Lecture 7--forearm Cont Flashcards
What would you see if you had a fracture at the distal humerus and it severs, compresses or damages the median nerve?
The hand of benediction. They can partially flex digits 4 and 5, but their thumb and digits two and three are unable to flex.
How do you get compartment syndrome
Thick antebrachial fascia helps pump blood in the veins back to the heart but this can cause compartment syndrome. Fascia limits the expansion and cuts off blood supply which impacts the nerve supply and impacts the muscles.
What is the only muscle that does flexion at the dips
Flexor digitorum profundus
How does an injured anterior interosseous nerve affect the thumb?
Flexor pollicis longus goes to the distal phalanx of the thumb. If you ask the patient to make the okay sign they will go pad to pad instead of tip to tip.
What muscles allows us to flex the fingers independently of one another
Flexor digitorum supeficialis.
All muscles of the posterior compartment of the forearm are Innervated by what
The radial nerve, deep branch of radial nerve, superficial radial nerve, and posterior interosseous brwnch of the deep branch of the radial nerve.
What is lateral epicondylitis known as
Tennis elbow
What muscles do not cross the wrist of the extensors
Supinator and brachioradialis
What is special about the brachioradialis
It does elbow flexion. It is rotated anteriorly and goes anterior to the elbow joint. This means that clinically if the musculocutaneous nerve is injured and you loose input to the anterior compartment of the arm, you can still have elbow flexion. If you lose your radial nerve you can still have elbow flexion due to the pronator teres.
Tendons of the extensor Carpi radialis longus and brevis are covered by what muscles
Abductor pollicis longus and extensor pollicis brevis
What compartment are the extensor Carpi radialis longus and brevis deep to the extensor retinaculum
2nd compartment
What muscle is medial to the extensor digitorum
Extensor digiti minimi
What compartment is the extensor digitorum in
4th compartment
What compartment is the extensor digiti minimi in
5th compartment
What compartment is the ecu tendon in
6th compartment
What passes between the heads of the supinator
The deep branch of the radial nerve
What compartment is the tendon of abductor pollicis longus in
1st compartment
What compartment is the extensor pollicis brevis tendon in
1st compartment
What compartment is the extensor pollicis longus tendon in
3rd compartment
What compartment is the extensor indices tendon in
4th compartment
Descends deep to the pronator teres and then the fcu with the ulnar nerve.
Ulnar artery
What are the three structures that go superficial to the flexor retinaculum
Ulnar nerve and artery as well as the palmaris longus.
Flexor Carpi ulnaris as well passes superficial and lateral
Branches of the ulnar artery
Anterior ulnar collateral– going to inferior ulnar collateral
Posterior ulnar collateral– going to superior ulnar collateral.
Then becomes a common interosseous. It gives off a posterior and anterior interosseous artery as well as a common recurrent artery.
Dorsal and palmar branches
What branches does the profunda brachii give off
Radial collateral (anterior) Middle collateral (posterior)
What does the anterior interosseous artery run with
The anterior interosseous nerve from the median nerve
Descends deep to the brachioradialis and then sits on the posterior surface of the radius. Takes a superficial course and then leaves the forearm by winding around the lateral aspect of the wrist crossing the floor of the anatomical snuff box.
Radial artery
Branches of the radial artery
Radial recurrent artery
Dorsal and palmar carpal branches.
Superior ulnar collateral runs ____
Posterior to the medial epicondyle
Inferior collateral artery runs ____
Anterior to the medial epicondyle
Radial artery think___
Ulnar artery think ___
Brachioradialis
Flexor Carpi ulnaris
Descends from the medial aspect of the forearm in the subcutaneous tissue to the wrist
Medial antebrachial cutaneous nerve
The medial antebrachial nerve is sensory to..
The medial aspect of the forearm
Termination of the musculocutaneous
Lateral antebrahial cutaneous nerve
Emerges lateral to the biceps on the Brachialis, descends along the lateral border of the forearm. Once of the three structures we pick up around the snuffbox.
Lateral antebrachial cutaneous nerve
What are the structures found in the snuff box
Lateral antebrachial cutaneous
Superficial radial nerve
Cephalic vein
Runs next to the brachial artery. Passes between the heads of the pronator teres, descends deep to the FDS and passes deep to the flexor retinaculum through the carpal tunnel and into the hand.
Median nerve
Carpal tunnel is caused by problems with what nerve
Median nerve
Distribution of the median nerve
Motor to anterior portion of the forearm except FCU and half of FDP.
Passes between the heads of the FCU, descends deep to the FCU, and passes superficially to the flexor retinaculum and into the hand.
Ulnar nerve
Distribution of the ulnar nerve
Motor to FCU and half of FDP
Radial nerve is by what structure
Lateral epicondyle it’s anterior to the elbow joint
Divides into the superficial and deep branches at the level of the lateral epicondyle of the humerus.
Radial nerve
Course of the deep branch of the radial nerve
Winds around the neck of the radius between the heads of the supinator and then becomes the posterior interosseous nerve, enters the posterior compartment, and terminates as the posterior interosseous nerve that passes inferiorly between the superficial and deep muscle groups.
The superficial radial nerve is deep to the
Brachioradialis in the distal 3rd of the forearm and then peaks itself superficially.
Describe the course of the superficial radial nerve
The lateral antebrachial cutaneous runs with the cephalic vein and the superficial radial nerve is deep to the brachioradialis then peaks superficially towards the snuffbox.
Distribution of the radial nerve
Motor to the posterior compartment muscles and sensory to the posterior aspect of the forearm.
What are the structures that pass the flexor retinaculum
Superficial: palmaris longus, ulnar artery and nerve, FCU tendon
Deep: carpal tunnel, compartment for the FCR tendon
What does the carpal tunnel contain
Tendons of the FDS, FDP, FPL and the median nerve (9tendons in here)
Boundaries of the snuffbox
Lateral: abductor pollicis longus and extensor pollicis brevis
Medial: extensor pollicis longus tendon.
Contents of the snuffbox
Deep within the snuffbox is the radial artery. The cephalic vein is superficial as well as the lateral antebrachial cutaneous nerve, and superficial branch of the radial nerve.
Describe the palmar aponeurosis
Continuous with the flexor retinaculum and the palmaris longus tendon. Located in the central part of the palm overlying the long flexor tendons. Inferiorly or distally forms 4 longitudinal bands that become continuous with what we have on our digits that are called fibrous digital sheaths.
Extend from the medial border to the 5th metacarpal
Medial fibrous septum
Extends from the lateral border to the 3rd metacarpal
Lateral fibrous septum
Overlies the interossei and surrounds the adductor pollicis
Adductor interossei fascia
What is dupuytren’s contracture
Shortening and thickening of the palmar aponeurosis
What are fibrous digital sheaths
They are continuous with the palmar aponeurosis. They extend from the head of the metacarpals to the bases of the distal phalanges. They attach along either side of the bones and create osseofibrous tunnels for our flexor tendons.
What is trigger finger
Narrowing of the osseofibrous tunnels
What tendons do the digital sheaths enclose
Digital sheaths 2-4 enclose FDS& FDP. digital sheath 1 encloses the FPL
Triangular aponeurosis that wraps around the dorsum and sides of the metacarpal and proximal phalanx. Divides into a median band that passes to the base of the middle phalanx and two lateral bands that veer off that pass to the bad of the distal phalanx.
Extensor expansions.
What do the extensor expansions do
Hold the extensor tendons in place.
What is mallet finger
You tear the distal attachment of the dip and you get flexion at the dip.
Where is the hood of the extensor expansion
Towards the mcp joint
