OA+ RA

Question 1

ACPA

Answer 1

Anti-cyclic citrullinated protein antibody- found in RA

Arg is modified by PAD to citrulline; antibodies formed against this.

Question 2

Sx at the joint in RA

Answer 2

Pain, swelling, morning stiffness lasting > 1 hour that improves with use

Deformities

Rheumatoid nodules

Question 3

2 mechanisms of bone loss in RA

Answer 3

1) Pannus- erodes bone + cartilage
2) Inflammatory cells simulate osteoclasts at synovial insertion sites- results in generalized bone loss

Question 4

Displacement of capital femoral epiphysis from femoral neck

Answer 4

Slipped capital femoral epiphysis

Question 5

Hyperextension of PIP w/ flexion of DIP

Answer 5

Swan-neck deformity; seen in RA

Question 6

Heberden nodes/ Bouchard nodes and how do they present

Answer 6

Heberden nodes: osteophytes at the DIP joint

Bouchard node: osteophytes at the PIP joint

Presents as enlargement + thickening of DIP/PIP

Question 7

Joint/ bone findings of OA (3)

Answer 7

1) Bone eburnation
2) Subchondral cysts/ sclerorsis
3) Joint space narrowing

Question 8

Felty’s syndrome

Answer 8

RA + Splenomegaly + pancytopenia

Question 9

HLA associated w/ RA

Answer 9

HLA-DR4

Question 10

Extra-articular manifestations of RA

Answer 10

1) systemic sx (fever, fatigue, weight losss)
2) Cardiac- autoimmune process affects pericardium (MI, pericardial effusion)
3) Pulmonary- inflammation of pleura (pleurtiis, effusions, interstitial fibrosis)
4) Ocular- Sjogren’s, keratoconjunctivitis sicca (dry eye)
5) Felty’s syndrome
6) Anemia of chronic disease
7) Secondary amyloidosis

Question 11

Why smoking/silica is associated with increased risk of RA

Answer 11

Inflammatory process in lungs causes production of peptidyl arginine deaminases (PAD), which forms citrullinated peptides; antibodies against these peptides involved in pathogenesis

Question 12

Histology of OA

Answer 12

Disorganized + fragmented “joint mice” cartilage

Question 13

3 consequences of loss of articular cartilage in OA

Answer 13

1) Development of subchondral bone cysts
2) Increased subchondral bone thickness (suchondral sclerosis) due to exposure of underlying bone
3) Formatino of osteophytes at the joint margins

Question 14

Non-reducible flexion at PIP w/ hyperextension of DIP

Answer 14

Boutonniere deformity; seen in RA

Question 15

Marker of tissue damage + disease activity in RA

Answer 15

Rheumatoid factor

Question 16

Pannus

Answer 16

In RA, inflamed granulation tissue within synovium due to inflammatory process which leads to erosion of bone + cartilage

Question 17

Findings of cervical subluxation and disease associated

Answer 17

Associated w/ RA

Inflammation of cervical joints can cause vertebral misalignment –> neurological dysfunction, problems w/ flexion of neck

Question 18

IgM autoantibody against body’s own IgG

Answer 18

Rheumatoid factor

Question 19

Pattern of joint involvement in RA

Answer 19

Symmetric joint involvement classically at small joints of hands + feet (most common- wrist, MCP, PIP); also occurs at elbows, ankles, and knees. DIP joints are spared!

Question 20

Pattern of joint involvement in OA

Answer 20

Asymmetric usually affecting hips, lower lumbar spine, knees, and DIP/PIP

Question 21

Most common areas of osteophyte formation in OA

Answer 21

DIP joints (Heberden nodes) + PIP joints (Bouchard joints) of fingers

Question 22

Etiology of osteonecrosis

Answer 22

CAST Bent LEGS

Corticosteroids, alcoholism, sickle cell disease, Trauma (fracture), “The Bends” (Caisson/ decompression disease), Legg-Calve-Perthese disease, Guacher disease, slipped capital femoral epiphysis

Question 23

Idiopathic avascular necrosis of femoral head

Answer 23

Legg-Calve-Perthes DIsease

Question 24

Presentation of OA

Answer 24

1) Joint pain/stiffness in the morning that worsens w/ activity (gets worse during the day) and relieved by rest
2) Enlargement and thickening of joints- due to osteophyte formation (e.g Heberden + Bouchard nodes)

No systemic manifestations

Question 25

Physical exam findings in RA

Answer 25

1) Fusiform swelling- soft tissue swelling (not due to bone growth); tender + warm, “boggy” feel
2) Deformities (Boutonnier, Swan-neck, ulnar finger deviation)
3) Rheumatoid nodules on extensor surfaces
4) Cervical subluxation

Question 26

Most common site for osteonecrosis and why

Answer 26

Femoral head- due to insufficiency of medial circumflex artery