HAND ANATOMY

Dorsum Of Hand

• Skin• Cutaneous innervation

Terminal branches of Radial Nerve Dorsal branch ulnar nerve

• Dorsal Venous network, arch proximal to MCHDrain from volar aspect as well

Pressure of gripping does not impede the venous return Radial Side Cephalic Vein Ulnar Side Basilic Vein

Cutaneous Innervation

Palm of the Hand

• Skin – Flexion creases and papillary ridges • Possibly improve the grip and increase the surface

area • Sweat glands abound, No sebaceous glands • Ulnar Nv. Little ,½ Ring and Hypothenar eminence • Median Nv. Thumb, Index Middle, ½ Ring and Thenar

eminence

Cutaneous Innervation

Palm Fascia

• Palmar Aponeurosis• Flexor Retinaculum, transverse carpal ligament

Radial - Scaphoid tubercle, ridge of Trapezium

Ulnar – Pisiform, hook of Hamate• Superficial relations, ulnar to radial

Ulnar Nv., Ulnar Art., Covered by fascia giving origin to the hypothenar ms. – Guyon’s canal

Palmar br. Ulnar nv , PL tendon, Palmar br. Median nv, Superficial palmar br. Radial art.

Palmar Spaces Thenar and Mid Palmar Spaces – Located dorsal to FT and volar to MC and Int. ms. Fascia

Midpalmar oblique Septum

Thenar Space between the thenar eminence and third metacarpal. Extends dorsally IbI the Int. ms. And Add. Pollicis .Mostly contains the first lumbrical

Midpalmar Space IbI thenar and hypothenar space overlying the 3,4,5 MC

Hypothenar Space

Dorsal Sub aponeurotic Space

Interdigital Web Space

Radial,Ulnar bursa,Parona’s

Carpal Tunnel

Guyon’s Canal

Blood Supply

• Radial Artery • Ulnar Artery • Superficial Palmar Arch • Deep palmar Arch• Anterior carpal arch • Posterior carpal arch

Radial Artery• Wrist - emerges medial to the brachioradialis • Superficial palmar branch – Superficial palmar arch• Dorsally IbI the radial carpal ligament and the APL EPB to

emerge in the snuff box • Branches - Radial digital collateral artery

Dorsal radial carpal branch, FDMA• Reenters palm IbI the two heads of 1st DI• A. radialis indices and A. princeps pollicis • Emerges IbI the transverse and oblique heads of adductor

pollicis – Deep palmar arch • Post. Carpal Arch – DRCB, Ulnar A., Int. A. – 2, 3, 4 DMAs

Ulnar Artery and Nerve

• Deep and radial to Ulnar nv and FCU• Superficial br.- Superficial palmar arch• Deep br.- Deep palmar arch • Ulnar nv ulnar and more superficial • Superficial br. Ulnar side of little and common digital

nv to the little and ring • Deep br. Supplies the hypothenar muscles Curves

around the hook of hamate and pierces the opponens digiti minimi along with the deep br. Ulnar A. to supply the 3,4th lumbricals and all interossei to end in the Adductor pollicis

Median Nerve

• Enters the palm through the carpal tunnel • Three branches • Medial – Common digital to the ring and middle and

common digital to the middle and index – gives a br to the second lumbrical

• Lateral – Radial digital to the index and the whole of thumb – gives a br to the first lumbrical

• Recurrent br./ muscular br. – thenar muscles

Thenar Eminence

• Abductor Pollicis Brevis – arises FR and scaphoid tubercle inserts radial side base of proximal phalanx

• Flexor Pollicis Brevis – arises FR and trapezium inserts radial sesmoid and radial border proximal phalanx – deep head ulnar nv

• Opponens Pollicis – arises FR and trapezium inserts radial border metacarpal

• Adductor Pollicis – arises 3rd MC transverse head, capitate oblique head inserts ulnar sesmoid and ulnar side base of proximal phalanx – Ulnar nv

Hypothenar Eminence

• Abductor Digiti Minimi – arises FR and pisiform inserts ulnar side proximal phalanx and ext. expansion

• Flexor Digiti Minimi Brevis – arises FR inserts base of proximal phalanx

• Opponens Digiti Minimi – arises FR and hook of hamate inserts ulnar border 5th metacarpal

Flexor Tendons

Flexor Digitorum Profundus

Flexor Digitorum Superficialis

Chiasma

Flexor Tendons

Flexor Tendons - Zones

Extensor Retinaculum

• Ribbon like band <2.5 cm wide• Oblique across dorsal surface wrist joint• Medial attach.Radius anterolateral border • Lateral attach. Pisiform and Triquetral passes

below the styloid process ulna• If attached to both the forearm bones the ER

would be 30 % longer in pronation • Being oblique it is able to maintain a constant

tension throughout the motion

• Divide into six compartments by fibrous septa to the bone

• Separate synovial sheaths for all the tendons except the EDC and EI

• Extensor Tendons Zones

EXTENSOR TENDONS

Dorsal Interossei - Abductors

Palmar Interossei - Adductors

MCPJ

Volar Plate

PIPJ

Volar Plate PIPJ

DIPJ

Volar Plate

Nail Anatomy

Perionychium – Nail Bed, Nail Fold, Eponychium, Paronychium, Hyponychium

Nail Bed – Germinal matrix, sterile matrix

Nail Fold – Dorsal roof, Ventral floor – germinal matrix – Lunula

Germinal matrix produces 90% of the nail, sterile matrix adds inner layer which keeps the nail adherent, dorsal roof gives the shine