Hand/Wrist Osteology
Anatomy Affected in RA
100

This joint lies intermediate to the carpo-metacarpal joint and proximal interphalangeal joint

Metacarpo-phalangeal (MCP) Joint

100

Tenosynovitis (tendon + synovial sheath inflammation) of the flexor tendons of the carpal tunnel can cause carpal tunnel syndrome symptoms in RA patients. Name them all

4 tendons of flexor digitorum superficialis

4 tendons of flexor digitorum profundis

tendon of flexor pollicis longus

200

This bone can be palpated in a divot on the dorsal surface of the hand in line with the third metacarpal

Lunate

Bonus: Lunate fractures usually result from what mechanism of injury?

200

Weakening of this wrist-stabilizing ligament contributes to the ulnar deviation characteristic of rheumatoid arthritis

Radial collateral ligament

300

These bony projections allow for abduction and adduction of the wrist joint

The radial and ulnar styloid processes

Bonus: Why can the wrist be abducted more than it can be adducted?

300

De Quervain's tenosynovitis (often found in RA patients) affects these 3 tendons comprising the anatomical snuffbox

abductor pollicis longus, extensor pollicis brevis, extensor pollicis longus

Bonus: Name/demonstrate the clinical test for De Quervain's tenosynovitis

400

The wrist joint is made up of these 5 structures

4 bones: radius, scaphoid, lunate and triquetrum

cartilage: articular disc over the ulnar head

400

While RA often affects multiple joints in the upper limb, this joint is usually unaffected

Distal interphalangeal joints

500
Name the 4 carpal bones of the proximal row (lateral to medial) and the 4 carpal bones of the distal row (lateral to medial)

Proximal row (L -> M): scaphoid, lunate, triquetrum, pisiform

Distal row (L -> M): trapezium, trapezoid, capitate, hamate

500

Tenosynovitis (tendon + synovial sheath inflammation) of the tendon of this forearm posterior compartment muscle can lead to erosion of the ulnar styloid process

Extensor carpi ulnaris

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