RA Flashcards
What serum marker is typically positive in RA?
rheumatoid factor
What is the RF antibody directed against?
IgG which activates the complement cascade
erosion in RA occur where in the joint?
Marginal erosions at the “bare area”
What is the “bare area”?
region of exposed bone just within the joint capsule that is not covered by thick cartilage
Type of joint space narrowing in RA
symmetric joint space narrowing
Radiographic hallmarks of RA
- marginal erosions - soft tissue swelling - symmetric joint space narrowing - periarticular osteopenia - joint subluxations
Earliest radiographic findings of RA
soft tissue swelling and peri-articular osteopenia (reflects synovitis and hyperemia)
First erosions to occur in the hand in RA patients
- radial aspects of the second and third metacarpal heads - ulnar styloid - bases of the proximal phalanges
Common place for RA involvement in the feet
- MTP joints in the forefoot - talocalcaneonavicular joint
Hip deformity associated with RA
protrusio deformity - >3mm medial migration of the femoral head beyond the ilioischial line in males and >6mm in females
Typical migration of the femoral head in RA
axial (symmetric joint space narrowing)
osteophytes plus symmetrical cartilage space narrowing in the knee
secondary OA in the setting of inflammatory arthropathy (like RA)
cervical spine is involved in what percentage of RA pts?
70%
Common association of RA in the cervical spine
atlantoaxial subluxation: - anterior: laxity of transverse ligament - vertical (atlantoaxial impaction): odontoid through foramen magnum secondary to facet erosion and collapse - posterior: due to odontoid fx
Finding in the shoulder commonly associated with RA
osteolysis of the distal clavicle (“penciling” of the distal clav)