Wrist Anatomy
WRIST JOINT
Definition
· Synovial joint
· Made of:
o Radius
o Articular disc
o Proximal row of carpal bones
· The ulna is not included (does not articulate with the carpal bones because of the
articular disc – a fibrocartilaginous ligament – lies over the superior surface of the
ulna)
· Carpal bones form a convex surface
· Has a joint capsule
o Outer Layer: Attaches to the radius, ulna, and proximal row of the
carpal bones
o Inner Layer: Synovial membrane that secretes fluid
· Has 4 ligaments
o Palmar radiocarpal
o Dorsal radiocarpal
o Ulnar collateral
o Radial collateral
· Wrist innvervation is from:
o Median nerve
o Radial nerve
o Ulnar nerve
Articulation
· Distal articulations
o Proximal row of the carpal bones (except pisiform)
· Proximal articulations
o Distal end of the radius
o Articular disc
· Articulates with the concave surface of the radius and articular disc
Movements
· Flexion
· Extension
· Adduction
· Abduction
Function
· Allows movement of the hand
· Transition between forearm and hand 1
Definition
· Synovial joint
· Made of:
o Radius
o Articular disc
o Proximal row of carpal bones
· The ulna is not included (does not articulate with the carpal bones because of the
articular disc – a fibrocartilaginous ligament – lies over the superior surface of the
ulna)
· Carpal bones form a convex surface
· Has a joint capsule
o Outer Layer: Attaches to the radius, ulna, and proximal row of the
carpal bones
o Inner Layer: Synovial membrane that secretes fluid
· Has 4 ligaments
o Palmar radiocarpal
o Dorsal radiocarpal
o Ulnar collateral
o Radial collateral
· Wrist innvervation is from:
o Median nerve
o Radial nerve
o Ulnar nerve
Articulation
· Distal articulations
o Proximal row of the carpal bones (except pisiform)
· Proximal articulations
o Distal end of the radius
o Articular disc
· Articulates with the concave surface of the radius and articular disc
Movements
· Flexion
· Extension
· Adduction
· Abduction
Function
· Allows movement of the hand
· Transition between forearm and hand 1
Anatomy of the Radius:
STYLOID PROCESS OF THE RADIUS
Definition
· Pyramidal process on the distal lateral end of the radius
Articulations
· Tip attaches to lateral carpal ligament
· Lateral surface attaches to the brachioradialus muscle
Function
· Attachment site for a tendon and ligament 2
Definition
· Pyramidal process on the distal lateral end of the radius
Articulations
· Tip attaches to lateral carpal ligament
· Lateral surface attaches to the brachioradialus muscle
Function
· Attachment site for a tendon and ligament 2
LISTER'S TUBERCLE
Definition
· Located on the posterior of the wrist
· Ulnar side contains the extensor pollicis longus, defining the ulnar boarder of the anatomical snuff box
Function
· Is a pulley for the extensor pollicis longus 3
Definition
· Located on the posterior of the wrist
· Ulnar side contains the extensor pollicis longus, defining the ulnar boarder of the anatomical snuff box
Function
· Is a pulley for the extensor pollicis longus 3
Anatomy of the Ulna:
STYLOID PROCESS OF THE ULNA
Definition
· Posteriomedial projection on the distal end of the ulna
· A non-articular surface 4
Function
· Tip is an attachment site for the ulnar collateral ligament of the wrist 5
(See image under "Styloid Process of the Radius")
Definition
· Posteriomedial projection on the distal end of the ulna
· A non-articular surface 4
Function
· Tip is an attachment site for the ulnar collateral ligament of the wrist 5
(See image under "Styloid Process of the Radius")
TRIANGULAR FIBROCARTILAGE COMPLEX (TFCC)
Definition
· Located on the ulnar side of the wrist
· Formed by the triangular fibrocartilage discus, the radioulnar ligaments, and
the ulnocarpal ligaments
· Consists of:
o Triangular fibrocartilage
o Meniscal homologue
o Ulnar collateral ligament
o Ulnar capsule
o Dorsal distal radioulnar ligament
o Volar distal radioulnar ligament
o Subsheath of the extensor carpi ulnaris
o Prestyloid recess 6
· Ligamentous stabilizer of the distal radioulnar joint and the ulnar carpus
Origin
· Ulnar boarder of the lunate faucet of the radius
Function
· Makes a gliding surface across the distal face of the forearm bones for flexion and extension
· Makes a flexible mechanism for stable rotations of the radiocarpal around the ulnar axis
· Suspends the ulnar carpus from the posterior ulnar face of the radius 7
Definition
· Located on the ulnar side of the wrist
· Formed by the triangular fibrocartilage discus, the radioulnar ligaments, and
the ulnocarpal ligaments
· Consists of:
o Triangular fibrocartilage
o Meniscal homologue
o Ulnar collateral ligament
o Ulnar capsule
o Dorsal distal radioulnar ligament
o Volar distal radioulnar ligament
o Subsheath of the extensor carpi ulnaris
o Prestyloid recess 6
· Ligamentous stabilizer of the distal radioulnar joint and the ulnar carpus
Origin
· Ulnar boarder of the lunate faucet of the radius
Function
· Makes a gliding surface across the distal face of the forearm bones for flexion and extension
· Makes a flexible mechanism for stable rotations of the radiocarpal around the ulnar axis
· Suspends the ulnar carpus from the posterior ulnar face of the radius 7
Anatomy of the Wrist:
CARPAL BONES
Definition
· 8 bones that make up the wrist:
· Scaphoid
· Lunate
· Triquetrum
· Pisiform
· Hamate
· Capitate
· Trapezoid
· Trapezium
Pneumonic: So Long Top Part, Here Comes The Thumb
Movement
· Gliding action between the carpal bones
Function
· Allows for intricate movements of wrist and hand 8
Definition
· 8 bones that make up the wrist:
· Scaphoid
· Lunate
· Triquetrum
· Pisiform
· Hamate
· Capitate
· Trapezoid
· Trapezium
Pneumonic: So Long Top Part, Here Comes The Thumb
Movement
· Gliding action between the carpal bones
Function
· Allows for intricate movements of wrist and hand 8
CARPAL TUNNEL
Definition
· Passageway from the wrist to the hand
· Located on anterior side of wrist
· Made of tendons, ligaments, and bones
· Median nerve passes through the tunnel 9
Articulations
· The tunnel is boardered by bones
Function
· Tunnel for the transverse carpal ligament 10
Definition
· Passageway from the wrist to the hand
· Located on anterior side of wrist
· Made of tendons, ligaments, and bones
· Median nerve passes through the tunnel 9
Articulations
· The tunnel is boardered by bones
Function
· Tunnel for the transverse carpal ligament 10
FLEXOR RETINACULUM
Definition
· Fibrous band that crosses the carpal bones
· Forms the roof of the fibro-osseous carpal tunnel
Attachments
· Attached to the hamulus of the hamate and the pisiform bone (on the ulnar side of the wrist)
· Tubercle of the scaphoid
· Medial part of the ridge of the trapezium
Function
· Forms the retinacular band for the digital flexor tendons
· Attachment site for palmaris longus and flexor carpi ulnaris 11
Definition
· Fibrous band that crosses the carpal bones
· Forms the roof of the fibro-osseous carpal tunnel
Attachments
· Attached to the hamulus of the hamate and the pisiform bone (on the ulnar side of the wrist)
· Tubercle of the scaphoid
· Medial part of the ridge of the trapezium
Function
· Forms the retinacular band for the digital flexor tendons
· Attachment site for palmaris longus and flexor carpi ulnaris 11
METACARPALS
Definition
· 5 bones that are attached to the carpal bones
· Give structure to the palm of the hand
· Are the connection between the carpal bones of the wrist and the phalanges of the
fingers and thumb
Articulations
· Each metacarpal has a base that articulates with the carpal bones
· Head of the metacarpals articulates with the phalanges (forming knuckles)
· 1st
o Trapezium carpal bone proximally
· 2nd
o Trapezoid carpal bone proximally
· 3rd
o Capitate carpal bone proximally
· 4th and 5th
o Hamate carpal bone proximally
Movement
· Limited range of movement
· Tightly fixed in place to the carpal bones
· Gliding between metacarpal and carpal bones
Function
· Give structure to the palm of the hand 12
Definition
· 5 bones that are attached to the carpal bones
· Give structure to the palm of the hand
· Are the connection between the carpal bones of the wrist and the phalanges of the
fingers and thumb
Articulations
· Each metacarpal has a base that articulates with the carpal bones
· Head of the metacarpals articulates with the phalanges (forming knuckles)
· 1st
o Trapezium carpal bone proximally
· 2nd
o Trapezoid carpal bone proximally
· 3rd
o Capitate carpal bone proximally
· 4th and 5th
o Hamate carpal bone proximally
Movement
· Limited range of movement
· Tightly fixed in place to the carpal bones
· Gliding between metacarpal and carpal bones
Function
· Give structure to the palm of the hand 12
PHALANGES
Definition
· Finger and thumb bones
· Each finger has 3 phalanges:
o Proximal
o Middle
o Distal
· Thumb has 2:
o Proximal
o Distal
· Bone has a base on its proximal end, a shaft in the middle, and a head on the
distal end 13
Articulation
· Phalange articulations form hinge joints
· Proximal bases articulate with the metacarpal bones
· Individual phalanges articulate with their proximal/mid/distal portions
Movement
· Flexion and extension
Function
· Allow bending of the fingers at the hinge joints
· Give structure to the fingers 14
Definition
· Finger and thumb bones
· Each finger has 3 phalanges:
o Proximal
o Middle
o Distal
· Thumb has 2:
o Proximal
o Distal
· Bone has a base on its proximal end, a shaft in the middle, and a head on the
distal end 13
Articulation
· Phalange articulations form hinge joints
· Proximal bases articulate with the metacarpal bones
· Individual phalanges articulate with their proximal/mid/distal portions
Movement
· Flexion and extension
Function
· Allow bending of the fingers at the hinge joints
· Give structure to the fingers 14
EXTENSOR TENDONS
Definition
· Located on the back of the hand and fingers
Function
· Allow straightening of the fingers and thumb
· Allow delicate finger motions and coordination 15
Definition
· Located on the back of the hand and fingers
Function
· Allow straightening of the fingers and thumb
· Allow delicate finger motions and coordination 15
FLEXOR TENDONS
Definition
· Flexor tendon system of the hand consists of:
o Flexor muscles and tendons of the forearm
o Digital flexor sheaths
Function
· Flexes the fingers 16
Definition
· Flexor tendon system of the hand consists of:
o Flexor muscles and tendons of the forearm
o Digital flexor sheaths
Function
· Flexes the fingers 16
MEDIAN NERVE
Definition
· One of the three major nerve of the forearm and hand
· Runs from the axilla to the hand
· Compression of this nerve causes carpal tunnel syndrome
· Normal measurement is 4-9 mm squared
o Over 10 mm squared is considered abnormal 17
Origin
· Brachial plexus in axilla
Insertion
· Phalanges
Movement
· Movement of hand and forearm muscles
Function
· Innervates the intrinsic muscles of the hand 18
Definition
· One of the three major nerve of the forearm and hand
· Runs from the axilla to the hand
· Compression of this nerve causes carpal tunnel syndrome
· Normal measurement is 4-9 mm squared
o Over 10 mm squared is considered abnormal 17
Origin
· Brachial plexus in axilla
Insertion
· Phalanges
Movement
· Movement of hand and forearm muscles
Function
· Innervates the intrinsic muscles of the hand 18
ULNAR NERVE
Definition
· Nerve of the arm
· Innervates arm, wrist, and hand
· Continuation of the medial cord
· Descends down the medial side of the arm
· Passes posterior to the medial epicondyle
· Passes down the forearm alongside the ulna
· At the wrist it travels superficially to the flexor retinaculum
Movement
· Gives rise to branches that flex the hand at the wrist and the fingers
· Innervates most of the muscles that control intricate hand movements
Function
· Innervates muscles of the forearm, wrist, and hand 19
Definition
· Nerve of the arm
· Innervates arm, wrist, and hand
· Continuation of the medial cord
· Descends down the medial side of the arm
· Passes posterior to the medial epicondyle
· Passes down the forearm alongside the ulna
· At the wrist it travels superficially to the flexor retinaculum
Movement
· Gives rise to branches that flex the hand at the wrist and the fingers
· Innervates most of the muscles that control intricate hand movements
Function
· Innervates muscles of the forearm, wrist, and hand 19
GUYON TUNNEL
Definition
· 4 cm long depression between pisiform and hook of hamate
· Starts at proximal end of transverse carpal ligament
· Ends at the aponeurotic arch of the hypothenar muscles
· Contains the ulnar nerve
Function
· Houses the ulnar nerve 20
Definition
· 4 cm long depression between pisiform and hook of hamate
· Starts at proximal end of transverse carpal ligament
· Ends at the aponeurotic arch of the hypothenar muscles
· Contains the ulnar nerve
Function
· Houses the ulnar nerve 20
References
1. Oliver, J. (2013). The Wrist Joint. Teach Me Anatomy. Retreived from http://teachmeanatomy.info/upper-limb/joints/wrist-joint/
2. Styloid Process of the Radius. (n.a.)(n.d.). Anatomy Expert. Retrieved from http://www.anatomyexpert.com/structure_detail/1284/
3. Wheeless, C. (2012). Lister’s Tubercle. Wheeless’ Textbook of Orthopaedics
4. Styloid Process of the Ulna. (n.a.)(n.d.). Anatomy Expert. Retrieved from http://www.anatomyexpert.com/structure_detail/1273/999/
5. Styloid Process of the Ulna. (n.a.)(n.d.). MediLexicon. Retrieved from http://www.medilexicon.com/medicaldictionary.php?t=72350
6. Lippincott, Williams, & Wilkins. (2004). Triangular Fibrocartilage Complex Injuries and Ulnar Impaction Syndrome. Hand Surgery: 1st Edition. Retrieved from http://www.msdlatinamerica.com/ebooks/HandSurgery/sid309978.html
7. Verheyden, J. (2012). Triangular Fibrocartilage Complex Injuries. Medscape. Retrieved from http://emedicine.medscape.com/article/1240789-overview
8. Seeley, R., VanPutte, C., Regan, J., Russo, A. (2011). Seeleys anatomy and physiology: Ninth edition. New York, NY: McGraw Hill.
9. Carpal Tunnel Syndrome. (n.a.)(n.d.). Mayo Clinic. Retrieved from http://www.mayoclinic.com/health/medical/IM02622
10. Wheeless, C. (2013). Anatomy of Carpal Tunnel. Wheeless’ Textbook of Orthopaedics. Retrieved from http://www.wheelessonline.com/ortho/anatomy_of_carpal_tunnel
11. Flexor Retinaculum of Wrist. (n.a.)(n.d.). Anatomy Expert. Retrieved from http://www.anatomyexpert.com/structure_detail/15535/620/
12. Anatomy Basics: Metacarpals and the thumb. (n.a.)(n.d.). Paint Draw Paint. Retrieved from http://www.paintdrawpaint.com/2012/01/anatomy-basics-metacarpals-and-thumb.html
13. (Terfera, D. (n.d.). Bones of the Wrist and Hand. For Dummies. Retrieved from http://www.dummies.com/how-to/content/bones-of-the-wrist-and-hand.html
14. Browns, R. (n.d.). Anatomy Basics: The finger bones. Paint Draw Paint. Retrieved from http://www.paintdrawpaint.com/2012/02/anatomy-basics-finger-bones.html
15. ASSH Public Education Committee. (2010). Extensor Tendon Injuries. American Society for Surgery of the Hand. Retrieved from http://www.assh.org/Public/HandConditions/Pages/ExtensorTendonInjuries.aspx
16. Bates, S. (2013). Flexor Tendon System. Medscape. Retrieved from http://emedicine.medscape.com/article/1245236-overview
17. Ultrasound Measurements. (n.a.)(2012). Carpal Tunnel.net. Retrieved from http://carpal-tunnel.net/ultrasound/measure
18. Amirlak, B. (2012). Median Nerve Entrapment. MedScape. Retrieved from http://emedicine.medscape.com/article/1242387-overview
19. James, O. (2013). The Ulnar Nerve. Teach Me Anatomy. Retrieved from http://teachmeanatomy.info/upper-limb/nerves/the-ulnar-nerve/
20. Wheeless, C. (2012). Tunnel of Guyon. Wheeless’ Textbook of Orthopaedics. Retrieved from http://www.wheelessonline.com/ortho/tunnel_of_guyon
1. Oliver, J. (2013). The Wrist Joint. Teach Me Anatomy. Retreived from http://teachmeanatomy.info/upper-limb/joints/wrist-joint/
2. Styloid Process of the Radius. (n.a.)(n.d.). Anatomy Expert. Retrieved from http://www.anatomyexpert.com/structure_detail/1284/
3. Wheeless, C. (2012). Lister’s Tubercle. Wheeless’ Textbook of Orthopaedics
4. Styloid Process of the Ulna. (n.a.)(n.d.). Anatomy Expert. Retrieved from http://www.anatomyexpert.com/structure_detail/1273/999/
5. Styloid Process of the Ulna. (n.a.)(n.d.). MediLexicon. Retrieved from http://www.medilexicon.com/medicaldictionary.php?t=72350
6. Lippincott, Williams, & Wilkins. (2004). Triangular Fibrocartilage Complex Injuries and Ulnar Impaction Syndrome. Hand Surgery: 1st Edition. Retrieved from http://www.msdlatinamerica.com/ebooks/HandSurgery/sid309978.html
7. Verheyden, J. (2012). Triangular Fibrocartilage Complex Injuries. Medscape. Retrieved from http://emedicine.medscape.com/article/1240789-overview
8. Seeley, R., VanPutte, C., Regan, J., Russo, A. (2011). Seeleys anatomy and physiology: Ninth edition. New York, NY: McGraw Hill.
9. Carpal Tunnel Syndrome. (n.a.)(n.d.). Mayo Clinic. Retrieved from http://www.mayoclinic.com/health/medical/IM02622
10. Wheeless, C. (2013). Anatomy of Carpal Tunnel. Wheeless’ Textbook of Orthopaedics. Retrieved from http://www.wheelessonline.com/ortho/anatomy_of_carpal_tunnel
11. Flexor Retinaculum of Wrist. (n.a.)(n.d.). Anatomy Expert. Retrieved from http://www.anatomyexpert.com/structure_detail/15535/620/
12. Anatomy Basics: Metacarpals and the thumb. (n.a.)(n.d.). Paint Draw Paint. Retrieved from http://www.paintdrawpaint.com/2012/01/anatomy-basics-metacarpals-and-thumb.html
13. (Terfera, D. (n.d.). Bones of the Wrist and Hand. For Dummies. Retrieved from http://www.dummies.com/how-to/content/bones-of-the-wrist-and-hand.html
14. Browns, R. (n.d.). Anatomy Basics: The finger bones. Paint Draw Paint. Retrieved from http://www.paintdrawpaint.com/2012/02/anatomy-basics-finger-bones.html
15. ASSH Public Education Committee. (2010). Extensor Tendon Injuries. American Society for Surgery of the Hand. Retrieved from http://www.assh.org/Public/HandConditions/Pages/ExtensorTendonInjuries.aspx
16. Bates, S. (2013). Flexor Tendon System. Medscape. Retrieved from http://emedicine.medscape.com/article/1245236-overview
17. Ultrasound Measurements. (n.a.)(2012). Carpal Tunnel.net. Retrieved from http://carpal-tunnel.net/ultrasound/measure
18. Amirlak, B. (2012). Median Nerve Entrapment. MedScape. Retrieved from http://emedicine.medscape.com/article/1242387-overview
19. James, O. (2013). The Ulnar Nerve. Teach Me Anatomy. Retrieved from http://teachmeanatomy.info/upper-limb/nerves/the-ulnar-nerve/
20. Wheeless, C. (2012). Tunnel of Guyon. Wheeless’ Textbook of Orthopaedics. Retrieved from http://www.wheelessonline.com/ortho/tunnel_of_guyon