Osteoarthritis

Osteoarthritis means degenerative inflammation of the joints which is symbolized by loss of cartilage. It is the most common leading cause of disability among older people. It is very rarely found in people less than 40 years and is widespread in adults older than 60years. It is much more common in women than men.

Most commonly affected joints are cervical (neck region), lumbo sacral joints (back region), hip, knee, first metatarsal phalangeal joint (toe), Distal and proximal interphalangeal joints (which includes joints of small fingers).

What is Osteoarthritis?

Osteo means bones

Arthro means Joints

Itis means Inflammation

Osteoarthritis means inflammation of the joints which is due to degeneration of the hyaline cartilage in the joints. There are several reasons for the malfunction of joints but the most common universal reason which stands on the top of the list is the failure of the protective mechanisms of joints.

What constitutes the defensive mechanism of joints?

Joint capsule & ligaments, muscle, sensory afferents (nerves) and underlying bone are structures that provide support to the joints by limiting the movement of joints.

There is synovial fluid which reduces friction between articulating cartilage and reduces friction induced tear of the cartilage.

The ligaments along with muscle and tendon consist of mechanoreceptor sensory afferent nerve. These nerves provide signals to the spinal cord supplying the tendons and muscle thereby limiting the range of motions.

Muscles and tendons contract together at the appropriate time with proper power and acceleration to fulfil a movement. The muscle contraction decelerates any extra force provided to the joint.

The bone beneath the joint also acts as a shock absorber.

Failure of any of the above mechanism can lead to injury of the joints or osteoarthritis.

What are the risk factors for osteoarthritis?

1. Two main risk factors

Susceptible Joints

Overloading of Joints

Susceptible joints are increased age, female gender, racial/ethnic factors, Genetic susceptibility and nutritional factors & previous damage, developmental abnormality.

Overloading of joints which means the stress given to the joint is much more that the specified limit. But in certain group of people even simple daily activities can be a burden to the bones. Overloading can be occupation related and joints affected depend on the joint that is frequently used. This is because during the long hours of using the joints, the muscle become exhausted and effective protective mechanism is lost.

2. Age

As age increases the natural defensive mechanism of the joints becomes fragile. Women in older age are more prone to increased risk to osteoarthritis which may be due to loss of hormone after menopause.

3. Genetics and heritability

It is a hereditary disease and it also depends on the joint affected. Fifty percent of hand and hip joints have increased risk to pass on to the future generations whereas osteoarthritis of the knee has a risk of thirty percent. Multiple joint involvements i.e. Generalised Osteoarthritis is rather due to aging process.

4. Repeated use of Joints

Though exercise is considered as one of the treatment modality, certain type of exercises can increased risk of joint damage. Compared to non-runners elite runners have high risk of getting osteoarthritis in the later years.

Symptoms of osteoarthritis

Joint pain is usually movement related. Pain appears on joint use and resolves later. During the earlier stage of the disease, pain is episodic i.e. the pain is related to movement. For example, if a patient has osteoarthritis in knee, climbing stairs or running may aggravate the pain and the pain will subside in few days. When the disease progress the pain becomes continuous and troublesome especially at night.

Stiffness of the affected joint becomes prominent and morning stiffness may be present.

Investigations Required

There is no specific blood investigation available.

X-ray is an excellent method of investigation for osteoarthritis, though it is not helpful in the earlier stages of the disease.

Treatment

The main objective of the treatment is to limit the damage of joints and to reduce the level of pain. So it could be non-pharmacologic mode of treatment and pharmacological way of treatment.

Non-pharmacologic treatment

1. Avoid activities that overload the joint.
2. Increase the strength and condition of the muscles
3. Distributing the weight by using cane or crutch.

It is advisable to end the activities that precipitate pain. Weight loss in obese may also alleviate the symptoms.

As pain is the main symptom of osteoarthritis, it results in immobility. This immobility can lead to obesity which in turn will have a negative impact on the cardiovascular system. Thus this is a vicious circle. Thus exercise regimens will help in strengthening muscles across the joint. Aerobic exercise and/or resistance exercise will focus on strengthening of the muscles. If an exercise increases the pain, then that particular exercise should be avoided. Patient can contact the general practitioner who can refer you to a physiotherapist. A physiotherapist can advice you about particular exercise that can help to reinforce the strength of muscles.

Pharmacotherapy

Acetaminophen (paracetamol), Non-steroidal Anti inflammatory drugs (NSAIDS) and COX 2 inhibitors are the drugs that control osteoarthritis.

1. NSAIDS are the most familiar drugs to treat osteoarthritis pain. Primarily NSAIDS should be given according to the threshold of the pain. NSAIDS include Naproxen, Salsalate & Ibuprofen. If occasional treatment with NSAIDS is ineffective, daily treatment should be commenced.

NSAIDS has side effects which includes gastrointestinal toxicity, dyspepsia, nausea, and bloating, gastrointestinal bleeding and ulcer disease.

To minimise the effect, the following must be maintained:

a. Take medication after food.

b. Avoid use of two NSAIDs

c. Use a relatively safer NSAIDS.

d. If at risk of gastrointestinal bleeding, prescribe gastro protective agent.

2. Intraarticular injections: Glucocorticoids and hyaluronic acid

In case of severe pain, intraarticular injections with glucocorticoids will be helpful.

Surgery

For knee osteoarthritis, several operations are available which includes arthroscopic debridement and lavage.

Osteoarthritis is not a reversible disease, only the symptoms can be treated. So it is sensible to avoid activities that will provoke the symptoms.

Osteoarthritis ends here and I will see you in the next post with a different topic.