Osteoarthritis is the most common joint disease in humans. The target tissues involved in osteoarthritis is articulating cartilage articulate. Articulating cartilage is the cartilage present between two joint surfaces which protects inflammation of joints by preventing rubbing of joints together. There is the destruction of articulating cartilage along with the destruction of bone. Unlike rheumatoid arthritis, osteoarthritis is a noninflammatory disease. The most common joint involved in osteoarthritis is knee joint and it leads long term disability in the elderly. The major joints effected are weight bearing joints and small joints of hands and fingers. The exact osteoarthritis causes are not known however it is believed that it is an age-related joint disease.
- Age: osteoarthritis is the leading cause of disability in individuals of increased age. As age advances the tendency to develop osteoarthritis increases. Osteoarthritis mostly occurs in population aging for more than 50 years.
- Gender: males and females both have the potential to develop osteoarthritis but it is more common in females. Females are three times more at risk of developing osteoarthritis as compared to males.
- Trauma: major joint trauma including accident, fall from height or any other joint injury may cause osteoarthritis
- Stress on joints: stress on joints can predispose osteoarthritis as it causes rubbing of joints together which leads to inflammation of joint surfaces and pain.
- Obesity: Obesity increases stress on joints. Weight bearing joints are most commonly affected due to obesity. Obesity is a modifiable factor and osteoarthritis in obese can be prevented by maintaining the optimal weight.
- Environmental factors: environmental factors like infections and cigarette smoking may also cause osteoarthritis. The exact mechanism is however unknown
Classification of Osteoarthritis:
The most common form of osteoarthritis is primary osteoarthritis in which there is no predisposing factor. It has no proper evidence of the causative factor and is idiopathic in nature.
Secondary osteoarthritis is attributable to an underlying cause for example
- Other arthropathies: other joint diseases like gout may cause secondary osteoarthritis
- Endocrinal causes: endocrinal diseases for example acromegaly, gigantism and diabetes mellitus can cause secondary osteoarthritis
- Deposition diseases: the deposition diseases like hemochromatosis is included in the list of osteoarthritis causes
- Mechanical factors: mechanical stress like an unequal lower Limb, length, valgus or varus deformity can cause joint destruction and eventually osteoarthritis
How does Osteoarthritis present?
Osteoarthritis is a long-term chronic disease affecting joints. The major joints involved are weight-bearing joints which are knee and hip joints and small joints of fingers which are proximal interphalangeal joint and distal interphalangeal joints. The most common joint to be affected is the knee joint, the second most common joint affected in osteoarthritis is the base of the thumb.
- Pain: onset of pain in osteoarthritis is Insidious, over months or years. Joint pain is the most common symptom and it is aggravated with movement and is relieved on rest. Pain is sometimes so severe that it wakes patient from sleep
- Tenderness: joint surfaces are tender to touch. By tenderness we mean the patient feels pain on putting pressure over the joint surfaces
- Crackling sounds: cracking sounds or crepitations may be heard with the movement of joints
- Morning stiffness: there is morning stiffness of fewer than 15 minutes. the morning stiffness may sometimes be of 30 minutes but if the morning stiffness increases from 30 minutes osteoarthritis is not a cause and hence something else is to be identified as a factor for causing the joint disease
- Effect of exercise: osteoarthritis causes severe joint pain and joint pain increase with exercise as inflamed surfaces rub against each other
- Systemic manifestations: systemic manifestations like fever, lymphadenopathy, pulmonary effusion or nodules, carditis, myocardial infarction, Glomerulonephritis, Kidney Disease are not present in osteoarthritis
How to Diagnose Osteoarthritis?
Osteoarthritis is usually diagnosed clinically. However various laboratory tests are available which may help diagnose osteoarthritis when there is Diagnostic uncertainty.
- Erythrocyte Sedimentation rate: erythrocyte sedimentation rate is normal. If ESR is elevated some other process is complicating osteoarthritis, for example, septic joint disease or it is not osteoarthritis we must think of something else.
- C reactive protein: the level of C reactive protein is in the normal range
- Complete blood count: complete blood examination is normal and there is no anemia or thrombocytopenia
- Antinuclear antibody: ANA is absent
- Rheumatoid factor: rheumatoid factor is absent
- X-ray of joints: x-ray findings include the formation of bone spurs which are also called osteophytes. These bones spurs are reparative efforts by bone as a result of inflammation of joint surfaces. They may occur in proximal interphalangeal joints or distal interphalangeal joints of fingers. When they involve proximal interphalangeal joints they are called Bouchard’s nodes whereas when they involve distal interphalangeal joints they are called Heberden’s nodes.
How to Treat Osteoarthritis?
Osteoarthritis is aimed at reducing pain and maintaining mobility as there is no cure for osteoarthritis. Various strategies are present to reduce inflammation and the progression of the disease.
Nonsteroidal anti-inflammatory drugs can be taken orally or can be applied locally over the joint surfaces. The chondroprotective effect of certain NSAIDS is not very well documented so NSAIDs should always be used to elevate pain only. Ibuprofen can be used to treat pain.
Acetaminophen is the first initial drug to relieve pain in osteoarthritis. If there is no cure with simply taking acetaminophen then nonsteroidal anti-inflammatory drugs can be added to the regimen
Steroids can be given orally or can be applied locally inside the joint surfaces. Steroids are only used if other medical therapy does not control the pain of osteoarthritis.
4- Pain Receptor blockers:
Caption cream capsaicin cream has been used which depletes sensory nerve endings of substance P so patients do not feel any pain over the joint surfaces.
Joint replacement is used reserved for cases in which aggressive medical therapy has not proven any benefits.
WHEN TO SEEK MEDICAL HELP?
When osteoarthritis causes severe pain, disability, the disease is progressing and you feel morning stiffness of more than 30 minutes then you should not wait to seek medical help.