Acetaminophen
Non-prescription pain reliever and fever reducer, such as Tylenol and Anacin-3.  Does not have anti-inflammatory effect but can help reduce mild to moderate pain.

Acupuncture
An alternative pain-relief therapy involving the insertion of needles into specific exterior body locations.  The National Institutes of Health says acupuncture can reduce pain and improve function for people with arthritis, and serve as an effective complement to more standard care.

Analgesics
Medications designed to relieve pain. Pure analgesics do not have an effect on inflammation.

Arthritis
A group of bone and joint disorders commonly marked by bone deterioration, joint inflammation, chronic pain, loss of mobility and flexibility, and other skeletal dysfunction.  Arthritis is one of the most common ailments (especially among older people) and the most common condition leading to joint replacement surgery.

Arthroplasty
The medical term for a total joint replacement procedure.

Arthroscopy
A surgical procedure in which a small fiberoptic telescope, called an arthroscope, is inserted into a joint – most commonly a knee.  With this device, a surgeon can view and irrigate structures in the joint, and conduct such procedures as trimming cartilage and removing bone chips.

Bone spurs
Small growths of bone that can occur on the edges of a joint affected by osteoarthritis. These growths are also known as osteophytes.

Cartilage
A hard but slippery coating on the end of each bone. The breakdown of joint cartilage is the primary feature of osteoarthritis.

Celebrex
A Cox-2 Inhibitor-type drug that has received attention regarding the risk of heart attack, stroke and other cardiovascular events as side effects.  The FDA permits continued use of Celebrex, but now requires strong warnings on its label about possible side effects.

Cemented joint
A type of replacement joint that is connected to natural bone using bone glue or "cement."  Cemented implants are preferred for older, less active people because results are consistently good and recovery time is relatively quick.

Chondroitin sulfate
A substance that occurs naturally in the body, providing the building blocks to make and repair cartilage.   Now used as an alternative therapy, taken in pill form, believed to slow progression of osteoarthritis.  It tends to work best when taken "early on," before the disease has significantly progressed.

Chondrocytes
Components of cartilage.  Chondrocytes are cells that produce cartilage, are found throughout cartilage, and help it stay healthy as it grows. Sometimes, however, they release certain enzymes that destroy collagen and other proteins.

Collagen
A family of fibrous proteins that are components of cartilage. Collagens are the building blocks of skin, tendon, bone, and other connective tissues.

Corticosteroid injections
Direct injections into a joint of anti-inflammatory drugs that imitate the natural body fluids produced in the adrenal gland.  These drugs lubricate an arthritic joint, reducing pain and swelling.

Cox-2 Inhibitors
A category of non-steroidal anti-inflammatory drugs (NSAIDs) that reduce joint pain and inflammation, but are easier on the stomach than other NSAIDs.  Cox-2s, however, have not been in use as long as other NSAIDs, and concerns have arisen about their potential adverse side effects.

Glucosamine
A substance that occurs naturally in the body, providing the building blocks to make and repair cartilage.   Now used as an alternative therapy, taken in pill form, believed to slow progression of osteoarthritis.  It tends to work best when taken "early on," before the disease has significantly progressed.

Hyaluronic acid
A substance that gives healthy joint fluid its viscous (slippery) property and that may be reduced in people with osteoarthritis. For some people with osteoarthritis of the knee, replacing hyaluronic acid with injections of agents referred to as viscosupplements is useful for increasing lubrication, reducing pain, and improving function.

Hybrid joint
A type of replacement joint that utilizes both cemented and uncemented components for the particular needs of the patient.

Implant
A generic term describing any artificial joint or component implanted into the body.

Joint
A joint is the point where two or more bones are connected. With a few exceptions (in the skull and pelvis, for example), joints are designed to allow movement between the bones and to absorb shock from movements like walking or repetitive motions.

Joint capsule
A tough membrane sac that holds the bones and other joint parts together.

Ligaments
Tough bands of connective tissue that attach bones to each other, providing stability.

Magnetic resonance imaging (MRI)
Provides high resolution computerized images of internal body tissues. This procedure uses a strong magnet that passes a force through the body to create these images.

Non-cemented (or uncemented) joint
A type of replacement joint that attaches to the body naturally.  Parts that fit inside the patient's bone are made of a material and feature a design that encourages the bone to grow into and around them.  This type of implant lasts longer.  It requires healthy bones that will grow into replacement joint, however, as well as a longer recovery time.

NSAIDs
Non-steroidal anti-inflammatory drugs are used in the treatment of osteoarthritis.  Some are prescription only; others are non-prescription (over-the-counter or OTC). Side effects can include stomach upset and gastrointestinal bleeding; certain Cox-2 Inhibitors, a category of NSAIDs, could increase risk for heart attack, stroke and other cardiovascular events.

Orthopaedist / Orthopaedic surgeon
A physician who specializes in bone conditions and performs joint replacement surgery.

Osteoarthritis
The most common form of arthritis, caused by breakdown of the cartilage that protects bones.

Osteophytes
Small growths of bone that can appear on the edges of a joint affected by osteoarthritis. These growths are also known as bone spurs.

Partial arthroplasty
A surgical procedure in which only part of a joint is removed and replaced with artificial components.

Prostheses / Prosthetic devices
Generic terms for a whole or partial artificial joint, limb or other "structural" body part.

Physical therapy
An individualized exercise program – usually designed, supervised and implemented by a trained professional – intended to improve or restore joint strength and mobility.  It is a "must" following arthroplasty.

Revision surgery
A subsequent surgery to correct problems from a less-than-successful arthroplasty.

Rheumatoid arthritis
An arthritic condition in which the immune system attacks the tissues of the joints, leading to pain, inflammation, and eventually joint damage and malformation. It typically begins at a younger age than osteoarthritis does, causes swelling and redness in joints, and may make people feel sick, tired, and uncommonly feverish. Rheumatoid arthritis may also affect skin tissue, the lungs, the eyes, or the blood vessels.

Stem cells
Primitive cells, usually taken from the bone marrow, that can transform into other kinds of cells, such as muscle or bone cells. In the future, researchers hope to be able to insert stem cells into cartilage and stimulate them to replace cartilage damaged by arthritis or injury.

Synovium
A thin membrane inside the joint capsule that secretes synovial fluid.

Synovial fluid
A fluid secreted by the synovium that lubricates the joint and keeps the cartilage smooth and healthy.

Tendons
Tough, fibrous cords that connect muscles to bones.

Transcutaneous electrical nerve stimulation (TENS)
A technique that uses a small electronic device to direct mild electric pulses to nerve endings that lie beneath the skin in a painful area. TENS may relieve some arthritis pain. It seems to work by blocking pain messages to the brain and by modifying pain perception.

X-ray
A procedure in which low-level radiation is passed through the body to produce a picture called a radiograph. X rays of joints affected by osteoarthritis can show such things as cartilage loss, bone damage, and bone spurs.