Wrist and Hand Fractures

23 Wrist and Hand Fractures



Anatomy of the Wrist and Hand



image

Carpal Bones


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Bones of Wrist and Hand



Carpal Bones: Lateral to Medial



• Proximal
image Scaphoid, lunate, triquetrum, pisiform

• Distal
image Trapezium, trapezoid, capitate, hamate


Metacarpals



• Numbered I/1 (thumb) to V/5 (digiti minimi)

• Parts: base, shaft, head

• Shafts triangular in cross section

• V/5 most commonly fractured metacarpal


Phalanges



• Proximal, middle, distal (3) in each finger

• Proximal, distal (2) in thumb

• Parts: base, shaft, tuberosity (in distal phalanges), head

• Distal phalanx 3 common fracture


Joints of Wrist and Hand



• Radiocarpal (RC) joint
image Synovial joint between distal radius and articular disc (concave) and scaphoid, lunate, and triquetrum (convex)

image Allows movement around 2 axes: flexion/extension, adduction/abduction (ulnar and radial deviation, respectively)

• Carpal joints
image Synovial joints between carpals

image Share common joint cavity

image Limited movement contributes to positioning of hand, grasp

• Carpometacarpal (CM) joints
image Synovial, between distal row of carpal bones and 5 metacarpal bases

image Saddle joint between trapezium and thumb metatarsal more mobile than others: flex/extend, abduct/adduct, rotate, circumduct

image CM joints II-V
image Synovial arthrodial/gliding

image Range of movement increases medially: metacarpal 5 greatest.

image Joint capsules reinforced by palmar and dorsal ligaments and medial and lateral collateral ligaments

• Metacarpophalangeal (MCP) joints
image Synovial condylar

image Between metacarpal heads and proximal phalanges

image Joint capsules reinforced by palmar ligaments and medial and lateral collateral ligaments

• Interphalangeal joints
image Synovial hinge

image Supported by palmar and medial, lateral collateral ligaments


Ligaments of Wrist and Hand



• Supporting wrist (RC) joint: palmar radiocarpal, palmar ulnocarpal, dorsal radiocarpal ligaments

• Flexor retinaculum (transverse carpal ligament) runs proximally between scaphoid (tubercle) and triquetrum and distally between trapezium (tubercle) and hamate (hook) and forms carpal tunnel.

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Aug 12, 2016 | Posted by in ANATOMY | Comments Off on Wrist and Hand Fractures

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