Presentation on theme: "Bones and Joints of the Wrist"— Presentation transcript:
1Bones and Joints of the Wrist WRIST COMPLEXBones and Joints of the Wrist
2Proximal Row of Carpal Bones Review- testableScaphoid:Most lateral.Forms floor of anatomical snuff box.Most commonly fractured wrist bone.Fractures may compromise radial artery in snuff box.Articulates with radius.
3Proximal Row of Carpal Bones Lunate:Articulates with radiusTriquetral:Articulates with ulna (via articular (ulnar) disc) during extreme ulnar deviation.Pisiform:Sesamoid boneForms in tendon of the flexor carpi ulnaris
4Distal Row of Carpal Bones: Trapezium:Most lateralTrapezoidCapitateHamate
5Distal Row of Carpal Bones: Entire complex enclosed in a common synovial membrane.Articulations are plane joints that perform gliding motions.
6Radiocarpal Joint Condyloid (ellipsoidal) synovial joint. Two degrees of freedom.Articular surfaces:Scaphoid (convex)Lunate (convex)Distal radius:Two concave fossae (lateral and medial)Triquetral (convex)Only during extreme ulnar deviation
8Radiocarpal Joint Functions Some flexion and extensionUlnar deviation
9Radiocarpal Joint Arteries Articular arteriesArise from dorsal and palmar carpal arches.
10Radiocarpal Joint Nerves Anterior interosseous branch of median nerve.Posterior interosseous branch of radial nerve.Dorsal and deep branches of the ulnar nerve.
11Radiocarpal Joint Injuries Colle’s fractureScaphoid fractureUsually at “waist”Compromises radial artery in snuffbox
12Midcarpal Joint Made up of intercarpal joints: Movements: Between proximal and distal rows of carpals and between carpals.Movements:Some flexion and extension.Radial deviation (abduction).Especially due to movement of head of capitate in its socket.Enclosed within synovial capsule.
13Midcarpal Joint Ligaments: Nerves and arteries: Dorsal ligaments. Palmar ligaments.Interosseous ligaments.Nerves and arteries:Same as for radiocarpal.
27Palmar AponeurosisTriangular layer of deep fascia located between two eminences.Provides protection for superficial vessels, nerves, and tendons.Anchored to skin and flexor retinaculum.Splits into four slips that blend with fibrous flexor sheaths of four medial digits (II – V).
28Flexor Retinaculum = Transverse carpal ligament. Laterally attaches to tubercles of scaphoid and trapezium.Medially attaches to hook of hamate and pisiform.
29Palmaris Brevis Muscle O: Flexor retinaculum and palmar aponeurosis.I: Skin on medial side of palm.A: Tenses skin on palm.
30Carpal Tunnel Contents Long flexor tendons of:Flexor digitorum superficialisFlexor digitorum profundusFlexor pollicis longusMedian nerveNote: ulnar nerve and artery pass through Guyon’s canal.
42Dorsal Interossei Four bipennate muscles. Each arises via two heads from adjacent sides of two metacapals.
43Dorsal Interossei Insertion: Abducts MP joints of digits 2-4: Onto extensor expansions and:Radial sides of proximal phalanges 2 and 3;Ulnar sides of proximal phalanges 3 and 4.Note: digit has two dorsal interossei.Abducts MP joints of digits 2-4:Reference is line through middle finger.
45Palmar Interossei Four unipennate muscles: First is sometimes considered part of flexor pollicis brevis.Supply each digit except third:Reference is middle finger.Innervation for all interossei (incl. dorsal):Ulnar nerve
47Lumbricals Four small, narrow, elongated muscles. Each arises from the radial side of a flexor digitorum profundus tendon.Innervation:Two on radial side:Median nerveTwo on ulnar side:Ulnar nerveFlex MCP joints and extend IP joints.
48Arterial Supply to Hand Superficial palmar arch:Continuation of ulnar artery.Deep palmar arch:Continuation of radial artery.
49Route of Radial Artery Smallest terminal branch of brachial artery. Passes proximally deep to brachioradialis muscle.Distally the artery lies against the radius lateral to the tendon of the flexor carpi radialis, where it can be felt (radial pulse).Passes across scaphoid in anatomical snuff box.
50Route of Radial Artery Wraps around the dorsum of first metacarpus: Gives off arteries to the thumb and index finger.Pierces the first dorsal interosseous muscle and reappears in the palm of the hand.Gives rise to the deep palmar arch.
52Boundaries of the Anatomical Snuff Box Lateral (anterior):Tendons of the:Abductor pollicis longus.Extensor pollicis brevis.Medial (posterior):Tendon of the:Extensor pollicis longus.
53Ulnar Nerve in the Hand Enters hand superficial to flexor retinaculum. Superficial branch:Muscular branch to palmaris brevisCutaneous to palmar aspect of ulnar side of little finger and adjacent sides of little and ring fingers, including tips and dorsum.
54Ulnar Nerve in the Hand Deep branch: Supplies hypothenar muscles, all interossei, two ulnar side lumbricals, and adductor pollicis.
56Median Nerve in the Hand Enters palm deep to flexor retinaculum.Divides into lateral and medial branches:Lateral branch:To thenar muscles and first lumbrical.Cutaneous to anterior surface of thumb and radial side of index finger.Medial branch:To second lumbrical.Cutaneous to adjacent sides of digits 2-4, including nail-bed and finger tips.
57Spaces in the Hand Thenar space: Midpalmar space: Located between the palmar side of the adductor pollicis muscle and the long flexor tendons to the index finger and the thumb.Midpalmar space:Located between metacarpals 4-5 and the long flexor tendons to digits 4-5.
58Clinical Notes Mallet finger: Dupuytren’s contracture: Avulsion by long flexor tendon.Results in hyperflexion of DIP.Dupuytren’s contracture:Progressive fibrosis of palmar aponeurosis.Results in marked flexion of fingers at MP joints.Colle’s fracture.Fracture of scaphoid.
59Clinical Notes Median nerve injury: Ulnar nerve injury: Loss of thumb opposition.Atrophy of thenar muscles.Ape hand.Ulnar nerve injury:Paralysis and atrophy of interossei.GutteringLoss of thumb adduction.Clawhand.