Joints of the upper limb

Question 1

Shoulder girdle

Answer 1

Shoulder girdle = incomplete bony ring - made up the scapulae and clavicles. Attach anteriorly to manubrium of sternum

Question 2

True Articulations

Answer 2

sternoclavicular joint
acromioclavicular joint
glenohumeral joint
Scapulothoracic articulation

Question 3

Sternoclavicular joint (SC joint)

Answer 3

synovial, saddle joint
Includes: sternal end of clavicle, manubrium of sternum, 1st costal cartilage
Only articulation between upper limb and axial skeleton
Articular disc: divides the joint space into 2 compartments, serves as a shock absorber

Question 4

Clavicle fracture

Answer 4

Common fracture site
Typically fractures in middle 1/3
Usually caused from a fall on an outstretched arm

Question 5

Acromioclavicular joint (AC joint)

Answer 5

Synovial, plane (gliding) joint
Includes: acromion of the scapula, lateral end of the clavicle
Loose fibrous joint capsule: allows for rotation of the acromion process on the end of the clavicle, no muscles move joint directly
Acromioclavicular ligament: strengthens AC joint superiorly

Question 6

AC joint ligaments

Answer 6

Main stabilizer of AC joint: prevents superior translation of the clavicle
Coracoclavicular ligaments: accessory ligament, anchors clavicle to coracoi dprocess. Cornoid ligament - located medial and slightly more posterior. Trapezoid ligament - located lateral and slightly more anterior

Question 7

Shoulder separation

Answer 7

AC joint dislocation

Question 8

Glenohumeral joint (GH joint)

Answer 8

Synovial, ball and socket joint - very mobile, but unstable
Articulation: large humeral head, shallow glenoid cavity (fossa). Deepened by glenoid labrum
Loose fibrous joint capsule strengthened by muscolo-tendinous rotator cuff

Question 9

GH joint ligaments

Answer 9

Strengthens anterior aspect of capsule
Intrinsic ligaments
Superior/middle/inferior GH ligament
Coracohumeral ligament: from coracoid process to anterior aspect of greater tubercle, part of fibrous capsule, strengthens capsule superiorly
Transverse humeral ligament: greater to lesser tubercle, holds the long head of the biceps brachii in place
Coracoacromial ligament: spans between coracoid process and acromion process. STRONG superior support

Question 10

GH joint dislocation

Answer 10

Anterior - more common
Posterior - rare
Name indicates where the humeral head is positioned
Median, radial, and axillary nerves are at risk

Question 11

Elbow joint

Answer 11

Synovial, hing joint
3 joints: humeroulnar, humeroradial, proximal radioulnar
Fibrous joint capsule: weak anteriorly and posteriorly. covers all 3 articulations

Question 12

Olecranon (elbow) bursitis

Question 13

Elbow joint ligaments

Answer 13

Radial collateral ligament: lateral aspect, lateral epicondyle to annular ligament, prevents against a varus force
Ulnar collateral ligament: medial aspect - three bands. Medial epicondyle to olecranon. Prevents against a valgus force

Question 14

Ulnar collateral ligament tear

Question 15

Proximal radioulnar joint

Answer 15

Annular ligament: encircles and holds head of the radius in the radial notch of the ulna
Permits pronation and supination of forearm

Question 16

Subluxation and dislocation of radial head

Question 17

Distal radioulnar joint

Answer 17

Synovial, pivot joint
head of ulna to ulnar notch of radius
Articular disc binds ulna and radius - triangular ligament
radius moves around ulna

Question 18

Wrist (radiocarpal) joint

Answer 18

Synovial, condyloid joint
Radiocarpal joint between: radius, scaphoid, lunate, triquetrum, articular disc. NOT the ulna

Question 19

Scaphoid fracture

Answer 19

most commonly fractured carpal bone
blood supplied by radial a. but there is poor blood supply to the prox. pole waist of bone
Clinical features: pain over anatomical snuffbox, often confused with wrist sprain

Question 20

Erb Duchenne Palsy

Answer 20

Brachial plexus injury
Damage superior trunk (C5-C6) causes waiter’s tip appearance
Typically occurs at birth
Result of increased angle between head and shoulder

Question 21

Damage ot ulnar nerve

Answer 21

Ulnar nerve palsy
Causes claw hand
ulnar nerve entrapment
loss of innervation to intrinsic hand mm.

Question 22

Damage ot median nerve

Answer 22

sign of benediction
median n. damage at elbow or in forearm
loss of innervation to 5 intrinsic hand mm.

Question 23

Damage to radial nerve

Answer 23

Wrist drop
damage to radial nerve by humerus break
unopposed flexion of digits

Question 24

Damage to C8-T1

Answer 24

Klumpke paralysis
stretch or tear of C8-T1
injury to lower brachial plexus (ex: ABduction of arm at birth)
complete claw hand