Osteology of scapula, clavicle + humerus Flashcards
What is the joint between the scapula + humerus?
Glenohumeral joint
What is the joint between the scapula + clavicle?
Acromioclavicular joint
What is the concave depression on the costal/anterior surface of the scapula?
Subscapular fossa
What is the hook-like projection under the clavicle?
Coracoid process (pec. minor inserts, coracobrachialis + short head of biceps brachii originate)
What is the glenoid fossa?
Shallow cavity on scapula, articulates with glenohumeral joint
What are the supraglenoid tubercle + infraglenoid tubercle?
Roughening superior/inferior to glenoid fossa, origin of long head biceps brachii or long head triceps brachii
What is the acromion of the scapula?
Projection @ lateral end of scapula = acromioclavicular joint
What are the supraspinous/infraspinous fossa?
Above/below spine of scapula, origin of supraspinatus/infraspinatus
What is the scapulothoracic ‘joint’?
Anterior scapula + rib cage = not a true joint
Cause of scapula fracture + why they don’t need fixation
Severe chest trauma = crushing/RTA/high-impact sports injuries
Tone of surrounding muscles holds fragments in place whilst healing occurs
Where does the clavicle extend between?
Manubrium of sternum + acromion
3 functions of clavicle
Attach upper limb to trunk
Transmit force from upper limb to axial skeleton
Protect neurovascular structures of upper limb
What is the shape of the clavicle?
Medial (sternal end) = convex anteriorly
Lateral (acromial end) = concave
What forms the coracoclavicular ligament?
Conoid ligament (medial) on conoid tubercle Trapezoid ligament (lateral) on trapezoid line
What are the 2 atypical features of the acromioclavicular (AC) joint?
Articular surfaces lined with fibrocartilage
Joint cavity partially divided by articular disc
What 3 ligaments strengthen the AC joint?
AC ligament = horizontal from acromion to lateral clavicle, reinforces superior aspect
Conoid + trapezoid = extrinsic, both from coracoid process
What movements are at the AC joint?
Passive as no muscles
Axial rotation
Anteroposterior movement
Where is the sternoclavicular joint?
Clavicle + manubrium of sternum, upper 1st costal cartilage
Why is the sternoclavicular joint in 2 compartments by a fibrocartilaginous articular disc?
Allow clavicle + manubrium to slide freely over each other
Rotation in 3rd axis
What movements of the shoulder also require movement @ the sternoclavicular joint?
Elevation/depression of shoulder joint
Protraction/retraction
Rotation
Where do 3 of the rotator cuff muscles insert?
Greater tubercle
What inserts onto the lesser tubercle?
Subscapularis
How to remember the insertion of muscles @ intertubercular sulcus
“Lady between 2 majors”
Latissimus dorsi between pec. major (lateral lip) + teres major (medial lip)
What is in close proximity to the surgical neck of the humerus?
Axillary nerve
Circumflex humeral vessels
What lies in the radial groove on posterior humerus?
Radial nerve
Profunda brachii artery
