Elbow - Ortho Flashcards
What is the function of the elbow?
To work with the shoulder to position the hand in spance
True or False: the stability of the elbow makes it resistant to over use injuries.
False: Since there is so little give it is very prone to over use injuries
What is the biomechanical function of the elbow?
It is a link in the biomechanical chain that allows for the transfer and dispersement of forces that occur in the upper extremity.
What are the joints of the elbow?
Humeroulna
Humeroradial
Proximal Radioulnar
When the elbow is extended, what is the relationship between the olcronon and the epicondyles?
Points of all three (Lateral eip, olecron, medial epi) will all lie in a straight line.
What is the relationship between the points of the epicondyles and the olectronon when the elbow if flexed. ?
they form an isosceles triangle
If the triangle is uneven than it is likely a sign of an orthopedic problem (ligamentous instability? I am guessing but I think I am right).
what is a Monteggia Fracture?
A fracture of the ulnar bone associated with a dislocation of the radial head.
How are monteggia fractures classified?
By the direction that the radial head dislocates.
What type of monteggia fracture is most common? Which way does it dislocate?
Type 1 (seen in 60% of monteggia fractures.)
The radial head is dislocated anteriorly, with palmar angulation of the fractured shaft of the ulna.
So the head of the raduis and the fractured segment of the ulna both move toward the palmer side of the forarm.
What type of joint is the Humeroulnar Joint?
Uniaxial Hinge Joint
What structures does the humeroulnar joint lie between?
between the trochlear notch of the proximal ulna and the butterfly shaped trochlea of the humerus.
What is the importance of the “carrying angle” of the elbow? what joints are responsible for forming it?
The posterior section of the humeral trochlear grove runs at about a 15 degree angle. This means that when the arms are extended the forearms and hands should be slightly away from the body. This allows for normal movements of the arms when walking or carrying objects.
What is the carrying angle in males and females?
Male: 11-14 degrees
Females: 13-16 degrees
What is the open-packed position of the humeroulnar
joint?
70° of flexion with 10° of forearm supination
What is the close packed-position of the humeroulanr joint?
full extension and maximum forearm supination
What is cubital valgus?
An increased carrying angel.
What MOI is associated with a cubital valgus?
Lateral Epicondylar Fracture.
What % of pediatric fractures are represented by lateral condyle fractures?
15% - 17%
What age are lateral epicondyler fractures most likely to occure?
5-7 years old
Compare Valgus and Varus
These are adjectives that describe the deviation of a distal segment in relationship to its close proximal segment.
Valgus: the distal segment has moved laterally in respect to the proximal segment
Varus: the distal segment has moved medially in respect to the proximal segment.
There is a fracture of the laterally epicondyle. What directional force was likely applied to cause this fracture?
A varus blow (the point of contact is medial and the affects are felt laterally.)
When a cubital valgus forms, what type of fracture was the lateral epicondyler fracture likely to be?
Avulsion
What muscles and ligaments are involved in a lateral epicondyler fracture?
extensor muscles
lateral collateral ligaments
What is the term for a decreased carrying angle?
cubital varus
aka gunstock deformity