 |
| Notice the neck of the swan extended near its body(proximally) and bent towards its head(distally) |
 |
| Notice the bent finger while sewing a hand stitched buttonhole |
 |
| Did you know? The beak of a duck is called duck bill |
Now that you see and know these wonderful facts, lets talk medicine.
Swan neck, boutenniere and duck bill deformities are noticed in the fingers of people affected with Rheumatoid arthrits. In some cases, these deformities can also occur due to traumatic finger injury.
Pathophysiology:Abnormal stress on the volar plates, the ligaments around the finger joints.
Boutonniere Deformity
From North West Orthopaedic Specialists
Swan neck deformity
Click on the link to view image: Swan neck deformity in RA
In Rheumatoid arthritis(RA), the affected finger bends like the neck of a swan. The affected finger has obvious hyperextension of the proximal interphalangeal (PIP) joint and flexion of the distal interphalangeal (DIP) joint. In addition to this, at times there can be flexion of the metacarpophalangeal (MCP) joint.
Duck bill deformity
Click to view image: Duck bill deformity in RA
Swan neck deformity can also occur in the thumb. In some cases, instead of the typical swan neck deformity, the affected thumb shows duck bill deformity where the MCP joint does not hyperextend but the IP joint bends to form a 90° angle.The ability to pinch is greatly impaired due to simultaneous thumb instability.
Boutonniere deformity
Click to view image:Boutonniere deformity in RA
Boutonniere (French:boutonnière=buttonhole) deformity looks exactly opposite to that of swan neck deformity and is also seen in RA. Football and basketball sports related injuries can also lead to this deformity. It was named so because the injury caused the proximal phalanx to protrude through like a finger through a buttonhole.The affected finger is flexed at the proximal interphalangeal joint (PIP), and there is hyperextension at the distal interphalangeal joint (DIP).
Click to learn more:
From North West Orthopaedic Specialists
Comments
Post a Comment