Arthritis is the inflammation of one or more joints. The main symptoms are joint pain, swelling and stiffness.
Arthritis, by virtue of the origin of the Greek word athron (joint) and the Latin suffix -itis (inflammation), can simply be defined as an inflammation of joints. Arthritis is commonly viewed as a disease of the older age group. In industrialized countries, it has been reported to be the major cause of disability in those aged 55 years and over. However, it is important to note that there are other types of arthritis that can be seen in the younger age groups . Arthritis can affect any joint in the body, from the larger hip joints to the smaller interphalangeal joints. There are numerous types of this condition.
Arthritis, as defined earlier is an inflammation of the joint. Therefore anything that can cause pain, swelling and loss of function in a joint can be said to be a cause of arthritis. Some of these factors that may cause or predispose to arthritis are obesity, infections, age, allergies, autoimmune diseases, diet, physical activity, and genetics .
There are different forms of arthritis and the commonest is osteoarthritis. Arthritis in any of its forms is the leading cause of disability worldwide in individuals aged 18 years and older. The exact incidence is dependent on the type of arthritis.
The prevalence, according to age distribution is about 7.3% in individuals aged between 18 and 44, and 30.3% in individuals aged between 45 and 64. In individuals 65 years and older, the prevalence is as high as 49.7%. Arthritis is generally more common in women.
To understand the pathophysiology of arthritis, we need to understand the anatomical makeup of joints. A joint is where two bones are come together. These bones are held together by ligaments. The bones are covered by cartilages which allow painless and smooth movement at the joints. There is a thin film of fluid, the synovial fluid, in the joint space and this provides nutrition for the joint and cartilage. The joint is covered by a capsule. If anything goes wrong with the components of a joint, it will lead to arthritis. Most types of arthritis involve more than one of the components. The individual pathophysiology depends on the type of arthritis.
For the most common one, osteoarthritis, there is initial cartilage damage due to some of the factors listed in etiology. The chondrocytes then attempt to repair this cartilage damage which causes an increased synthesis of proteoglycans which are responsible for the resilience of the cartilages. The increased synthesis leads to a hypertrophic repair of the cartilage which causes the visible swelling in patients with osteoarthritis. Eventually, due to a long term increase in chondrocyte metabolism, degradative enzymes associated with inflammation are released which results in a loss of proteoglycans which causes the cartilage, now increased in size, to soften and lose its elasticity leading to stiffer joints and loss of joint space.
Another common form of arthritis is rheumatoid arthritis. The exact pathway that leads to the development of this condition is unclear. An external factor, like trauma, triggers an autoimmune response that leads to synovial hypertrophy and chronic joint inflammation. There are many cellular factors involved in this process like phagocytes, fibroblasts, and inflammatory mediators amongst others that eventually lead to inflammation and excess proliferation of the synovium resulting in the destruction of cartilage and many surrounding tissues .
Infectious arthritis is another common form of arthritis and is also known as septic arthritis. There are three ways in which the microorganism invades the joint. It could be via the blood stream, which is the most common form of infection. It could also be through contiguous spread from infectious tissues or by direct inoculation. Because the synovial fluid has adequate bactericidal activity, this condition is more commonly seen in more susceptible individuals. This susceptibility could be as a result of previous damage due to rheumatoid arthritis or an immunosuppressive state like systemic lupus erythematosus. Previously damaged joints are especially susceptible due to neovascularization which increases the chance of infection via the blood stream. Organisms responsible for this condition are mostly bacteria like Staphylococcus aureus and Neisseria gonorrhoeae, although viruses like rubella have also been implicated. The main effect of bacteria invasion is damage to articular cartilage either due to the organism’s pathologic processes or the host’s response. As the damage progresses, pannus formation begins and eventually there is cartilage erosion at the lateral margins of affected joints. These processes can be seen very early into the course if an untreated disease .
Juvenile rheumatoid arthritis affects patients aged 16 years and under. It is included because, even though the exact disease causing mechanism is not clearly understood, it remains one of the common chronic disease of childhood. It is however said that there is an overlap between the pathophysiology and this condition and other autoimmune diseases of childhood.
Arthritis is generally a chronic condition with the only exception being septic arthritis. The prognosis varies for patients with the different types of arthritis. The best prognosis is with septic arthritis if treated early while the rheumatoid type carries the worst prognosis. Other factors like age, lifestyle modification, obesity, other chronic diseases like diabetes and hypertension can also greatly affect prognosis.
Most patients with arthritis present with symptoms of inflammation. The commonest presentation of arthritis is pain. Other symptoms include:
Other symptoms are peculiar to the type of arthritis.
Despite the advent of better imaging techniques like CT scan and MRI, the plain radiograph remains the investigation of choice in suspected cases. This is because of its availability and cost effectiveness. The most common feature of arthritis on the plain radiograph is the loss of joint space. Other features are specific to the type of arthritis.
Laboratory studies are mainly used as an adjunct since diagnosis is mostly through clinical and radiological findings. Laboratory studies usually find their use in the rheumatoid type and are mainly used for monitoring the progression or remission of the disease .
There is no definite cure for most forms of arthritis. Treatment is mainly supportive and includes:
Patient with the rheumatoid type arthritis may benefit from corticosteroid use. Selected surgical procedures have also been shown to be beneficial in the treatment of this disease condition.
Many of the causes of arthritis are beyond human control and as such no clear preventive measures can be instituted. Some healthy diet and lifestyle choices could however help in preventing this condition .
Arthritis is a disease of the joints. It is mostly seen in the elderly but can also be present in children.
There is no specific cause of this disease. Many factors contribute to the development of arthritis. It however has a familial history.
Signs and symptoms
The main symptoms are pain at the joint, swelling of the joint, stiffness and inability to move the joint.
There is no known cure for most types of arthritis. It would however be beneficial to eat healthy and have healthy lifestyle practises like regular exercise .