PBL 2

Question 1

what are the changes of the articular cartilage in osteoarthritis

Answer 1

Loss of superficial chondrocytes (necrosis)

Isogenic proliferation of chondrocytes with larger extracellular matrix regions

Duplication of tide mark

Loss of collagen scaffold and proteoglycans

Question 2

what does osteoarthritis primarily effect

Answer 2

• primarily effects the articular cartilage

Question 3

define pseudo-laxity

Answer 3

When a ligament no longer has to span the same distance in a joint as before; results when there is persistent inflammation of the synovium, caused by progressive erosion of the articular joint due to joint space narrowing.

Question 4

Why does pseudo laxity happen in osteoarthritis

Answer 4

• the space between the joint capsule decreases this means that there is a smaller distance between the two joints
• therefore the collateral ligaments sublax

Question 5

what are the three clinical symptoms of osteoarthritis

Answer 5

• pain on use
• short lived morning stiffness
• functional limitation

Question 6

What are the 3 clinical signs of osteoarthritis

Answer 6

• crepitus
• restricted movement
• bony enlargement

Question 7

What are the risk factors for developing osteoarthritis

Answer 7

• older age
• women
• obesity
• joint injury
• long term overuse of the joint
• genetics
• malformed joints such s knocked knees
• inactivity

Question 8

What are the lifestyle treatments for osteoarthritis

Answer 8

• exercise - strength muscle and decrease joint pain and increase flexibility
• weight loss if overweight
• change the way you walk

Question 9

what are the medication options of OA

Answer 9

• paracetamol and/or topical NSAID
• COX -2 inhibitors
• give intra-articular injections = corticosteroid injections

Question 10

name non pharmacological treatment for OA

Answer 10

Exercise – core treatment

• Local muscle strengthening
• General aerobic fitness
• Weight loss

Transcutaneous electrical nerve stimulation (TENS) as an adjunct for pain relief

Aids and devices

• Orthopaedic insoles
• Walking stick

lifestyle changes

diet

Thermotherapy
- use of local heat or cold

Nutriceuticals

• increase intake of omega 3 rich foods
• Chondroitin sulphate and glucosamine supplements – no longer recommended that they should be recommended or approved

Question 11

What are the surgical options for OA

Answer 11

Arthroscopic lavage – not used, soemtiems they do it to have a look inside

Arthroscopic lavage plus debridement – normally lavage plus now

Microfracture

Mosiacplasty (osteochondral transplant)

Chondrocyte grafts

Joint replacement

Question 12

When should surgery be offered for those with OA

Answer 12

when they wake up during the night

- pain is now unbearable and effects there quality of life

Question 13

describe an antalgic gait

Answer 13

Short stepping

Asymmetrical stride length

Step length on affected side is shorter

Unaffected limb brought forward more quickly than normal in swing phase

Duration of stance phase increased on normal side

Question 14

What are the phases of walking

Answer 14

stance and swing phases

Question 15

describe the stance and swing phase

Answer 15

Stance

• Begins with heel strike and ends when toe leaves the ground
• 60% of cycle
• 5 segments

Swing

• 40% of walking cycle
• Begins with toe off
• 3 segments

Question 16

describe how walking occurs

Answer 16

Stance

1. Intintial contact (Heel strike) - Foot inverted and dorsiflexed as heel makes contact on lateral side
2. Loading response - Foot brought into full contact, ankle rocker action begins
3. Midstance - Body weight brought over to the planted foot
4. Terminals stance – (heel off) Heel lifted off ground (foot everted and plantar flexed). Body weight advances ahead of single-supporting foot
5. Pre-swing (toe off) - Lower limb positioned to quickly swing forward beneath body, transfer of weight from one limb to other

Swing

1. Initial swing - foot pushed off ground, limb accelerates forward
2. Mid swing - Limb moves beneath body until tibia of leg is vertical. Foot dorsiflexed to prevent toes dragging on ground
3. Terminal swing - Limb decelerates forward movement, prepares for initial contact again

Question 17

1 What are three main classes of oral analgesics on the analgesic ladder? (3 marks)

Answer 17

simple analgesics and NSAIDs NSAIDs plus weak opiods Stronger opiods

Question 18

2 What are the 4 main signs of OA that you would find on an x-ray? (2 marks)

Answer 18

loss of joint space subchondral sclerosis osteophytes

trabeculae fractures subchondral cysts

Question 19

What biochemical changes are observed in the osteoarthritic articular cartilage? (2 marks)

Answer 19

Reduced proteoglycan content Change from collagen type 2 to type 1

Question 20

Name the three articulations that make up the knee joint. (3 marks)

Answer 20

Lateral femoral and tibia condyles with corresponding meniscus

Medial femoral and tibia condyles with corresponding meniscus

Patella with the femur

Question 21

• What is the name of the proteoglycan complexes that you find in articular cartilage?

Answer 21

aggrecan

Question 22

• Explain why weight bearing joints are more likely to develop osteoarthritis?

Answer 22

They are under more mechanical stress so the chondrocytes are more likely to have more oxidative stress and more age related changes as a consequence so are less able to maintain the normal cartilage in these joints.