal system.

Orthopaedics: Orthopaedic medicine treats a wide variety of injuries and disorders in children and adults pertaining to the skeleton and its supporting muscles (musculoskeletal or MSK system), including:

  • joint destruction because of arthritis and fractures resulting from osteoporosis;
  • trauma resulting from industrial and motor-vehicle accidents and sports injuries;
  • spinal deformities (scoliosis of the spine) and other inherited skeletal deformities;
  • neuromuscular conditions (such as cerebral palsy, muscular dystrophy, para- and quadraplegia)
  • bone disorders (such as avascular necrosis).

Orthopaedic surgery (or orthopaedics): The medical specialty devoted to the diagnosis, treatment, rehabilitation, and prevention of injuries and diseases of the body's musculoskeletal system.

Osseous tissue: Bone tissue.

Ossification: Process of bone formation.

Osteoarthritis: A condition caused by wear and tear that causes inflammation of the joint, causing swelling, pain, and stiffness.

Osteoblast: A cell that makes bone. It does so by producing a matrix that then becomes mineralized. Bone mass is maintained by a balance between the activity of osteoblasts that form bone and other cells called osteoclasts that break it down.

Osteoclast: A cell that nibbles at and breaks down bone and is responsible for bone resorption.

Osteogenesis: the production of bone.

Osteomyelitis is an infection in the bone. Infection is more common in the long bones of the body, but it can affect any bone in the body. Osteomyelitis can occur in children of any age, but is more common in premature infants and babies born with complications.

Osteonecrosis: death of bone, often as a result of obstruction of its blood supply.

Osteoporosis: Abnormal reduction in quantity of bone tissue; a condition that develops when bone is no longer replaced as quickly as it is removed.

Osteotomy: Taking out part or all of a bone, or cutting into or through bone.

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Pannus: Inflamed, edematous synovial membrane.

Paraplegia: Paralysis of the lower part of the body including the legs.

Parietal bone: The main side bone of the skull.

Patella: The kneecap by another name, the patella is the small bone that is in the front of the knee. The patella is a sesamoid bone, a little bone (sesamoid = like a sesame seed) that is embedded in a joint capsule or tendon, in this case the tendon of insertion of the quadriceps muscle (the "quad"). The patella in an adult is about 2 inches (5 cm) across.

Patellectomy: surgical excision of the patella.

Pelvis: lower part of the abdomen located between the hip bones.

Periosteum: Connective tissue membrane covering a bone.

Phalanx or Phalanges: any bone of the finger or toe.

Plantar: sole or flexor surface of the foot.

Plantar fasciitis: irritation of the plantar fascia; a common cause of heel pain.

Planus: flattening of the arch of the foot.

Prosthesis: an artificial substitute for a missing body part, such as a hip, knee, shoulder or ankle joint.

Pubis: front centre portion of the pelvis.

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Quadraplegia: Paralysis of all four limbs, both arms and both legs, as from a high spinal cord accident or stroke.

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Radius: forearm bone below the elbow.

Revascularization: A procedure to provide an additional blood supply to a fractured bone.

Rheumatoid arthritis: Systemic disease affecting connective tissue, especially synovial joints.

Rib: one of the 12 paired arches of bone which form the skeletal structure of the chest wall (the rib cage). The ribs attach to the building blocks of the spine (vertebrae) in the back. The 12 pairs of ribs consist of true ribs, the first seven ribs attached to the sternum in the front; and false ribs, the lower five ribs that do not directly connect to the sternum.

Rotator cuff: made up of four muscles and their tendons that combine to form a "cuff" over the head of the humerus. The rotator cuff helps to lift and rotate the arm and to stabilize the ball of the shoulder within the joint.

Rotator cuff tear: an injury of the rotator cuff.

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Sacral: Referring to the sacrum, the 5 vertebral bones situated between the lumbar vertebrae and the coccyx (the lowest segment of the vertebral column). The 5 sacral vertebrae are represented by the symbols S1 through S5. The sacral vertebrae are normally fused to form the sacrum.

Sacroiliac joint: formed by the articulation of the sacrum and ilium.

Sacrum: one of three bones (sacrum and two pelvic bones) that make up the pelvic ring.

Scapula: shoulder blade.

Scoliosis: The condition of side-to-side spinal curvature.

Skeleton: supporting framework of the human body composed of 206 bones.

Sphenoid bone: A prominent, irregular, wedge-shaped bone at the base of the skull. The sphenoid bone has been called the "keystone" of the cranial floor since it is in contact with all of the other cranial bones.

Spinal column: central supporting bony structure of the body; vertebral column.

Spine: column of 33 vertebrae extending from the base of the skull to the tip of the coccyx.

Sprain: partial or complete tear of a ligament.

Spongy bone: Bone composed of meshwork of small, bony plates filled with red marrow.

Sternum: breast bone.

Strain: partial tear of a muscle.

Synarthrosis: Immovable joint.

Synovia: The slippery fluid that lubricates joints and provides nutrients to the cartilage. Also known as synovial fluid.

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Tarsus: bones in the heel are collectively called the bony tarsus.

Talus: ankle bone.

Temporal bone: A large irregular bone situated at the base and side of the skull. The temporal bone is connected with the mandible (the jaw bone) via the temporomandibular (TM) joint.

Tendons: Cords of fibrous connective tissue that attach muscles to bones.

Tendinitis: Inflammation of a tendon (the tissue by which muscle attaches to bone). Tendinitis most commonly occurs as a result of injury, such as to the tendons around the shoulder or elbow. It can also occur as a result of an underlying inflammatory rheumatic disease, such as reactive arthritis or gout. Tendinitis is synonymous with tendonitis.

Tendinosis: an avascular degenerative process that represents the result of failed tendon healing seen with aging or following repetitive microtrauma.

Tibia: The larger of the two bones in the leg (the smaller one being the fibula). The tibia is familiarly known as the shinbone.

Thoracic: pertaining to the chest.

Tophi: Plural of tophus; deposits of uric acid.

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Ulna: inner and larger bone of the forearm.

Unilateral: affecting only one side (example, unilateral knee replacement would replace just one knee, not both).

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Vertebrae: a vertebra is one of 33 bony segments that form the spinal column. There are 7 cervical, 12 thoracic, 5 lumbar, 5 sacra (fused into one sacrum bone) and 4 coccygeal (fused into one coccyx bone).

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Zygomatic bone: The part of the temporal bone of the skull that forms the prominence of the cheek. Also known as the zygomatic arch, the zygoma, the malar bone, the cheek bone and the yoke bone.

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