Week 13 Task Sheet - Rheumatoid Arthritis Flashcards
What structures cause MCP stability?
- Palmar ligament
- Collateral Ligaments
- Long flexor and extensor tendons
- Extensor hood
- Lumbricals and Interossei
What is the palmar ligament?
Fibrocartilagenous plate increasing the articular surface on the palmar side of the MCPs
What position are the collateral ligaments of the MCP joints taut?
in flexion
Define Rheumatoid Arthritis?
Autoimmune, progressive, chronic, inflammatory disease of peripheral connective tissue – particularly synovial joints
What is the pattern of RA?
Most commonly effect distal joints bilaterally, undergoing periods of relapse and remission
Who is most likely to get RA?
women
in their 50s
Smokers
What happens in the intimal layer of the synovial during RA?
Synovial cell hyperplasia leading to thickened layers of tissue
Type A synoviocytes cause phagocytosis
Type B synoviocytes cause synthesis of synovial fluid
What happens in the subintimal layer during RA?
Blood vessels dilate leading to increased permeability & increased proliferation of vessels:
o Allowing the influx of plasma proteins, plasma cells and leucocytes into the synovium and synovial fluid
o Inflammatory cascade = proteolytic enzymes secreted by synoviocytes
What is the swelling seen in RA?
Excess synovial fluid production - containing destructive enzymes which leads to the starvation of the cartilage cells
What causes MCP joint subluxation during RA?
Swelling in the MCP joint stretches the joint capsule - also stretching the collateral ligaments
Lengthening of the supporting tissues causes Palmar subluxation
What are rheumatoid nodules?
Pannus formation = abnormal highly vascularised granulation tissues containing macrophages, mast cells and fibroblasts - enters the articular cartilage and destroys underlying bone = joint buckling
Why does ulnar drift occur in RA?
hands usually rest in UD, and ulnar interossei are stronger than radial interossei - functionally more likely to move into ulnar deviation
What is a zig zag deformity?
flexion and ulnar deviation at the MCP joints - prologued swelling and connective tissue destruction means that the supporting ligaments are unable to stabilise the joints
What is trigger finger?
When the tendons are unable to glide smoothly due to formation of panes - so the tendons are fixed
What causes swan - neck deformity in RA?
PIP synovitis = capsular distension and stretching of volar plate = hyperextension at PIP = extensor slips of ED at DIP migrate around the side of the hinge and become flexors muscles = FFD at DIP
