Skeleton (Joints of the Upper limb)

Question 1

What are 3 Joints of the Pectoral Girdle?

Answer 1

1. Sternoclavicular joint
   * Clavicular movement
2. Acromioclavicular joint
   * Scapular movement
3. Glenohumeral joint
   * Humeral movement

*All three joints move at the same time

Question 2

What is the Sternoclavicular Joint?

Answer 2

1. Sellar Joint or “saddle joint”
   * Flexion-Extension
   * Abduction-Adduction
2. Articular surface:

• Clavicle (sternal end)
• Manubrium sterni (sternal notch)
• 1^st costal cartilage

3. Articular disc: divides the joint’s interior into 2 compartments
4. Dislocation is rare
   * Clavicle breaks first
5. Costoclavicular ligament

• Anchors sternal end of 1^st rib
• Limits elevation of pectoral girdle

Question 3

What is the Acromioclavicular Joint?

Answer 3

1. Plane Joint (gliding/sliding)

• Movement:
  
  • Associated with scapular and humeral movements
  • Elevatation/Depression
  • Protraction/Retraction
  • Rotation

2. Articular surfaces:

• Lateral end of clavicle
• Acromion of scapula
• Partially separated by an articular disc

3. Contains:

• Coracoclavicular ligament- Maintains joint integrity
  
  • Trapezoid ligament
  • Conoid ligament

4. Dislocation- Not uncommon
   * Rupture of coracoclavicular ligament

Question 4

What is the Glenohumeral Joint?

Answer 4

1. Spheriodal
   * Synovial ball-and-socket joint
2. Articular surface:

• Humeral head
• Glenoid cavity (deepened by Glenoid labrum)

3. Articular capsule

• Very loose
• Attaches to anatomical neck of humerus (laterally)
• Supported by rotator cuff
  
  • Main stabilizing factor
• Weakest area
  
  • Inferior part of the capsule

4. Synovial membrane
   * Tubular synovial shealth for the tendon of the Long Head of Biceps Brachii
5. Dislocation-

• Usually Anterior/inferior
• Damage to axillary nerve (seen in young individuals)

Question 5

What are the ligaments of the Glenohumeral Joint?

Answer 5

1. Ligaments:

• Glenohumeral (Superior, Middle, Inferior) Ligament
  
  • Reinforces the Anterior part of the capsule
• Coracoacromial Ligament
  
  • Blends with supraspinatus tendon
• Transverse humeral Ligament
  
  • Bridges the intertubercular groove
• Coracoacromial arch
  
  • Coracoacromial ligament
  • Coracoid process
  • Acromion

2. Bursae: Protect tendons from rubbing against the bone

• Subscapular bursa
  
  • Behind the subscapularis tendon
• Subacromial bursa
  
  • Between the Coracoacromial arch and Supraspinatus tendon

Question 6

What injuries occur in the Glenohumeral Joint?

Answer 6

1. Subacromial bursitis
   * Pain even at rest
2. Supraspinatus tendinitis
   * Calcification of tendon
3. Painful arc syndrome
   * Pain beyond 50 degree motion of abducting the arm
4. Anterior shoulder dislocation

• Head of humerus losing contact with the glenoid cavity
  
  • Hyperextension
  • Excessive lateral rotation
    *

Question 7

What is the Elbow Joint?

Answer 7

1. Articular Surface

• Humeral trochlea
  
  • Hinge: Flexion/Extension
• Trochlear notch
• Humeral capitulum
  
  • Spheroidal
• Radial head

2. Articular Capsule

• Medial and lateral Epicondyles (outside the capsule)
• Radial and Ulnar collateral ligament
• Anular Ligament
• Superior radioulnar capsule

Question 8

What injuries occur on the Elbow Joint?

Answer 8

1. Articular capsule

• Thin anterior and posterior
  
  • Dislocation- falling on the hands and elbow flexed
    
    • Common in children

2. Bursae:

• Subcutaneous olecranon
  
  • Pressure/Friction
    
    • Student’s elbow
• Subtendinous elecranon
  
  • Repeated flexion/extension
    
    • Inflammation

Question 9

What is the Proximal Radioulnar Joint?

Answer 9

1. Pivot Joint
   * Pronation/Supination
2. Articular surfaces:

• Circumference of radial head
• Radial notch of ulna

3. Articular capsule
   * Covers the Joint
4. Annular ligament- attach to the radial notch of ulna

• Osteofibrous ring
• Pronation /Supination of radiusr

Question 10

What is the Distal Radioulnar Joint?

Answer 10

1. Pivot Joint
   * Pronation/Supination
2. Articular Surface:

• Head of ulna
• Ulnar notch of radius

3. Main uniting structure

• Articular/ Triangular disc
  
  • Superior surface articulates with ulnar head
  • Inferior surface articulates with Lunate/triquetral
    
    • Appears in L shaped joint cavity

Question 11

What injuries occur in the Proximal Radioulnar Joint?

Answer 11

1. Subluxation of radial head

• Nursemaid elbow- dislocation of radial head
  
  • Lift to upper limb while forearm is pronated
  • Tearing of the loosely attachment of the annular ligament of the radial head

Question 12

What is the Radiocarpal Joint?

Answer 12

1. Ellipsoid Joint

• Flexion-Extension
• Abduction-Adduction

2. Articular Surface

• Carpal articular surface of radius
• Articular (triangular) disc
• Proximal row of carpal bones (except pisiform)

3. Ligaments

• Palmar (volar) radiocarpal and ulnocarpal
• Dorsal radiocarpal and ulnocarpal
• Collateral (radial and ulnar)

Question 13

What is the Intercarpal Joint?

Answer 13

1. Plane
   * Increase the range of movement of radiocarpal joint
2. Articular surface:

• Carpal bones
  
  • First row
  • Second row
  • Midcarpal

Question 14

What is the Carpometacarpal of the Thumb?

Answer 14

1. Sellar or saddle joint
   * Flexion-Extension
   * Abduction-Adduction
2. Articular surface

• Trapezium
• Base of 1^st metacarpal

Question 15

What is the Intermetacarpal Joint?

Answer 15

1. Plane Joint
   * Common fibrous capsule
2. Articular surface
   * Metacarpal bases with each other
3. Ligaments

• Carpometacarpal (Dorsal and palmar)
• Metacarpal (Dorsal and palmar)

Question 16

What is the Metacarpophalangeal Joint?

Answer 16

1. Ellipsoid

• Flexion-Extension
• Abduction-Adduction

2. Articular surface

• Head of metacarpals
• Base of proximal phalanges

3. Articular capsule

• Collateral ligamens
• Deep transverse metacarpal ligaments (connection)

Question 17

What is the Interphalangeal Joint?

Answer 17

1. Hinge Joint
   * Flexion-Extension
2. Articular surfaces

• Head of phalanges
• Base of phalanges

3. Articular capsule
   * Collateral ligaments