Page 493 - First Aid for the USMLE Step 1 2020, Thirtieth edition [MedicalBooksVN.com]_Neat

Musculoskeletal, skin, and connective tissue ` anatomy and physiology Musculoskeletal, skin, and connective tissue ` anatomy and physiology section iii 449

Wrist region Scaphoid, Lunate, Triquetrum, Pisiform, A
Hamate, Capitate, Trapezoid, Trapezium A .
B
(So Long To Pinky, Here Comes The Thumb) 1st MC
Scaphoid (palpable in anatomic snuff box B ) Trapezoid Capitate Hamate
is the most commonly fractured carpal bone, Trapezium
typically due to a fall on an outstretched hand. Triquetrum
Complications of proximal scaphoid fractures Scaphoid Pisiform
include avascular necrosis and nonunion due Lunate
to retrograde blood supply from a branch of
Radius Ulna
the radial artery. Fracture not always seen on
initial x-ray.
Dislocation of lunate may cause acute carpal
tunnel syndrome.

Flexor retinaculum (transverse carpal ligament)
Ulnar artery Flexor digitorum
Ulnar nerve superficialis tendons
Palmar surface
Guyon canal Median nerve
Flexor carpi
radialis tendon
Hypothenar
eminence Thenar
eminence

Plane of
section Carpal bones
Flexor pollicis
Flexor digitorum
profundus tendons longus tendon
Carpal tunnel (with contents)

FAS1_2019_11-Musculo.indd 449 11/7/19 5:23 PM