MSK - Elbow Joint and Wrist Flashcards
What are the three major ligaments associated with the elbow joint?
Describe their origins and insertions.
What are their functions?
Radial collateral ligament - fan like, attaches between the lateral epicondyle of the humerus and annular ligament of the radius below. It keeps the head of the radius and capitulum in close association.
Ulnar collateral ligament - triangular, attaches to the medial epicondyle of the humerus and the Coronoid process and olecranon of the ulnar. It consists of three bands, the strong anterior band, fan like weak posterior band and slender oblique band which deepens the socket for the trochlear of the humerus
Annular ligament - surrounds the lower part of the head of the radius and maintains its contact with the radial notch of the ulnar
What is the origin and insertion for the radial collateral ligament?
What is its function?
Fan like, attaches between the lateral epicondyle of the humerus and annular ligament of the radius below.
It keeps the head of the radius and capitulum in close association.
What is the origin and insertion for the ulnar collateral ligament?
What is its function?
Triangular, attaches to the medial epicondyle of the humerus and the Coronoid process and olecranon of the ulnar.
It consists of three bands, the strong anterior band, fan like weak posterior band and slender oblique band which deepens the socket for the trochlear of the humerus
What is the origin and insertion for the annular ligament?
Surrounds the lower part of the head of the radius and maintains its contact with the radial notch of the ulnar
What are the main flexors of the elbow?
What muscles produce extension of the elbow?
Brachialis
Biceps brachii
Brachioradialis
Triceps and anconeus
Where does supination and pronation occur?
What muscles is supination produced by?
When do these muscles NOT act together?
Proximal radioulnar joint
Supinator and biceps brachii
Always act together except when the elbow joint is fully extended
In what joint does pronation occur?
What muscles produce pronation?
Proximal radioulnar joint
Pronator quadrus and pronator teres
What are the names of the two important bursae around the elbow joint?
Why can they become inflamed?
When is pain most severe?
Subcutaenous olecranon bursa - lies in the subcutaenous connective tissue overlying the olecranon. Inflammation - Repeated pressure and friction
Subtendious bursa - lies between the triceps tendon and the olecranon. Inflammation due to repeated flexion and extension in the elbow e.g. Assembly line workers.
During flexion of the forearm - pressure exerted on the inflamed subtendinous olecranon bursa by triceps tendon
What may become inflamed during repeated pronation/supination movements?
A bursa between the biceps tendon and the radius
What may dislocate when attempting to life a child or swing a child by the hands when the arm is fully abducted?
Dislocation of the radial head
When can avulsion of the medial epicondyle occur?
How does it occur?
After a fall which causes severe abduction of the fully extended forearm.
Traction on the ulnar collateral ligaments pulls the medial epicondyle medially.
What may cause a posterior dislocation?
A fall on the flexed elbow
What type of joint is the distal radioulnar joint?
What muscles are involved in moving it?
Pivot joint - in which the distal end of the radius moves around the distal end of the ulnar
Supinator and biceps brachii
What does the interosessous membrane do?
Where is it attached?
Form a fibrous joint between the radius and ulnar
From the radius proximally to the ulnar distally
The membrane keeps the bones in close apposition during the movements of supination and pronation and prevents proximal displacement of the radius if a force is applied to the outstretched hand
What type of joint is the wrist/radiocarpal joint?
Where is it formed between?
What ligaments stabilise it?
Condyloid type of synovial joint
Between the distal end of the radius and the scaphoid, lunate, triquetrum
What are the three articulation of the elbow joint?
Where do they attach?
What type of joints are they? and what are they surrounded by?
Humeroulnar joint - between the trochlea of humerus and the trochlear notch of ulna
Humeroradial joint - between the capitulum of the humerus and the radial head
Proximal radioulnar joint - between the edge of the head of the radius and the radial notch of the ulnar
Synovial joints - surrounded by a capsule that attaches near the margins of the articular surfaces
What lines the fibrous capsule and humerus?
Synovial membrane
What nerves are at the elbow?
Radial - passes anterior to lateral epicondyle
Ulnar - posterior to medial epicondyle
What are the names of the two bursae that give rise to problems?
Subtendinous olecranon bursa
Subcutaneous olecranon bursa
What is the neurovascular supply to the elbow?
Arterial anastomoses formed by collateral arteries and recurrent branches of ulnar, radial and interosseus arteries
What is the second most common joint in the body to be dislocated?
What tends to be the direction of dislocation?
What are the concerns of this dislocation?
Elbow - very stable joint, requires considerable force to dislocate
90% posterior
Brachial artery
Median and ulnar nerves
What type of joint is the proximal radioulnar joint?
What bones does it include and which parts?
Pivot joint
Head of radius
Radial notch of ulnar
Where is the annular ligament attached?
What is the name of the collar that surrounds the annular ligament?
Ulna anterior and posterior to its radial notch
Ligamentous collar
What happens anatomically to pulled elbow?
Head of radius subluxates from from annular ligament
Define dislocation
Define subluxation
Complete loss of contact of the joint surfaces
Partial dislocation of a joint, so that the bone ends are misaligned but still in contact
What type of joint is the interosessous membrane?
What is the importance of the fibres running inferio-medially?
Fibrous
Allows distribution of force from radius to ulna - force can be spread between two bones
What parts of bone are at the distal radioulnar joint?
What structure gives it joint integrity stability?
What allows twisting of the capsule?
Rounded head of ulna
Ulnar notch on medial border of radius
Articular disk - separates cavity of distal radioulnar joint from wrist cavity
Sacciform recess superior extension of synovial capsule
What muscles are involved in movement of the radioulnar joint?
Supinator
Biceps brachii
Pronator quadrus and pronator teres
What facilitates supination/pronation?
Bones?
Ligament?
Head of radius and capitulum
Annular ligament
Sacciform recesses - extensions of synovial membrane on neck of the radius and at distal radius and ulna
What is the sacciform recesses?
Where are they found?
Extensions of synovial membrane
Neck of the radius and at distal radius and ulna (superiorly from Articular disk)
What is the anatomical name of the wrist?
What bones are involved?
What are the ligaments?
What are the roles of each ligaments?
Radiocarpal joint
Distal radius
Carpus - proximal row of carpal bones (other than pisiform) I.e. Scaphoid, lunate and triquetrum
Radial collateral and ulna ligament
Palmar radiocarpal ligament- ensure hand follows radius during supination
Dorsal radiocarpal ligament - ensure hand follows radius during pronation
What are the movements at the wrist?
What is abduction limited by?
Flexion/extension
Abduction(radial deviation)/adduction (ulnar deviation)
Radial styloid process
How does a colles fracture differ from a smiths fracture?
What is the most common?
Both are fractures of distal radius
Colles - Posterior displacement of distal fragment of radius. Distal fracture displaced dorsally. Fall on outstretched hand.
Smith - anterior displacement of distal fragments. Distal fracture displaced ventrally. Falling on flexed wrist, tends to be direct trauma of forearm
Smiths fractures are less common
How does fractures of the scaphoid occur?
If you suffer a scaphoid fracture what will be tender?
What artery is of importance?
Why may repair take several months?
Fall on outstretched hand.
Tenderness over anatomical snuffbox
Radial artery - wraps around scaphoid and goes back in to innervate it - avascular necrosis - possible sequela.
Blood supply to proximal part of scaphoid is poor.
What ligaments stabilise the radiocarpal/wrist joint?
Collateral
Palmar
Dorsal ligaments
What are the prime flexors of the wrist?
What are the prime moves for wrist extension?
Flexor carpi radialis and flexor carpi ulnaris
Extensor carpi radialis longus and brevis
Extensor carpi ulnaris
Why may radial growth be impaired following a fracture of distal radius?
Fracture of distal radius may extend through the distal epiphyseal plate.
During healing there may be premature closure of the epiphyseal plate and radial growth may be impaired.
