CASE REPORT

61         SA JOURNAL OF RADIOLOGY • September 2007

We present a case of a 2-year-old child who fell and injured his elbow. 
Plain films were taken and had the appearance of an elbow dislocation 
(Fig. 1). Subsequent MRI confirmed a Salter Harris I fracture of the 
distal humeral epiphysis (Figs 2a & b).

Discussion
Pure dislocation of the elbow is uncommon. It involves a disarticulation 
of the radial head from the capitellum and the semi-lunar notch of the 
olecranon from the trochlea.1  In this instance, the child’s radius head 
and proximal ulna are displaced as a unit  with the distal cartilagenous 
humerus. This is obvious on MRI (especially GE sequence) because it 
demonstrates the cartilagenous components which are not visible on 
plain radiograph.

Separation of the entire distal humeral epiphysis is classified into 
three groups based on the age of the child and  the degree of ossification 
of the lateral condyle:2

•   Group A includes infants whose lateral condyle ossification centre has 
not appeared.

•   Group B cases are between ages 1 and 3 years when the ossification 
centre is present (our patient).

•   Group C includes older children and produces a metaphyseal frag-
ment.

The distal epiphysis is usually displaced posteromedially.3

Diagnosis of this type of fracture can be challenging. X-rays are 
usually taken of both elbows but further imaging is usually needed. 
Modalities that have been used are ultrasound4 and arthrography. 
Although they help to make the diagnosis, ultrasound is operator-
dependent and not consistently accurate. Arthrography is associated 
with the risks of an invasive procedure.

MRI, as demonstrated in this patient, is an excellent modality to 
obtain the diagnosis of separation of the distal humeral epiphysis and 
avoid misdiagnosis of dislocated elbow when the elbow epiphyses are 
largely unossified.

1.   Rasool MN. Elbow dislocation with lateral condyle fracture in children. SA Orthopaedic Journal 2006; 
Aug: 72-78.

2.   Campbell WC.  Fractures and dislocations in children. In: Crenshaw AH, ed. Campbell’s Operative 
Orthopedics. St Louis: Mosby, 1987: 1885-1886.

3.   Ruo GY. Radiographic diagnosis of fracture-separation of the entire distal humeral epiphysis. Clin Radiol 
1987; 38: 635-637.

4.   Dias JJ, Lamont AC, Jones JM. Ultrasonic diagnosis of neonatal separation of the distal humeral epiphysis. 
J Bone Joint Surg Br 1988; 70: 825-828.

    
 

Elbow fracture in a child

D J van der Merwe, MB ChB
S Andronikou, MB BCh, FC Rad (SA),  

FRCR (Lond), PhD
Department of Radiology, Tygerberg Hospital  

G J Vlok, MB ChB, MMed (Orth), FC Orth (SA)
Department of Orthopaedics, Tygerberg Hospital

G Dekker, MB ChB, MMed (Fam)
M Pienaar, MB ChB, BSc
S Hlongwane, MB ChB

A Brandt, MBChB
Department of Radiology, Tygerberg Hospital

Fig. 1. Plain film of the elbow demonstrates malalignment of the distal 
humeral metaphysis with the proximal radial and ulnar metaphyses. The 
unossified epiphyses are not visible.

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CASE REPORT CASE REPORT

62         SA JOURNAL OF RADIOLOGY • September 2007

Figs 2 a & b. Sagittal STIR MRI of the elbow demonstrates good alignment of the capitellum (a) (showing a small ossified centre) with the radial head epiphysis 
and a well-positioned trochlea at the trochlear notch of the ulna. (b) Malalignment is therefore due to a Salter Harris fracture through the distal humeral physis 
with posterior displacement of the distal epiphysis which is articulating with the trochlear notch. 

a
b

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