Orthopedic Medicine Glossary

A helpful guide of common terms used by your orthopedic surgeon.




A movement of any body part away from the medial plane or the outward rotation of an eye away from the midline.


Found in the hip bone, the acetabulum is a cup-shaped cavity found on the lateral surface. This is where the head of the femur articulates.


Anterior Cruciate Ligament: the ACL passes through the center of the knee attaching to the front of the tibia. The main function of the ACL is to keep the tibia from sliding forward of the femur and to provide rotational stability to the joint. The ACL is commonly torn in sports injuries.

Adaptive Equipment

Devices used to assist patients with completing daily activities. May including equipment for grooming, feeding, toileting, and other self-care activities.


When a limb moves toward the body’s midline or a digit moves towards the limb’s axis.

Ankle foot orthosis

Also referred to as AFO, ankle-foot orthosis is an external orthopedic appliance, splint, or brace used to control, assist, or limit the movement of the ankle or foot.

Anterior spinal fusion

A surgical procedure used to correct issues with smaller bones found in the spine.


A term used to refer to an inflammatory disorder affecting the joints. Arthritis often comes with joint stiffness and pain. It may also include redness, swelling, and a decreased range of motion.


A series of images taken of a joint after a contrast medium has been injected. An arthrogram is commonly done by fluoroscopy or MRI. The injection is commonly done under local anesthetic.


Used for certain joint conditions, Arthroscopy is a minimally-invasive treatment or diagnostic procedure. The procedure includes a small, lighted optic tube known as an arthroscope. This tube is inserted into the joint through a small incision and projects images of the joint onto a screen. 

Articular cartilage

The cartilage lining the joints of the body.


A decrease in size or wasting of body tissue or organ due to injury, lack of use, or disease.

Avascular necrosis (AVN)

A disease impacting the bone tissues, avascular necrosis is a result of disrupted or impaired blood supply. AVN often results in severe pain and a weakened bone susceptible to collapse.

Baker’s Cyst

A fluid-filled sac found behind the knee, also known as a popliteal cyst. A Baker’s Cyst will likely cause a feeling of tightness and may cause a bulge behind the knee.


Involving both the right and the left side of the body or a structure within the body.

Bone age

X-rays are used to determine a person’s age based on their bone development, which is known as bone age or chronological age.

Bone graft

Transplanting bone from one area of the body to another.

Brachial plexus

Found in the axilla and the neck, the brachial plexus is a nerve plexus that originates from the ventral branches of the cervical spinal nerves.


Swelling or inflammation impacting the bursa on the first joint of the big toe is known as a bunion.


A bursa is a fluid-filled sac located between a bone and a tendon.


When a bursa becomes inflamed, it is known as bursitis. It is most common in the shoulder, knee, or elbow joint and may include symptoms such as decreased mobility, pain, and tenderness.


A join capsule suture.

Carpal Tunnel Syndrome

Impacting the wrist, carpal tunnel syndrome happens when the median nerve is put under pressure. It comes with many symptoms including pain, tingling in the fingers, and weakness.


An elastic tissue lining the joints of the body, Cartilage is tough and helps to cushion against shock.


Commonly used to hold a broken bone in place, a cast helps to prevent movement, including muscle contractions, while the injury heals. Casts will immobilize a specific area of the body, typically a joint, to ensure proper healing.

CAT Scan

A combination of computer technology and x-rays used for diagnostic imaging is known as a CAT scan. This type of scan produces cross-sectional images of the body, both vertically and horizontally. CAT scans are used to view bones, fat, organs, and muscles with more detail than a general x-ray.

Cervical spine

The section of the neck including vertebrae C1-C7 and the intervertebral discs separating the vertebrae.

Clavicle (collarbone)
A thin, curved bone between the shoulder blade in sternum. The clavicle is prone to injuries like Distal Clavicle Osteolysis when put under excessive stress.


Commonly seen in trisomy 18 syndrome, clinodactyly is a permanent deflection or deviation of one or more of the fingers.

Congenital scoliosis

When scoliosis is presented at birth, typically due to defective embryonic development of the spine.


When muscle tissue is abnormally shortened or becomes highly resistant to stretching, it’s known as contracture. This could lead to a permanent disability.


A bruise or an injury where the skin is not broken is known as a contusion.


A pain relief injection used to alleviate issues, such as tendonitis or bursitis. Cortisone is a steroid often injected into an arthritic joint to provide relief from the pain.

DeQuervain’s syndrome

Impacting the wrist, DeQuervain’s syndrome is commonly found on the side of the wrist closest to the thumb. This syndrome is caused by tendons rubbing against their associated sheath. It can be treated with a cortisone injection, surgery, or a brace to help take the pressure off the tendons.


The determination of the cause, manifestations, or nature of a condition, injury, or disease.


A rounded or circular flat plate found within the body.


Often caused by extreme force on a ligament, which results in two bones in a joint separating, a dislocation is common in shoulders. A dislocation may also impact a ball-and-socket joint when the ball joint is partially or completely removed from the socket.

Dupuytren’s contracture

When the fascia, a layer of deep tissue under the skin of the palm, shrinks or thickens, it is known as a Dupuytren’s contracture. A common symptom of this injury is the fingers becoming drawn into a bent position.


Abnormal development, including an alteration in shape, size, or organization of adult cells.


Muscular tone impairment or an abnormal muscle contraction is producing involuntary twisting or posture.

EMG (Electromyogram)

A nerve or muscle test recording the electrical activity.


The thighbone is known as the femur.

Flexion deformity

When you can’t fully straighten or extend your knee, it’s known as flexion deformity.


A crack, rupture, or break in the bone or cartilage is known as a fracture.

Ganglion cyst

Often located on the hand or wrist, a Ganglion cyst is a fluid-filled cyst on the tendon or the top of a joint.


Commonly known to attack smaller joints, including the big toe, Gout is the result of a defect in body chemistry. It is caused by uric acid found in the joint fluid and can be treated with medication or changes in diet.


When a toe, most commonly the second toe, is permanently flexed downward in a claw-like shape, it is known as hammertoe.

Heel Spur

A bone growth happening on the heel bone is known as a heel spur.

Herniated disc

When the cushion located between the vertebrae of the spine is pushed outside the normal position causing a rupture to the outer cartilage, it’s known as a herniated disc. This type of injury may be accompanied by many symptoms including numbness or weakness in the legs or arms, along with pain.

High tone

Also known as hypertonia, this is an increase in tension in the muscles. It makes it hard to relax and may lead to a loss of independence and ability to complete everyday tasks.

Hip impingement

When something prevents the painless, free movement and painless movement of the ball-and-socket joint, it’s known as hip impingement.


The humerus is the bone found in the upper arm.


Increased tonicity in an abnormal way in the walls of the arteries or the skeletal muscles.


An abnormal decrease in strength and tonicity.


The body’s reaction to disease or injury, inflammation results in pain, stiffness, and swelling.


Intravenous or an apparatus used to provide intravenous injections.


A joint is where two or more bones meet, such as the elbow, knee, ankle, and shoulder.

Knee Replacement (arthroplasty)

An orthopedic procedure in which portions of damaged bone and cartilage are removed from the knee and replaced mechanical joint. The purpose of knee replacement surgery is to relieve pain and increase mobility.


The soft tissue rim around the socket portion of the hip and shoulder. Injuries often result in pain and instability.

Lateral Epicondylitis

Commonly known as tennis elbow, Lateral Epicondylitis is damage to one of the tendons responsible for extending the wrist.


The freedom or looseness of the movement of a joint, excessive or normal.


Fibrous tissue with a white and shiny appearance, a ligament is a flexible band connecting various bones and cartilage. Ligaments also help bind joints together.


The presence of abnormally large toes or fingers.

Magnetic Resonance Imaging

More commonly referred to as an MRI, Magnetic Resonance Imaging is a diagnostic procedure using radio frequencies, large magnets, and computer technology to create detailed images of structures and organs within the body.


A faulty union coming from the fragments from a bone fracture.


Growth or development happening at an abnormal pace.

Medial Epicondylitis

A type of pain caused by tendon damage impacting the tendons used to bend the wrist toward the palm. Medial Epicondylitis also goes by many other names including golfer’s elbow, baseball elbow, and suitcase elbow.

Menisci (Meniscus)

Found in the knees, menisci are crescent-shaped discs of connective tissues acting as shock absorbers. They help to cushion the lower leg from the rest of the body’s weight.


A microscopic injury or lesion.

Morton’s neuroma

Typically found between the third and fourth toes, Morton’s neuroma is a benign nerve tissue growth. It comes with common symptoms, such as stinging toes, numbness in the foot, and/or burning or sharp pain in the ball of the foot.

Musculoskeletal System

The entire body’s system of muscles and skeleton, including nerves, tendons, joints, and ligaments. 


An x-ray study allowing careful evaluation of the nerve roots and spinal cord, Myelogram includes injecting contrast material or dye into the spinal cord.

Orthopaedic Surgeon

Also known as an Orthopaedist, an Orthopaedic Surgeon diagnoses and treats patients suffering from disease or injury within the musculoskeletal system. This type of surgeon will also help manage rehabilitation and offer prevention protocols.

Orthopaedic Surgery

The specialty of Orthopaedic Surgeons is known as Orthopaedic Surgery. This specialty includes diagnosing, treating, rehabilitating, and the prevention of disease and injury within the musculoskeletal system of the body.


Wear and tear on the joints may cause swelling, stiffness, pain, and inflammation known as osteoarthritis. The chronic deterioration, usually in older patients, of joint cartilage, is the cause of the pain and swelling.


The dissolution of bone typically due to the loss or removal of calcium from the bone.


When the bone mass is decreased due to an insufficient compensation of normal bone lysis. May also refer to a decrease in bone mass below normal.


A bony outgrowth or excrescence.


When bone mass and density cannot be replaced as fast as it’s removed, it’s a condition known as Osteoporosis. The results of this condition are weaker bones prone to deformities and fractures.


Transection or incision of the bone.

Overuse Conditions

Injuries affecting the muscles, ligaments, tendons, and/or bones due to minor trauma involving soft-tissue injuries are known as overuse conditions.


The kneecap.


A long bone found in the hand or foot. Fourteen total are found in each hand or foot.

Physical therapy

A commonly prescribed rehabilitation for sports injuries and other ailments. Typically, physical therapy will include specific exercises and stretches designed to return strength and range of motion to the inflicted area.

Plantar Fascia

Connecting fibrous tissue formed in a tough, long band running from the ball of the foot to the heel.

Plantar fasciitis

An injury including inflammation of the fibrous tissue running from the base of the toes to the heel bone is known as plantar fasciitis. Symptoms often include mild heel pain, especially in the morning after waking. Without treatment, this injury may cause issues with the knee, foot, hip, and back.

Platelet-rich plasma

Platelet-rich plasma is substance used in plasma therapy to promote healing. The plasma is injected into the specific area of the body that needs healing. Plasma comes from the blood and provides helpful proteins that promote clotting.


Anything done or happening after a surgical operation, including care or treatment.


Anything happening or done before surgery, including care, preparation, or treatment.


An artificial replacement part for the body is known as a prosthesis.


An acronym standing for Rest, Ice, Compression, Elevation, the R.I.C.E Method is a common treatment for sprains, strains, and other injuries.


One of the two bones found in the forearm is known as the radius. It is larger at the wrist and small at the elbow and allows for rotation at the wrist.

Range of motion

The distance a limb of the body can normally move in a linear or angular distance.

Rheumatoid Arthritis

Most commonly affecting the feet and hands, Rheumatoid Arthritis is an inflammatory disease found in the lining of the joint. 

Rotator cuff

The tendons and muscles connecting the shoulder joint and the arm are known as the rotator cuff. Rotator cuff tears are a common injury among athletes.


The hardening of the tissue.


A sideways or lateral curvation of the spine, often causing the appearance of a person leaning is known as scoliosis.

Shin Splints

Painful condition of the shin resulting from repetitive high impact activity. Also called medial tibial stress syndrome, shin splints are pain found along the inside edge of the shinbone. It’s due to inflammation found in the tissue between the middle and lower leg.

Shoulder impingement

When a bursa in the shoulder or a rotator cuff tendon becomes compressed when the arm is raised, it is known as shoulder impingement. This type of injury may come with shoulder or arm pain, most commonly occurring when lifting the arm.

SLAP lesion

When the top of the cartilage lining the shoulder joint socket (labrum) becomes torn, it is known as a SLAP lesion. This type of injury often requires arthroscopic surgery to repair the tear or remove the bicep.

Soft tissue

Muscles, tendons, nerves, and ligaments found throughout the musculoskeletal system are known as the soft tissue of the body.

Spinal stenosis

When the spinal canal becomes narrow and causes pressure on the nerve roots and spinal cord, it is known as spinal stenosis. Usually, this type of injury comes with lower back pain and leg pain.


When the ligaments of a joint become stretched or they completely tear, it’s a sprain. A sprain will be accompanied by inflammation, discoloration, swelling, and hemorrhage. Sprains are most common in the ankle and the knee.


A partial tear or stretching of the ligaments or tendons is known as a strain.

Stress Fracture

When overuse or excessive activity causes a small crack or hairline fracture in the bone, it is known as a stress fracture.

Synovial Fluid

A sticky and clear fluid released by the synovial membrane, the synovial fluid provides a lubricant for tendons and joints.


The thin membrane found in joints capable of secreting fluid to allow movement within the joint is the synovium.


Fibrous tissue formed into a tough band connecting muscles to bones and other tissues is a tendon.


When a tendon suffers from inflammation, it’s known as tendonitis.

Tennis elbow

Painful condition involving breakdown of the tissue on the outer side of the elbow is known as tennis elbow. It is usually caused by twisting and straining the forearm excessively.


The larger bone of the lower leg is the tibia or shin bone.

Total joint replacement

When a prosthesis is used to replace a damaged or arthritic joint, the surgical procedure is known as a total joint replacement.

Trigger finger

If a finger becomes difficult to bend or straighten, it is known as a trigger finger. This is an abnormal condition caused by inflammation or thickening of tendons found in the fingers. Tendons could become stuck and snap back into the straightened position quickly.

Trochanteric bursitis

Trochanteric bursitis occurs when a bursa (fluid-filled sac) forms in an area of friction around the outside of the hip. It can cause mild to severe, and sometimes debilitating pain.

Ulnar Bone

Along with the radius, one of the two bones of the forearm.

Ulnar Nerve

The ulnar nerve, otherwise known as the funny bone starts in the neck and travels done the arm (close to the ulna bone) and into the fingers. Pressure or stretching of the ulna nerve can sometimes cause cubital tunnel syndrome. 


Used to diagnose internal organs, an ultrasound uses high-frequency sound waves to form an image.


Found in the spinal column, each vertebra is an irregular bone, including hyaline cartilage.


Used to diagnose bones, organs, and internal tissues, an x-ray uses invisible electromagnetic energy beams to create an image.