Lecture 14 - Hand and Wrist Flashcards
Carpal bones proximal row (lateral to medial)
Scaphoid, lunate, triquetrum, pisiform
Carpal bones distal row (lateral to medial)
Trapezium, trapezoid, capitate, hamate
Carpal tunnel affect which nerve
Median nerve
Scaphoid fratures that result in AVN are most likely found in which area of scaphoid
Proximal
Disease that causes
Thickening and shortening of fibers of the palmar aponeurosis, resulting in continuous flexion of the metacarpophalangeal (MP) and proximal interphalangeal (PIP) joints of the involved digits (usually the ring and little fingers)
Most commonly affects males over 50 with a hereditary disposition
Dupytren’s contracture
Main compartments of the hand
Thenar
Hypothenar
Central
interosseous-adductor
Muscles in thenar compartment
- Abductor pollicis brevis, which also abducts the CM joint and helps flex the MP joint
- Flexor pollicis brevis, which also flexes the MP and CM joints
- Opponens pollicis
Muscles in the hypothenar compartment
- Abductor digiti minimi, which takes origin from the pisiform bone; it abducts the little finger and helps flex the MP joint
- Flexor digiti minimi brevis, which shares an origin with the opponens from the hook of the hamate and flexor retinaculum; it flexes the MP joint
- Opponens digiti minimi, which laterally rotates the metacarpal bone at the CM joint, cupping the hand to improve grip
Intrinsic Hand Muscles: Adductor Pollicis action
Adducts the thumb and helps flex its MP joint
Intrinsic hand muscles: Lumbricals action
Extend the PIP and DIP joints and help to flex the MP joint
Intrinsic hand muscles: Interossei action
Palmar interossei:
originate on metacarpals inserting into the proximal phalanges of digits 2, 4, & 5; they adduct (PAD)
Dorsal interossei
Bipennate and insert on the lateral sides of 2 & 3 and the medial sides of 3 & 4 proximal phalanges; they abduct (DAB)
