Joints Flashcards
Classify the elbow (humero-ulnar) joint
Synovial hinge joint (uniaxial), capable of one degree of freedom
Briefly describe the articular surfaces of the humero-ulna articulation
The humerus has a trochlear which articulates with the trochlear notch of ulna.
The trochlea surface is concave from side to side but convex from front to back. The medial part of the trochlea extends downwards to a lower level than the lateral sides.
The trochlear notch has a rounded curved, longitudinal ridge extending from the tip of the olecranon to the tip of the coronoid process, which fits the groove of the trochlea.
All articular surfaces are covered in hyaline cartilage.
Classify humero-radial joint
Modified synovial ball & socket joint
Briefly describe the articular surfaces of the humero-radial articulation
The head of the radius articulates with the capitulum of the humerus.
The head of the radius is concave with continuous convex cartilage around the sides and is thickest on the middle of the concavity.
The capitulum is a bony hemisphere on the anterior inferior surface of the distal humerus.
All articular surfaces are covered in hyaline cartilage.
Name the ligaments which support the elbow joint
Lateral (Radial) collateral ligament
medial (Ulnar) collateral ligament
Name the movements that occur at the elbow joint
Flexion and Extension
Classify superior and inferior radio-ulnar joints
Synovial pivot joint, uniaxial - capable of 1 degree of freedom
Briefly describe the articular surfaces of the superior radio-ulnar joint
Circular and convex Head of proximal radius id received by the reciprocally concave radial notch of proximal ulna
Only one-fifth of radial notch articulates with radial head - annular ligament surrounds the radial head and holds it tight against the radial fossa of ulna
Included in elbow joint capsule
All articular surface covered with hyaline cartilage
Name ligaments of superior radio-ulnar joint
Annular ligament
Quadrate ligament
State attachments of elbow joint capsule
attaches around the edge of the ulnar articular surfaces including the radial notch
Encompasses humero-ulnar, humero-radial and superior radio-ulnar joints
Synovial membrane - originates from the edges of the articular cartilage and lines the radial fossa, the coronoid fossa, the olecranon fossa, the deep surface of the joint capsule, and the medial surface of the trochlea
Fibrous layer - thickened medially and laterally to form collateral ligaments
support the flexion and extension movements of the elbow joint
Classify the inferior radio-ulnar joint
Synovial pivot joint
Uniaxial - capable of 1 degree of freedom
Briefly describe the articular surfaces of the inferior radio-ulnar joint
Between crescent-shaped convex distal head of ulna and the concave ulnar notch of distal radius.
Both surfaces are lined by the hyaline cartilage.
Also contains triangular fibrocartilage complex (TFCC) - Separates the inferior RUJ from the wrist joint
Give attachments of the triangular fibrocartilage complex (TFCC)
apex - lateral surface of the styloid process of ulna
base - inferior margin of the ulnar notch of radius
Give attachments of the inferior radio-ulnar joint capsule
fibrous capsule that attaches to the margins of the articular surfaces
synovial membrane projects superiorly to the interosseous space between the radius and ulna, extending beyond the joint capsule (recessus sacciformis/saccular recess)
Classify the middle radio-ulnar joint
Fibrous syndesmosis
Joint also known as interosseous membrane
Briefly describe the articular surfaces of the middle radio-ulnar joint
Attaches to medial and lateral borders of the radius and ulna, respectively
2 layers in perpendicular directions - adds tension; helps transfer force from radius to ulnar thus from hand to humerus
Describe function of the middle radio-ulnar joint (interosseous membrane)
Two hiatus for transmission of neurovascular bundles
Serves as an attachment for deep muscles of forearm
Stabilises Radius and Ulna - prevents disruption between bones
State attachments and functions of the medial (ulnar) & lateral (radial) collateral ligaments
Capsular ligaments - support flexion and extension movements of the elbow joint
• Radial (lateral) collateral ligament
○ single triangular thickened band from the lateral epicondyle of humerus to the annular ligament
○ Does not attach directly to radial head, allowing it to pivot
○ Prevents varus strain (ADD) of elbow
• Ulna (medial) collateral ligament
○ thick triangular band, which fans out from the medial epicondyle of humerus and has anterior, posterior, intermediate and transverse bands inserting onto the medial aspect of the coronoid process and olecranon of ulna
○ Prevents valgus strain (ABD) of elbow
State attachments and function of annular ligament
forms a ring that surrounds the radial head, attaching to the anterior and posterior margins of the radial notch of the ulna
Stabilises proximal RUJ
Inferior diameter is smaller - providing a tight fit about the neck of the radius
Inner surface lined with fibrocartilage - facilitating free rotation of radial head
State attachments and function of the quadrate ligament
Small ligament arising from the inferior border of the radial notch to the neck of radius
Tested by full pronation and full supination - sufficient laxity to allow for full pronation/supination but tension occurs preventing over pronation/supination
State function the olecranon bursa
Facilitates smooth movement of the skin over Olecranon process during flexion/extension
Bursitis - infection/inflammation, e.g. lorry drivers leaning elbow on window w/ constant vibrations for a prolonged period
