Hand and Wrist Flashcards
What muscles can be found on the superficial palm?
• Flexor Retinaculum
• Deep attachments – 3rd
and 5th Metacarpals
• Palmar Aponeurosis
• Palmaris longus
• Fibrous digital sheaths
• Thenar eminence
• Hypothenar eminence
• Dupuytren's contracture
• Palmar BreviceWhat spaces may be found in the palm and how do they arise?
- Deep attachments create mid palmar and thenar spaces
* Mid palmar space continuous with forearm
What is found where the tendon passes under ligaments and through osseofibrous tunnels?
Synovial sheaths
What synovial sheaths are found on the tendons of the muscles that act on the hand?
- Common flexor synovial sheath wrist → mid palm
- Flexor policis longus; separate sheath → distal phalanx
- Synovial sheaths for each digit
- Digiti minimi sheath; continuous to palm
Where are fibrous sheaths in reference to synovial sheaths?
Superficial
What structures do fibrous sheaths form in the hand?
Osseofibrous tunnels
What shape do the osseofibrous tunnels on the hand take?
- Annular rings over the bone
* Cruciform (exes) near joints
What occurs to the tendon of flexor digitorum superficialis where it intersects with flexor digitorum profundus?
• Tendon of FDS splits to allow FDP trough distally
What nerves supply the hand?
Median
Radial
Ulnar
Where do the palmar nerves lie?
- Neurovascular structures lie superficially
* Common digital arteries and verves run together
Where do the deep branches of the ulnar nerve occur?
Around halfway between Gyon’s canal and the beginning of the medial beginning of the superficial palmar arch
Does the median nerve have a recurrent branch in the proximal part of the hand
Ye
What major arteries are present in the hand?
Superficial palmar arch
Ulnar artery
Radial artery
Deep palmar arch
What other arteries are present in the hand?
Common palmar digital arteries Proper palmar digital arteries Deep palmar branch of Ulnar artery Palmar metacarpal arteries Princeps pollicis artery Radialis indicis artery
How many thenar muscles are there?
4
What are the four thenar muscles?
– Abductor pollicis brevis
– Opponens pollicis
– Flexor pollicis brevis
• 2 heads: Superficial and Deep
– Adductor pollicis
• 2 heads: Transverse and ObliqueWhat nerve(s) supply the flexor pollicis brevis?
Superficial (recurrent median (C8, T1))
Deep (deep ulnar
nerve C8, T1)
What two thenar muscles are supplied by the recurrent branch of median nerve (C8, T1)?
– Abductor pollicis brevis
– Opponens pollicis
What nerve roots make up the recurrent branch of the median nerve in the hand?
C8
T1
What nerve(s) supply the adductor pollicis?
Deep branch of ulnar (C8,T1)
How many hypothenar muscles are there?
Three
What are the three hypothenar muscles?
– Abductor digiti minimi
– Opponens digiti minimi
– Flexor digiti minimi
What nerve supplies all three hypothenar muscles
Deep branch of Ulnar nerve (C8,T1)
What is the extensor hood?
the special connective attachments by which the extensor tendons insert into the phalanges
What is the structure of the extensor hood?
The flattened tendons (aponeurosis) of extensor muscles span the proximal and middle phalanges
At the distal end of the metacarpal, the extensor tendon will expand to form a hood, which covers the back and sides of the head of the metacarpal and the proximal phalanx
What the hell are lumbricals?
intrinsic muscles of the hand that flex the metacarpophalangeal joints, and extend the interphalangeal joints
What is the origin of the lumbricals?
Radial side of the flexor digitorm profundus tendon (a bit distal to the flexor retinaculum)
Where is the insertion of the lumbricals?
The extensor expansion (extensor hood) of the associated phalanges
What is the action of the lumbricals?
• Flex metacarpophalangeal and extend interphalangeal joints
What is the innervation of the lumbricals?
- Medial 2: Deep Ulnar (C8,T1)
* Lateral 2: Median (C8,T1)
How many interossei are there?
4 Dorsal
3 Palmar
What is the purpose and structure of the dorsal interossei?
– Abduct digits
– Bipennate
What is the purpose and structure of the palmar interossei?
– Adduct digits
– Unipennate
What may the interossei act with?
• Can act together with each other, and lumbricals
What is the innervation of the interossei?
• All innervated by Deep Ulnar Nerve (C8,T1)
What is the origin of the dorsal interossei?
The metacarpals
What is the insertion fo the dorsal interossei?
Proximal phalanx and extensor hood
How many dorsal interossei act on the 3rd digit?
Two
How many palmar interossei act on the 3rd digit?
None! no adduction is possible on the 3rd digit
What is the origin of the palmar interossei?
• Adductor side of
Metacarpal
What is the insertion of the palmar interossei?
• Proximal phalanx and extensor hood
Fraser Chisholm
Does the 1st digit have a palmar interossei?
• Thumb:
• Has own adductor
• 1st palmar interosseous
debated
• We will not consider itWhat is the claw hand or ulnar claw?
a deformity or an abnormal attitude of the hand that develops due to ulnar nerve damage causing paralysis of the lumbricals.
What is the ulnar paradox?
The ulnar nerve also innervates the medial half of the flexor digitorum profundus muscle. If the ulnar nerve lesion occurs more proximally, the flexor digitorum profundus muscle may also be denervated. As a result, flexion of the IP joints is weakened, which reduces the claw-like appearance of the hand. Instead, the fourth and fifth fingers are simply paralyzed in their fully extended position.
This is called the “ulnar paradox” because one would normally expect a more proximal and thus debilitating injury to result in a more deformed appearance
So as the higher lesion heals the claw will get worse before any more distal damage is repaired
What is a simple way to remember the ulnar paradox?
The closer to the paw the worse the claw
What is Froment’s sign?
a test of the wrist for palsy of the ulnar nerve, specifically, the action of adductor pollicis
A patient is asked to hold a usually flat object such as a piece of paper, between the thumb and index finger (pinch grip). The examiner attempts to pull it out of the subject’s hands
With ulnar nerve palsy, the patient will experience difficulty maintaining a hold and will compensate by flexing the flexor pollicis longus of the thumb to maintain grip pressure causing a pinching effect.
What is carpal tunnel syndrome?
A condition due to compression of the median nerve as it travels through the wrist at the carpal tunnel.
What is Phalen’s test?
The Phalen maneuver is performed by having the patient place the wrists in complete unforced flexion for at least 30 seconds –\/–. If the median nerve is entrapped at the wrist, this maneuver reproduces the symptoms of carpal tunnel syndrome. (This is a +ve result but you can fail this test and still have CTS)
What is the hand of benediction?
A cool sounding DnD quest item
(Also known as preacher’s hand)
Damage to the median nerve as a result of prolonged compression or injury of the MEDIAN NERVE at the forearm or elbow
patients with this median nerve problem usually can flex all fingers except for the index finger
The index finger is not flexed at the proximal interphalangeal and distal interphalangeal joints, which looks like a POINTING FINGER
What is ape hand?
It is an inability to abduct the thumb
It can occur with an injury of the median nerve either at the elbow or the wrist, impairing the thenar muscles and opponens pollicis muscle
