Osteoarthritis (OA)Osteoarthritis (OA)

••OA is the most common form of arthritis OA is the most common form of arthritis and the most common joint diseaseand the most common joint disease

••Over 10 million Americans suffer from OA Over 10 million Americans suffer from OA of the knee aloneof the knee alone

••Most of the people who have OA are older Most of the people who have OA are older than age 45, and women are more than age 45, and women are more commonly affected than men.commonly affected than men.

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

Osteoarthritis (OA) the most Osteoarthritis (OA) the most common localisationscommon localisations

AgeAgeAge is the strongest risk factor for OA. Although OA Age is the strongest risk factor for OA. Although OA

can start in young adulthood, if you are over 45 can start in young adulthood, if you are over 45 years old, you are at higher risk.years old, you are at higher risk.

Female genderFemale genderIn general, arthritis occurs more frequently in In general, arthritis occurs more frequently in women than in men. Before age 45, OA occurs women than in men. Before age 45, OA occurs

more frequently in men; after age 45, OA is more more frequently in men; after age 45, OA is more common in women. OA of the hand is particularly common in women. OA of the hand is particularly

common among women. common among women. Joint alignmentJoint alignment

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

more likely to develop OA in those joints.more likely to develop OA in those joints.

OA –Risk FactorsOA –Risk Factors

OA –Risk FactorsOA –Risk Factors

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

injuryinjuryJoint injury or overuse caused by physical labor or sportsJoint injury or overuse caused by physical labor or sports

Traumatic injury (ex. Ligament or meniscaltears) to the knee Traumatic injury (ex. Ligament or meniscaltears) to the knee or hip increases your risk for developing OA in these joints. or hip increases your risk for developing OA in these joints. Joints that are used repeatedly in certain jobs may be more Joints that are used repeatedly in certain jobs may be more

likely to develop OA because of injury or overuse. likely to develop OA because of injury or overuse.

ObesityObesityBeing overweight during midlife or the later years is among Being overweight during midlife or the later years is among

the strongest risk factors for OA of the knee. the strongest risk factors for OA of the knee.

OA –SymptomsOA –Symptoms

OA usually occurs slowly -It may be OA usually occurs slowly -It may be many years before the damage to many years before the damage to the joint becomes noticeablethe joint becomes noticeable

Only a third of people whose X-rays Only a third of people whose X-rays show OA report pain or other show OA report pain or other symptomssymptoms

OA –SymptomsOA –Symptoms

Steady or intermittent pain in a joint Steady or intermittent pain in a joint Stiffness that tends to follow periods Stiffness that tends to follow periods

of inactivity, such as sleep or sitting of inactivity, such as sleep or sitting Swelling or tenderness in one or more Swelling or tenderness in one or more

joints [not necessarily occurring on joints [not necessarily occurring on both sides of the body at the same both sides of the body at the same time] time]

Crunching feeling or sound of bone Crunching feeling or sound of bone rubbing on bone (called crepitus) rubbing on bone (called crepitus) when the joint is usedwhen the joint is used

Osteoarthritis (OA) -Definition

Osteoarthritis may result from wear and tear on the joint•The normal cartilage lining is gradually worn away and the underlying bone is exposed.

The repair mechanisms of tissue absorption and synthesis get out of balanceand result in osteophyte formation (bone spurs) and bone cysts

OA –Articular Cartilage

Articular cartilage is the main tissue affected OA results in: Increased tissue swelling Change in color Cartilage fibrillation Cartilage erosion down to subchondral bone

OA –Articular Cartilage

OA –Articular Cartilage

Normal articular cartilage from 21-year old adult (3000X)

Osteoarthritic cartilage (3000X)The surface changes alter the distribution of biomechanical forces further triggering active changes by the tissue

OA –Articular Cartilage The cartilage damage causes chondrocyte

cloning in an attempt to restore articular surface (Normal adult chondrocytes are fully differentiated and do not proliferate)

(A) Normal articular cartilage (B) Osteoarthritic cartilage

The newly dividing cells do not differentiate fully and cannot effectively synthesize the elements needed for matrix maintenanceThis results in a net loss of matrix components

•Collagen content stays constant but fibrils are thinner and more disorganized -Decreased tensile strength

•Proteoglycan loss results in an inability to hold on to water content:-Decreased resistance to compression –especially with repeated stress

OA –Articular Cartilage

OA vs. Aging

OA –Overall Changes

Osteoarthritis with lateral osteophyte, loss of articular cartilage and some subchondral bony sclerosis-X-ray shows loss of joint space

Osteoarthritis of the Hand Osteoarthritis of the Hand - - diagnosis diagnosis

Hand pain, aching, or stiffness and;Hand pain, aching, or stiffness and; Hard tissue enlargement of two or more of 10 selected Hard tissue enlargement of two or more of 10 selected

joints and;joints and; Fewer than three swollen MCP (metacarpophalangeal) joints Fewer than three swollen MCP (metacarpophalangeal) joints

and;and; Hard tissue enlargement of two or more DIP (distal Hard tissue enlargement of two or more DIP (distal

interphalangeal) joints or deformity of two or more of 10 interphalangeal) joints or deformity of two or more of 10 selected jointsselected joints

The 10 selected joints include:The 10 selected joints include:

Second and third DIP joints of both handsSecond and third DIP joints of both hands Second and third PIP (proximal interphalangeal) joints of Second and third PIP (proximal interphalangeal) joints of

both handsboth hands First CMC (carpometacarpal) joints of both handsFirst CMC (carpometacarpal) joints of both hands

OA OA Osteoarthritis of the Osteoarthritis of the Knee - Knee - diagnosis diagnosis

Knee pain and;pain and;

At least three of the following 6 criteria: At least three of the following 6 criteria: 50 years of age or older50 years of age or olderstiffness lasting less than 30 minutes,stiffness lasting less than 30 minutes,crepitus, crepitus, bony tenderness, bony tenderness, bony enlargement, bony enlargement, no warmth to the touchno warmth to the touch

Osteoarthritis of the Hip - Osteoarthritis of the Hip - diagnosis diagnosis

Hip pain and pain and Femoral and/or acetabular osteophytes evident on x-ray Femoral and/or acetabular osteophytes evident on x-ray

or or sedimentation rate less than or equal to 20 mm/hour sedimentation rate less than or equal to 20 mm/hour

and;and; Joint space narrowing evident on x-rayJoint space narrowing evident on x-ray

AAdditional criteria which are useful for diagnosing dditional criteria which are useful for diagnosing osteoarthritis of the hiposteoarthritis of the hip::

Internal hip rotation of less than or equal to 15 degrees,Internal hip rotation of less than or equal to 15 degrees, morning stiffness in the hip lasting less than or equal to morning stiffness in the hip lasting less than or equal to

1 1 hour, and hour, and age of 50 years or older are.age of 50 years or older are.

OA –Radiographic Diagnosis

Asymmetrical joint space narrowingfrom loss of articular cartilageThe medial (inside) part of the knee is most commonly affected by osteoarthritis.

OA –Radiographic Diagnosis

•Asymmetrical joint space narrowing •Periarticularsclerosis •Osteophytes •Sub-chrondralbone cysts

OA –Arthroscopic Diagnosis

Arthroscopy allows earlier diagnosis by demonstrating the more subtle cartilage changes that are not visible on x-ray

Normal Articular Cartilage

Ostearthritic degenerated cartilage with exposed subchondral bone

OA –Disease Management

OA is a condition which progresses slowly over a period of many years and cannot be cured

Treatment is directed at decreasing the symptoms slowing the progress of the condition

Functional treatment goals:•Limit pain•Increase range of motion•Increase muscle strength

OA –Non-operative Treatments

•Pain medications•Physical therapy•Walking aids•Shock absorption•Re-alignment

through orthotics•Limit strain to

affected areas

In the procedure to realign the angles, a wedge of bone is removed from the lateral side of the upper tibia.

A staple or plate and screws are used to hold the bone in place until it heals.

This converts the extremity from being bow-legged to knock-kneed.•

The Proximal Tibial Osteotomy buys some time before ultimately needing to perform a total knee replacement.

The operation probably lasts for 5-7 years if successful.

Proximal tibial osteotomy

Total knee replacement

The ultimate solution for osteoarthritis of the knee is to replace the joint surfaces with an artificial knee joint:

Usually considered in people over the age of 60

Artificial knee joints last about 12 years in an elderly population