Osteoarthritis

Question 1

What are the cells that build and maintain the ECM of cartilage?

Answer 1

Chondrocytes (from mesenchymal stem cells)

Question 2

What components are found within the ECM of cartilage?

Answer 2

Collagen type 2 (type 1 in fibrous)
Proteoglycans
Glycosaminoglycans -Hyaluronic Acid Chains (links contain chondroitin and keratan sulphate)

Question 3

What are the 3 types of cartilage?

Answer 3

Hyaline (articular), Elastic (ear/nose), Fibrocartilage (pubic ramus, meniscus)

Question 4

Where is subchondral bone found?

Answer 4

At joints, beneath the articular cartilage, superficial to the trabeculae of bone

Question 5

What are some observable differences in normal vs osteoarthritic joints?

Answer 5

Osteoarthritic joints tend to have:

• Reduced articular cartilage
• Cysts formation in subchondral bone due to synovial fluid leaking through cartilage
• Osteophytic lipping (outgrowth of bone)
• Shelving fibrillated cartilage (softening, forming of vertical clefts, spaghetti like appearance)
• Synovial hypertrophy
• Thickened capsule
• Altered contour of subchondral bone

Question 6

What components make up a normal synovial joint?

Answer 6

Capsule 
Synovium
Synovial Fluid
Articular Cartilage
Subchondral bone/ bone

Question 7

What is the role of hyaluronic acid chains and proteoglycans within the ECM of cartilage?

Answer 7

They protect the chondrocytes from loading forces

Question 8

Explain the pathogenesis of Osteoarthritis, talking about fluid content, and functional loss of different components within the joint.

Answer 8

Initial increase in water (caused by aggrecan exposure) which makes cells swell and changes loading pattern.
Water loss in cells then occurs (aggrecan breakdown), ECM is not as robust, decreased proteoglycans (which cushion and aid in homeostasis) causing less collagen cross linking (weakening), main structure of cartilage is lost
Spurs and cysts at the margin then occur

Question 9

Is it the most common joint disease?

Answer 9

Yup

Question 10

What is the most common age group impacted by osteoarthritis?

Answer 10

over 45

Question 11

Is osteoarthritis more prevalent in males or females?

Answer 11

Females (in ages 45+)

Males (in <45 years)

Question 12

What is the primary cause of osteoarthritis?

Answer 12

Degeneration

Question 13

What are secondary causes of osteoarthritis?

Answer 13

Trauma (more common in <45yrs)
Hip dysplasia
Infection (cartilage and bone destroyed)
Diabetes

Question 14

What are risk factors for osteoarthritis?

Answer 14

Age
Genetics (small)
Gender
Nutrition

Question 15

What are some joint biomechanical risks to osteoarthritis?

Answer 15

Joint trauma
Obesity
Occupation (manual labour)
Abnormal joint biomechanics (typically born with it)

Question 16

What are the key symptoms of osteoarthritis?

Answer 16

Pain during load bearing activities
Stiffness in morning for less than 30 min
Difficulty moving the affected joints doing certain activities
Stiffness
Sleep disturbance

Question 17

How do you diagnose osteoarthritics?

Answer 17

X-Ray
Joint space narrowing
Osteophytes (extra pieces of bone at joint periphery)
Cyst formation
Subchondral Sclerosis at weight bearing portions of joint (seen as white lines on x-ray)

Question 18

What is the management of osteoarthritis?

Answer 18

Manage symptoms, it cant be cured
Medication 
Joint injections
Physiotherapy
Surgical (last resort)

Question 19

What are examples of types of medications that can be used to treat osteoarthritis?

Answer 19

Paracetamol,
Non-steroidal anti-inflammatories drugs (Ibuprofen, Diclofenac),
Chondroitin Sulphate or Glucosamine (for articular cartilage repair)

Question 20

How can physiotherapy help treat osteoarthritis?

Answer 20

Strengthening muscles
Aerobic conditioning (weight control- reliefs weight on joint)
Range of motion exercises

Question 21

How are injections used to treat osteoarthritis?

Answer 21

Less common
Cortisone/ Corticosteroids- reduces inflammation and pain, more rapid than NSAIDs
Viscous supplement- replace synovial fluid, increase viscosity

Question 22

What are surgical ways to treat severe osteoarthritis?

Answer 22

Arthroscopy (look at joint)
Cartilage transplantation (rare- typically for younger patients or well defined (<1.5cm) osteoarthritis)
Joint replacement- most successful

Question 23

When would uni-compartmental knee replacement be used?

Answer 23

When only one side of the knee joint has osteoarthritis, you replace the affected side

Question 24

When is cartilage transplantation used?

Answer 24

When osteoarthritis is VERY well defined (less than 1.5cm lesion), and the transplant may be successful n preventing the progression of the disease

Question 25

What are the types of Osteo-articular transplants?

Answer 25

Autologous chondrocyte implantation from a non-weight bearing joint
Cadaver allograft

Question 26

What is the trendelenburg sign?

Answer 26

Dropping of the hip, unilaterally, when standing straight