Radioulnar, Wrist & Hand Joints PDF MSB Lecture 16 2024

Radioulnar, Wrist & Hand Joints Proximal & Distal Radioulnar Joints, Wrist & Hand Joints Dr. Brennan DO NOT DISTRIBUTE/ANY NO RECORDING...

Radioulnar, Wrist & Hand Joints Proximal & Distal Radioulnar Joints, Wrist & Hand Joints Dr. Brennan DO NOT DISTRIBUTE/ANY NO RECORDING OFDISTRIBUTION THIS LECTURE OF CONTENT THIS E-mail: [email protected] LECTURE CONTENT ANAT20080 Musculoskeletal Biology Lecture 16 5th November 2024. 1 Proximal Radioulnar Joint Pivot type of synovial joint Head of radius articulates with radial notch of ulna Fibrous capsule & synovial membrane continuous with that of elbow joint Anular ligament forms osteo- ligamentous ring with radial notch of ulna Rotation of head of radius Blood Supply from anterior & posterior interosseous arteries Innervation from Musculocutaneous, Median, Radial & Ulnar nerves ANAT20080 Musculoskeletal 2 2  Distal Radioulnar Joint Pivot type synovial joint Distal Head of Ulna articulates with ulnar notch of radius Fibrous Articular Disc From ulnar styloid to ulnar notch of radius Separates distal radioulnar joint from wrist joint Fibrous capsule is attached to articular margins including fibrocartilage disc inferiorly. Blood Supply and innervation provided by the Anterior/Posterior interosseous arteries & nerves ANAT20080 3 Musculoskeletal 3 Pronation / Supination Supination (palm up) Pronation (palm down) ANAT20080 4 Musculoskeletal 4  Pronation / Supination Ulna is the stabilizing bone of the forearm located medially Laterally positioned radius can pivot around the ulna Rotation of radius at elbow Movement of distal end of radius over ulna Allows rotation of the hand when the elbow is flexed Movement required at both proximal & distal radioulnar joints ANAT20080 5 Musculoskeletal 5 Pronation / Supination At the elbow: The superior articular surface of the radial head spins on the capitulum At the same time at the proximal radio-ulnar joint: The radial head slides against the radial notch of the ulna & adjacent areas of the joint capsule and anular ligament. ANAT20080 6 Musculoskeletal 6  Pronation / Supination At the distal radio-ulnar joint: The ulnar notch of the radius slides anteriorly over the convex surface of the head of the ulna. Because the hand articulates mainly with the radius, movement of the distal end of the radius medially over the ulna moves the hand from the palm anterior (supinated) to the palm posterior (pronated) position ANAT20080 7 Musculoskeletal 7 Pronation / Supination During pronation/supination movements the forearm bones are held together by: The anular ligament of the radius at the proximal radioulnar joint The interosseous membrane along the lengths of the radius and ulna The articular disc at the distal radio-ulnar joint ANAT20080 8 Musculoskeletal 8  Muscles of Supination Two muscles supinate the hand Supinator In the posterior compartment of the forearm Biceps brachii Supinator & flexor of the elbow joint Most effective as a supinator when the forearm is flexed The tendon of the biceps brachii & the supinator muscle both become wrapped around the proximal end of the radius when the hand is pronated When they contract, they unwrap from the bone, producing supination of the hand. ANAT20080 Musculoskeletal 9 9 Muscles of Pronation Two muscles located in anterior compartment of forearm pronate the hand Pronator Teres Pronator Quadratus When these muscles contract, they pull the distal end of the radius over the ulna resulting in pronation of the hand ANAT20080 10 Musculoskeletal 10  Hand The hand is the region of the upper limb distal to the wrist joint. Subdivided into Wrist (carpus) Metacarpus Digits Thumb, index, middle, ring & little fingers The hand has An Anterior Surface (palm) A Dorsal Surface (dorsum of hand) ANAT20080 11 Musculoskeletal 11 Bones of Hand There are three groups of bones in the hand: 8 Carpal bones Bones of the wrist The five metacarpals (1-5, I to V) Bones of the metacarpus Phalanges Bones of the digits Thumb has only 2 Other digits have 3 ANAT20080 12 Musculoskeletal 12  Carpal Bones Start from Thumb: Some Lovers Try Positions That They Cannot Handle ANAT20080 13 Musculoskeletal 13 Carpal Bones Proximal Row Scaphoid Boat-shaped Lunate Crescent shaped Triquetrum Three-sided bone Pisiform Pea-shaped The pisiform is a sesamoid bone in the tendon of the flexor carpi ulnaris Articulates with the anterior surface of the triquetrum ANAT20080 14 Musculoskeletal 14  Carpal Bones Distal Row Trapezium Four-sided bone Articulates with the metacarpal bone of the thumb Trapezoid Small irregular four-sided bone Capitate Largest of the carpal bones Articulates with the base of metacarpal 3 Hamate Has a prominent hook (hook of hamate) on its palmar surface that projects anteriorly. ANAT20080 15 Musculoskeletal 15 Articular Surfaces The carpal bones have numerous articular surfaces Articulate with other carpal bones Distal row articulates with the metacarpals All movements of the metacarpals on the carpal bones are limited With the exception of the metacarpal of the thumb Proximal surfaces of the scaphoid and lunate articulate with the radius to form the wrist joint ANAT20080 16 Musculoskeletal 16  The Wrist (Radiocarpal) Joint Ellipsoid Type Synovial Joint Condyloid, Ovoid Between: Distal end of Radius Articular disc at distal end of ulna Carpal bones - scaphoid & lunate Capsule Strengthened by ulnar & radial collateral ligaments Movements Flexion / Extension Adduction (Ulnar deviation)/ Abduction (Radial Deviation) Due to radial styloid process extending further hand can be adducted to a greater degree ANAT20080 Musculoskeletal 17 The Intercarpal Joints Articulations of the carpal bones Articulations of proximal row Articulations of distal row Proximal & Distal Rows with each other (Mid-carpal joint) ANAT20080 Musculoskeletal 18  Carpal Arch The carpal bones form the carpal arch Medial side formed by pisiform & hamate Lateral side formed by scaphoid & trapezium Medial Lateral Medial Lateral ANAT20080 19 Musculoskeletal 19 Carpal Tunnel Flexor retinaculum spans between medial & lateral sides to form the anterior wall of the carpal tunnel ANAT20080 20 Musculoskeletal 20  Clinical - Carpal Tunnel Syndrome Passing through the Carpal Tunnel: 4 tendons of the flexor digitorum profundus 4 tendons of the flexor digitorum superficialis Tendon of the flexor pollicis longus The median nerve ANAT20080 21 Musculoskeletal 21 Clinical - Carpal Tunnel Syndrome Carpal tunnel syndrome Entrapment of the median nerve within the carpal tunnel Most common nerve compression syndrome Precise cause is unknown: Overuse Swelling of the tendons and tendon sheaths (rheumatoid arthritis) Cysts arising from the carpal joints Symptoms Numbness Tingling - pins & needles Wasting of thenar muscles Tinel's sign - Tapping over the median nerve (in the region of the flexor retinaculum) produces these symptoms Therapy: Splinting, Anti-inflammatories, Surgery ANAT20080 Musculoskeletal 22 22  Metacarpals Each of the five metacarpals relates to a particular digit Thumb - Metacarpal 1(I) Index finger - Metacarpal 2 (II) Middle finger - Metacarpal 3 (III) Ring finger - Metacarpal 4 (IV) Little finger - Metacarpal 5 (V) Metacarpal consists of Base Shaft (body) Head ANAT20080 23 Musculoskeletal 23 Metacarpals Base of the metacarpals articulate with Carpal bones (Carpometacarpal Joints) Articulate with each other (Intermetacarpal Joints) Heads of the metacarpals articulate with The proximal phalanges of the digits (Metacarpophalangeal Joints) The metacarpal heads form the knuckles on the dorsal surface of the hand when the fingers are flexed ANAT20080 24 Musculoskeletal 24  Metacarpals Boxers Fracture/Brawlers Fracture A fracture of a metacarpal bone after the patient strikes an object with a closed fist Classically the fracture occurs transversely across the neck of the metacarpal Often occurs in the 4th or 5th metacarpal bones of the ring finger or little finger. ANAT20080 25 Musculoskeletal 25 Carpometacarpal Joints Thumb Saddle joint between metacarpal 1 & Trapezium Allows mobility of thumb Carpometacarpal joints digits 2-5 Only limited gliding movements Plane type joints ANAT20080 26 Musculoskeletal 26  Phalanges The thumb has 2 phalanges Proximal phalanx Distal phalanx Other digits have 3 phalanges Proximal phalanx Middle phalanx Distal phalanx Each phalanx has a Base, Shaft (body) & Head distally Base of each proximal phalanx articulates with the head of the related metacarpal bone The head of each distal phalanx is non-articular Flattened into crescent-shaped palmar tuberosity at the end of the digit. ANAT20080 27 Musculoskeletal 27 Metacarpophalangeal (MCP) Joints Joints between the distal heads of the metacarpals & proximal phalanges of digits Condylar (ellipsoid, ovoid) synovial joints Movements flexion, extension, abduction, adduction, circumduction Joint capsule reinforced by palmar ligament & medial and lateral collateral ligaments Deep transverse metacarpal ligaments Connect the palmar ligaments together Restrict movement of bones relative to each other ANAT20080 28 Musculoskeletal 28  Interphalangeal (IP) Joints Uniaxial Hinge Joints Between base & head of phalanx bones Movements Mainly flexion & extension Reinforced by medial & lateral collateral ligaments and palmar ligaments Distal interphalangeal joints (DIP) Proximal interphalangeal Joints (PIP) ANAT20080 29 Musculoskeletal 29 YouTube Playlist https://www.youtube.com/playlist?list=PLROCMs7AwS_m- PrIL9fD7zjHBNPg12n3N ANAT20080 30 Musculoskeletal 30