Wrist and Hand
Wrist Wrist is a joint complex consisting of radio-carpal joint and many relationships between the carpal bone 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 Distal radius with proximal carpals “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
Ligaments
Ligaments
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
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
Metacarpal – Phalangeal Joints Ellipsoid 2 DOF Passive rotation Collateral Ligaments Deep Transverse Metacarpal Ligaments Palmar Ligaments (Plates)
Ligaments
Ligaments
Interphalangeal Joints Hinge Collateral Ligaments Palmar Ligaments (Plates)
Ligaments
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
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
Dorsal Hood
Dorsal Hood
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
Volar (Palmar) Interrossei
Dorsal Interossei
1st Dorsal Interosseous
Digit Movement
Digit Movement Cont.
Blood Supply Ulnar aa Radial 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
Deep Palmar Arch
Digital Supply
Median Cutaneous
Ulnar Cutaneous
Radial Cutaneous (Hand)
Common Nerve Injuries Median Symptoms Ulnar