KNEE OESTEOARTHRITIS

Dr. Md. Mazharul Alam

INTRODUCTION :

Global estimates reveal more than 100million people are affected by OA.

Between the ages of 30 and 65 years the general incidence and prevalence of Knee OA has been reported to increase by as much as 10 times  that of younger age groups, affecting nearly 33.6% of people more than 65 years or an incidence of 1 in 10. Person aged more that 65 years are more commonly affected by Knee OA.

Etiology and Disease Diagnosis

Despite numerous studies conducted, the etiology, onset and specific causes for OA remain unknown. Scientists believe that a combination of physical factors such as obesity, aging and joint injury coupled to genetic predisposition ultimately predispose some individuals to earlier onset of disease.

Some factors that influence the development of Osteoarthritis are :-

• Age

The older you are, the more likely it is that, you will develop OA. We put our joints through a lot of daily stress and over the years, this can start to wear down the Cartilage. Most people affected by Osteoarthritis are older than 45.

• Playing Particular Sports :

Running, soccer and tennis all puts extra strain on the knee joint and this can lead to the eventual development of Osteoarthritis.

• Repetitive Stress :

This is similar to playing certain sports – it’s all about the strain you put on your knees. Certain jobs that require a lot of lifting, squatting or kneeling may make people more prone to Osteoarthritis.

• Weight :

If you carry extra weight, this can put more strain on the knee joint, making it more likely to wear out.

• Gender :

In people older than 45, woman are more likely than men to develop OA.

• Heredity :

It is known that genetics plays a role in developing OA. If someone in your family has or had Osteoarthritis, you may be more at risk for developing it.

Within a joint such as the knee, there is a smooth fibrous connective tissue known as articular cartilage. This cartilage surrounds the bone where it comes into contact with another bon e. In a normal joint, the cartilage acts as a shock absorber as well as it allows for even movement of the joint without pain. When cartilage degrades, it becomes thinner and may even disappear altogether leading to   joint  pain   and  difficulty  in  movement  such  a   in  Knee  OA.  A  repetitive  inflammatory response of the articular cartilage due to focal loss or erosion of the articular cartilage and a hypertrophy of Osteoblastic activity or a reprarative  bone response known as Osteophytosis. Both of these defining characteristics result in a joint space narrowing or subchondral sclerosis, leading to pain, immobility and often disability.

To diagnose OA, the clinician might assess the nature and severity of the pain. It can also be diagnosed to measure the amount of movement in the joint. An X-ray shows narrowing of Joint space is a good indicator of OA. Bony Spurs can also be seen on an X-ray. MRI Scan may necessary to see soft tissue injury. In certain cases, a blood sample may be necessary to rule out the presence of other types of arthritis.

Treatment and management

Knee OA is associated with symptoms of pain and functional disability. Physical disability arising from pain and loss of functional capacity reduces quality of life and increases the risk of further morbidity and mortality. Current treatments aim at alleviating these symptoms by several different methods :-

• Non-pharmacological treatment
• Pharmacological treatment
• Invesive interventions.

Non-pharmacological treatment

• Education
• Exercise (Quadriceps strengthening exercise)
• Appliances (Sticks, insoles, knee bracing)
• Weight reduction

Pharmacological therapy

• Paracetamol is the oral analgesic to try first and if successful, the preferred long term oral analgesics.
• Topical applications (NASID, Capsaicin) have clinically efficacy and are safe.
• Weak opiod with or without paracetamol
• NSAIDS – Ibuprofen is choice with or without paracetamol.
• Some disease modifying agents like Chondrotin sulphate and glucosamine sulphate.

Interventions

1. Intra-articular injections of corticosteroid (Traimcinolone 40 mg) not more than 4 time per year.
2. Tidal irrigation
3. Arthroscopy
4. Surgery
5. Prolotherapy and prolozone therapy
6. Platelet reach plasma injection