Fractures through the capitellum are rare injuries, particularly in
children1-6,
and, to our knowledge, such an injury has not been reported in a young child.
A lateral condylar physeal fracture with possible displacement of the
capitellum is much more common in this
population7-9.
It is important to recognize a fracture of the body of the capitellum because,
if such a fracture is undiagnosed and untreated, it may go on to cause
substantial disability by limiting elbow
motion1-6.
To our knowledge, the youngest reported patient with a fracture through an
unfused capitellum was eight years and eleven months
old2. The most
recent and largest study, consisting of seven patients, was reported by Letts
et al. in 19976. The
patients in that report were a mean of 14.7 years old, with the youngest
patient being 11.6 years old.
We describe the case of a six-year-old patient with a capitellar fracture
who was followed for two years. The fracture plane was markedly oblique in the
body of the capitellum and was not visible on either anteroposterior or
lateral radiographs. It was, however, visible on an oblique radiograph,
illustrating the importance of the oblique radiograph in detecting this
fracture pattern. The parents were informed that data concerning this case
would be submitted for publication.
Asix-year-old girl presented with pain in the left elbow following a fall
on the outstretched hand that occurred while she was playing on monkey bars at
school. She was unable to move her elbow actively secondary to pain. Physical
examination revealed mild swelling and tenderness over the lateral aspect of
the distal part of the humerus. The patient was able to supinate and pronate
to 90° without difficulty, but active flexion and extension were markedly
limited by pain. Distally, the limb was intact.
Anteroposterior and lateral radiographs of the distal part of the left
humerus did not reveal a definite fracture
(Fig. 1, left and center).
However, lateral soft-tissue swelling and both anterior and posterior fat pad
signs were visible. Another radiograph
(Fig. 1, right), made at the
time of presentation but rejected as being technically inadequate, also was
available. This radiograph, an unconventional oblique view of the elbow,
revealed a 2-mm displaced fracture that passed through the body of the
capitellum and extended obliquely in the coronal plane. The posterior fragment
had rotated posterolaterally and was not readily discernible on the
anteroposterior and lateral radiographic projections.
The capitellar fracture was treated with open reduction and percutaneous
pinning with Kirschner wires through a lateral approach
(Fig. 2). The unusual fracture
pattern was confirmed visually. The extremity was immobilized in approximately
90° of flexion in a long-arm posterior splint spanning the elbow
joint.
At the time of follow-up after three weeks of immobilization, there was
evidence of fracture-healing with no evidence of redisplacement of the
fracture fragment. The pins were removed, and range-of-motion exercises were
started. At six weeks postoperatively, the patient was asymptomatic and the
range of motion of the elbow was almost full and symmetrical compared with
that on the right side. Two years following the injury, the elbow-carrying
angle and range of motion were similar to those on the normal side. Repeat
radiographs were not made at the time of the final follow-up.