Elbow and Forearm - Anatomy & Problems Flashcards
(41 cards)
Which 3 joints make up the elbow and what types are they?
UlnoHumeral - hinge joint, 1 axis - back and forth.
RadioHumeral - ball and socket, 2 planes - hinge and swivel.
Proximal RadioUlnar joint - trochoid (1 element rotates in own axis).
The synovial hinge joint of the elbow is independent of the shoulder joint and can move the hand to and from the body in flexion and extension. What limits extension?
The olecranon fitting into the olecranon fossa.
The elbow joint is lined by a capsule and covered by a synovial membrane, what is the alignment?
Carrying angle is not straight down and arms must clear the hip when walking.
If the allignment of the know joint occurs, the forearm may be more vertical or the opposite. What is the name of these situations and which is more severe?
The deformities may occur if supraepicondylar fractures heal wrong.
More vertical - Cubitus Varus
More horizontal - Cubitus Valgus
Cubitus Valgus is more severe as it can result in more functional issues with the ulnar nerve stretching as a result leading to tardy ulnar nerve palsy, whereas Cubitus Varus is more of a cosmetic issue.
Describe the ligaments of the elbow joint.
Medial collateral ligament (anterior, posterior and transverse parts).
Lateral collateral ligament (radial collateral and ulnar collateral).
Annular ligament - around head of radius.
Which 3 things provide stability to the elbow? What happens to them when the elbow gets dislocated?
Capsule, ligaments, muscles.
In dislocation, joint surfaces are completely lost, so all ligament complexes are disrupted.
What use is finding a fat pad on an X-ray of an elbow?
If there’s effusion on the joint, for instance because of bleeding from a fracture, fluid will collect in the capsule and the black fat pads will be pushed superiorly.
The ulnohumeral joint is responsible for (concentric) flexion and (eccentric) extension of the forearm, which range of angles can be achieved?
-5 to 140 degrees.
Which muscles (and so nerves) contribute to flexion of the forearm?
Biceps brachii (musculocutaneous N.) - main, long and short head
Brachialis (musculocutaneous N.)
Brachioradialis (radial N.)
Pronator teres (median N.)
Which muscles (and so nerves) contribute to extension of the forearm?
Triceps brachii (radial N.) - long, lateral and medial heads Aconius (radial N.)
Which joint is responsible for to 90-90 degree pronation and supination of the forearm?
The upper/proximal radioHumeral joint.
Which muscles (and so nerves) contribute to pronation of the forearm?
Pronator Teres (median N.) Pronator quadratus (branch of median nerve - anterior interosseous N.)
Which muscles (and so nerves) contribute to supination of the forearm?
Biceps brachii (musculocutaneous N.) - main Supinator muscle (radial N.)
In the forearm, the median nerve supplies 4 superficial muscles, which one branch supplying the deep group, name the 4, which can be absent in some people?
Pass fail pass fail: Pronator Teres Flexor carpi radialis Palmaris longus - may be absent Flexor carpi ulnaris
Nerves and vessels are at risk during injury, what does the ulnar nerve pass behind at the elbow and which muscle does the radial nerve supply?
Medial epicondyle
Extensor muscle, so if damage to radial nerve in humeral fracture, loss of strength in elbow and risk extensors.
Name 5 muscles coming from the common flexor pronator origin of the medial epicondyle and 3 deep flexor muscles.
Pronator Teres, flexor carpi radialis, palmaris longus, flexor carpi ulnaris and flexor digitorum superficialis.
Flexor digitorum profundus, flexor policies longus and pronator quadratus.
Name 4 extensor muscles of the wrist and fingers - what are they innervated by?
Extensor carpi radialis longus, extensor carpi radialis brevis, extensor carpi ulnaris and extensor digitorum communis.
All are supplied by the radial nerve.
Name 5 flexor of the wrist and fingers, what are they innervated by?
Flexor pollicus longus, superficial flexor digitorum, palmaris longus, flexor carpi radialis - all supplied by the radial nerve.
Flexor carpi ulnaris (ulnar N.).
What series of events causes Compartment syndrome?
If a fracture occurs, pressure builds up in a compartment, so veins collapse and arterial supply is eventually cut off, leading to necrosis.
What does the cubical fossa contain?
Lateral to medial TAN: tendon, artery, nerve - biceps tendon, brachial artery, then median nerve.
A fragment of bone may impair a vessel or stretch a nerve, what’s the point of bursae around the elbow?
A bursa is a potential sac that can fill with fluid in inflammation.
There are 8 carpal bones. Name them.
Some lovers try positions that they can’t handle.
Scaphoid, lunate, triquetral, pisiform
Trapezium, trapezoid, capitate, hamate
Information organisations can be key when presenting a patient, the order can be helped by the following phrase, meaning what?
In A Surgeon’s Gown A Physician Might Make More Progress
Incidence Age Sex Geography Aetiology Pathogenesis Macroscopic Microscopic Management Prognosis
Elbow dislocation:
Usually occurs in ______\ _______ after FOOSH. Could present with ____, _____ and _____ ___ ______.
Usually posterior or anterior and what other feature may be present?
Children/young adults
Pain, deformity, loss of function
Usually posterior and may present with or without fractures.
