Flashcards in "Elbow, Forearm and Wrist" Questions Deck (45)
What are the bones involved in the forearm?
Humerus (distal end)
Carpal bones (hamate, capitate, trapezoid, trapezium, scaphoid, lunate, triquetrum, pisiform)
What are the important structures at the proximal end of the ulna?
Coronoid process (sits in the coronoid fossa of the humerus)
Olecranon (sits in olecranon fossa of humerus)
Trochlear notch (space where the trochlea of humerus inserts)
Radial notch of the ulna (little dip for head of radius to sit next to the ulna)
What are the identifiable tuberosities on the ulna and the radius?
Both found on the anterior surface of proximal end of radius and ulna
What are the two important structures at the distal end of the radius and the ulna?
Styloid process (protrusion of bone from end of radius)
Styloid process of the ulna (much smaller protrusion of bone from the end of the ulna)
How do the ulna and radius differ and how do they fit together?
Ulna = large proximal end, small distal end, "hook" shape at proximal end for insertion into olecranon/coronoid fossae
Radius = small proximal end, large distal end, large articular surface at distal end, small cylindrical flat articular surface at proximal end
What important muscle tendon attaches to the olecranon of the ulna?
Triceps brachii tendon
- extension of the elbow
What carpal bones does the distal end of the radius articulate with?
(the two big bois)
What are the two condyles of the humerus?
What are the four bones of the proximal row of carpal bones?
- lateral to medial
What are the four bones of the distal row of carpal bones?
- medial to lateral
What kind of joint is the elbow joint and which bones are involved?
Synovial hinge joint
- humerus (proximally)
- ulna + radius (distally)
Ulna with humerus via trochlea
Radius with humerus via capitulum
What are the ligaments involved in the elbow that contribute to joint stability?
Medial (ulnar) collateral ligaments (anterior cord-like band, posterior fan-like band, oblique band)
Lateral (radial) collateral ligaments
Anular ligament (part of radio-ulnar joint)
What are the muscles involved in flexion and extension of the elbow joint?
Flexion - biceps brachii, brachialis, brachioradialis (pronator teres to a degree)
Extension - triceps brachii, anconeus
What is the proximal joint between the radius and the ulna called, what is it stabilised by, and what is important for?
Proximal radio-ulnar joint
Pivot joint that allows the head of the radius to move around the ulna in rotation
Allows supination and pronation
Stabilised by the anular ligament
What are the muscles producing pronation and supination of the forearm?
Supination - supinator, biceps brachii
Pronation - pronator quadratus, pronator teres
What is the other joint between the radius and the ulna?
Distal radio-ulnar joint
- allows radius to move around ulna in rotation
What kind of joint is the wrist joint and which bones is it between?
- between the distal radius and its associated triangular fibrocartilage with the proximal row of the carpal bones (except pisiform)
What are the ligaments which stabilise the wrist joint?
Ulnar collateral ligament
Radial collateral ligament
Palmar radio-carpal ligaments
Dorsal radio-carpal ligaments
Radio-carpal and inter-carpal ligaments are frequently injured
What are the movements of the wrist?
Flexion and extension
Radial and ulnar deviation (abduction and adduction)
Circumduction (rotation in a circle)
What are the muscles of the anterior compartment of the UPPER arm and what nerve supplies these muscles?
- musculocutaneous nerve (C5,6)
What are the muscles of the posterior compartment of the UPPER arm and what nerve supplies these muscles?
- radial nerve (C7,8)
What are the muscles of the (superficial) anterior compartment of the forearm?
Flexor carpi radialis
Flexor digitorum superficial
Flexor carpi ulnaris
All innervated by median nerve apart from flexor carpi ulnaris (ulnar nerve)
What are the muscles of the (deep) anterior compartment of the forearm?
Flexor digitorum profundus
Flexor pollicis longus
(All innervated by median nerve, digitorum profundus is special as divides into two parts; medial and lateral. medial part is supplied by ulnar nerve (4/5th fingers) and lateral part by the median nerve (2/3rd fingers))
What are the muscles of the posterior compartment of the forearm?
- extensor carpi radialis longus
- extensor carpi radialis brevis
- extensor carpi ulnaris
- extensor digitorum
- extensor indicis
- extensor digiti minimi
- abductor pollicis longus
- extensor pollicis brevis
- extensor pollicis longus
All supplied by the radial nerve
Brachioradialis (only partly in the posterior compartment but included here because it's innervated by the radial nerve C5/6), this is an accessory flexor of the elbow
Where does the ulnar artery run and what branches does it give off?
Runs in the anterior compartment of the forearm. Lies medial to flexor carpi ulnaris and lateral to the ulnar nerve.
Gives off the common interosseous, anterior interosseous and posterior interosseous arteries.
Terminates in the hand to form the palmar arches with the radial artery
Where does the radial artery run and where does it terminate?
Passes down the lateral aspect of the forearm under the cover of the brachioradialis muscle.
Crosses the floor of the anatomical snuff box and anastomoses with the ulnar artery in the hand as the palmar arches.
What are the borders of the anatomical snuff box?
Anterior border - abductor pollicis longus + extensor pollicis brevis
Posterior border - extensor pollicis longus
Floor - scaphoid proximally and trapezium distally
What are the contents of the anatomical snuff box?
Demonstrate and name the main veins of the upper limb.
Superficial and deep veins
Cephalic and Basilic veins are the main superficial veins. The cephalic vein is formed from the lateral side of the dorsal venous arch of the hand and runs up the lateral aspect of the forearm. The basilic vein is formed from the medial side of the dorsal venous arch of the hand and runs up the medial aspect of the forearm.
The two are conjoined by the median cubital vein. The median ante-brachial vein and the interosseous veins join the basilic vein at the medial side of the elbow.
Both superficial veins continue up the arm and join the axillary vein (deep system) at delto-pectoral triangle.
Deep veins accompanying (venae comitantes?) radial/ulnar arteries flow into the brachial vein.
What do the veins have which is important in transition of blood between deep and superficial venous systems?
The deep and superficial veins have numerous connections with these connections gated by valves which allows one-way flow of blood from the superficial to the deep system.
How is the lymphatic system of the arm structured?
Superficial and deep systems which run with their respective venous systems. There are some cubital lymph nodes in the cubital fossa and these also drain into the axillary lymph nodes.
What are the borders of the cubital fossa?
Base - line between the two humeral epicondyles
Lateral - medial border of brachioradialis
Medial - lateral border of pronator teres
Floor - brachialis and supinator muscles
Roof - bicipital aponeurosis, skin/fascia
What are the contents of the cubital fossa?
- moving lateral to medial
Lateral cutaneous nerve
Medial cutaneous nerve
Tendon of biceps brachii is in there somewhere (lol)
Median cubital vein
What are the 3 main nerves of the forearm?
What is the course of the ulnar nerve, how can it be damaged, and what part of the forearm does it innervate?
Runs posterior to the medial epicondyle of the elbow
- Can be damaged by elbow joint fracture/dislocation
- innervates the medial muscles of the anterior compartment of the forearm (FCU + medial branches of FDP) but is the main nerve of the hand
What is the course of the radial nerve, how can it be damaged, and what part of the forearm does it innervate?
Passes around the body of the humerus in the radial groove
- can be damaged by a fracture of the humeral shaft
- supplies the posterior compartment of the upper arm and forearm
What is the course of the median nerve, how can it be damaged, and what part of the forearm does it innervate?
Passes anterior to the distal humerus
- can be damaged by fracture/dislocation of the elbow joint
- supplies the anterior compartment of the forearm (superficial and deep) except for FCU + ulnar part of FDP
What is the clinical test of the biceps brachii muscle and which nerve + nerve roots are being tested?
Flex elbow against resistance
- musculocutaneous nerve, C5,6,7
What is the clinical test of the triceps brachii and which nerve + nerve roots are being tested?
Extend (already flexed) elbow against resistance
- radial nerve, C6,7,8
What is the clinical test of the brachioradialis and which nerve + nerve roots are being tested?
Flex elbow, with forearm in mid-prone position, against resistance
- radial nerve, C5,6,7
What is the clinical test of the flexor carpi ulnaris and which nerve + nerve roots are being tested?
Flex wrist against resistance
- ulnar, C7,8
What is the clinical test of the palmaris longus and which nerve + nerve roots are being tested?
Flex wrist against resistance
- median, C6,7
What is the clinical test of the flexor carpi radialis and which nerve + nerve roots are being tested?
Flex wrist against resistance
- median, C6,7
How would the major vessels of the forearm be tested clinically?
- Palpate radial and ulnar arteries as pulses on their respective sides of the wrist
- Palpate the brachial artery as a pulse at cubital fossa/elbow and along the mid-humeral shaft