Wrist and Hand

Wrist

Wrist is a joint complex consisting of radio-carpal joint and many relationships between the carpal bones

Review of carpals Proximal row = Pisiform, Triquetrum, Lunate,

and Scaphoid* Distal row = Hamate, Capitate, Trapezoid, and

Trapezium *Scaphoid has a notoriously poor blood supply

and recovers poorly following injury

Osteology

Osteology

Osteology

Scaphoid

Cross Section at Wrist

Wrist

All carpal bones articulate via gliding or plane joints

A more or less joint exists between proximal row and distal row of bones called mid-carpal – truly is a series of gliding joints

Scaphoid, Lunate and Triquetrum with Trapezium, Trapezoid, Capitate and Hamate

Pisiform is not involved

Wrist

True Wrist = Radio-Carpal• “Ulnar-Carpal” = interposed disc

Distal radius with proximal carpals Condyloid joint – 2 degrees of freedom Major Ligaments Palmar radio-carpal, palmar ulnocarpal,

dorsal radio-carpal, dorsal ulno-carpal, radial and ulnar collateral

Radio-Carpal

Ligaments

Ligaments

Interactive Wrist

Wrist

Mid-Carpal Proximal row of carpals with distal row A series of gliding joints – 3 DOF MAJOR Ligaments – Capsule plus Pisohamate, pisometacarpal,

capitotriquetral, palmar and dorsal carpometacarpal

Ligaments

Interactive Wrist

Wrist

Movements Flexion/Extension – about 70-80 degrees of ROM

• Radiocarpal v. Mid Carpal

• Flexion is initiated in mid carpal joint and 60% occurs there

• Extension is also initiated at mid carpal but most occurs in radio-carpal. Need 35 degrees for good function – at least 10 for any significant function.

Abduction/Adduction – about 15 to 20 degrees• Intercarpal – proximal row slides over distal row

Movements

Movements

Movements

Carpo-Metacarpal Joints

2-5• Hamate with 4 and 5

• Capitate with 3

• Trapezoid with 2

Gliding joints with limited range – mostly passive

Palmar and Dorsal carpometacarpal ligaments

C-M Joints

C-M Joints

C- M Thumb

Trapezium with 1st met Saddle Adds rotary component – very mobile Capsule support

C-M Thumb

Interactive Hand

Metacarpal – Phalangeal Joints

Ellipsoid 2 DOF Passive rotation Collateral Ligaments Deep Transverse Metacarpal Ligaments Palmar Ligaments (Plates)

Ligaments

Ligaments

Interactive Hand

Interphalangeal Joints

Hinge Collateral Ligaments Palmar Ligaments (Plates)

Ligaments

Interactive Hand

Definition of Finger Movements

Reference is imaginary line through the middle of long (3rd) finger

Adduction of 2-5 = towards that point Abduction = away –1, 4, and 5 Thumb

• Flexion

• Extension

• ABD

• ADD

• Rotation

• Opposition = flexion with adduction and rotation

Finger Movements

Finger Movements

Flexor Tendons

Tenosynovium (AKA Fibro-Osseous Tunnels)

Anular Pulleys AKA Vaginal Ligaments• Anular and Cruciform

• Relationship to Palmar Plates

Vinculum Longa and Breve

Tunnels

Tunnels

Interactive Hand

Dorsal Hood

Dorsal Hood

Dorsal Hood Mechanism

Insertion of Long Extensor Tendons• Ext. Dig. Communis

• Ext. Indicis Proprius

• Ext. Digiti Minimi

Extensor Expansion – MP Joints Central Band – Middle Phalanx Lateral Band –Distal Phalanx Relationship to Intrinsic Muscles

Dorsal Hood

Dorsal Hood

Interactive Hand

Intrinsic Muscles

Thenar Eminence - median Hypothernar Eminence - ulnar Intermediate – ulnar and some median There are NO muscles in the hand

innervated by the Radial nerve

Palmar Aponeurosis

Thenar Eminence

Flexor Pollicus Brevis Abductor Pollicus Brevis Opponens Pollicus

Thenar Muscles

Hypothenar Eminence

Abductor Digiti Minimi Flexor Digiti Minimi Opponens Diditi Minimi

Intermediate

Adductor Pollicus Lumbricales Volar (Palmar) Interossei Dorsal Interossei

Adductor Pollicus

Lumbricales

Lumbricales

Dorsal Interossei

1st Dorsal Interosseous

Volar (Palmar) Interrossei

Digit Movement

Digit Movement Cont.

Blood Supply

Ulnar aa• Superficial Palmar Arch

• Common Palmar aa

• Proper palmar digital aa Radial aa

• Deep Palmar Arch

• Dorsal digital aa

• Princeps Pollicus

• Radialis Indicis

Superficial Palmar Arch

Superficial Palmar Arch

Superficial Palmar Arch

Deep Palmar Arch

Deep Palmar Arch-Dorsal View

Deep Palmar Arch

Digital Supply

Median Cutaneous

Ulnar Cutaneous

Radial Cutaneous (Hand)

Common Nerve Injuries

Median Symptoms Ulnar Symptoms