Elbow Flashcards
Elbow Complex
made up of three articulations:
humeroulnar joint
humeroradial joint
proximal radioulnar joint
Monteggia Fracture
fracture of the proximal ulna with radial head dislocation, often classified by the direction of radial head dislocation
Type 1 Monteggia Fracture
60% of the time
anterior radial head dislocation with palmar angulation
Humeroulnar joint
uniaxial hindge between the trochlear notch of the proximal ulna and the trochlea of the humerus
carrying angle: 11-14 in males and 13-16 in females
humeroulnar joint open pack position
70 deg of flexion and 10 deg supination
humeroulnar joint close pack position
full extension and maximum forearm supination
cubital valgus
increased angulation
can be caused by lateral epicondylar fracture
cubital varus
decrease in carrying angle
aka gunstock deformity
usually a supracondylar fracture due to extension injury
Humeroradial joint
uniaxial hinge between capitellum of humerus and concave head of the radius
open pack position of the humeroradial joint
extension and forearm supination
close pack position of the humeroradial joint
90 deg elbox flexion and 5 deg supination
Proximal radioulnar joint
uniaxial pivot between radial head and radial notch of the ulna
annular ligament forms 80% of the articular surface
open pack position of the Proximal radioulnar joint
70 deg flexion and 35 deg forearm supination
close pack position of the Proximal radioulnar joint
5 deg forearm spunation
Annular ligament
maintains the relationship between the head of teh radius and the humerus and ulna
Nursemaids elbow
aka pulled elbow
radial head slippage from under the annular ligament trapping the ligament in the radiohumeral articulation
Elbow joint capsule
thin but strong
does not respond well to injury or prolonged immobilization and commonly forms thick scar tissue which may result in flexion contractures of the elbow
Medial Collateral Ligament
functionally most important ligament in the elbow for providing stability against valgus stress three components: anterior bundle transverse bundle posterior bundle
Anterior bundle of the MCL
anterior band is the strongest and stiffest, stabilizes the elbow against valgus stress in 20-120 deg of flexion
posterior band is taut beyond 55 deg of elbow flexion, primary restraint to passive elbow extension, equal co-restraint with the anterior band at terminal elbow flexion, resists valgus stress
transverse bundle of the MCL
aka coopers ligament
fibers originate and insert on the ulna and have little role in elbow stability
posterior bundle of the MCL
a thickening of the posterior elbow capsule
provides secondary restraint to valgus stress at greater than 90 deg flexion
little leaguer’s elbow
avulsion of the medial epicondyle
usually found in child or adolescent and is associated with sports requiring strong throwing motions
overuse injury
Lateral collateral ligament of the elbow
consists of annular ligament, fan-like radial collateral ligament, accessory collateral ligament, and lateral ulnar collateral ligament
functions to maintain the ulnohumeral and radiohumeral joints in a reduced position when the elbow is loaded in supination
Olecranon bursa
main bursa of the elbow complex, lies posteriorly between the skin and olecranon process
Olecranon bursitis
aka miners elbow/ student’s elbow
chronic or acute trauma to the tip of the elbow
Myositis Ossificans Elbow Flexor
most common sites are brachialis anterior, quad, adductor, and MCL of the knee
most occur following any local injury sufficient to cause bruising or frank hemmorhage within a muscle
heterotrophic bone formation in the soft tissue
Contents of the cubital fossa
biceps tendon median nerve brachial artery radial nerve median cubital or intermediate cubital cutaneous vein
elbow flexion
150 degrees
elbow extension
0 degrees
forearm supination
80 degrees
at radio-ulnar joint
forearm pronation
80 degrees