Wrist and Forearm Anatomy and Positioning PDF 2024

RAD 101 References: Bontrager 10th Edition & Radiographic Positioning & Related Anatomy 11th Edition  Learning Objectives Identify the following parts and prominences on an image or skeleton: Radius Ulna Head...

RAD 101 References: Bontrager 10th Edition & Radiographic Positioning & Related Anatomy 11th Edition  Learning Objectives Identify the following parts and prominences on an image or skeleton: Radius Ulna Head Olecranon process Neck Coronoid process Radial tubercle (tuberosity Trochlear notch Shaft or body Radial notch Styloid process Shaft or body Ulnar notch Head Styloid process Coronoid tubercle  Learning Objectives Identify the following parts and prominences on an image or skeleton: Metacarpal bones: Carpal bones: Base or proximal end Lunate Body Scaphoid Head or distal end Triquetrum Pisiform Capitate Trapezoid Trapezium hamate Learning Objectives Identify the structures best shown on routine images for the upper extremity Which carpal bone is the most commonly fractured & what projection is taken to best demonstrate the fracture Routine and special projections for: Wrist Forearm Carpals (wrist) 8 carpals in each wrist Proximal row (4) Distal row (4)  Starting on the thumb side: 1. Scaphoid Proximal Row Boat shaped & is largest bone in the proximal row Articulates with the radius proximally Most frequently fractured carpal bone 2. Lunate Moon shaped Articulates with the radius 3. Triquetrum 4. Pisiform Pea shaped & smallest carpal bone Located anterior to the triquetrum Distal Row Starting on the thumb side: 1. Trapezium Located medial and distal to scaphoid Proximal to first metacarpal https://images.squarespace-cdn.com/content/v1/510dee82e4b0b75977432f4b/1537904586386-9ND7PQ12YYH5P71HBW8S/flying+trapez.jpg 2. Trapezoid Smallest bone in the distal row 3. Capitate – means “large bone” Largest of all the carpal bones 4. Hamate Distinguished by its hooklike process: Hamulus or hamular process Located on palmar surface (anterior side) https://www.wealthmanagement.com/sites/wealthmanagement.com/files/Mnemonics%20gall  Mnemonics for Carpal Bones 1st example 2nd example Send (Scaphoid) Steve (Scaphoid) Letter (Lunate) Left (Lunate) To (Triquetrum) The (Triquetrum) Peter (Pisiform) Party (Pisiform) To (Trapezium) To (Trapezium) Tell ‘ em (to) (Trapezoid) Take (Trapezoid) Come (Capitate) Carol (Capitate) Home (Hamate) Home (Hamate) Practice Naming the Carpals  Carpal Sulcus (Carpal canal or Tangential projection) Carpal sulcus (carpal tunnel or canal) Major nerves and tendons pass through Pisiform & hamulus process best visualized in this view Wrist Ligaments Ulnar collateral ligament -attached to the styloid process of ulna and fans out to attach to the triquetrum and the pisiform Radial collateral ligament -extends from the styloid process of the radius and connects primarily to the scaphoid, but also the trapezium Fat Stripes - Wrist Absence or displacement of fat stripe may be an indicator for fracture Scaphoid fat stripe Visualized on PA and oblique projections Elongated and slightly convex in shape Located between the radial collateral ligament and adjoining muscle tendons lateral to scaphoid Pronator fat stripe Visualized on lateral view Located ¼ of an inch anterior to the radius Fat Stripe Names:  Ulnar Deviation *Best demonstrates carpals on the opposite side of the wrist Scaphoid Trapezium Trapezoid Which carpal bone is most commonly fractured? Radial Deviation *Less frequently done than ulnar deviation *Best demonstrates Hamate Pisiform Triquetrum lunate Common Wrist Fractures Barton: Fracture and dislocation of the posterior lip of the distal radius involving the wrist joint Colles: Transverse fracture of the distal radius in which the distal fragment is displaced posteriorly Smith : Reverse of colles fracture, transverse fracture of the distal radius with the distal fragment displaced anteriorly Radiographic Positioning Position patient with arm and shoulder on the same plane Remove jewelry 40 SID Cast Conversion Chart Small to Medium plaster cast – increase 5-7 kVp Large plaster cast – increase 8-10 kVp Fiberglass cast – increase 3 – 4 kVp  Routine Projections PA PA Lateral Oblique  PA - Wrist Clinical Indications: Fractures of distal radius or ulna, isolated fractures of radial or ulnar styloid processes, and fractures of individual carpal bones 40 SID Align long axis of hand and wrist to IR Pronate hand Curl fingers to place wrist and carpal area in close contact with IR CR at midcarpal area  Alternative AP - Wrist Clinical Indications: Fractures of distal radius or ulna, isolated fractures of radial or ulnar styloid processes, and fractures of individual carpal bones 40 SID Align long axis of hand and wrist to IR Hand supinated, fingers curled to place wrist and carpals close to IR Best demonstrates intercarpal spaces and carpals (if patient can assume position easily) CR at midcarpal area Practice labeling anatomy A F B G C H D I E J  PA Oblique - Wrist Clinical Indications: Fractures of distal radius or ulna, isolated fractures of radial or ulnar styloid processes, and fractures of individual carpal bones. Pathologic processes, such as osteomyelitis and arthritis 40 SID Pronate hand then rotate hand/ wrist laterally 45˚ Can place sponge for support if necessary CR at midcarpal area Practice labeling E anatomy A F B G C H D I J Lateral - Wrist 40 SID Hand and wrist placed in true lateral position (karate chop) CR – Midcarpal area Evaluation Criteria: ulnar head should be superimposed over distal radius, proximal second through fifth metacarpals should be superimposed https://friendlystock.com/wp-content/uploads/2020/03/1-man-karate-chopping-stack-of-wood-cartoon-clipart.jpg Clinical Indications: Fractures or dislocations of the distal radius or ulna, specifically anteroposterior fragment displacements for Barton, Colles, or Smith fractures. Osteoarthritis also may be demonstrated primarily in the trapezium and first CMC joint Tips/Tricks  A B Practice labeling C anatomy D A E B F C D E F Special Projections Scaphoid projections CR angle with ulnar deviation Modified Stecher Method Radial Deviation Gaynor Hart  PA and PA Axial Scaphoid – With Ulnar Deviation- Wrist *If patient has possible wrist trauma routine series should be completed and evaluated to rule out fracture before proceeding Clinical Indication: Possible scaphoid fracture 40 SID Position for a PA wrist Without moving forearm gently evert hand toward ulnar side as far as patient can tolerate without lifting or rotating distal forearm PA – CR @ scaphoid (3/4 in distal and medial to radial styloid process) PA Axial – CR angled 10-15˚ proximally (toward elbow), directed at scaphoid NOTE: obscure scaphoid fractures may require a four-projection series with the CR angled proximally 0˚, 10˚, 20˚, and 30˚ Evaluation Criteria – PA Axial Scaphoid Scaphoid clearly seen without superimposition Scaphoid not foreshortened 15˚ CR angle Practice labeling A anatomy Ulnar deviation B C D E F PA Scaphoid – Hand elevated and ulnar deviation (Modified Stecher Method) Clinical Indication: Possible scaphoid fracture 40 SID Place hand and wrist palm down on IR with hand elevated on 20˚ sponge Ensure wrist is in direct contact with IR Gently evert or turn hand outward (toward ulnar side) (unless patient has a severe injury) CR perpendicular to IR and directed to Scaphoid PA Projection - Radial Deviation - Wrist Clinical Indications: possible fractures of the carpals on ulnar side (lunate, triquetrum, pisiform, and hamate) 40 SID Position for PA wrist Gently invert hand toward thumb side CR perpendicular to IR, directed to midcarpal area Practice labeling anatomy Radial deviation A. B C.. D. E. F. G.  Carpal Canal (tunnel) Tangential, Inferosuperior Projection (Gaynor Hart Method) Clinical Indications: rule out abnormal calcification & bony changes in the carpal sulcus that may impinge on the median nerve, as with carpal tunnel syndrome. Possible fractures of the hamulus process of the hamate, pisiform, and trapezium 40 SID Ask patient to hyperextend wrist (dorsiflex) as far as possible (Use tape or band to pull on) Try to get fingers near vertical (90 degrees to forearm) without lifting wrist Internally rotate the hand & wrist 10 degrees CR angled 25-30˚ proximally, directed to 1in distal to base of third metacarpal (center of palm) *Sonography may be used for carpal tunnel  Evaluation Criteria – Gaynor Hart Carpals are demonstrated in a tunnel-like, arched arrangement Pisiform and hamulus process should be separated and visible Forearm Distal Forearm Anatomy Styloid process: Located on both distal ends of the radius and ulna Ulnar notch: Small depression on the medial aspect of the distal radius Head of ulna: Located on the distal end of ulna fits in ulnar notch to form the distal radioulnar joint Mid Forearm Anatomy Radius Body (Shaft) Ulna Body (Shaft)  Proximal Forearm Anatomy Radius Head Near elbow joint Neck Tapered area directly below head Radial tuberosity Rough oval process on the medial and anterior side of the radius, just distal to the neck Proximal Forearm Anatomy Ulna Olecranon process Palpated on the posterior aspect of elbow joint Coronoid tubercle Is the medial process located on the coronoid process opposite of the radial notch Trochlear notch (semilunar notch) Large concave depression that articulates with the distal humerus  Proximal Forearm Anatomy Ulna (continued…) Radial Notch Small shallow depression located on lateral aspect of proximal ulna Head of radius articulates with the ulna proximal radioulnar joint Lateral View  Forearm Rotational Movements Forearm is routinely positioned AP with the hand supinated WHY? Routine Projections - Forearm  AP Projection - Forearm Clinical Indications: Fractures and dislocations of the radius or ulna Pathologic processes such as osteomyelitis or arthritis Palm up Arm fully extended on same plane as shoulder Palpate medial and lateral epicondyles to ensure they are the same distance from IR CR – Mid- Forearm Evaluation Criteria Carpals to distal humerus included Humeral epicondyles are in profile Slight superimposition of distal radioulnar joint Exposure factors Identify Anatomy  Lateral - Forearm Clinical Indications: Fractures and dislocations of the radius or ulna Pathological processes, such as osteomyelitis or arthritis 40 SID Drop shoulder so entire upper limb is on the same plane Ensure both wrist and elbow joints are included Bend elbow 90 degrees Rotate hand/wrist into true lateral position CR – Mid-forearm Evaluation Criteria Carpals and distal humerus included Elbow flexed 90° Head of ulna superimposed over radius Exposure factors Practice labeling Anatomy