Upper Limb: Hand and Wrist Flashcards
Describe what is present in the superficial palm
- Flexor retinaculum
- Palmer aponeurosis
- Fibrous digital sheaths
- Thenar eminence
- Hypothenar eminence
What is Dupuytren’s contracture
Palmar aponeurosis becomes thickend, fibrosed and contracted. It flex’s the 5th and 4th digit and you cannot pull them back - associated with alcoholics
Where are the midpalmar and thenar spaces found?
Midpalmar - between central and interosseous compartment
Thenar space - between thenar and adductor compartments
What are the different synovial sheaths in the hand?
- Common flexor synovial sheath for flexor digitorum superficialis and flexor digitorum profundus tendons
- Separate synovial sheath for the tendon of flexor policis longus
- Synovial sheaths for each digit with the digiti minimi sheath being continuous with the palm
Where are fibrous sheaths found and what is their function?
Found superficial to synovial sheaths in the digits (means they are covering them). They act as pullys making movement more efficient
What are the types of fibrous sheaths and where are they found?
Annular - over bone
Cruciform - over joints
How do the tendons of the flexor digitorum superficialis and flexor digitorum profundus appear in the digits
FDS splits to allow FDP through distally
Describe the sensory supply of the hand
Radial nerve - Covers lateral boarder of the hand and including anatomical snuffbox
Median Nerve - Lateral 3 digits on the anterior side and nail beds of the lateral three digits on the posterior side.
Ulnar nerve - Supplies the 5th and 1’2 of the 4th digits on both sides
Of the thenar muscle, what two are supplied by the recurrent branch of the median nerve (C8,T1)
Abductor pollicis brevis and Opponens Pollicis
Name the two other muscles of the thenar muscles, their two heads and nerve supply.
Flexor pollicis brevis - Superficial head supplied by recurrent median N and Deep head supplied by deep ulnar nerve (C8, T1)
Adductor pollicis - Transverse and Oblique both supplied by deep branch of ulnar (it is a deeper thenar muscle)
Name the three hypothenar muscles and their nerve supply
- Abductor digiti minimi
- Opponens digiti minimi (deep to the flexor digiti minimi)
- Flexor digiti minimi brevis
All supplied by the deep branch of Ulnar nerve (C8,T1)
On the back of the hand what holds the synovial sheaths of tendons in place at the wrist?
Extensor retinaculum
What occurs to the tendons of the extensor digitorum?
They flatten as they reach the metacarpals and become extensor expansions. Lumbricals then insert into the extensor expansion/hood
What is the origin of the lumbrical muscles?
The radial side of the flexor digitorum tendon
Where do the lumbrical muscles insert?
Into the extensor expansion
What is the action of the lumbrical muscles?
Flex the metacarpal-phalangeal joint and extend the interphalangeal joints
what is the innervation of the lumbricals
Medial Two Muscles - Bipennate and are innervated by the deep ulnar (C8,T1)
Lateral Two Muscles - Unipennate and are innervated by the median nerve (C8,T1)
How many dorsal interossei muscles are there? What are their actions? What is their structure?
4 Dorsal - because the 1st and 5th digits have their own abductors and the middle finger gets two! (one for medial abduction and one for later abduction)
Abduct digits (Dab)
Bipennate
How many palmar interossei muscles are there? What are their actions? What is their structure?
3 Palmar
Adduct (Pad)
Unipennate
What are the interossei muscles innervated by?
The deep ulnar nerve (C8,T1)
What is the origin of the dorsal interossei muscles
Metacarpal
What is the insertion of the dorsal interossei muscles
Proximal phalanx and extensor hood
Why doesn’t the middle finger have a palmar interossei?
Because it cannot adduct
Where is the origin of the palmar interossei muscles?
Adductor side of the metacarpal
Where is the insertion of the palmar interossei muscles?
Proximal phalanx and extensor hood
What an ulnar nerve injury, what muscles of the hand are effected? What appearance does this give
Muscles - Two medial lumbricals, all interossei and 1/2 of flexor digitorum profundus. This gives an ulnar claw appearance which is where the MCP joint is extended but IP joint is flexed
What is the ulnar paradox? why does this occur?
This is where distal injury is worse than a proximal injury. This is because of the action of the flexor digitorum profundus
What is froment’s sign?
It is a clinical test for palsy of the ulnar nerve. It is when you ask a patient to grip paper between their thumb and first digit. If they do have an ulnar injury they will only be able to do this by flexing the thumb.
What is Phalen’s test?
It is used to test for carpal tunnel syndrome. It is when you ask patient to do reversed prayer sign (flexion of wrist) if they do have carpal tunnel syndrome this will exacerbate pain
What will a median nerve injury effect?
Lateral 2 lumbricals, Flexor digitorum superficialis and 1/2 of flexor digitorum profundus and thenar muscles.
What is the hand of benedict?
A test for median nerve damage. Ask patient to make a fist, if median nerve damage then the first 3 digits will stay extended.
What is Ape hand?
Clinical test for median nerve damage, patient will not be able to oppose thumb
What will test for anterior interosseous nerve damage?
Asking patient to make ‘Ok’ sign but instead they will make a pinched sign
