MSK 2 Flashcards
(115 cards)
What are the three main functions of the clavicle?
- Connects the upper limb to the trunk
- Protects underlying neurovascular structures supplying upper limb
- Transmits force from upper limb to axial skeleton
What are the medial and lateral attachments of the clavicle?
Medially to sternum - Sternoclavicular joint
Laterally to the acromion - Acromioclavicular joint
What is the most common fracture of the clavicle?
Junction of the medial 2/3 and lateral 1/3
How is the clavicle most commonly displaced during a fracture and why?
Lateral end is displaced inferiorly by weight of arm and medially by pectoralis major
Medial end is pulled superiorly by sternocleidomastoid muscle
What are the nerves that could be at risk during a clavicular fracture?
Suprascapular nerves by upwards movement (they innervate the lateral rotator cuff muscles)
What is the purpose of the glenoid fossa on the scapula?
Articulates with humerus to form glenohumeral joint
What is the purpose of the supraglenoid tubercle and infraglenoid tubercle respectively?
Supraglenoid tubercle - Attachment for the long head of biceps brachii
Infraglenoid tubercle - Attachment for the long head of triceps brachii
When is a scapula fracture usually seen?
Severe chest trauma - hight speed road collisions, crushing injuries, sports injuries
What causes winging of the scapula?
Damage to the long thoracic nerve - as it innervates serratus anterior which attaches to costal face of scapula pulling it against ribcage
What does the proximal region of the humerus form?
Glenohumeral joint with glenoid fossa of scapula
What are the bony landmarks of the proximal region of the humerus?
Head Anatomical neck Greater tubercle Lesser tubercle Intertubercular sulcus Surgical neck
What attaches to the greater tubercle of the humerus?
3 rotator cuff muscles:
Supraspinatus, infraspinatus, teres minor
What attaches to the lesser tubercle of the humerus?
Subscapularis
What sits in the intertubercular sulcus of the humerus?
Tendon of long head of biceps brachii
What attaches to the lips of the intertubercular sulcus of the humerus?
Pectorialis major
Teres major
Latissimus dorsi
What are the common fractures of the humerus?
Surgical neck of humerus caused by falling on an outstretched hand
Mid-shaft fracture
Supraepicondylar fracture - falling on flexed elbow
Medial epicondyle
What neurovascular structures are at risk during a surgical neck fracture of the humerus?
Axillary nerve
Posterior circumflex artery
What does damage to the axillary nerve result in?
Paralysis of deltoid and teres minor muscles - patient will not be able to abduct their arm
Sensory innervation of regimental badge area will also be lost
What bony landmarks are found on the shaft of the humerus?
Deltoid tuberosity
Radial groove
What other muscles attach to the humerus shaft?
Anteriorly - Corocobrachilais, deltoid, brachialis, brachioradialis
Posteriorly - Medial and lateral heads of triceps
What neurovascular structures are at risk during a mid-shaft fracture of the humerus?
Radial nerve and prrofunda brachii artery - bound in radial groove
What would be seen in radial nerve damage in a mid-shaft fracture of humerus?
Wrist drop - Radial nerve innervates extensors of the wrist, so damage will lead to paralysis giving unopposed flexion
Sensory loss over dorsal surface of the hand and proximal ends of lateral 3 and a half fingers dorsally
What are the bony landmarks of the distal region of the humerus?
From lateral to medial: Lateral epicondyle Capitulum Radial fossa Trochlea Coronoid fossa Medial epicondyle
What is the role of the trochlea of the humerus?
Articulates with ulna