Hand and wrist Flashcards
What are the carpal bones?
scaphoid
lunate
triquetrum
pisiform
hamate
capitate
trapezoid
trapezium
How many metacarpals are there?
5
How many phalanges are there?
14
The wrist joint is a ______?
radiocarpal synovial joint
What is the radiocarpal synovial joint between?
between the radius and an articular disc covering the distal ulna, and the proximal articular surfaces of the scaphoid, lunate, and triquetrum?
What does the radiocarpal synovial joint permit?
a wide range of movements
What are the movements that the radiocarpal synovial joint allows for?
flexion
extension
abduction
adduction
circumduction
The carpal bones themselves (intercarpal and midcarpal) provide for what?
gliding movements and significant wrist extension and flexion
What do the carpometacarpal (CMC) joints allow?
some gliding
Why is the 1st CMC joint unique?
it is the thumb joint- allows for flexion, extension, abduction, adduction, and circumduction
What is the first CMC joint a common site for?
arthritis
What do the metacarpophalangeal (MCP) joints allow for?
flexion, extension, abduction, adduction, and circumduction at the metacarpals
What do the proximal interphalangeal (PIP) and distal interphalangeal (DIP) joints do?
complete the joints of the hand- allows flexion and extension
How many PIP and DIP joints are on the hand?
5 PIP joints
4 DIP joints
The palmar fascia is a continuation of the forearm fascia that will thicken centrally to form what?
the palmar aponeurosis
What attaches distally to the palmar aponeurosis?
palmaris longus muscle
What is the proximal attachment of the palmaris longus muscle?
flexor common tendon at the medial epicondyle
What structures are associated with the flexor common tendon?
- pronator teres
- flexor carpi radialis
- palmaris longus
- flexor carpi ulnaris
Where can you find the fibrous digital sheath?
palmar aspect of each digit
What does the palmar aponeurosis protect against?
infection and invaders
The palmar fascia is a continuation of what?
antebrachial/forearm fascia
What are the characteristics of the palmar aponeurosis?
-part of the deep fascia
-thick and strong, continuous with forearm and dorsal surface
-contains palmar branch of the median n
Where is the fibrous digital sheath located?
on the palmar aspect of each digit
What occurs in Dupuytren’s contracture?
the medial longitudinal aponeurotic digital bands shorten, thicken and become fibrotic, causing the degeneration of the medial longitudinal digital bands of the aponeurosis on the medial side of the 4th and 5th digits
What increases your risk of developing Dupuytren’s contracture?
if you are:
-male
-between 40 and 60 years old
-northern european descent
-have a family history of the condition
-smoke or drink alcohol
-have diabetes
The thenar muscles are innervated by what nerve except for what muscle(s)?
recurrent branch of the median nerve
flexor pollicis brevis deep head and adductor pollicis
What is the flexor pollicis brevis deep head and adductor pollicis muscle innervated by?
deep branch of the ulnar nerve
What are the 2 clinically relevant fascial potential spaces on the palmar aspect of the hand?
- deep to the thenar muscle compartment (thenar space)
- deep to the central mm compartment: FDS, FDP, FPL; (midpalmar space)
What is the mid palmar space communicated with?
carpal tunnel
What is the clinical significance of the potential spaces such as the thenar and mid palmar space?
-if they become infected, it can show direction of spreading and how extensive the infection is (spread of pus formed in infected areas)
-depending on the site, puss with accumulate in the thenar, hypothenar, or adductor compartments
What sheath creates the thenar space?
index finger synovial sheath
What sheath created the midpalmar space?
3-5 digits synovial sheath and carpal tunnel
What are the characteristics of the dorsum/dorsal fascia?
thinner than the palmar fascia, thus, infectious swellings usually appear on the dorsum of the hand
Why do infections usually track to the back of the hand?
the dorsal fascia is thinner than the palmar fascia so the infectious swellings usually appear on the dorsum of the hand
What should snuffbox tenderness be equated with?
scaphoid fractures unless radiographs prove otherwise
What is the most commonly fractured carpal bone?
scaphoid
What are scaphoid fractures often misdiagnosed as?
severely sprained wrist
How does a scaphoid fracture usually occur?
falling with an outstretched hand
A patient fell with an outstretched hand and comes in complaining of pain and tenderness over the snuff box, what has likely occured?
scaphoid fracture
Optimal healing of a scaphoid fracture depends on adequate blood supply from what?
palmar carpal branch of the radial artery
Disruption of the blood supply to the proximal portion of the scaphoid in a fracture can result in what?
-avascular necrosis
-arthritis
What is the lateral border of the anatomical snuff box?
-abductor pollicis longus tendon
-extensor pollicis brevis tendon
What is the medial border of the anatomical snuff box?
extensor pollicis longus tendon
What makes up the floor of the anatomical snuffbox?
-radial artery
-scaphoid and trapezium
What makes up the roof of the anatomical snuffbox?
superficial radial nerve
What is the anatomical snuffbox clinically correlated with?
scaphoid fracture
What is the most important nerve in the hand?
ulnar nerve
The intrinsic muscles of the hand are located in how many compartments?
5
What are the 5 compartments that contain the intrinsic hand muscles?
- thenar compartment
- hypothenar compartment
- adductor compartment
- central compartment
- interosseus compartment
What are the thenar muscles are in the thenar compartment?
- adbuctor pollicis brevis
- flexor pollicis brevis
- opponens pollicis
What are the hypothenar muscles are in the hypothenar compartment?
- adbuctor digiti minimi
- flexor digiti minimi brevis
- opponens digiti minimi
What the the adductor muscles in the adductor compartment of the hand?
adductor pollicis
What are considered the short muscles of the hand?
lumbricals
What muscles are in the central compartment of the hand?
lumbricals and long flexor tendons
What is found in separate interosseous compartments between the metacarpals?
the interossei
What muscles in the hand allow for thumb abduction?
Abductor pollicis longus and abductor pollicis brevis
What muscles in the hand allow for adduction of the thumb?
adductor pollicis and 1st dorsal interosseous
What muscles in the hand allow for extension of the thumb?
Extensor pollicis longus
extensor pollicis brevis
abductor pollicis longus
What muscles in the hand allow for flexion of the thumb?
flexor pollicis longus
flexor pollicis brevis
What muscles in the hand allow for opposition of the thumb?
opponens pollicis
What is the common proximal attachment of the opponens pollicis, abductor pollicis brevis, and flexor pollicis brevis?
flexor retinaculum and tubercles of the scaphoid and trapezium
What is the proximal attachment of the adductor pollicis oblique head?
bases of 2nd and 3rd metacarpals, capitate, and adjacent carpals
What is the proximal attachment of the adductor pollicis transverse head?
anterior surface of the shaft of 3rd metacarpal
What is the distal attachment of the opponens pollicis?
lateral side of 1st metacarpal
What is the distal attachment of the abductor pollicis brevis and flexor pollicis brevis (superficial and deep head)?
lateral side of base of proximal phalanx of thumb
What is the distal attachment for the oblique and transverse head of the adductor pollicis?
medial side of the base of the proximal phalanx of the thumb
What thenar hand muscles are innervated by the recurrent branch of the median nerve?
-opponens pollicis
-abductor pollicis brevis
-superficial head of the flexor pollicis brevis
What thenar hand muscles are innervated by the deep branch of the ulnar nerve?
-deep head of the flexor pollicis brevis
-oblique and transverse head of the adductor pollicis
What is the main action of the opponens pollicis?
to oppose the thumb (draw 1st metacarpal medially and rotate it medially)
What is the main action of the abductor pollicis brevis?
abduct the thumb; helps oppose it
What is the main action of the superficial and deep head of the flexor pollicis brevis?
flexes thumb
What is the main action of the oblique and transverse head of the adductor pollicis muscle?
adducts thumb toward lateral border of palm
What gives roundness to the hand?
thenar eminence
Is the recurrent median nerve motor or sensory?
motor only
What is the proximal attachment of the abductor digiti minimi muscle?
pisiform
What is the proximal attachment of the flexor digiti minimi brevis and the opponens digiti minimi”?
hook of hamate and flexor retinaculum
What is the distal attachment of the abductor digiti minimi and the flexor digiti minimi brevis?
medial side of the base of the proximal phalanx of the 5th finger
What is the distal attachment of the opponens digiti minimi?
medial border of the 5th metacarpal
What is the innervation of the hypothenar muscles, abductor digiti minimi, flexor digiti minimi brevis, and opponens digiti minimi?
deep branch of the ulnar nerve
What is the main action of the abductor digiti minimi?
abducts 5th finger; assists in flexion of the proximal phalanx
What is the main action of the flexor digiti minimi brevis?
flexes proximal phalanx of 5th finger
What is the main action of the opponens digit minimi?
draws 5th metacarpal anterior and rotates it, bringing 5th finger into opposition with the thumb
What does the palmaris brevis allow for?
protection of ulnar nerve and artery
Is the palmaris brevis in the hypothenar compartment?
no
What does the deep branch of the ulnar nerve innervate?
hypothenar muscles, 3/4 lumbricals, all interosseous muscles
What part of the hand does the ulnar nerve provide sensory information to?
medial side of the hand (1 1/2 digits)
What does the ulnar nerve provide motor information to?
most intrinsic hand muscles except:
-thenar muscles (OP, APB, FPB superficial head)
-1st and 2nd lumbricals
What does the ulnar nerve course through?
Guyon’s canal (between proximal border of pisiform and distally at the hook of hamate)
What is the proximal attachment of the 1st and 2nd lumbrical muscles?
lateral 2 tendons of flexor digitorum profundus
What is the proximal attachment of the 3rd and 4th lumbrical muscles?
medial three tendons of flexor digitorum profundus
What is the proximal attachment of the dorsal interossei muscles 1-4?
adjacent sides of 2 metacarpals
What is the proximal attachment of the palmar interossei muscles 1-3?
palmar surfaces of 2nd, 3rd, and 5th metacarpals
What is the distal attachment of the lumbrical muscles 1-4?
lateral sides of the extensor expansions of the 2nd-4th fingers
What is the distal attachment of the dorsal interossei muscles 1-4?
bases of proximal phalanges; extensor expansions of digits 2-4
What is the distal attachment of the palmar interossei muscles 1-3?
base of proximal phalanges; extensor expansions of digits 2, 4, and 5
What is the innervation of the lumbrical muscles 1 and 2?
median nerve
What is the innervation of the lumbrical muscles 3 and 4, dorsal interossei muscles 1-4, and palmar interossei muscles 1-3?
deep branch of the ulnar nerve
What is the main action of the lumbricals?
-flex MCP joints
-extend interphalangeal joints of digits 2-5
What is the main action of the dorsal interossei muscles?
-abduct digits 2-4 from axial line
-act with lumbricals in flexing MCP joints and extending interphalangeal joints
What is the main action of the palmar interossei muscles?
-adduct digits 2, 4, and 5 toward axial line
-assist lumbricals in flexing MCP joints and extending interphalangeal joints
What is included in the central compartment of the hand?
-flexor tendons and sheaths (flexor digitorum superficialis, flexor digitorum profundus, flexor pollicis longus)
-lumbricals
-superficial palmar arterial arch
-digit vessels and nerves
What are lumbricals 1 and 2 innervated by?
median nerve
What are lumbricals 3 and 4 innervated by?
deep branch of the ulnar nerve
What do the dorsal interosseous muscles do?
Adbuct digits 2-4 (DAB)
What do the palmar interosseous muscles do?
adduct digits 2, 4 and 5 (PAD)
What does the superficial branch of the ulnar nerve supply?
skin of the palmar aspect of the little finger and medial half of ring finger, and the palmaris brevis muscles
What does the superficial branch of the ulnar nerve become as it travels distally?
digital cutaneous branches
What is the clinical name for an ulnar nerve lesion at the wrist?
ulnar (Guyon’s) tunnel syndrome
What can Guyon’s tunnel syndrome be caused by?
-laceration
-compression (pneumatic drills, crutches, handlebars)
What are the motor deficits associated with Guyon’s tunnel syndrome?
“claw hand”
-atrophy of hypothenar and interossei mm
-loss of all interossei mmm (adbuction/adduction)
-loss of abductor digiti minimi
What are the sensory deficits of Guyon’s tunnel syndrome?
-palmar digital nn of ulnar n
-medial 1 1/2 digits on palmar side
What does Guyon’s tunnel syndrome spare?
dorsal innervation of the palm
How does an ulnar nerve lesion distal to the hook of hamate usually occur?
injured with sports involving a racket, baseball bat, golf club
What are the motor deficits associated with an ulnar nerve lesion distal to the hook of hamate?
-“claw hand”
-atrophy of hypothenar mm
-loss of all interossei mm (palmar: inability to adduct, dorsal: inability to abduct)
What are the sensory deficits of an ulnar nerve lesion distal to the hook of hamate?
none
In what type of injury with you have difficulty making a fist by:
-being unable to flex digits 4,5 at interphalangeal joints
-being unable to extend interphalangeal joints
-impaired power of wrist adduction
ulnar lesion distal to the hook of hamate
What are the borders of the carpal tunnel?
roof- flexor retinaculum
lateral- scaphoid and trapezium
medial- pisiform and hamate (hook)
floor- carpal ligaments
At the level of the wrist, how many tendons of the anterior forearm compartment traverse the carpal tunnel?
9 from 3 muscles and 1 nerve
**8 share a common synovial flexor sheath
What runs through the carpal tunnel?
-Flexor digitorum superficialis tendons (4)
-Flexor digitorum profundus tendons (4)
-Flexor pollicis longus tendon (1)
median nerve
What occurs if you have a median nerve lesion at the wrist?
carpal tunnel
What are the motor deficits associated with a median nerve lesion at the wrist?
-“Ape’s hand”
-NO “Hand of benediction”
What are the sensory deficits associated with a median nerve lesion at the wrist?
-paraesthesia: radial 3 1/2 digits
(PALM SPARED)
What passes superficial to the carpal tunnel?
superficial palmar cutaneous branch of the median nerve
Inflammation/impingement of the tendons (FPL, FDP, FDS) running through the carpal tunnel could have an impact on what?
“OK” sign because of pain
-would also have an impact on flexion of digits 4 and 5
What etiology is associated with the recurrent median nerve lesion at the hand?
-pounding thenar eminence
-laceration
-thenar eminence wasting
What sensory deficits are associated with a recurrent median nerve lesion at the hand?
none
What motor deficits are associated with recurrent median nerve lesions at the hand?
-paralysis of thenar mm
-“Ape’s hand”
What is “Ape’s hand”
prominence of the base of the thumb
What is “hand of benediction”
inability to make a full fist (minimal flexion of digits 1-3)
What provides all of the blood to the hand?
ulnar and radial arteries and their branches
What enters the hand anterior to the flexor retinaculum between the pisiform and hook of hamate vis the Guyon canal?
ulnar atery
What artery lies lateral to the ulnar nerve?
ulnar artery
What does the ulnar artery give rise to?
-deep palmar branch of the ulnar artery (which continues superficially to the long flexor tendons?
What is the main contributor to the superficial palmar arch?
deep palmar branch of the ulnar artery
What does the superficial palmar arch give rise to?
3 common palmar digital arteries
What do the 3 common palmar digital arteries anastomose with?
palmar metacarpal arteries from the deep palmar arch
What does each common palmar digital artery divide into?
a pair of proper palmar digital arteries (run along the adjacent sides of digits 2-4)
What curves dorsally around the scaphoid and trapezium in the floor of the anatomical snuff box and enters the pal by passing between the heads of the 1st dorsal interosseous muscle?
radial artery
How does the radial artery end?
it anastomoses with the deep branch of the ulnar artery to form the deep palmar arch
What does the deep palmar arch give rise to?
-3 palmar metacarpal arteries
-princeps pollicis artery
What is the main contributor to the superficial palmar arch?
ulnar artery
What is the main contributor to the deep palmar arch?
radial artery
What are the branches of the ulnar artery?
-anterior and posterior ulnar recurrent (elbow)
-common interosseous
**recurrent interosseous (elbow)
-palmar carpal branch (palmar carpal arch)
-dorsal carpal branch (dorsal carpal arch)
Where can you find the radial artery?
near the neck of the radius; deep to the brachioradialis
