Exam #6: Hand Flashcards
Review the osteology of the hand.
N/A
What is special about the phalanges of the thumb?
The thumb does NOT have a middle phalanx
What bones are in the proximal row of the hand on the palmar view?
Scaphoid
Lunate
Triquetrum
Pisiform
What bones are in the distal row of the hand?
Trapezium
Trapezoid
Capitate
Hamate
What is the mneomic for the bones of the hand?
Some Lovers Try Positions That They Can't Handle
What is the distal radioulnar joint?
Pivot joint between the radius & ulna that flips between pronation & supination
What is the radiocarpal joint?
This is the MAIN wrist joint
- Occurs between the radius & the scaphoid/ lunate
What bone takes place in the main wrist joint, which does NOT?
Ulna does NOT
Radius does
What are the cmc joints? What type of joints are these?
- Joints between the carpals & the metacarpals
- Plane joint
What are the mcp joints? What type of joints are these?
- Metacarpophalangeal
- Condyloid
What are the PIP joints?
Proximal interphalangeal joint
What are the DIP joints?
Distal interphalangeal joint
Review the radiographic anatomy of the hand.
N/A
What is the hamulus or the hook of the hamate (hamulus()?
This is an important attachment for muscles
What is a Colles Facture?
- This is the most common forearm fracture
- Occurs when you trip & fall, and fall on hand
- More common in older women
What is the characteristic of a Colles Fracture?
Distal fragment is displaced dorsally
- This is called a “dinner-fork” deformity
What is a Scaphoid Fracture?
This is a fracture of the scaphoid bone, which is the most commonly fracture bone & most difficult to diagnose radiographically
- Mechanism is same as Colles
Why is it important to diagnose a scaphoid fracture early?
Fracture disrupts blood flow to the bone–>AVN
Note that blood flows from distal to proximal & fracture can lead to
What finger cannot abduct or adduct?
Middle finger
What is it important to remember about the movement of the thumb?
Flexion and extension occur in the lateral plane
Adduction and abduction occur perpendicular to flexion & extension
What are the two main compartments of the thumb?
Hypothenar
Thenar
What are muscles of the thenar eminence innervated by? What is the exception?
Recurrent branch of the median n.
*****The deep head of the flexor pollicis brevis is innervated b the ulnar nerve.
What are the muscles of the hypothenar eminence innervated by?
Deep branch of the ulnar n.
What are the thenar muscles?
Flexor pollicis brevis
Abductor pollicis brevis
Opponens pollicis
What are the hypothenar muscles?
Opponens digiti minimi
Flexor digiti minimi
Abductor digiti minimi
What is an alternate name for the flexor digiti minimi?
Flexor digiti minimi brevis
What is the adductor pollicis?
This is the adductor of the thumb, innerated by the ulnar n.
*****This is NOT a thenar muscle
What are the lumbricals?
Intrinsic muscles of the hand
What is the origin of the lumbricals?
Tendon of the flexor digitorum profundus
What is the insertion of the lumbricals?
Extensor expansion
What is the function of the lumbricals?
Flex MCP joints
Extend PIP & DIP joints
**Remember the the lumbricals are your “bye-bye” muscles
What nerves innervate the lumbricals?
Lateral 2= median n.
Medial 2= ulnar n.
What are the interossei?
These are the intrinsic muscles of the hand between the fingers
What is the function of the dorsal interossei? How many are there?
4
DAB= Dorsal ABduct
What is the function of the palmar interossei?
3
PAD= Palmar ADduct
Describe the path of the ulnar artery.
- Travels with the nerve in the ulnar canal
- Gives off a deep branch
- Becomes superficial palmar arch in the hand
What are the branches of the ulnar artery in the hand?
1) Common palmar digital arteries branch off
2) Proper palmar digital arteries brach from the common
Describe the path of the radial artery.
Goes to the dorsum of the hand and dives between the two heads of the first dorsal interossei
What are the branches of the radial artery?
1) Princeips pollicis
2) Radial indicis
What are the anastasmoses of the hand?
Superficial arch= common palmar arteries
Deep arch= palmar metacarpal arteries
What is the difference between the deep and superficial branches of the ulnar nerve? Functionally?
Superficial= sensory innervation to the hand Deep= motor innervation to the hand
**Almost never get one or the other
What are the branches of the median nerve?
- Recurrent branch of the median
- Palmar digital= lumbricals
What does the recurrent branch innervate?
Thenar muscles
If there is damage to the recurrent branch are there any manifestations in the lumbricals? Why or why not?
No–palmar digital nerves innervate the lumbricals, NOT the recurrent median
What is the ulnar canal?
Narrow passage between the pisiform & hook of the hamate (hamulus) through which the ulnar nerve passes
What is handle bar neuropathy? What is an alternate name for this?
Ulnar canal syndrome
- Compression of the ulnar canal
- Numbness/tingling in digits #4 & 5
- Weakness in making a fist b/c intrinsic muscles of the hand are all effected
What is ulnar claw?
Lumbricals lost= no balance/ neutral position of the hand
- Ulnar nerve
- Complete distruption
**Also involves loss of flexor digitorum profundus (medial)
Describe the cutaneous innervation of the hand.
Ulnar
Radial
Median
What is the mnemonic for the muscles innervated by the median nerve?
LOAF
L=lateral two lumbricals
O= opponens pollicis
A= abductor pollicis brevis
F= flexor pollicis brevis
*****Adductor is NOT part of this group (ulnar)
What passes through the carpal tunnel?
Tendons
Median nerve
What is carpal tunnel syndrome?
Compression of the median nerve in the carpal tunnel
- Numbness 1-3
- Loss of motor function to thenar eminence
- Thenar wasting
