6- Rhematoid Arthritis Flashcards
Give me some general information on Rheumatoid Arthritis
15
or 1010 of text
- generalized connective tissue disorder of known cause that selectively targets synovial tissue, particularly in joints of hands and feet, as well as larger joints and cervical spine.
- characterised by bilateral symmetry and progressive nature
What are the clinical features of Rhematoid arthritis?
15
- onset 20-60 yrs peaking between 40-50
- F:M, 3:1, after 40 yrs if age, 1:1
- insidious onset, with articular pain, tenderness, swelling, stiffness
- Bilateral, symmetric peripheral joint involvement hands and feet
- C-spine is affected in 80% in the late stages
- fatigue, malaise (general discomfort), muscle weakness, fever, tedon rupture, bursitis
- Firm non-tender nodules in 20% of patients forearms, knees, ankles and hands
- Haygarth’s nodes soft tissue swelling adjacent to the MCP
- course of disease is unpredictable, periods of remission and exacerbation with progressive deformity and disability.
Lab evaluation:
70% of patients will have RH factor, but it isn’t specific (antibody directed against an organism’s own tissues) that was first found in rheumatoid arthritis.)
What are the radiographic feature of RH
pg 1014 text
- Bilateral symmetry–> Parallel changes will be seen on both sides of the body simultaneously and to a similar degree of involvement.
- Periarticular Soft Tissue Swelling–> Owing to soft tissue edema and intra-articular effusion, displacement of fat lines and peripheral skin contours will be seen.
- Juxta-articular Osteoporosis –> because of inflammatory hyperaemia, there is a localised loss of bone density of epiphysis and metaphysis adjacent to the involved joint.
- Unifrom loss of joint space–> The entire joint space is reduced, with no intra-articular compartmentalisation unlike DJD
- Rat bite erosion(marginal erosion) –> a localised loss of articular cortex at the bare area of the joint margin with no definite sclerotic boarder at its edge is characteristic
- Large pseudo-cysts–> due to synovial fluid and extension of the pannus (thickening of syovial tissue) into the subarticular bone
- Deformity –> Combination of joint destruction, ligament laxity, altered muscular action
- dislocation and misalignment are common and patterns are predictable.
Targeted sites of involvement:
Tell me about RH in the hand
17
-targeted articulations are PIP and MCP joints.
-there is a distinct absence of DIP joint involvement unlike psoriasis, DJD and erosive arthritis.
Soft tissue Changes:
-Soft tissue swelling (earliest sign)
-Articular changes- earliest change is rat bit (marginal) erosion, with most common site at the of the 2nd and 3rd MC heads, and distal and prix end of proximal phalanges.
-Bone changes- osteoporosis is common early in the epiphysis and metaphyses
-Deformities–> swan neck, and ulnar deviation 9pg (1018). following joint dislocation joint erosions occur at site of bone compressions.
-boutinniere Deformity (extension of DIP’s and flexion of PIP’s. Stretching of the tendon at base of mid phalanx.
Targeted sites of involvement:
wrist- tell me about RH in the wrist
17
1018 txt book
- in 60% of patients, wrist changes are more sever than hand. In 20% no hand changes are present
- soft-tissue swelling over distal ulna is usually first sign. Erosion of ulnar styloid is secondary
b) distal Radius–> marginal (rat bite) erosions seen at radial styloid and adjacent scaphoid.
c) Carpus–> rat bit erosions seen on multiple carpal bones, especially the triqetrum and pisiform. When rate bites are seen all through carpals its called ‘spotty carpal sign’ (1015)
d) Seperation of the scapholunate joint due to interosseous ligament disruption = ‘terry Thomas sign’
Targeted sites of Involvement
Tell me about RH in the foot pg 17
-1019 txt
- common target site for RH
- most common articulation affected is interphalangeal joint of big toe and 5th MTP later moving towards big toe.
- radiogaphic changes of these are soft tissue swelling, rat bite erosion, junta-articular osteoporosis, uniform loss of joint space and deformities.
- erosions more prominent at medial surface except the 5th MTP head
- Calcaneus- plantar or a chillies attachment site may demonstrate poorly defined erosions, bone spurs.
- Lanois Deformity - fibular deviation of the toes. (i.e. toes point outwards) pg 1020
Targeted sites of Involvement
Spine
18
1020-txt
- most commonly involves the cervical spine
- MUST EVALUATE UPPER C-SPINE STABILITY (ADI space) -Atlanto-Dens Interval
- Up to 50% of RA patients will have ADI joint involvement
- up to 36% will have migration greater than 3mm
- Pannus, ligamentous weakening leads to ADI instability
- Migration up to 12mm can have no neurologic signs
- Steeles rule of thirds: 1/3 dens, 1/3 fat, 1/3 cord at C1
- Facet erosions (usually occur first, but hard to see)
- Subchondral sclerosis and loss of disc height can be seen (5%)
- erosion/ pannus lead to whittling of the dean and spinous processes
- anterolisthesis can be seen from C2-C4. Stepladder affect from loss of disc height, apophyseal joint disease, ligament laxity
- late stages can result in ankylosis or overlying degenerative disease.
Targeted sites of involvement
Hip
pg 18
1023 txt
- affected in 35% of patients
- the radiographic features are generally distributed bilateral and symmetric.
- migration of the femoral head is superior and medial
- with time, secondary degenerative changes will become evident as subchondral sclerosis, and osteophytes complicate the picture.
- protrusio- acetabuli in 15% of pts. ie migration past ilioischial line.
- RA is the m/c csudr of bilateral protrusion acetabuli
- overlying DJD changes, possible osteonecrosis (<5 yrs steroid use)
Targeted site of RH involvement Sacroiliac Joints pg 18 1024 txt
- its an uncommon site for involvement unlike ankylosing spondylitis (less than 25% of RA have SI disease)
- loss of joint space, erosions, UNILATERAL, may be bilateral ASYMMETRIC
- lower 2/3 involved, no sclerosis, rare to ankylose
Targeted site of RH
Shoudler
1024 text
- prominent bilateral and symmetric findings are common I’m both the glenohumeral joint and acromioclavucular
- soft tissue swelling over joint
- loss of joint space isn’t prominent at glenohumeral joint
- distance between acromion head and humeral head is diminished
- may be concavity on inferior surface of acromion.
- sclerosis and cyst formation on both opposing surfaces
- Clavicle resorption can occur at the AC joint
Targeted site of RH
Elbow
pg 19
1025 txt
- the extensor surface of the forearm is a common region for development of rheumatoid nodules -pg 1025
- olecranon bursitis (may be most pronounced finding)
- fat pads are displaced (fat pad sign)
- at the joint there is: loss of interosseus space, osteoporosis, and erosion (minimal)
Targeted site of RH
Knee
pg19
1025
− Frequent site of involvement
− Soft tissue swelling from synovial effusion,
suprapatellar and popliteal regions, baker’s
cyst
− Uniform bicompartmental loss of joint space
is seen, without osteophyte formation − Patellofemoral joint also involved
