The term arthritis literally means inflammation of a joint, but is generally used to describe any condition in which there is damage to the cartilage. Inflammation is the body’s natural response to injury. The warning signs that inflammation presents are redness, swelling, heat and pain.

The cartilage is a padding that absorbs stress. The proportion of cartilage damage and synovial inflammation varies with the type and stage of arthritis. Usually the pain early on is due to inflammation. In the later stages, when the cartilage is worn away, most of the pain comes from the mechanical friction of bone rubbing on bone or roughened cartilage.

There are many different types of arthritic joint disease. The most common are:

Osteoarthritis: Osteoarthritis is also called degenerative joint disease; this is the most common type of arthritis, which occurs more frequently as we age. This condition affects cartilage, the tissue that cushions and protects the ends of bones in a joint. With osteoarthritis, the cartilage starts to wear away. In extreme cases, the cartilage can completely wear away, leaving nothing to protect the bones in a joint, causing bone-on-bone contact. Bones may also bulge, or stick out at the edges of a joint, called a bone spur.

Osteoarthritis causes joint pain and can limit a person’s normal range of motion (the ability to freely move and bend a joint). When severe, the joint may lose increasing movement, causing a person to become disabled. Disability most often happens when the disease affects the spine, Knees, and Hips.

Rheumatoid Arthritis: This is an auto-immune disease in which the body’s immune system (the body’s way of fighting infection) attacks healthy joints, tissues, and organs. Occurring most often in women of childbearing age (15-44), this disease causes inflammation of the lining (or synovium) of joints. It can cause pain, stiffness, swelling, and loss of function in joints. When severe, rheumatoid arthritis can deform, or change, a joint. For example, the joints in a person’s finger can become deformed, causing the finger to bend or curve.

Rheumatoid Arthritis affects mostly joints of the hands and feet and tends to be symmetrical. This means the disease affects the same joints on both sides of the body at the same time and with the same symptoms. No other form of arthritis is symmetrical. About two to three times as many women as men have this disease.

Post-traumatic arthritis: Arthritis developing after an injury to the joint is called ‘post-traumatic’ arthritis. The condition may develop years after any trauma such as a fracture, severe sprain, or ligament tears.

Psoriatic arthritis: This form of Arthritis occurs in some patients with psoriasis, a scaling skin disorder, affecting the joints at the ends of the fingers and toes. It can also cause changes in the fingernails and toenails. Back pain may occur if the spine is involved.

Causes of knee arthritis

Osteoarthritis is caused by wear of the cartilage covering the bone ends in the knee joint. This may be due to excessive strain over prolonged periods of time, or due to other joint diseases, injury or deformity. Primary osteoarthritis is commonly associated with ageing and general degeneration of joints.

Secondary osteoarthritis is generally the consequence of another disease or condition, such as repeated trauma or surgery to the knee joint, or abnormal knee joint structures from birth.

Rheumatoid arthritis occurs when the gene responsible for the disease is triggered by infection or environmental factors. With this trigger, the body produces antibodies, the defence mechanism of body, against the joint which results in rheumatoid arthritis.

Fractures at joint surfaces and joint dislocations may predispose an individual to the development of post-traumatic arthritis.

Uric acid crystal build-up is the cause of gout and long-term crystal deposition in the knee joints may cause problems.

Symptoms of arthritis

There are more than 150 different forms of arthritis. Symptoms vary according to the form of arthritis. Each form affects the body differently. Arthritic symptoms generally include swelling and pain or tenderness in one or more joints for more than two weeks, redness or heat in a joint, limitation of motion of the joint, stiffness, and can sometimes be associated with skin changes including rashes.


Arthritis should be diagnosed with a medical history, physical examination and X-rays of the affected part. Computed tomography (CT) scans and magnetic resonance imaging (MRI) scans may also be performed to help support the diagnosis.

Treatment Options

There is no cure for arthritis. It may be beneficial to to consider anti-inflammatory medicine. They may recommend physiotherapy or occupational therapy, which may include exercise, deep tissue massage, ultrasound and other treatments. In severe cases, surgery may be suggested. The type of surgery will depend on a variety of factors including your age, activity level and severity of the disease.

Initial treatment for arthritis is non-surgical (conservative), consisting of rest, avoidance of vigorous weight bearing activities, and the use of pain killing (analgesic) and/or anti-inflammatory medications. With worsening symptoms a walking aid or a brace may be helpful. For more severe symptoms, an injection of cortisone into the joint can be helpful. When conservative measures have been exhausted, offer no relief, and symptoms become disabling, surgery may be recommended. Surgery is usually considered if nonsurgical treatment fails to give relief. There are different surgical procedures that can be used and may include:

Arthroscopy: Arthroscopy is sometimes used to assess damage, for surgical planning, to remove loose bodies (fragments of bone or cartilage which can break off inside the joint) and to remove torn cartilages if they are causing mechanical features such as clicking, clunking or locking.

Osteotomy: Realignment (osteotomy) surgery is used where part of the joint is well preserved and part is worn. By re-aligning the leg, the forces across the damaged part of the joint can be redistributed to load up the preserved parts, reducing pain and improving function. This surgery has the advantage of avoiding the need for joint replacement but it is technically complex, specialist surgery.

Arthroplasty (Knee replacement/resurfacing): In this procedure, your knee surgeon will remove the worn joint lining and replace it with an artificial surface. It is usually performed when the joint is severely damaged by osteoarthritis, rheumatoid arthritis, post-traumatic arthritis or avascular necrosis. The goal of the surgery is to relieve pain and restore the normal functioning of the joint. Total knee joint replacement can be performed with open or minimally invasive approaches. Partial replacement of the joint can be performed to replace the worn compartment if other parts are well preserved.

Arthrodesis (Knee fusion): Arthrodesis involves removal of the joint lining and fusion of the bones of the joint using metal rods or screws across the joint. This surgery is usually indicated when the joints are severely damaged, when there is limited mobility, damage to the surrounding ligaments and tendons, failed previous arthroplasty, and when heavy manual use is expected. The knee will not move at all after an arthrodesis.

Synovectomy: This surgery is usually indicated for early cases of inflammatory arthritis where there is significant swelling (synovitis) that is causing pain or is limiting the range of motion. Synovectomy is a surgical removal of the inflamed synovium (tissue lining the joint). The procedure may be performed using arthroscopy.

Your surgeon will discuss the options and help you decide which type of surgery is the most appropriate for you.

RCS Logo British Orthopaedic AssociationRoyal College of Surgeons of EdinburghOTSISBritish Association for knee surgeryISOAMDU LogoOTSIS