Elbow, Forearm Flashcards
Elbow Joint
- complex
- 3 distinct joints
- 2 DoF (flex/ext, pro/sup)
Carrying Angle
- anatomical position
- normal = 5-15 degrees
- if >15, cubitus valgus
- if <15, cubitus varus
- disappears when forearm pronates
Synovial Membrane of Elbow
- fat pads in fossae to provide cushion at end of ROM
- fibrous membrane
- tendon attachments
Elbow Ligaments
- radial collateral ligament (RCL)
- ulnar collateral ligament (UCL)
- anular ligament
RCL
- one band going over anular ligament
- prevents active adduction
UCL
- 3 bands (anterior, posterior, oblique)
- prevents active abduction
Anular Ligament
- circular over radial head
- keeps radial head in place
Tommy John Surgery
- for UCL (tears, overuse, stretching)
- 2 options = autograft from palmaris longus or plantaris, synthetic ligament
Monteggia Fracture
- ulnar fracture w/ radial head dislocation
- surgery needed
Galleazzi Fracture
- radial fracture w/ distal radioulnar joint dislocation
- surgery needed
Elbow Vascular Supply
- anastomotic network
- brachial artery splits into radial a. and ulnar a.
Humeroulnar Joint
- trochlea of distal humerus + trochlear notch of olecranon process of proximal ulna
- “elbow proper”
- elbow flexion & extension
Humeroradial Joint
- capitulum of humerus + radial head
- “elbow proper”
- synovial, hinge (flex/ext)
Proximal Radioulnar Joint
- radial head + radial notch of ulna
- synovial, pivot (supination/pronation)
Median Cubital Vein
- in cubital fossa
- venopuncture (punctured to draw blood)
Cubital Fossa
- superior border = line b/w epicondyles
- medial border = pronator teres
- lateral border = brachioradialis
- contents = tendon (biceps), artery (brachial), nerve (median)
Radioulnar Articulation
- complex of 3 joints
- proximal radioulnar joint
- interosseous membrane
- distal radioulnar joint
Forearm Supination/Pronation
- radius spins (functionally shortens) over relatively stable ulna
- at elbow: radial head spins on capitulum and slides on radial notch of ulna
- at wrist: ulnar notch of radius slides over ulnar head
Common Flexor Tendon
- at medial epicondyle
- formed by 4 muscles … pronator teres, flexor carpi radialis, palmaris longus, flexor carpi ulnaris
Superficial Anterior Forearm Muscles
pronator teres
flexor carpi radialis
palmaris longus
flexor carpi ulnaris
What muscle is the only one of the four muscles attaching to the medial epicondyle not innervated by median nerve?
flexor carpi ulnaris, ulnar nerve
Pronators
pronator teres
pronator quadratus
(both innervated by median nerve)
Supinators
supinator
biceps brachii (both heads)
Interosseous Membrane
- ligament that hold radius and ulna together
- increases SA for attachments
- transfer forces from distal radius to proximal ulna
- gaps for arteries to run through
Quadrate Ligament
- runs from radial notch of ulna to neck of radius
- keeps radial head in place by ulna
Oblique Cord
- runs from radial tuberosity to below the radial notch of ulna
- limits distal (inferior) motion of radius (“pulled elbow”)
Distal Radioulnar Joint
- ulnar head + ulnar notch of radius
- synovial, pivot (supination/pronation)
- articular disc
