Our knowledge of orthopaedics. Your best health.

from the American Academy of Orthopaedic Surgeons

Diseases & Conditions



Staying Healthy

Arthritis: An Overview

Find an Orthopedist

Arthritis is inflammation of one or more of your joints that causes pain and stiffness. While arthritis is mainly an adult disease, some forms affect children.

There are many types of arthritis. Some of these include osteoarthritis, rheumatoid arthritis, post-traumatic arthritis, septic arthritis, and psoriatic arthritis.

While each of these conditions have different causes, the symptoms and treatment are often the same. Pain, swelling, and stiffness are the primary symptoms of arthritis. Any joint in the body may be affected by the disease, but it is particularly common in weight-bearing joints such as the knee, hip, and spine.

Although there is no cure for arthritis, there are many treatment options available to help manage pain and keep people staying active.


Arthritis is a disease of the joint. A joint is where the ends of two or more bones meet. The knee joint, for example, is formed between the bones of the lower leg (the tibia and the fibula) and the thighbone (the femur). The hip joint is where the top of the thighbone (femoral head) meets a concave portion of the pelvis (the acetabulum).

Cartilage. A smooth tissue of cartilage covers the ends of bones in a joint. Cartilage cushions the bone and allows the joint to move easily without the friction that would come with bone-on-bone contact.

Synovium. A joint is enclosed by a fibrous envelope, called the synovium, which produces a fluid that also helps to reduce friction and wear in a joint.

Muscles, tendons, and ligaments. Ligaments connect the bones and keep the joint stable. Muscles and tendons power the joint and enable it to move.


Arthritis may be caused by wear and tear on the articular cartilage through the natural aging process (osteoarthritis), or may develop following an injury (post-traumatic arthritis).

Other types of arthritis, such as crystalline arthritis, may come from an inflammatory process.

Still others, such as rheumatoid arthritis or lupus arthritis, are the result of a systemic disease throughout the body.

Regardless of whether the cause is from injury, normal wear and tear, or disease, the joint becomes inflamed, causing swelling, pain and stiffness. Inflammation is one of the body's normal reactions to injury or disease. In arthritic joints, however, inflammation may cause long-lasting or permanent disability.


 The most common type of arthritis is osteoarthritis. Also known as "wear and tear" arthritis, osteoarthritis occurs when the cartilage that cushions and protects the ends of your bones gradually wears away.

 It results from overuse, trauma, or the natural degeneration of cartilage that occurs with aging.  

 Osteoarthritis is often more painful in joints that bear weight, such as the knee, hip, and spine. However, joints that are used extensively in work or sports, or joints that have been damaged by injury may show signs of osteoarthritis.

 In many cases, bone growths called "spurs" develop at the edges of osteoarthritic joints. The bone can become hard and firm (sclerosis). The joint becomes inflamed, causing pain and swelling. Continued use of the joint is painful.

Rheumatoid Arthritis

 Rheumatoid arthritis is a long-lasting disease.

Rheumatoid arthritis affects many parts of the body, but mainly the joints. The body's immune system, which normally protects the body, begins to produce substances that attack the body. In rheumatoid arthritis, the joint lining swells, invading surrounding tissues. Chemical substances are produced that attack and destroy the joint surface.

Rheumatoid arthritis may affect both large and small joints in the body and also the spine. Swelling, pain, and stiffness usually develop, even when the joint is not used. In some circumstances, juvenile arthritis may cause similar symptoms in children.

Post-traumatic Arthritis

Post-traumatic arthritis results from an injury to the joint. If a broken bone or fracture extends into a joint it will damage the smooth cartilage that covers the joint surfaces. The surface becomes uneven and causes friction as the joint moves. Over time, the joint breaks down and becomes arthritic.

Septic Arthritis

Septic arthritis is an infection of the joint. Most often bacteria reach the joint through the bloodstream from an infection in another part of the body, such as the urinary tract. Infected joints are typically warm, red, and acutely tender. They are often swollen due to pus in the joint. An infected joint often needs surgical drainage in addition to antibiotics.

Psoriatic Arthritis

Psoriatic arthritis is associated with the skin disease psoriasis. While it may involve larger joints such as the knees it often presents with symptoms in smaller areas such as the distal joints at the tips of the fingers and toes.

Gouty Arthritis

Gouty arthritis develops as the result of uric acid buildup in the bloodstream. The uric acid forms crystals which cause acute inflammation in a joint. The big toe, ankle, knee, and elbow are the most common joints affected. A gout attack can be acutely painful. The inflamed joint becomes red and very sensitive to touch. Gout attacks are most often treated with medicine rather than surgery. Long term, many patients develop soft tissue masses (tophi) over the affected joints.

Lyme Arthritis

Lyme arthritis can be one of the side effects of Lyme disease, a systemic infection caused by a tick bite. Lyme arthritis can present acutely as pain and swelling in early stages of the disease. Lyme disease is treated with antibiotics. Left untreated, Lyme disease can lead to chronic arthritis.

Spondylytic Arthritis

Spondylytic arthritis mostly affects the spine. The most common form is ankylosing spondylitis. It often presents as low back pain with initial changes seen at the sacroiliac joints in the pelvis. Your doctor can confirm this diagnosis with a positive blood test, HLA-B27.

Lupus Arthritis

Lupus is an autoimmune disease that affects multiple organs including the kidneys, skin, blood, and the heart. Lupus arthritis can be systemic and cause chronic pain in multiple joints.

Juvenile Arthritis

Juvenile arthritis is the most common type of arthritis in children. It is estimated that more than 250,000 children under 16 in the United States are affected. There are several types of the disease and most are different from rheumatoid arthritis in adults. 

Doctor Examination

Arthritis is diagnosed through a careful evaluation of symptoms and a physical examination. X-rays are important to show the extent of any damage to the joint. Blood tests and other laboratory tests may help to determine the type of arthritis. Some of the findings of arthritis include:

  • Weakness (atrophy) in the muscles
  • Tenderness to touch
  • Limited ability to move the joint passively (with assistance) and actively (without assistance).
  • Signs that multiple joints are painful or swollen (an indication of rheumatoid arthritis)
  • A grating feeling or sound (crepitus) with movement
  • Pain when pressure is placed on the joint or the joint is moved


There is no cure for arthritis, but there are many treatments to help relieve the pain and disability that it can cause. 

Nonsurgical Treatment

  • Medications. Over-the-counter medications can be used to control pain and inflammation in the joints. These medications, called anti-inflammatory drugs, include aspirin, ibuprofen, and naproxen. Acetaminophen can be effective in controlling pain.

    Prescription medications also are available. A physician will choose a medication by taking into account the type of arthritis, its severity, and the patient's general physical health. Patients with ulcers, asthma, kidney, or liver disease, for example, may not be able to safely take anti-inflammatory medications.

    Injections of cortisone into the joint may temporarily help to relieve pain and swelling. It is important to know that repeated, frequent injections into the same joint can cause damage and undesirable side effects.

    Viscosupplementation or injection of hyaluronic acid preparations can also be helpful in lubricating the joint. This is typically perfomed in the knee.
  • Exercise and therapy. Canes, crutches, walkers, or splints may help relieve the stress and strain on arthritic joints. Learning methods of performing daily activities that are the less stressful to painful joints also may be helpful.

    Certain exercises and physical therapy may be used to decrease stiffness and to strengthen the weakened muscles around the joint.

Surgical Treatment

In general, an orthopaedic surgeon will perform surgery for arthritis when other methods of nonsurgical treatment have failed to relieve pain and other symptoms. When deciding on the type of surgery, the physician and patient will take into account the type of arthritis, its severity, and the patient's physical condition.

There are a number of surgical procedures. These include:

  • Removing the diseased or damaged joint lining
  • Realignment of the joints
  • Fusing the ends of the bones in the joint together, to prevent joint motion and relieve joint pain
  • Replacing the entire joint (total joint replacement)

Long-Term Management

In most cases, persons with arthritis can continue to perform normal activities of daily living. Exercise programs, anti-inflammatory drugs, and weight reduction for obese persons are common measures to reduce pain, stiffness, and improve function.

In persons with severe cases of arthritis, orthopaedic surgery can often provide dramatic pain relief and restore lost joint function.

Some types of arthritis, such as rheumatoid arthritis, are often treated by a team of health care professionals. These professionals may include rheumatologists, physical and occupational therapists, social workers, rehabilitation specialists, and orthopaedic surgeons.


At present, most types of arthritis cannot be cured. Researchers continue to make progress in finding the underlying causes for the major types of arthritis. In the meantime, orthopaedic surgeons, working with other physicians and scientists, have developed many effective treatments for arthritis.

Find an Orthopedist
Find an Orthopedist

Last Reviewed

August 2016

AAOS does not endorse any treatments, procedures, products, or physicians referenced herein. This information is provided as an educational service and is not intended to serve as medical advice. Anyone seeking specific orthopaedic advice or assistance should consult his or her orthopaedic surgeon, or locate one in your area through the AAOS Find an Orthopaedist program on this website.