130 - Joints of Upper Limb 1 - Shoulder Complex Flashcards
Components of synovial joints 1 2 3 4 5
1) Articular cartilage – avascular & aneural
2) Fibrous capsule – may be reinforced by stabilizer muscles
3) Capsule strengthened by intrinsic ligaments
4) Extrinsic (accessory ligaments) may be primarystabilisers
5) Synovial membrane - linesall non-articular surfaces
Consequence of having a lot of hyaline cartilage on a bone
Only will have a narrow area where blood vessels can enter (hyaline cartilage is avascular).
Therefore bone is vulnerable to necrosis
Structure from which most pain comes in a broken bone
Periosteum
What lines all non-articular surfaces in a synovial joint?
Synovial membranes
Examples of 'special' synovial joint structures 1 2 3 4 5 6
1) Labrum
2) Fat pad
3) Intra-casular tendon
4) Discs, menisci
5) Bursae
6) Ligaments
Labrum
A fibro-cartilagenous rim that deepens the socket in ball-and-socket joints.
Increases congruence of a joint quite markedly (EG: by 1/3 in shoulder joint)
Fat pad
Intra-articular, extra-synovial structures.
Fill out irregularly-shaped structures in joints
Ligaments
Thickenings of capsule (intrinsic) or extrinsic ligaments.
Stabilise joints
What can a ligamentous injury in children involve?
An avulsion injury (because ligament is stronger than growing bone)
Discs and menisci
Shock absorb.
Might bear weight.
Have blood and nerve supply to outer third.
EG: In knee
Bursae
Can communicate with joint cavity.
If it can communicate, can have flow of synovial fluid into communicating bursa, EG: In the case of infection.
What does stability of mobile joints often depend on?
Short fixator or stabiliser muscles
Joints of the clavicle
1
2
Sternoclavicular joint.
Acromioclavicular joint.
Feature on the posterior aspect of scapulae
Spinous process.
Divides into supraspinous fossa and infraspinous fossa
How do muscles attach to scapula?
With muscle attachment, not tendinous attachment.
Lateral fossa on scapulae
Glenoid fossa
Processes overhanging gelnoid fossa
Acromion process.
Coracoid process
Where does the acromion process come from?
Part of the spinous process of the scapula
Function of clavicles
Orientates the shoulder laterally for greater ROM.
Where does clavicle articulate with midline?
On bulbous part
Why is the clavicle curved?
So that it doesn’t impinge on structures (EG: blood vessels, nerves) that travel under the clavicles
Two ligamentous attachments to clavicle
Both on underside of clavicle.
Costoclavicular ligament
Coraco-clavicular ligament