Hand And Wrist (Bones And Ligaments) Flashcards
What are the 3 types of bones found in the hand/wrist?
Carpals
Metacarpals
Phalanges
How many carpal bones are there?
8
How are the 8 carpal bones arranged?
2 rows of 4
Proximal row + Distal row
What is the mneumonic for remembering the proximal row of carpal bones?
Straight Line To Pinky
How does the mnuemonic for the proximal row of the carpal bones help remember the bones?
Straight Line To Pinky
Gives the direction (Goes from Radial to the Ulnar pinky finger side)
Using the mnuemonic, what is the proximal row of carpal bones from Radial to Ulnar?
Straight Line To Pinky
Scaphoid
Lunate
Triquetral/Triquetrum
Pisiform
What is special about where the pisiform bone sits?
Pisiform sits on top of the Triquetral/triquetrum bone
What is the mneumonic for remembering the distal row of carpal bones?
Here Comes The Thumb
How does the mnuemonic for the distal row of the carpal bones help remember the bones?
Here Comes The Thumb
Gives the direction (goes from Ulnar to the Thumb/Radial side)
Using the mnuemonic, what is the distal row of carpal bones from Ulnar to Radial?
Here Comes The Thumb
Hamate
Capatate
Trapezoid
Trapezium
There are 3 carpal bones beginning with T in the hand.
How can you remember what row the Triquetral/Triquetrum bone is in?
TriquetrAL = ProximAL
There are 3 carpal bones beginning with T in the hand.
How can you remember where the Trapezium and the Trapezoid bone is?
TrapeziUM = under the thUMb
Trapezoid is the other T bone
What are the 4 main types of joint in the wrist and hand?
Radiocarpal joint = Wrist joint
Carpometacarpal joints
Metacarpalphalangeal joints
Interphalangeal joints (Proximal, Distal or if thumb only has an interphalangeal joint)
What makes up the floor of the carpal tunnel?
The concave U shaped carpal bones
What makes up the roof of the carpal tunnel?
Flexor retinaculum
What is Flexor retinaculum?
Thick connective tissue which makes up the roof of the carpal tunnel
What are the 2 attachments of the flexor retinaculum on the medial/ulnar carpal bones?
Hamate
Pisiform
What are the 2 attachments of the flexor retinaculum on the lateral/radial carpal bones?
Scaphoid
Trapezium
What are the contents of the carpal tunnel?
9 long flexor tendons
Median nerve
They run into the hand
What are the 9 long flexor tendons which run through the Carpal Tunnel into the hand?
Flexor digitorum superficialis (4 tendons)
Flexor digitorum profundus (4 tendons)
Flexor pollicis longus (1 tendon)
Where is the Carpal tunnel?
Proximal region of hand
What is Carpal Tunnel Syndrome?
Compression of the Median nerve in the carpal tunnel
What nerve branches off of the median nerve just before it enters into the carpal tunnel?
Palmar cutaneous nerve
What does the branch of the median nerve called the Palmar cutaneous nerve innervate?
Sensation to the lateral aspect of palm
When the median nerve is in the carpal tunnel what 2 branches does it terminate into?
Recurrent branch
Palmar digital branch
What does the recurrent branch from the median nerve innervate?
Thenar muscles
What does the palmar digital branch from the median nerve innervate?
Palmar surface and finger tips of lateral 3.5 digits
Lateral 2 lumbricals
What would a patient likely present with in Carpal Tunnel Syndrome?
Numbness, tingling and pain in distribution of the Median nerve
(Numbness and tingling usually in the lateral 3.5 digits, palm is usually ok)
Pain often radiates to the forearm
Why does the lateral palm not usually have tingling/numbness in carpal tunnel syndrome?
Lateral surface of palm supplied via Palmar Cutaneous nerve
This nerve branches from the median nerve before it enters the carpal tunnel and doesn’t pass through the carpal tunnel so doesn’t get compressed
Why can Thenar muscle wasting occur with Carpal Tunnel Syndrome?
Median nerve is compressed
Recurrent branch is no longer supplying the Thenar muscles
This leads to muscle atrophy/wasting via Denervation
What is the treatment of carpal tunnel syndrome?
Splint hand in dorsiflexed position at night to relieve pressure on median nerve while asleep
Corticosteroid injections into CT if above unsuccessful
Surgical decompression if above unsuccessful
When doing a physical examination for Carpal Tunnel Syndrome what is Tinel’s Sign?
Tap the median nerve in the carpal tunnel which elicits pain in the median nerve distribution
When doing a physical examination for Carpal Tunnel Syndrome what is Phalen’s manoeuvre?
Hold wrist in Flexion for 60s to elicit pain/numbness in median nerve distribution
What are the contents of Guyons canal?
Ulnar neurovascular bundle which travels to the hand:
-Ulnar nerve
-Ulnar artery
-Venae comitantes of ulnar artery
-Lymphatic vessels
What bones form the borders of the Guyons canal?
Hook of hamate and pisiform
What is the Laymanns term for the radiocarpal joint?
The Wrist
What type of joint is the radiocarpal joint?
Condyloid type synovial joint
What bones articulate in the radiocarpal joint?
3 proximal carpal bones and radius
Radius with the:
-Scaphoid
-Lunate
-Triquetral/triquetrum
Pisiform is not involved
What 2 planes of movement can the radiocarpal joint do?
Flexion + Extension
ABduction + ADuction
What movement can the radiocarpal joint do since it can do 2 planes of motion?
Circumduction
What is ABduction of the wrist also called?
Radial deviation
What is ADduction of the wrist also called?
Ulnar deviation
Where does the fibrous capsule surrounding the radiocarpal joint attach?
Distal end of radius + ulnar
Scaphoid
Lunate
Triquetral/triquetrum
What are the 4 ligaments of the radiocarpal joint?
Anterior = Palmar radiocarpal ligament
Posterior = Dorsal radiocarpal ligament
Ulnar side = Ulnar collateral ligament
Radial side = Radial collateral ligament
Where does the palmar radiocarpal ligament (anterior) attach to?
Both forearm bones and all 8 carpals
Where does the dorsal radiocarpal ligament (posterior) attach to?
Both forearm bones and all 8 carpals
Where does the ulnar collateral ligament (ulnar side) attach to?
Styloid process of ulna to Triquetral bone
Where does the radial collateral ligament (radial side) attach to?
Styloid process of radius to scaphoid
What is the function of the Palmar radiocarpal ligament?
Takes hand with it in supination
What is the function of the Dorsal radiocarpal ligament?
Takes hand with it in pronation
What articulates in the Proximal radioulnar joint?
Rounded head of radius with the radial notch of the ulnar
What holds the radial head in the radial notch of the ulnar at the Proximal radioulnar joint?
Annular ligament
What type of joint is the proximal radioulnar joint and the distal radioulnar joint?
Pivot type synovial joint
What bones articulate at the distal radioulnar joint?
Rounded head of ulnar articulates with ulnar notch on radius
Where is the fibrous capsule weak surrounding the distal radioulnar joint and why?
Weak superiorly
Allows radius to move around ulnar
Where is the triangular ligament?
From the medial edge of the ulnar notch to the lateral edge of the Styloid process of the ulnar at the distal radioulnar joint
What is the triangular ligament and what does it do?
A fibrocartilaginous articular disc that binds the radius and ulnar together at the distal radioulnar joint
What movement does the articulation between the capitulum and the radial head help?
Pronation + supination
What row of carpal bones do the radial collateral and ulnar collateral ligaments attach to?
Proximal row