Lecture 8

Question 1

Name the sub categories of arthritis

Answer 1

Osteoarthritis
Inflammatory arthritis
Septic arthritis

Question 2

What’s osteoarthritis?

Answer 2

Degeneration of joint cartilage and associated bone abnormalities

Joint fluid lab analysis typically shows no inflammatory cells

• can be primary (aged) or secondary osteoarthritis

Usually asymmetric but can be symmetric.
Good mineralisation
Subchondral sclerosis occurs (stressed areas under cartilage remodel)
Joint narrowing occurs due to thinning articular cartilage
Osteophytes (Spurs) at articular margin that arent under stress
Subchondral cysts (geodes)

Question 3

What’s inflammatory arthritis?

Answer 3

Chronic inflammatory conditions of body that are associated with arthritis, but often have other systemic symptoms

• rheumatoid and psoriatic arthritis
• crystal induced arthritis (gout and pseudo gout)

Question 4

What’s septic arthritis?

Answer 4

Life and limb threatening bacterial infection in joint

Required antibiotics and emergent treatment by physician, usually an orthopaedic surgeon

Question 5

What’s primary OA

Answer 5

Spontaneous occurrence with no specific cause for occurrence, but it’s usually associated with aging. Usually asymmetric but can be symmetric.
Good mineralisation
Subchondral sclerosis occurs (stressed areas under cartilage remodel)
Joint narrowing occurs due to thinning articular cartilage
Osteophytes (Spurs) at articular margin
Subchondral cysts (geodes)

Degenerative OA. Involves small (phalanges) or large joints

Can come as a varus or a valgus (one side of joint more narrowed) deformity
But varus is most common (most joint narrowing)

Question 6

What’s secondary OA?

Answer 6

Caused by previous injury to joint and can begin at young age

So only affects the joint impacted (asymmetrical)

Question 7

What’s rheumatoid arthritis?

Answer 7

Autoimmune, chronic inflammation of synovial membrane of joint

It’s symmetrical

Question 8

What’s psoriatic arthritis?

Answer 8

Autoimmune and associated with psoriasis (skin condition)

Involves multiple joints

Question 9

What’s crystal induced arthritis?

Answer 9

When crystals are deposited in the joint space

Can lead to gout or pseudo gout

Gout = deposit of monosodium urate monohydrate crystals (bone destruction)
Pseudogout = deposit calcium pyrophosphate crystals

Question 10

Compare OA AND RA

Answer 10

RA= autoimmune, morning stiffness lasts more than 30 mins, inflammation of synovial membrane, extra articular involvement, symmetrical, joint narrowing, little bony reaction (trabeculae),

• articular cartilage isn’t effected, but the synovial membrane becomes inflamed (thickened - syniovitis)
• bare areas
• usually between 25-40. Develops within weeks
• fatigue, weight loss, anemia
• no osteophytes
• RF present

OA = dramatic joint narrowing due to cartilage loss, but good bony reaction NO BONE DESTRUCTION OCCURS but you can get erosive OA.
Non inflammatory and more so degenerative joint. Morning stiffness lasts less than 30 mins, asymmetrical
- effects smaller joints more than weight bearing but they still do
- cartilagenous destruction but synovial membrane stays in tact (doesn’t thicken or inflamed)
- after 40 yo, develops slowly over many years
- feeling of unwell ness
- osteophytes present
- RF absent

Question 11

Regarding osteoarthritis and it’s characteristics, why do we see loss of joint space?

Answer 11

Cartilaginous fibrillation (destruction of cartilage ie. softening) and erosion

Question 12

Regarding osteoarthritis and it’s characteristics, what causes bone erbunation (degeneration of bone, increase in sclerotic appearance on margins)?

Answer 12

Increased cellular it’s and hypervascularity of subchondral bone

Question 13

Regarding osteoarthritis and it’s characteristics, what causes subchondral cysts

Answer 13

Synovial fluid intrusion (pushed into bone) or bone contusion

Areas like knees, there would be a lot of erbunation as there is greater pressure being applied to those joint, even hips ie. weight bearing joints

But fingers and shoulder, there will be less.

Question 14

Regarding osteoarthritis and it’s characteristics, osteophytes?

Answer 14

Revascularisation of remaining cartilage and capsular traction

Growing out from the capsule

Question 15

Regarding osteoarthritis and it’s characteristics, what causes osteophytes and buttressing of bone?

Answer 15

Periosteal and synovial membrane stimulation

Question 16

Regarding osteoarthritis and it’s characteristics, what causes the collapse of the bone?

Answer 16

Compression of weakened and defined trabeculae

Question 17

Regarding osteoarthritis and it’s characteristics, what causes intra articular osseous bodies

Answer 17

Fragmentation of osteochondral surface

Lose fragments

Question 18

Regarding osteoarthritis and it’s characteristics,deformity and malalignemnt

Answer 18

Disruption and distortion of capsular and ligamentous structures

Question 19

Discuss OA in terms of compartments of the joint that it has occurred within

Answer 19

Eg. Knee joint. Tri-compartment OA with varus deformity

1. Medial tibiofemoral
2. Lateral tibiofemoral
3. Patellofemoral

You can even grade OA

Question 20

Go over the stages of knee OA

Answer 20

Stage 1 = small amount of narrowing of joint. Min joint disruption

Stage 2 = mild joint narrowing (cartilage breaks down) with osteophytes. One side narrowing more than other therefore, valgus

Stage 3 = moderate joint space reduction. Gaps in cartilage can expand until they reach bone. Eg. Valgus deformity

Stage 4 = severe! Joint space greatly reduced. 60 % of cartilage lost with large osteophytes. Eg. Varus deformity

Question 21

Explain what the osteoarthritis of the acromion region is

Answer 21

It’s referred to as the acromial enthescophyte which is an abnormal bony projection along insertion of lig or tendon
Ie. can even get it at olecranon of elbow

It’s different to an osteophytes (associated with a joint) but both are produced as a result of OA

Question 22

Briefly describe the distribution of arthritides in the wrist

Answer 22

Thumb and distal phalanges = OA

Carpals and MCP = RA

Index finger (looks like sausage on presentation), 1-3 DIP = PA

Scaphoid, MCP of 2 and 3 = Calcium Pyrophosphate Deposition disease (pseudo gout)

Question 23

Compare OA AND RA in terms of regions they effect

Answer 23

OA = not the carpals! Lower spine and neck, head of femur, CMC 1ST, knees, phalanges, not the MC

RA = carpals, shoulders, elbows, foot, knees, hand, neck (C1-2)

Question 24

How does RA of the hands look on a scan

Answer 24

Erosions and/or peri articular osteopenia (loss of density) in hand joints

Synovial erosion into bone ie. cartilage gap going into bone BARE areAs

Capsular erosions

Question 25

What do you use to test for RA?

Answer 25

ESR or C-reactive protein Anti-CCP Rheumatoid factor

Question 26

How does RA effect the cervical spine?

Answer 26

It effects the C1-2 region by effecting the allar ligament The altar lig loops around back of auditory process (stops your head from sliding down when you look down) They put in a screw to help stabilise the region

Question 27

What does the rheumatoid arthritis diagnostic criteria comprise of?

Answer 27

Mornin stiffness lasts at least 1 hour before maximal improvement Soft tissue swelling of 3 or more joints observed by physician Swelling of proximal IP, MCP, or wrists joints Symmetric swelling Rheumatoid nodules (superficial - seen as swelling) Presence of rheumatoid factor Erosions and/or periarticular osteopenia in hand or wrist joints

Question 28

Describe how psoriatic arthritis looks radiogroahically

Answer 28

Looks very similar to RA . Can be in feet or hands. Look at index finger Erosion of bare areas of lateral and medial aspects of base of distal phalanges (gives mouse ear appearance). Beginning stages is indicted by a lack of that smooth cortical margin you can see Pencil in cup appearance Distal erosions with bone proliferation (proximal is less impacted)

Question 29

Compare Psoriatic and rheumatoid arthritis

Answer 29

RA = effects MCP mainly, but can effect small or large joints - periarticular osteopenia is common (but this can occur for many other complications that doesn’t involve RA) - bilateral - Sacral iliac joints not involved - RH factor yes - bone proliferation not common - erosions are seen in synovial reflections and capsular insertion area OA = effects mainly distal IP, and effect small joints - no periarticular osteopenia - unilateral - SI joint effected - no RH factor - yes to bone proliferation - erosions of peripheral bare area

Question 30

Explain what a gout is

Answer 30

Fever (even in RA) concentrations of Uric acid crystals (tophi) Pain, swelling, and stiffness in multiple joints (even in RA) Attacks often strike big toe, but can migrate to other joints Can involve the hips, ie. SI joints and distal LS spine but it’s very uncommon

Question 31

What’s pseudo gout (calcium pyrophospahte deposition disease)

Answer 31

This is the only disease that has the tendancy to calcify cartilage Domestic cause bone destruction, but only deposits crystals