Elbow arthrology (wk8)

Question 1

Identify and label the palpable bony landmarks on the elbow:

Answer 1

• Medial epicondyle
• Lateral epicondyle
• Lateral supracondylar ridge

Question 2

Describe the articulating surface of the radius/ulna:

Answer 2

• Radius/ ulna -> The radius and ulna is held tightly together between the proximal and distal articulations by an interosseous membrane, that the joint between the shafts of these bones is referred to as a syndesmosis type of joint. The interosseus membrane is helpful in absorbing and transmitting forces received by the hand, mostly during upper extremity weight bearing.

Question 3

Describe the articulating surface of the humerus:

Answer 3

• Humerus -> The humeroulnar and the humeroradial joints are the joints that give the elbow its characteristic hinge like properties. The rounded surfaces of the trochlea and capitulum of the humerus rotate against the concave surfaces of the trochlea notch of the ulna and head of the radius

Question 4

Describe the articulating surface of the elbow joint:

Answer 4

• Elbow joint -> The proximal radioulnar joint is considered to be a separate articulation than those forming the elbow joint itself. The proximal radioulnar joint is the articulation between the circumferential head of the radius and a fibro-osseous ring formed by the radial groove of the ulnar and the annular ligament that holds the head of the radius in this groove. The proximal radioulnar joint is functionally a pivot joint , allowing a rotational movement of the radius on the ulna.

Question 5

Identify and label the elbow and radioulnar joints:

Answer 5

• Humeral trochlear -> Fits into the trochlear notch of the ulna
• Radio capitellar joint (humeroradial joint) -> The head of the radius has a small amount of contract with the capitulum of the humerus
• Olecranon process of the ulna -> As the elbow reaches full extension, the olecranon fossa of the humerus is received by the olecranon process of the ulna
• Humeroulnar joint -> The joint between the trochlea on the medial aspect of the distal end of the humerus and the trochlear notch on the proximal ulna

Question 6

Describe the ligaments providing stability to the elbow joint:

Answer 6

The arrangement if the elbow and radioulnar joints provides increased joint stability when the elbow is fully extended. Similarly, when the elbow is forced into full flexion, the coronoid fossa receives the coronoid process unless the soft tissue mass on the anterior aspect of the arm and forearm prevents full flexion.

Question 7

Describe the ligaments providing stability to the elbow joint
-Lateral/radial collateral ligaments, medial/ulnar collateral ligaments, annular ligament

Answer 7

• Lateral or radial collateral ligaments (especially medial or ulnar collateral ligament) -> The stability of the elbow in flexion is more dependent on the collateral ligaments. The ulnar collateral ligament is critical to providing medical support to prevent the elbow from abducting when stressed in physical activity.
• Radial collateral and lateral ulnar collateral ligaments -> Are located on the opposite side and provide lateral stability and are rarely injured.
• Annular ligament -> Provides a sling effect around the radial head to secure it’s stability.

Question 8

Complete the table for the joint/structure of the elbow from lecture 11/11