OSTEOARTHRITIS

The most common arthritis in the UK

About 60-90% of people over age 65Under 45 years it is equally common in men and women

Over 55 years its more common in women

Premature OA associated with gene mutations that encode collagen types 2, 9, 10

Large economic impact as a result of medical costs

OA is a disease of joints that affects all of the weight-bearing components of the joint:

•Articular cartilage•Menisci•Bone

OA most often occurs at the ends of the fingers, thumbs, neck, lower back, knees, and hips

Risk factorsmetabolic (hemachromatosis) inflammatory (RA, infection)

agegender

genetic factorstraumaweight

Age

Age is the strongest risk factor for OA. Although OA can start in young adulthood, people over 45 years

old are at higher risk.

Female gender

In general, arthritis occurs more frequently in women than in men. OA of the hand is particularly common

among women.

Joint alignment

People with joints that move or fit together incorrectly, such as bow legs, a dislocated hip, or double-

jointedness, are more likely to develop OA in those joints.

Hereditary gene defectA defect in one of the genes responsible for the cartilage component collagen can cause deterioration of

cartilage.

Joint injury or overuse caused by physical labour or sports

Traumatic injury (ex. Ligament or meniscal tears) to the knee or hip increases the risk for developing OA

in these joints. Joints that are used repeatedly in certain jobs may be more likely to develop OA

because of injury or overuse.

Obesity

Being overweight during midlife or the later years is among the strongest risk factors for OA of the knee.

Symptoms• OA usually occurs slowly • Only a third of people

whose X-rays show OA report pain or other symptoms

– Steady or intermittent pain in a joint – Stiffness that tends to follow periods of inactivity, such as

sleep or sitting – Swelling or tenderness in one or more joints – Crunching feeling or sound of bone rubbing on bone

(crepitus) when the joint is used

Classification

Primary• Idiopathic• Localized or generalized• Local: knee, hip, spine,

hands• Generalized: large

joints and spine, Small peripheral joints and spine, Mixed and spine

Secondary• Post-traumatic• Congenital or

developmental• Localized or generalized• Calcium deposition

diseaseOther:• Inflammatory• Avascular necrosis

• Articular cartilage gets disrupted

• Damage progresses deeper to subchondral bone

• Fragments of cartilage released into joint

• Matrix degenerates

• Eventually there is complete loss of cartilage

• Bone is exposed

• Cartilage matrix has increased water content and decreased proteoglycan

• With aging cartilage dries up.• Increased activity of proteinases compared to inhibitors of

proteinases.• Breakdown products of cartilage cause inflammatory

reaction of synovium• Cytokines coming from chondrocytes cause matrix

degeneration.

• Cycle of destruction starts • Compensatory bone overgrowth occurs - subchondral bone

increases in density• Bony proliferations at joint margins form osteophytes• Cause joint motion restriction

Subchondral sclerosisJoint space narrowing where there is stress

Subchondral cystsOsteophytes

Examination

• Joint line tenderness• Bony enlargement of

joint• +/- effusion• Crepitus

• Decreased range of motion

Treatment• Non-pharmacokinetic

• NSAIDS• Analgesics (acetominophen)

• Topical pain releivers• Narcotics

• Intra-articular steroids• Chondroprotective agents

• Anti-depressants• Surgery

Non-pharmacokinetic:• Exercise – prevent disuse atrophy of muscles• Physical therapy: Hydrotherapy/heat/cold• Weight loss• Education • Wedges shoe insoles/braces/supportive devices

MedicationsWhen osteoarthritis flares up, many patients find relief with pain and anti-inflammatory medication, such as aspirin, ibuprofen, or acetaminophen. Pain-relieving creams or sprays can also help when applied directly to the sore area. If pain persists despite the use of pills or creams, injection of steroids or hyaluronans directly into the joint could be suggested.

Supplements: No benefits of glucosamine and chondroitin

Surgery• arthroscopy is not recommended for nonspecific

cleaning of the knee.

• Joint replacement: If all treatment is ineffective, and pain is severe, there is loss of joint function