Hand Anatomy PDF

Dr. Mahir R. Ibrahim Orthopaedic surgeon Bon es Carpal bones mnemonics She Looks Too Proud, Try To Chase Her Carpal bones (lateral to medial):  Proximal row: Scaphoid, Lunate, Triquetrum, Pisiform  Distal row: Trapezium, Trapezoid, Capitate, Hamate  Flexor Retin...

Dr. Mahir R. Ibrahim Orthopaedic surgeon Bon es Carpal bones mnemonics She Looks Too Proud, Try To Chase Her Carpal bones (lateral to medial):  Proximal row: Scaphoid, Lunate, Triquetrum, Pisiform  Distal row: Trapezium, Trapezoid, Capitate, Hamate  Flexor Retinaculum It is a thickening of deep fascia that holds the long flexor tendons in position at the wrist. It is attached medially to the pisiform bone and the hook of the hamate and laterally to the tubercle of the scaphoid and the trapezium bones  Structures pass deep to Flexor Retinaculum From medial to lateral: 1) Flexor digitorum superficialis tendons, FDP 2) Median nerve 3) Flexor pollicis longus tendon 4) FCR Structures pass Superficial to Flexor Retinaculum From medial to lateral: 1) Flexor carpi ulnaris tendon 2) Ulnar nerve 3) Ulnar artery 4) Palmar cutaneous branch of the ulnar nerve 5) Palmaris longus tendon 6) Palmar cutaneous branch of the median nerve  Carpal Tunnel It is a fibro-osseous canal formed anteriorly at the wrist by a deep arch formed by the carpal bones and the flexor retinaculum. Contents : 1) Tendons of FDS 2) Tendons of FDP 3) Tendon of FPL 4) Median nerve  Muscles of the Hand Hand muscles divided into two groups: A. Extrinsic group: Muscles that originate outside the hand and inserted into the hand bones, e.g. FDS, FDP. B. Intrinsic group: arranged in five parts 1) Thenar Eminence 2) Hypothenar Eminence 3) Adductor pollicis 4) Interosseous muscles 5) Lumbrical muscles  Thenar Eminence ① Three muscles responsible for the prominent swelling on the lateral side of the palm at the base of the thumb. 1) Opponens pollicis 2) Flexor pollicis brevis 3) Abductor pollicis brevis All are supplied by recurrent branch of median nerve  Hypothenar Eminence ② Three muscles responsible for the swelling at the base of the little finger. 1) Opponens Digiti minimi 2) Abductor Digiti minimi 3) Flexor Digiti minimi brevis All supplied by deep branch of Ulnar nerve.  Adductor Pollicis ③  It originates as two heads: transverse head from the anterior aspect of the shaft of 3rd metacarpal oblique head, from the capitate and adjacent bases of 2nd and 3rd metacarpals.  inserts into the medial side of the base of the proximal phalanx.  It supplied by Deep branch of ulnar nerve.  Adduction  ④ Interosseous Muscles The interossei are muscles between and attached to the metacarpals, inserted into the proximal phalanx of each digit. They are divided into two groups, the dorsal interossei and the palmar interossei. All are supplied by deep branch of Ulnar nerve. Palmar( Adduction ), Dorsal (abduction).  ⑤ Lumbrical Muscles They are four (worm-like)  muscles, each of which is associated with one of the fingers. The muscles originate from the tendons of FDP in the palm. The medial two lumbricals are innervated by the deep branch of the ulnar nerve; the lateral two lumbricals are innervated by digital branches of the median nerve. Flex MPJ and extend IPJ.  Blood vessels of the Hand Blood supply to the hand is by the radial and ulnar arteries. They form two interconnected vascular arches (superficial and deep) in the palm. The radial artery contributes substantially to the supply of the thumb and the lateral side of the index finger The remaining digits and the medial side of the index finger are supplied mainly by the ulnar artery.  Superficial Palmar Arch It is formed by ulnar artery on the medial side of the palm, completed by palmar branch of radial artery. Branches: 1) a palmar digital artery to the medial side of the little finger. 2) three large, common palmar digital arteries  Deep Palmar Arch It is formed by radial artery on the lateral side of the palm and completed by deep branch of ulnar artery. This arch lies across the metacarpals just distal to their bases. Branches: 1) three palmar metacarpal arteries 2) three perforating branches Two vessels, the princeps pollicis artery and the radialis indicis artery, arise from the radial artery in the plane between the first dorsal interosseous and adductor pollicis.  Dorsal Carpal Arch Before penetrating the back of the hand, the radial artery gives rise to: 1) Dorsal carpal branch, which passes medially as the dorsal carpal arch, gives rise to dorsal metacarpal arteries, which subsequently divide to become small dorsal digital arteries, which enter the fingers. 2) First dorsal metacarpal artery, which supplies adjacent sides of the index finger and thumb. 3) Princeps pollicis artery 4) Radialis indicis artery  Veins of the Hand Deep veins follow the arteries. Superficial veins drain into a dorsal venous network on the back of the hand over the metacarpal bones. The Cephalic vein originates from the lateral side of the dorsal venous network and passes over the anatomical snuffbox into the forearm. The Basilic vein originates from the medial side of the dorsal venous network and passes into the dorso- medial aspect of the forearm.  Nerves of the Hand The hand is supplied by the ulnar, median, and radial nerves The ulnar nerve innervates all intrinsic muscles of the hand except for the three thenar muscles and the two lateral lumbricals, which are innervated by the median nerve. The radial nerve only innervates skin on the dorsolateral side of the hand. ULNAR MEDIAN RADIAL  Extensor Retinaculum It is a strong, fibrous band extends obliquely across the back of the wrist. It is attached laterally to the anterior border of the radius, medially to the triquetral and pisiform bones.  Extensor Retinaculum Superficial structures from medial to lateral: 1) Dorsal (posterior) cutaneous branch of the ulnar nerve 2) Basilic vein 3) Cephalic vein 4) Superficial branch of the radial nerve  Extensor Retinaculum Deep structures from medial to lateral: 1) Extensor carpi ulnaris tendon 2) Extensor digiti minimi tendon 3) Extensor digitorum and extensor indicis tendons 4) Extensor pollicis longus tendon 5) Extensor carpi radialis longus and brevis tendons 6) Abductor pollicis longus and the extensor pollicis brevis tendons