CASE 72
By: Dr. Amna Kashgari MD,SSC-Rad
HISTORY: A 6-year-old boy with history of trauma and elbow pain.
What are your findings?
What is your diagnosis?
What are the complication of this diagnosis?
FINDINGS:
AP and lateral radiograph of the right elbow joint demonstrate a positive fat pad sign with subtle undisplaced suprachondylar fracture. Mild displacement of the anterior humeral line is noted which passes through the anterior third of the capitellum.
DIAGNOSIS:
Supracondylar fracture type I.
Complication:
Nerve injury: most commonly median nerve then radial nerve.
Vascular insuffiency.
Malunion and deformity.
Cubitus varus, or ‘gun-stock deformity’: Partial growth arrest of the medial condyle with malunion.
PEARLS AND DISCUSSION:
Supracondylar fracture of the humerus is the common pediatric elbow injury. It results from fall onto an outstretched hand, so the elbow forced into hyperextension position.
Rarely fall onto a flexed elbow causes Flexion-type supracondylar fracture.
The next most common fracture in pediatric elbow injury is lateral condyle fracture followed by medial condyle fracture.
Radius fracture is less frequent in children and usually result from impaction injury. Ulnar fracture is also uncommon and most commonly affect the olecranon process.
Peak age 5-7 years:
Types of supracondylar fracture:
Type I: Un-displaced.
Type II: displaced with intact cortex.
Type III: Completely displace.
Radiology diagnosis:
Approach to pediatric elbow X-ray:
Positive posterior fat bad sign: On lateral radiograph of the elbow joint distention secondary to hemoarthrosis of the joint with fluid causes displacement of the posterior fat bad.
Normal alignment: To exclude elbow joint dislocation.
Two important lines are assessed:
Radiocapitellar line: A line drawn through the center of the radial neck should pass through the center of the capitellum in any view or position.
The Anterior Humeral line: A line drawn along the anterior surface of the humerus should pass through the middle third of the capitellum only in proper lateral view.
Ossification center: It is important to know the chronological age of the ossification center to avoid misinterpretation. The ossification center order of appearance is specified in the mnemonic C-R-I-T-O-E (Capitellum - Radius - Internal or medial epicondyle - Trochlea - Olecranon - External or lateral epicondyle). The age at which they appear is 1-3-5-7-9-11y.
Look for subtle fracture.
It is very important to know any visible fat pad sign without the demonstration of a fracture considered as an occult fracture. These patients treated as having a nondisplaced fracture with 2 weeks splinting.
Complications:
Nerve injury: most commonly median nerve then radial nerve.
Vascular insufficiency.
Malunion and deformity.
Cubitus varus, or ‘gun-stock deformity’: Partial growth arrest of the medial condyle with malunion.
FURTHER READING:
Jacob W. Brubacher, Seth D. Dodd. Pediatric supracondylar fractures of the distal humeru. Curr Rev Musculoskelet Med (2008) 1:190–196
Lane F Donnelly. Fundamental of pediatric radiology. ISBN-13: 978-0721690612
Johan G Blickman, Bruce R Parker, Patrick D Barnes. Pediatric Radiology: The Requisites, 3e. ISBN-10: 0323031250
