Shoulder Arthrology Flashcards
Joints of the shoulder complex
- Glenohumeral joint (shoulder)
- Acromioclavicular joint (AC)
- Sternoclavicular joint (SC)
- Scapulothoracic articulation
Suprahumeral articulation
Glenohumeral Joint
Classification:
* Multi-axial synovial
ball and socket
Articulation:
* Head of the
humerus
* Glenoid fossa of
the scapula
Hyaline Cartilage
Glenoid Fossa
- Situated superiorly and laterally
on the scapula - Covered in hyaline cartilage
- Pear shaped – narrow superiorly
- Concave
- Deepened by the glenoid labrum
Glenoid Labrum
Glenoid Labrum
- Deepens glenoid
- Composed of fibrocartilage
- Triangular in cross section – thin edge
- Lined by cartilage continuous with the
glenoid fossa - Inner surface in contact with the
humerus - Attached to the LHB superiorly
- Attaches to margins of glenoid; the joint
capsule superiorly and posteriorly
Ligaments of the glenohumeral Joint
Glenohumeral Ligaments:
- Superior
- Middle
- Inferior
Passive stabilization:
- Lateral rotation – all under
moderate tension
Medial rotation – all relaxed
Abduction – middle and
inferior taut, superior relaxed
Joint Capsule
- Loose cylindrical sleeve
- Surrounds joint and attaches to
the outside of the glenoid labrum
(ant and inf), to the glenoid
labrum (sup and post) and on the
humerus to the anatomical neck - Direction of fibres: horizontal
from scapula to humerus but
there are some oblique and
transverse also - Lined with synovial membrane
Acromioclavicular Joint
Acromion of Scapula and Acromial
(lateral) end of Clavicle
FOOSH INJURY
* Synovial Plane Joint
* Fibrocartilage disc
* Both surfaces are covered in
fibrocartilage
* Loose fibrous capsule, attaches to
the articular margins. Strong fibres
run parallel
* Synovial membrane lines the
capsule
Shapes:
* Oval, slightly convex shaped facet
on the lateral clavicle
* Reciprocally shaped anteromedial
border of the acromion
Ligaments of the Acromioclavicular Joint
- Acromioclavicular
ligament - Coracoclavicular ligament
(not directly related,
accessory ligament) - Trapezoid and Conoid
parts - Limit protraction and
retraction
AC ligament= small
CC ligament= larger,strong
Coracohumeral ligament
- Strong broad band
- Originates from the lateral border of the coracoid process
- Inserts into the anatomical neck and transverse humeral ligament
- Blends with tendons of subscapularis anteriorly and supraspinatus superiorly
Coracoacromial ligament
- Strong triangular ligament
- Originates from the coracoid process and
inserts into the apex of the acromion in
from of the AC joint - Forms an osseoligamentous arch which
helps support the head of humerus during
upwards translation
The Sternoclavicular Joint
- Classification:
- Synovial saddle-shaped joint
with fibrocartilage disc - Articulation:
- Medial aspect of the clavicle
- Clavicular notch of the sternum
Sternoclavicular Joint cont
- The only attachment of the upper limb to the rest of the body (trunk)
- Sternal end of clavicle, clavicular notch on
manubrium and costal cartilage of 1st rib. - Reciprocally curved joint
surfaces
Limited movement through gliding
The Scapulothoracic Joint
- Allows Scapula to slide over ribcage during movements to increase Glenohumeral ROM
- The scapulothoracic joint is not a true joint - it has no capsule or ligamentous attachments.
- It is formed between the anterior scapula and the posterior thoracic rib cage (ribs 2-7).
- The scapula’s attachment to the skeleton in a healthy shoulder is purely musculotendinous in nature, formed by the Trapezius and Serratus Anterior muscles.
