HAND AND FOREARM LABS 5+6

Flexor retinaculum

(transverse carpal ligament, or anterior annular ligament) is a fibrous band on the palmar side of the hand near the wrist. It arches over the carpal bones of the hands, covering them and forming the carpal tunnel. *This thick retinaculum runs between the trapezium and the hook of the hamate *Superficial to flexor retinaculim you have the deep branch of ulnar never and ulnar artery* both of which ARE NOT going through the carpal tunnel *NO BLOOD VESSELS GO THROUGH THE CARPLE TUNNEL*

Deep palmar arch

Deep palmar arch is a continuation of the radial artery -gives anastomotic blood supply to the fingers and provides most of the blood supply to the thumbing contributes to common and proper digital arteries

Extensor pollicis longus tendon

Extensor pollicis longus tendon

Hamate

Hamate

Lunate

Lunate

Metacarpals

Metacarpals (articulating in the hand)

o

Oblique head

Superficial branch

Superficial branch

Synovial (ganglion) cysts

swelling or inflammation underneath the retinaculum. It can bulge and this means your tendons cannot slide well in those tunnels and this can cause pain. Usually found on the lateral side of the wrist

Hypothenar eminence

the fleshy mass at the base of the little finger

Supinator

upinates the forearm deep radial nerve recurrent interosseous a.

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Adductor pollicis

Opponens pollicis

As its name suggests, the main function of opponens pollicis is to produce an opposition of the thumb. *Opposition refers to the rather complex movement of the thumb which is a combination of flexion, adduction and medial rotation at the first carpometacarpal joint.* (CMP joint)

Capitate

Capitate

Superficial and Deep branch of radial nerve

Deep branch (motor) - innervates the muscles in the posterior compartment of the forearm. Superficial branch (sensory) - contributes to the cutaneous innervation of the dorsal hand and fingers.

Extensor pollicis brevis

Extensor pollicis brevis goes to the 1st phalanx extends the thumb at the metacarpophalangeal joint deep radial nerve posterior interosseous a

Extensor pollicis longus

Extensor pollicis longus goes to distal phalynx extends the thumb at the interphalangeal joint deep radial nerve posterior interosseous a

Extensor retinaculum

Extensor tendons from forearm pass deep to this

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Fibrous digital sheath

Anterior interosseus nerve

From median nerve. Injury: motor deficits only. Innervates FDP of index, FPL, pronator quadratus. Impinged by deep head of pronator teres. Test: unable to make OK sign, weak grip. Pain w writing picking up small objects. Syndrome: most often w trauma or slow progression w pain. Consider parsonage-turner syndrome as differential diagnosis. Not sensory, motor only At risk w volar surgical approach to stabilize radius fx Pinch make an O test

•Median nerve

Median nerve

Posterior interosseous nerve

The posterior interosseous nerve supplies multiple muscles, four superficial extensors and five deep extensors in the posterior compartment of the forearm. These are: superficial extensor carpi radialis brevis (ECRB): deep branch of radial nerveextensor digiti minimi (EDM)extensor carpi ulnaris (ECU)extensor digitorum deep supinator: deep branch of radial nerveextensor indicisabductor pollicis longus (APL)extensor pollicis longus (EPL)extensor pollicis brevis (EPB)

o

Transverse head

Which bone is closest to the thumb

Trapezium

Trapezoid

Trapezoid

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Flexor digitorum profundus

Opponens digiti minimi

Opponens digiti minimi extends mainly between the hamate bone, which is a carpal bone, and the fifth metacarpal bone. By acting on the carpometacarpal joint, this muscle helps with flexion, lateral rotation and opposition of the little finger.

Phalanges

Phalanges (articulating in the hand)

Pisiform

Pisiform

Median nerve of hand

Remember this median nerve *goes through the carpal tunnel* Motor- recurrent branch to the thenar musculature and will supply 2 lumbricals 2 and 3 Proximal palm sensory branch is before the carpal tiunnel

Superficial palmar arch

Superficial palmar arch is ulnar

Carpal bones

Try To Create History So Life Tastes Perfect

Flexor pollicis longus

flexes the metacarpophalangeal and interphalangeal joints of the thumb median nerve anterior interosseous a.

Thenar eminence

Fleshy mound on the palm at the base of the thumb

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Flexor digitorum profundus tendon

•Lumbricals

Origin flexor digitorum profundus TENDONS Insertion extensor expansion *Nerve* = *3rd and 4th deep branch of ulnar* nerve, = *1st and 2nd median nerve* Actions =flex metacarpophalangeal joints (MCP JOINTS) =extend interphalangeal joints (IP JOINTS) These fingers MAKE THE DUCK SHAPE Numbered lateral to medial

__________and __________ are the bones that have a bony synovial articulation with the forearm of the radius

Scaphoid and lunate are the bones that have a bony synovial articulation with the forearm of the radius

What is the most common traumatic fracture of hand bone

Scaphoid fracture and avascular necrosis From fall on outstretched hand, radial styloid contacts waist of scaphoid Can result in avascular necrosis of distal pole of scaphoid due to poor blood supply Radial artery gives off a small branch to supply the bones with blood

Tunnels of wrist

The extensor tendon compartments of the wrist are six tunnels which transmit the long extensor tendons from the forearm into the hand They are located on the posterior aspect of the wrist. Each tunnel is lined internally by a synovial sheath and separated from one another by fibrous septa.

Common digital nerves

The superficial branch (ramus superficialis [n. ulnaris] supplies the Palmaris brevis, and the skin on the ulnar side of the hand, and divides into a proper palmar digital branch for the ulnar side of the little finger, and a common palmar digital branch which gives a communicating twig to the median nerve and divides into two proper digital nerves for the adjoining sides of the little and ring fingers. The proper digital branches are distributed to the fingers in the same manner as those of the median.

Palmar digital arteries

Three Common Palmar Digital Arteries (aa. digitales volares communes) arise from the convexity of the superficial palmar arch and proceed downward on the second, third, and fourth Lumbricales. Each receives the corresponding volar metacarpal artery and then divides into a pair of proper palmar digital arteries (aa. digitales volares propriæ; collateral digital arteries) which run along the contiguous sides of the index, middle, ring, and little fingers, behind the corresponding digital nerves; they anastomose freely in the subcutaneous tissue of the finger tips and by smaller branches near the interphalangeal joints. Each gives off a couple of dorsal branches which anastomose with the dorsal digital arteries, and supply the soft parts on the back of the second and third phalanges, including the matrix of the finger-nail. The proper volar digital artery for medial side of the little finger springs from the ulnar artery under cover of the Palmaris brevis.

3 hypothenar muscles

abductor digiti minimi, flexor digiti minimi brevis, opponens digiti minimi

Abductor digiti minimi

abducts little finger

Abductor pollicis brevis

abducts thumb, median nerve

Extensor indicis

extends the index finger at the metacarpophalangeal, proximal interphalangeal and distal interphalangeal joints deep radial nerve posterior interosseous a

Extensor digitorum

extends the metacarpophalangeal, proximal interphalangeal and distal interphalangeal joints of the 2nd-5th digits; extends wrist deep radial nerve interosseous recurrent a. and posterior interosseous a

Extensor digiti minimi

extends the metacarpophalangeal, proximal interphalangeal and distal interphalangeal joints of the 5th digitdeep radial nerve interosseous recurrent a.

Antebrachial fascia

fascia that surrounds the forearm

What passes through the carpal tunnel?

9 tendons and a nerve 4 FDP (flexor digitorum profundus) 4FDS (flexor digitorum superficialis) FPL (flexor pollicis longus) Median nerve Carpal tunnel syndrome indicating there is something inflamed in the carpal tunnel it presses on the median nerve and you have signs and symptoms related to this compression.

Abductor pollicis longus

Abductor pollicis longus extends to the first metacarpal abducts the thumb at carpometacarpal joint radial nerve, deep branchposterior interosseous a.

Distal Tendon sheath and clinical significance

Tenosynovitis -inflammation of the synovial tendon which causes tightness and swelling of the finger secondary inflammation. (The thumb is the most common place you can get this synovitis)- De Quervain's Tenosynovitis

Hand of Benediction

damage to MEDIAN nerve at or proximal to the elbow resulting in loss of flexion RESTING POSTURE IS HAND OF BENEDICTION

thenar muscles

3 MUSCLES FORM THENAR MUSCLES abductor pollicis brevis, flexor pollicis brevis, opponens pollicis innervated by recurrent median nerve which is superficial and easily damaged *MOTOR ONLY TO THE THENAR MUSCLES*

Palmar interossei

3 palmar interossei- originate from the sides of the corresponding phalanges PAD-palmar adduct toward the 3rd digit INNERVATED BY THE deep branch of ULNAR NERVE if ulnar nerve is damage then abduction and adduction of muscles in hand is compromised

Dorsal interossei

4 dorsal interossei --originate from either side of the metacarpals (in between) they come up and attach to the sides of the phalanges and the extensor expansions ABDUCTION- pulling fingers away from the 3rd digits DAB- DORSAL ABDUCT- innervated by ulnar nerve

Anatomical snuffbox

A depression on side/back of the hand, just beneath the thumb, that is formed by two tendons (the extensor pollicis brevis and the extensor pollicis longus). Radial artery can be found in here

ABDUCTION AND ADDUCTION OF FINGERS

ABDUCTION- pulling fingers away from the 3rd digits ADDUCTION- Pulling fingers toward the third digit

Sometomes the collateral circulation of the radial andulnar arteries are not good. What test can test for this?

ALLEN'S TEST Positive modified Allen test - If the hand flushes within 5-15 seconds it indicates that the ulnar artery has good blood flow; this normal flushing of the hand is considered to be a positive test. Negative modified Allen test - If the hand does not flush within 5-15 seconds, it indicates that ulnar circulation is inadequate or nonexistent; in this situation, the radial artery supplying arterial blood to that hand should not be punctured.

•Dorsal interossei

DAB 4 dorsal interossei --originate from either side of the metacarpals (in between) they come up and attach to the sides of the phalanges and the extensor expansions ABDUCTION- pulling fingers away from the 3rd digits DAB- DORSAL ABDUCT- innervated by ulnar nerve if ulnar nerve is damage then abduction and adduction of muscles in hand is compromised

Palmar aponeurosis of the palm clinical significance

Especially in older males--you have a fibrous degeneration or tightening of the superficial facia of the palmar aponeurosis. This can cause a contraction of the fingers called a *DUPUYTREN'S CONTRACTURE* and it will pull the fingers into partial flexion.

•Extensor (dorsal digital) expansion

Extensor (dorsal digital) expansion which extends all the way to the phalanx - acts like a big tendon so when the muscles pull on this it will in effect the action of the fingers. the extensor expansion is bound down to the digits and this is what the tendons insert into.

Extensor carpi radialis brevis

Extensor carpi radialis brevis goes to 3rd metacarpal extends the wrist; abducts the hand deep radial nerve radial a.

Extensor carpi radialis longus

Extensor carpi radialis longus goes to 2nd metacarpal extends the wrist; abducts the hand radial nerve radial a.

Extensor carpi ulnaris

Extensor carpi ulnaris extends to 5th metacarpal extends the wrist; adducts the hand deep radial nerve ulnar a.

Extensor digitorum tendon

Extensor digitorum tendon Extensor digitorum is a superficial muscle of the posterior compartment of the forearm. ... This tendon serves as a proximal attachment for extensor digiti minimi, extensor carpi radialis brevis and extensor carpi ulnaris muscles. From its origin, the muscle descends superficially down the posterior aspect of the forearm.

Flexor digiti minimi brevis

Flexes little finger at metacarpophalangeal joint

Intermediate layer of anterior compartment of forearm

Flexor digitorum superficialis

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Flexor digitorum superficialis tendon

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Flexor pollicis longus tendon

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Flexor retinaculum

If the median nerve is damaged at the elbow or more proximal what will you lose?

Lose: Flexor digitorum superficialis Lateral 1/2 flexor digitorum profundus lateral 2 lumbricals thenar muscles

Extensor compartment/ Dorsum of hand

Notice the intertendinous connections which makes it hard to extend your fingers independently of each other

Median nerve

OriginBrachial plexus (C6-T1) Motor supply Flexor muscles in the forearm except flexor carpi ulnaris and the ulnar head of flexor digitorum profundus; Muscles of the thenar eminence and the radial two lumbricals. Mnemonic: 'Ulnar nerve supplies all intrinsic muscles of the hand except the LOAFmuscles.' (refers to Lateral two lumbricals, Opponens pollicis, Abductor pollicis brevis, Flexor pollicis brevis) Sensory supply The skin of the: - Palmar and distal dorsal aspects of the lateral three-and-the-half digits and adjacent palm- Palmar and distal dorsal aspects of the thumb and radial half of 2nd digit- Palmar and distal dorsal aspects of the adjacent sides of 2nd-4th digits- Central palm Clinical relations Carpal tunnel syndrome, hand of Benediction, simian/ape hand deformity, pronator syndrome Mnemonic: DR. CUMA (standing for Dropped wrist = Radial nerve lesion, Claw hand = Ulnar nerve lesion, Ape hand = Median nerve lesion)

Radial nerve

Radial nerve is continuation of the posterior cord of the brachial plexus. It supplies motor innervation to the posterior arm compartment and the posterior forearm compartment. (The specific branches of the radial nerver are: superficial radial n, deep radial n., and, posterior interosseus n.) Motor: triceps brachii and posterior forearm muscles Sensory: majority of posterior arm, forearm, and lateral hand

Common interosseous artery

Short branch given off the ulnar artery near its origin and divides into anterior and posterior interosseous arteries The common interosseous artery is a branch of the proximal part of the ulnar arteryat the level of the pronator teres in the distal part of the cubital fossa. It is a short vessel that dives laterally and deeply before bifurcating into anterior and posterior interosseous arteries

Anterior interosseous artery

The anterior interosseous artery contributes to the blood supply of the radius, ulna, flexor digitorum profundus, flexor pollicis longus, and pronator quadratus. The anterior interosseous artery is one of the two branches of the short common interosseous artery (from the ulnar artery). The artery courses deep in the anterior compartment of the forearm on the anterior surface of the interosseous membrane along with the anterior interosseous nerve (from the median nerve).

Palmaris longus tendon

The apex of the palmar aponeurosis is directed proximally to attach to the flexor retinaculum, where it receives the insertion of the Palmaris longus tendon

Palmaris longus tendon

The apex of the palmar aponeurosis is directed proximally to attach to the flexor retinaculum, where it receives the insertion of the...

Posterior interosseous artery

The posterior interosseous artery is one of the two terminal branches of the short common interosseous artery (from the ulnar artery). The artery courses deep in the proximal anterior compartment of the forearm to pierce the upper aspect of the interosseous membrane and enter the posterior compartment of the forearm.

Posterior interosseous artery

The posterior interosseous artery is one of the two terminal branches of the short common interosseous artery (from the ulnar artery). The artery courses deep in the proximal anterior compartment of the forearm to pierce the upper aspect of the interosseous membrane and enter the posterior compartment of the forearm. The posterior interosseous artery supplies blood to the ulna, abductor pollicis longus, supinator, and extensor muscles of the forearm

Radial artery

The radial artery is a continuation of the brachial artery and is one of the major blood supplying vessels to the structures of the forearm. The brachial artery terminates at the cubital fossa where it bifurcates into the ulnar artery and a smaller radial artery.

Proper digital nerves

The superficial branch (ramus superficialis [n. ulnaris] supplies the Palmaris brevis, and the skin on the ulnar side of the hand, and divides into a proper palmar digital branch for the ulnar side of the little finger, and a common palmar digital branch which gives a communicating twig to the median nerve and divides into two proper digital nerves for the adjoining sides of the little and ring fingers. The proper digital branches are distributed to the fingers in the same manner as those of the median.

Common palmar digital arteries

Three Common Palmar Digital Arteries (aa. digitales volares communes) arise from the convexity of the superficial palmar arch and proceed downward on the second, third, and fourth Lumbricales. Each receives the corresponding volar metacarpal artery and then divides into a pair of proper palmar digital arteries (aa. digitales volares propriæ; collateral digital arteries) which run along the contiguous sides of the index, middle, ring, and little fingers, behind the corresponding digital nerves; they anastomose freely in the subcutaneous tissue of the finger tips and by smaller branches near the interphalangeal joints. Each gives off a couple of dorsal branches which anastomose with the dorsal digital arteries, and supply the soft parts on the back of the second and third phalanges, including the matrix of the finger-nail. The proper volar digital artery for medial side of the little finger springs from the ulnar artery under cover of the Palmaris brevis.

CLAW HAND

Ulnar nerve damage AT or PROXIMAL to wrist. You lose a interossei muscles of the hand, median 2 lumbricals and medial 1/2 of flexor digitorum profundus you have hypothenar wasting. Test to see if a person can hold a piece of paper between the fingers which requires adduction and if they can't that is indication that their ulnar nerve is damaged

Ulnar artery

artery that supplies blood to the muscle of the little finger side of the arm and palm of the hand

RECURRENT BRANCH OF MEDIAN NERVE DAMAGE

cannot do opposition with thumb with damage--no ability to oppose bone to other digits and what happens is your thumb will end up being adducted laterally rotated and you lose these muscles. If this goes on for a long time you get thenar wasting and a smaller thenar muscle *ape hand* RECURRENT BRANCH OF MEDIAN NERVE SITS Superficial and therefore it is a common injury -MOTOR ONLY TO THENAR MUSCLES

Carpal tunnel syndrome

compression of the median nerve as it passes between the ligament and the bones and tendons of the wrist You see specific symptoms 1. paresthesias of the 3.5 fingers but NOT PROXIMAL PART OF MEDIAL PALM 2. Lose function of thenar muscles can't oppose thumb to other digits 3. lose action of first 2 lumbricals

Brachioradialis

flexes the elbow, assists in pronation & supination radial nerve radial recurrent a.

Flexor digitorum superficialis

flexes the metacarpophalangeal and proximal interphalangeal joints median nerve ulnar a.

Flexor digitorum profundus

flexes the metacarpophalangeal, proximal interphalangeal and distal interphalangeal joints median nerve (radial one-half); ulnar nerve (ulnar one-half) ulnar a., anterior interosseous a.

Palmaris longus

flexes the wrist median nerve ulnar a. *palmaris longus is absent in about 13% of forearms; it may be present on one side only*

Flexor carpi radialis

flexes the wrist, abducts the hand median nerve ulnar a.

Flexor pollicis brevis

flexes thumb

Flexor carpi ulnaris

flexes wrist, adducts hand ulnar nerve ulnar a.

Deep layer of anterior compartment of forearm

flexor digitorum profundus, flexor pollicis longus, pronator quadratus

3 thenar muscles

flexor pollicis brevis, abductor pollicis brevis, opponens pollicis

Boxer's fracture

from punching something hard. Usually 5th metacarpal, other digits less commonly broken because of direct path of force transmission through digits 4,3,2 (uses 2nd and 3rd knuckles when you punch someone lol)

Palmar aponeurosis

insertion of palmaris longus

Carpal tunnel image 2

note all the structures that go through 9 tendons + median nerve = 10 structures

Superficial layer of anterior compartment of forearm

pass fail pass fail

Pronator teres

pronates the forearm median nerve ulnar a., anterior ulnar recurrent a.

Pronator quadratus

pronates the forearm median nerve via the anterior interosseous nerve anterior interosseous a.

Radial artery of hand

provides NO motor innervation in the hand but it will giver dorsal skin sensation

Deep layer of posterior compartment of forearm

supinator, abductor pollicis longus, extensor pollicis brevis, extensor pollicis longus, extensor indicis

Ulnar nerve

supplies all hypothenar muscles, 3 and 4 lumbricals and supply sensation to skin of 5th digits and dorsal palm and all DAB + PAD ESSENTIALLY provides sensation and innervation to everything but the thenar and first 2 lumbricals