MSK Joints of the upper limb Flashcards
What type of joint is the sternoclavicular joint?
What cartilage type is present in the sternoclavicular joint?
A saddle - type synovial joint between the clavicle and manubrium of the sternum
A fibrocartilaginous articular disc is present which is part of the 1st costal cartilage
What are the 4 major ligaments of the sternoclavicular joint?
Anterior and posterior stenoclavicular ligaments:
Strengthen the joint capsule anteriorly and posteriorly
Interclavicular ligament:
Spans the gap of the sternal ends of each clavicle reinforcing the joint capsule superiorly
Costaclavicular ligament:
The 2 parts of this ligament (separated by bursa) bind at the 1st rib inferiorly and to the clavicle superiorly. Very strong and the main stabiliser of the joint
What is the neurovascular supply to the sternoclavicular joint?
Arterial supply: internal thoracic artery and suprascapular artery
Nerve supply: medial supraclavicular nerve (C3-4) and nerve to the subclavius (C5-6)
How mobile is the sternoclavicular joint?
How stable is the sternoclavicular joint?
High degree of mobility - saddle joint so can move in 2 axis
Articular disc allows free sliding allows for rotation and movement in a 3rd axis
Has to be very stable as it is the only joint connecting the upper limb to the axial skeleton
- strong joint capsule
- strong ligaments, especially costaclavicular ligament
What is the consequence of a dislocation of the sternoclavicular joint?
Rare.
- Anterior dislocations most common and are caused by blow to anterior shoulder which rotates shoulder backwards
- Posterior dislocations result from force driving shoulder forwards or direct impact
Usually in young a dislocation is accompanied by a fracture through the epiphyseal growth plate of clavicle
What type of joint is the acromioclavicular joint?
What cartilage type is present in the sternoclavicular joint?
Plane type synovial joint can be palpated on shoulder
Articular surfaces lined with fibrocartilage, and there is a fibrocartilage articular disc suspended from joint capsule
What are the 3 major ligaments of the acromioclavicular joint?
Acromioclavicular ligament: runs from accordion to clavicle reinforcing superior part of joint capsule
Conoid ligament: runs vertical from coracoid process to conoid tubercle of clavicle
Trapezoid ligament: runs from coracoid process to trapezoid line of clavicle
Conoid and trapezoid make up the coracoclavicular ligament that is very strings and supports weight of upper limb
What are the movements of the acromioclavicular joint?
Allows degree of axial rotation and anteroposterior movement (no muscles so all movement passive)
What is the neuromuscular supply to the acromioclavicular joint?
Blood supply: suprascapular artery and thoraco-acromial artery
Nerve supply: suprascapular and lateral pectoral nerves
What is the consequence of a dislocation of the acromioclavicular joint?
Known as ‘separated shoulder’ and is associated with soft tissue damage - Commonly occurs due to direct blow or fall an an outstretched hand
More serious if there is ligament rupture, if the coracoclavicular ligament is torn the weight of the upper limb is not supported so moves inferiorly.
What type of joint is the glenohumeral joint?
What cartilage type is present in the glenohumeral joint?
A ball and socket joint
Articulating urfaces lined with hyaline cartilage
How mobile is the glenohumeral joint?
How stable is the glenohumeral joint?
One of the most mobile joints of the body:
- ball and socket joint with a lax joint capsule
- shallow cavity and larger humeral head
but also one of the most unstable.:
This is because the humeral head is much larger than the glenoid fossa
- rotator cuff muscles help pull the humeral head into the glenoid fossa
- glenoid fossa is deepened by a fibrocartilage rim called the glenoid labrum
- ligaments reinforce joint capsule
What are the major bursae present in the glenohumeral joint?
Subacromial bursa - inferior to deltoid and acromion and superior to supraspinatus tendon and joint capsule.
Subscapular bursa - located between subscapularis tendon and scapula
What are the major ligaments of the glenohumeral joint?
Glenohumeral ligaments (superior, middle, inferior): 3 bands that runs with the joint capsule from glenoid fossa to anatomical neck of humerus. Stabilises anteriorly
Coracohumeral ligament: base of coracoid to greater tubercle of humerus. Supports superiorly
Transerve humeral ligament: Spans tubercles of humerus and holds biceps tendon in intertubecular groove
(all thickenings of the joint capsule)
The coracoacromial ligament prevents superior displacement of the humeral head
What is the neurovascular supply to the glenohumeral joint?
Blood supply: posterior circumflex humeral artery and suprascapular artery
Nerve supply: axillary, suprascapular and lateral pectoral nerves (all C5-6 so erbs palsy affects shoulder)
What is the consequence of a dislocation of the glenohumeral joint?
Anterior dislocations most prevalent (superior movement prevented by coraco-acromial arch)
Usually caused by excessive extension and lateral rotation
Tearing of joint capsule increased risk of future dislocations
Axillary nerve can be damaged resulting in paralysis of deltoid and loss of sensation of regimental badge area
What is rotator cuff tendonitis?
Relatively common
Inflammation of the rotator cuff tendons due to overuse
Characteristic sign in the painful arc pain in the middle of abduction where the tendon comes into contact with the acromion
What type of joint is the elbow joint?
Structurally a synovial joint but functionally a hinge joint
What are the articulations involved in the elbow joint?
Trochlea notch of ulna and trochlea of humerus
Head of radius and capitulum of humerus
What structures contribute to the stability of the elbow joint?
Radial collateral ligament: extends from lateral epicondyle to anular ligament of the radius
Ulnar collateral ligament: extends from medial epicondyle to coronoid process and olecrannon of ulna
What are the major bursae of the elbow joint?
Intratendinosus bursa: within triceps tendon
Subtendinosus bursa: between olecrannon and triceps tendon
Subcutaneous bursa: between olecrannon and overlying CT
What types of bursitis can arise at the elbow joint?
Subcutaneous bursitis - repetitive friction and pressure of the elbow
Subtendinosus bursitis - repeated flexion and extension. Flexion more painful as more flexion put on bursa
What is the consequence of a dislocation of the elbow joint?
Most dislocations posterior
Usually occurs when child falls on hand with elbow flexed
Humerus driven through weakest part of joint capsule which is the anterior side
Ulnar collateral ligament usually torn
What is the consequence of a supraepicondylar fracture?
A transverse fracture caused by falling on a flexed elbow
Can cause disruption to blood supply of forearm as swelling can affect brachial artery. This can cause volkmanns ischemic contracture (uncontrolled flexion of hand)
Also can be damage to medial, ulnar or radial nerves
What are the 2 articulations between the radius and ulna and what type of joint are they?
Proximal radioulnar joint: between head of radius and radial notch of ulna
Distal radioulnar joint: between head of ulna and ulnar notch of radius
Both pivot joints responsible for pronation/supination
What ligaments are present at the 2 radioulnar articulations?
Proximal radioulnar joint: The radial head is held in place by the annular radial ligament (is lined with synovial membrane to reduce friction)
Distal radioulnar joint: anterior and posterior ligaments, also a fibrocartilaginous ligaments called the articular disk (holds bones together and separates joint from wrist)
What is the interosseous membrane and what is its function?
A sheet of CT connecting medial radius and lateral ulna
There are holes for the forearm vasculature
3 major functions:
- holds bones together during pronation and supination providing stability
- sites of attachment for muscles
- transfers forces from radius to ulna
What are the 2 main types of fracture/dislocation combo of the radius and ulna?
Monteggias fracture - usually caused by force behind ulna
Proximal shaft of ulna fracture and radial head dislocates anteriorly at the elbow
Galeazzis fracture
A fracture to distal radius with the ulna head dislocating at the distal radio-ulnar joint
What type of joint is the radiocarpal joint?
An ellipsoid type synovial joint - allows for movement in 2 axis
What are the articulating surface of the wrist joint?
Proximally - Distal radius articulates with articular disk
Distally - Distal radius with proximal row of carpals except pisiform
What is the neurovascular supply to the radiocarpal joint?
Blood supply: branches derives from radial and ulnar arteries
Nerve supply: branches of radial nerve, ulna nerve and median nerve
What are the ligaments stabilising the radiocarpal joint?
Palmar + dorsal radiocarpal ligament - they extend from radius to both rows of carpals. They stabilise and ensure hand follows forearm during supination + pronation (respectively)
Ulnar collateral ligament - ulnar styloid process to triqutrum and pisiform. Prevents excessive lateral joint displacement
Radial collateral ligament - radial styloid process to scaphoid and trapezium. Prevents excessive lateral joint displacement
What causes an anterior dislocation of the lunate and what are the consequences?
Fall on dorsiflexed wrist
Lunate forced anteriorly compressing the carpal tunnel giving symptoms of carpal tunnel syndrome
Lunate can also undergo avascular necrosis
What is the palmar aponeurosis and what is its function?
It is palmar fascia that thickens in the centre of the hand (it is a continuation of the flexor retinaculum and palmaris longs tendon).
It protects underlying muscle compartments
What is dupuytren contracture?
Prevents partial flexion of one or more fingers as a result of thickening of palmar fascia due to fibrosis.
Patients cannot fully extend fingers and have problems gripping objects
Treatment is surgery to relieve tension in the CT
What are the major ligaments of the hand?
- The flexor retinaculum. A thick strip of CT forming the roof go the carpal tunnel and protecting structures within it. It attaches to pisiform+ hook of hamate, and to trapezium and scaphoid
- The extensor retinaculum. A thickening of dorsal fascia which keeps extensor tendons in position
- The palmar plates. Present of palmar side of each MCP and IP joint which enhance stability by preventing hyperextension
- Collateral ligaments. Medial and lateral sides of each MCP and IP joint, they are taut when fingers are flexed which limits abduction in a clenched fist. The are lax when fingers are extended allowing abduction
What tendons are present in the hand?
Flexor tendons of the fingers: (of flexor digitorum profundus and flexor digitorum superficialis). Pass through carpal tunnel
Extensor tendons of the fingers: the tendons of extensor digitorum flatten as they reach metacarpals and become extensor hoods which wrap around the metacarpal.
