3: Forearm and wrist Flashcards
Medial supracondylar ridge of humerus
Lateral supracondylar ridge of humerus
What does it articulate with?
Capitulum of humerus (lateral)
Articulates with the radius
Trochlea of humerus (medial)
Articulates with the ulna
Coronoid fossa of humerus
Olecranon fossa of humerus
Radial Fossa of humerus
What is the main function of the ulna?
To stabelise the forearm
Olecranon of Ulnar
Coronoid process of ulna
Styloid process of ulna
What is the head of the ulna?
articular surface that joints with the triangular articular disc and the ulnar notch of the radius
Identify the Trochlea and radial notch of the ulna
What are the articulate surfaces of the bones in the ellbow joint covered with?
Hyaline cartilage
What are the medial and lateral epicondyle of the humerus?
How are the ligaments in the elbow joint arranged?
They should stabelise the joint, but also allow movement of the joint
Explain the articulations of the bones in the elbow joint in anatomical position and in flexion
The Trochlea of the Humerus articulates witht the Ulna in the anatomical position
The Radius additionally articulates with the capitulum in full flexion
What is the carrying angle?
How big is it normally and what is the sex difference?
It is the deviation of the long axis of the radius and ulnar in the anatomical position
On average, it is 7°, but larger in women
(Elbow)
Medial/Ulnar collateral ligaments
Radial collateral ligament
Anular ligement of radius
What is it?
Which clinical problems can occur with the structure?
It is the olecralon bursa, that can get inflammed
Name all the proximal and distal carpal bones
Proximal Row:
From lateral to medial when vieved anteriorly:
Proximal row
- Some - Scaphoid
- Lovers - Lunate
- Try - Triquetrum
- Positions - Psisiform
Distal row
- That - Trapezium
- They - Trapezoid
- Can’t - Capitate
- Handle - Hamate
What is a “pulled elbow” in children?
The subluxion of the radial head out of the proximal radio-ulnar joint
This can be painful but can easily be repositioned (in supination)
Explain the anatomy of the proximal radial-ulnar joint
Pivot-type synovial joint, that allows the head of the radius to rotate within the annular ligament at the radial notch of the ulnar
What happens during pronation/supination at the proximal radio-ulnar joint?
The radial head turn in the radial notch of the ulnar
What happens during pronation/supination at the distal radio-ulnar joint?
During pronation, the radius rotates over/around the distal ulnar
What are the bony compartment of the wrist joint?
It is a joint between the
- radius
- articular disc of the distal end of the ulna
- And the three carpal bones:
- Scaphoid
- Lunate
- Triquetrum
How is the fibrous connection between the ulnar and the radius called?
What is its function?
- It is the interosseous membrane of the foream
It
- gives rise fo muscle attachmetns
- transfers forces between the bones (radius, ulna, humerus)
What are the superficial muscles of the anterior compartment of the arm?
The most superficial layer
- Pronator Teres
- Flexor carpi radialis (FCR)
- Palmaris Longus (PL)
- Flexor carpi Ulnaris (FCU)
–> PFPF
+ 5. Flexor Digitorium Superficialis (one layer deeper)
Which nerves supplies most of the superficial anterior compartment of the forearm?
Which muscle is the exception?
Most muscles are supplied by the Median Nerve
- Pronator Teres, Flexor Carpi Radialis, Palmaris longus, Flexor digitorium superficialis
Exept from Flexor Carpi Ulnaris –> supplied by Ulnar Nerve
Which muscles are part of the deep anterior compartment of the forearm?
- Flexor digitorum profundus (FDP)
- Flexor pollicis longus (FPL)
- Pronator quadratus (PQ)
When coming to the forearm and wrist, where are most Flexors and where are most Extensors located?
- Flexors are usually located in the Anterior compartment of the Forearm
- Extensors are usually located in the posterior compartment of the forearm
Which nerves supplied the deep anterior compartment of the forearm?
Mainly Median Nerve
- Flexor digitorium Profundus for 2nd and 3rd digit
- Flexor pollicis longus
- Pronator quadratum
Exept
- Flexor digitorium Profundus of 4th and 5th digit –> ulnar nerve
What are the proximal and distal attachment of the brachioradialis?
- Proximal:
- Lateral supracondylar ridge of Humerus
- Distal
- Styloid process of radius
Brachioradialis
Which nerves innervates the Brachioradialis muscle?
Radial Nerve (C5-7)
What are the proximal and distal attachments of the supinator muscle?
Proximal:
- Lateral epicondyle of humerus
- Anular ligament of radius
- Radial Collateral ligament
- Supinator crest of ulnar
Distal
- Anterior, lateral and posterior Surface of Radius
Which nerves innervates the supinator?
Radial Nerve (C5-7)
What are the proximal and distal atachments of the pronator teres muscle?
Proximal (common flexor tendon)
- Medial supracondylar ridge of humerus (common flexor origin)
- Coronoid process of ulna
Distal
- Lateral surface of radius
Which nerve innervates the pronator Teres?
Median Nerve (C5-8+T1)
What are the proximal and distal attachments of the pronator quadratus?
- Proximal
- Anterior surface of ulnar
- Distal
- Anterior surface of radius
Which nerves innervates the pronator quadratus?
Median Nerve (C5-8+T1)
What is the Flexor retinaculum of the hand?
What is its function?
The transverse carpal ligament
–> tansverse ligament that includes all the flexors of the hand (including the median nerve) and forms the roof of the carpal tunnel
What is the anatomical snuff box?
What does it contrain and what is its clinical significance?
The area between the tendon of the extensor pllicis longus and the extensor pollicis brevis
It contains the
- Radial artery
- scaphoid bone
Explain the arterial supply from the Clavicle to the elbow
- Subclavian artery
- •passes over the first rib to become…
- Axillary artery
- at the lower border of teres major becomes the…
- Brachial artery
- Gives off a large branch in the arm – Profunda brachii (Picture: green: brachial artery, lext next to it profunda brachii)
What happens to the brachial artery at the elbow?
Explain the further supply
Brachial artery devides into
- Radial artery
- Ulnar artery
Both terminate at the Hand to anastomose with each other and and form the palmar arches
Explain the route of the ulnar artery
- descends in the anterior compartment of the forearm
- passes into the hand anteriorly, on the ulnar side of the wrist (just lateral to FCU).
- The ulnar nerve lies medial to it at the wrist joint, i.e. from medial to lateral, the relationships are FCU, ulnar nerve, ulnar artery.
What does the ulnar artery supply?
- medial muscles of the forearm,
- via branches including the
- common interosseous artery,
- the anterior interosseous artery
- and the posterior interosseous artery.
Explain the route of the radial artery
- descends lateral aspect of the forearm under the the brachioradialis muscle.
- It is easily palpable at the wrist
- It crosses the floor of the anatomical snuff box and ultimately anastomosis with branches of the ulnar artery to form the palmar arches.
Summarise the superficial venous drainage of the Arm
- Superficial venous dorsal network and superficial venous palmar arch drain into
- Cephalic vein (Lateral)
- Basilic vein (Medial)
- The Median cubital vein connects the two veins at the elbow
- Basilic vein forms the axillary vein which is joined by the cephalic vein to give the subclacian
Explain the route of the deep veins in the forearm
Deep veins (venae comitantes) accompany the radial and ulnar arteries. They eventually flow to the brachial vein in the arm
What are the boundries of the cubital fossa?
- brachioradialis muscle (lateral),
- pronator teres muscle (medial),
- the line between the humeral epicondyles (superior).
What are the contents of the cubital fossa?
How are they related to one another
Deep
- Biceps tendon
- Brachial artery (medial to biceps tendon)
- Median nerve (Medial to brachial artery)
- Radial nerve laterally
Superficially
- median cubital vein
What is a sesamoid bone?
A bone embedded in tendons/ muscles
What kind of bone is the pisiform bone?
Sesamoid bone
Which bone of the carpital bone regularly gets fractured that you can feel in the anatomical sniff box?
What is the associated probelm?
- The scaphoid regularly gets fractured
- has recurrent blood flow that might get damaged –> necrosis
- leading to problems+ pain in the wrist
What is the anatomical snuff box?
Which structures pass through it?
- Space between the extensor pollicis longus tendon and the extensor pollicis brevis tendon on the thumb side
- The radial artery
- (+ radial nerve nearby)
What are the superficial muscles of the posterior forearm?
7 Muscles
What are the deep muscles of the posterior forearm?
5 Muscles
- 3x tumb
- 1x index finger
What is the origin of the superificial extensors of the forearm?
extensor carpi radialis brevis, extensor digitorum, extensor carpi ulnaris and extensor digiti minimi= lateral epicondyle of humerus (common tendon origin)
- extensor carpi radialis longus= supracondylar ridge
