Download Anatomy of the Elbow

Anatomy of the Elbow
Bones of the Elbow
• Humerus
• Radius
• Ulna
Joints of the elbow
• Humeral-Ulnar joint – main hinge action of
joint
• Proximal Radio-ulnar joint – Pronation &
Supination of forearm
• Humeral-Radial joint – part of hinge action
Functional Anatomy
• Elbow ROM = flexion, extension, pronation and
supination
– 145 degrees of flexion
– 90 degrees of supination and pronation
• Stable joint: protection from overuse and traumatic
injuries
– Bony limitations, ligamentous support, and muscular stability
at the elbow help to
• Carrying angle due to distal projection of humerus
– Normal in females is 10-15 degrees, males 5 degrees
• Critical link in kinetic chain of upper extremity
Elbow X-ray
• Basic views: AP & lateral
• Fat pad sign or “sail sign”
• In kids, be aware of the apophyses
Elbow X-ray - AP
Elbow X-ray - Lateral
Elbow Fat Pads
• Fat is normally present within the joint capsule of the
elbow, but outside the synovium
• Typically "hidden" in the concavity of the olecranon
and coronoid fossae
• Injuries that produce intra-articular hemorrhage cause
distension of the synovium
forcing the fat out of the
fossa
producing triangular radiolucent shadows
anterior and posterior to the distal end of the humerus
– the FAT PAD SIGNS
Fat Pad Sign
Fat Pad Sign
Normal
The Sail Sign
Fat Pad Sign
Fat Pad Sign Pearls
• X-rays
– No visible fracture
– Positive fat pad sign
• Think occult fracture
– Kids: supracondylar fracture
– Adults: radial head fracture
Ossification Centers
• There are 6 ossification centers around the elbow
• Always appear in same order: C-R-I-T-O-E
–
–
–
–
–
–
Capitellum
Radius
Internal or medial epicondyle
Trochlea
Olecranon
External or lateral epicondyle
• Age of appearance is highly variable but as general
guide remember 1-3-5-7-9-11 years
Elbow Anatomy - Ossification
C = capitelum
1y
R = radial head
3y
I = medial epicondyle
5y
T = trochlea
7y
O = olecranon
9y
E = lateral epicondyle
11 y
Elbow Anatomy - Ossification
Ossification Centers
Ossification Centers
Ossification Centers
• Age of closure is between ages 14-16
• Radial & the lateral epicondyle are generally last
to close
Anterior Humeral line
•
Should bisect the capitellum
•
If capitellum displaced
posteriorly:
–
•
Extension supracondylar #
If capitellum displaced
anteriorly:
–
Flexion supracondylar #
Radio-capitellar line
•
Should bisect the capitellum
•
Can be used on any view
•
Disruption represents radial
head #/dislocation
Fracture Types:
•
Supracondylar:
–
Type 1
–
Type 2
–
Type 3
Fracture Types:
•
Supracondylar:
–
Type 1
–
Type 2
–
Type 3
Fracture Types:
•
Supracondylar:
–
Type 1
–
Type 2
–
Type 3
Case
• 11 y.o. RH year round
baseball player
– pitches on 3 different
teams
– medial sided Rt elbow
pain
– no acute injury
• Concerns?
Little League Elbow
• Medial epicondyle apophysitis
• Overuse injury
• Common cause of medial sided
elbow pain in throwing athletes
• X-rays: normal or widening
of the apophysis
• Need comparison views
Case
Case
Case