Hand Flashcards
What are the bones of the hand and wrist?
Proximal row: scaphoid, lunate, triquetrum, pisiform
Distal row: hamate, capitate, trapezoid, trapezium
What bone articulates with the wrist and hand bones?
The radius articulates with the scaphoid and lunate
Which bone in the hand is most commonly broken?
The scaphoid, because all the force is transferred there during a fall
What are the attachment sites for the carpal tunnel ligaments?
Hook of hamate, tubercle of the trapezium, scaphoid, and pisiform
What bone in the hand is most commonly dislocated?
The lunate
What are the metacarpals?
5 bones, one per finger, that all have a base that articulates with the carpal bones, they have a linear shaft and a rounded head
What are the phalanges?
They are bones that attach to the metacarpals, each with a base, a shaft, and a head. There are 2 phalanges in the thumb (proximal and distal) and 3 in every other digit (proximal, middle, and distal)
What are the cutaneous innervations of the palmar side of the hand?
The thumb, index, middle finger, and half of the ring finger are done by the median nerve. The rest of the ring finger and the pinky are done by the ulnar nerve
What are the cutaneous innervations of the dorsal side of the hand?
The pinky half of the hand is done by the ulnar nerve and the thumb half of the hand is done by the radial nerve
What is the palmar aponeurosis?
It is deep palmar fascia that has a strong, heavy, dense, well-defined triangular layer of deep fascia in the middle of the palm
What is Dupuytren’s Contracture?
It is a progressive fibrosus, which produces abnormal bands of tissue that extend from the aponeurosis to the bases of the phalanges. This pulls the digit(s) into flexion at the metacarpophalangeal joints so that they can’t be straightened.
What are synovial sheaths?
They are spaces filled with fluid to allow tendons to slide easily
What is found in the carpal tunnel?
The median nerve, the flexor pollicis longus (1 tendon), the flexor digitorum superficialis (4 tendons), and the flexor digitorum profundus (4 tendons)
What is the anterior boundary of the carpal tunnel?
The flexor retinaculum
What is carpal tunnel syndrome?
It is due to repetitive movements that impinge the median nerve. It decreases the size of the carpal tunnel, specifically wasting of the thenar muscles
What is the thenar compartment of the hand?
It consists of three muscles - the opponens pollicis, the abductor pollicis brevis, and the flexor pollicis brevis.
What is the reccurrent median nerve?
It innervates the opponens pollicis and is known as the million dollar nerve because if injured, will prevent someone from opposing their thumb.
In the thenar compartment of the hand, where are the OAF muscles?
Opponens pollicis runs across the longitudinal length of the thumb.
Abductor pollicis brevis is the most superficial muscle that covers the other two muscles.
Flexor pollicis brevis is the smallest of the three muscles and is the most medial.
What is the hypothenar compartment of the hand?
It consists of the opponens digiti minimi, the abductor digiti minimi, and the flexor digiti minimi
In the hypothenar compartment of the hand, where are the OAF muscles?
Abductor digiti minimi is the most prominent and superficial.
Flexor digiti minimi is lateral to the abductor and the most medial.
Opponens digiti minimi is deep to all the muscles.
What nerve innervates the thenar side?
Recurrent branch of the median nerve
What nerve innervates the hypothenar side?
Ulnar nerve
Where do the lumbricals originate from?
The flexor digitorum profundus tendons
What nerve innervates the lumbricals?
Lumbricals 1 and 2 are innervated by the median nerve. Lumbricals 3 and 4 are innervated by the ulnar nerve.
What are the dorsal interossei?
They are 4 bipennate muscles that abduct the fingers. It is found between the bones in the hand.
What nerve innervates the dorsal interossei?
The ulnar nerve
Where do the dorsal interossei originate from?
The metacarpals
What are the palmar interossei?
They are 3 unipennate muscles that adduct the fingers.
What is the arterial supply for the muscles of the hand?
The ulnar artery supplies superficial muscles and the radial artery supplies deep muscles. (USRD)
What does the superficial branch of the ulnar artery become?
The superficial palmar arch which anastamoses with the superficial branch of the radial artery
What are the branches of the radial artery in the hand?
The princeps pollicis (which supplies the medial side of the thumb) and the radialis indicis (which supplies the lateral side of the index finger).
What are the branches of the median nerve in the hand?
The recurrent (thenar) branch, common palmar digital nerves, and the proper palmar digital nerves
What are the branches of the ulnar nerve in the hand?
The palmar cutaneous branch, dorsal cutaneous branch, superficial branch, and distal branch
What are the branches of the radial nerve in the hand?
The superficial branch and the dorsal digital nerves.
What is claw hand?
It is also known as ulnar claw and it is due to ulnar nerve palsy usually at the wrist. It leads to weakness of the intrinsic muscles of the hand (such as the lumbricals). There will be hyperextension of the 4th and 5th metacarpophalangeal joints. There is also the loss of ability to spread fingers because the loss of the interossei.
What is ape hand?
This is due to median nerve palsy and it causes the wasting of thenar muscles, specifically the inability to oppose the thumb. This can occur with an injury of the median nerve either at the elbow or at the wrist.
What is Hand of Benediction?
This is due to median nerve palsy and results from prolonged compression or injury of the median nerve at the level of the elbow or upper arm. The deformity is visible when trying to making a fist. It is caused by the inability to flex the first 3.5 fingers.
What is wrist drop?
It is palsy of the radial nerve and causes loss of motor innervation to the wrist extensors in the forearm.
