- See:
Pediatric Elbow Injuries
- Ossification Centers of the Elbow:
- C apetellum (appears age 1-2)
- R adial Head (appears age 2-4)
- I nteranal epicondyle (appears age 4-6)
- T rochlea (appears age 8-11)
- O lecranon (9-11 years)
- E xternal epicondyle (appears age 10-11)
- AP View:
- medial and lateral epicondyles and humeral-ulnar/radial articulation;
- carrying angle;
- if flexion contracture is present, 2 AP views should be taken, one perpendicular to the forearm and one perpendicular to the humerus;
- technique: AP
- forearm is positioned supine (palm up) on the table;
- elbow joint is fully extended and the fingers slightly flexed;
- central beam is directed perpendicular to the elbow joint;
- AP views with the beam perpendicular to the proximal forearm and perpendicular to the distal humerus should be obtained;
- Lateral View:
- forearm flexed to 90;
- line from radial head to capitulum;
- film should demonstrate trochlea & capitellum overlapping w/ space between the humerus and the radial head;
- soft tissue structures:
-
anterior fat pad:
- superficial part of anterior fat pad should be in front of coronoid fossa;
- in normal elbow the anterior fat pad should be barely visualized;
- look for small radiolucent area between bony rim & moderate opaque shadows of brachialis;
- w/ joint effusion (2nd to a minimally displaced
radial head frx) there will be anterior & superior displacement of anterior fat pad;
-
posterior fat pad should not be seen at all;
- w/ a posterior fat pad sign and no obvious frx, obtain an oblique radiograph to help rule out
supracondylar or
lateral condyle frx;
- in the study by DL. Skaggs MD and R Mirzayan MD (JBJS 1999) the authors prospectively examined a group of children with acute elbow trauma and a posterior fat pad sign,
but no evidence of radiographic fracture;
- at three weeks, new radiographs were taken and were evaluated for signs of fracture healing;
- they found that 34 out of 45 patients (76%) had evidence of a fracture.
- 53% of patients had supracondylar frx, 26% had a proximal ulnar frx, 12% had a frx of the lateral condyle, and 9% had a frx of the radial neck;
- the authors conclude that children w/ a history of acute elbow trauma and a posterior fat pad sign, should be treated as if they have a
non displaced frx about the elbow;
- technique:
- forearm rests on its ulnar side on cassette w/ elbow flexed 90 deg;
- central beam is directed vertically toward the radial head;
- Internal oblique:
- trochlear notch of ulna and tip of olecranon process;
- shows medial epicondyle and coronoid process of ulna;
- External oblique:
- capitulum and head of radius; proximal radioulnar joint;
- Misc Features:
- radiocapitellar articulation: axis of radius should poiont toward center of capitellum on all views;
- when this relationship is disrupted consider:
-
radial neck fracture;
-
elbow dislocation;
-
lateral condyle fracture;
-
Monteggia Frx
The Posterior Fat Pad Sign in Association with Occult Fracture of the Elbow in Children*
DL. Skaggs MD and R Mirzayan MD.
J Bone Joint Surg [Am] 81-A: 1429-33, 1999
Radiology of postnatal skeletal development. VI. Elbow joint, proximal radius, and ulna.
Radiology of postnatal skeletal development. V. Distal humerus.
