AJR 2000; 174:1115-1117
© American Roentgen Ray Society
Using Sonography to Diagnose an Unossified Medial Epicondyle Avulsion in a Child
David A. May1,
David G. Disler1,2,
Elizabeth A. Jones1 and
David A. Pearce2
1
Department of Radiology, Virginia Commonwealth University, Medical College of
Virginia, P. O. Box. 980615, Richmond, VA 23298-0615.
2
Department of Orthopedic Surgery, Virginia Commonwealth University, Medical
College of Virginia, Richmond, VA 23298-0615.
Received June 2, 1999;
accepted after revision September 15, 1999.
Address correspondence to D. A. May.
Introduction
Childhood avulsion of the humeral medial epicondyle can be difficult to
diagnose. Physical examination findings may not be specific and radiographic
findings may be nondiagnostic in young children. The medial epicondyle of the
humerus usually does not begin to ossify before the age of 4 or 5 years and
hence is not shown on radiographs of young children. Because sonography has
been useful in the diagnosis of supracondylar and condylar fractures in
neonates and infants
[1,2,3],
it might also provide a rapid, painless, and inexpensive method of locating
the cartilaginous medial epicondyle. We report a case in which sonography
helped to diagnose a displaced avulsion fracture of an unossified humeral
medial epicondyle in a 5-year-old boy.
Case Report
A 5-year-old boy was seen in our emergency department with left elbow pain
after an unobserved fall while running. Examination by an orthopedic surgeon
revealed soft-tissue swelling around the elbow joint, especially medially, and
decreased range of motion with guarding. Radiographs revealed medial
soft-tissue swelling (Fig. 1A),
but elevation of the posterior fat pad was not seen. No fracture was shown.
The medial epicondylar apophysis, concordant with the child's age, was not
ossified. A comparison radiograph of the asymptomatic contralateral right
elbow showed the right medial epicondyle was not ossified. Sonography of the
elbows was performed with a 10-MHz linear array transducer (HDI 3000; Advanced
Technology Laboratories, Bothell, WA) and showed the left medial epicondyle to
be displaced 1 cm distally and slightly anteromedially from its expected
position (Figs. 1B and
1C). A small joint effusion was
shown. Sonography was completed in less than 5 min. The child was initially
treated with an elbow splint followed after 5 days by a sling, with
encouragement to use the elbow as tolerated. Four weeks after the injury, the
child was pain free, with full range of motion, and had returned to normal
activities. Radiographs obtained at this time revealed early ossification of
the displaced medial epicondylar apophysis
(Fig. 1D). No further
displacement was shown.
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Fig. 1A. —5-year-old boy with avulsion of medial epicondyle. Anteroposterior
radiograph of left elbow obtained at presentation shows medial soft-tissue
swelling (X). Note absence of ossification of medial epicondyle.
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Fig. 1B. —5-year-old boy with avulsion of medial epicondyle. Coronal sonograms
of injured left elbow (B) and uninjured right elbow (C) obtained
for comparison shortly after A and oriented similarly to A show
cortical bone of humeri (arrows). Cartilaginous medial epicondyles
are seen as well-defined hypoechoic regions without acoustic enhancement. Note
medial soft-tissue swelling (X) in A. Avulsed left medial epicondyle in
B is displaced from cortical bone of distal humerus and shows different
orientation from healthy medial epicondyle in C, reflecting fragment
rotation. Additional sonograms (not shown) revealed healthy appearance of
articulation between ulna and trochlea, and radius and capitellum, without
evidence of entrapped medial epicondyle or current dislocation. E = medial
epicondyle, T = trochlea, H = distal humerus.
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Fig. 1C. —5-year-old boy with avulsion of medial epicondyle. Coronal sonograms
of injured left elbow (B) and uninjured right elbow (C) obtained
for comparison shortly after A and oriented similarly to A show
cortical bone of humeri (arrows). Cartilaginous medial epicondyles
are seen as well-defined hypoechoic regions without acoustic enhancement. Note
medial soft-tissue swelling (X) in A. Avulsed left medial epicondyle in
B is displaced from cortical bone of distal humerus and shows different
orientation from healthy medial epicondyle in C, reflecting fragment
rotation. Additional sonograms (not shown) revealed healthy appearance of
articulation between ulna and trochlea, and radius and capitellum, without
evidence of entrapped medial epicondyle or current dislocation. E = medial
epicondyle, T = trochlea, H = distal humerus.
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Fig. 1D. —5-year-old boy with avulsion of medial epicondyle. Anteroposterior
radiograph of left elbow obtained 4 weeks after A-C shows that
medial epicondyle (arrow) has begun to ossify and is unchanged from
position seen in B.
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Discussion
Many applications of sonography in the assessment of elbow pain have been
described, such as diagnosis of tendonitis and bursitis, tendon tear, joint
effusion, intraarticular bodies, nerve injury, and fractures, including
fractures of unossified epiphyseal cartilage
[1,2,3].
Reports of elbow sonography in infants and young children have emphasized its
use in the diagnosis of humeral condylar and supracondylar fractures
[1,
2]. We are not aware of a
previous description of sonographic diagnosis of avulsion of the unossified
humeral medial epicondyle. Accurate characterization of medial humeral
epicondyle avulsion is essential to initiate proper therapy. Because
sonography provides visualization of unossified cartilage, it should allow
localization of a displaced apophysis such as the humeral medial
epicondyle.
Fractures involving the humeral medial epicondyle in children are
relatively infrequent [1,
2]. Avulsion fractures may be
subdivided into four categories: simple avulsion of the medial epicondyle,
avulsion with entrapment of the medial epicondyle between the ulna and
trochlea, avulsion in association with elbow dislocation, and the rare
Salter-Harris type IV fracture of the medial humeral condyle
[1,
2] (Fig.
2A,2B,2C,2D,2E).
Treatment of medial epicondylar fractures depends on the type of injury
[4,
5]. As with our patient, most
simple avulsions are treated with a splint, followed by a sling, to allow
rapid resumption of normal range of motion
[5]. Although such treatment
results in a high rate of fibrous nonunion on radiographs, these patients
rapidly regain full function and are rarely symptomatic
[5]. In contrast, avulsion with
entrapment requires aggressive manipulation under deep sedation or general
anesthesia to reduce the medial epicondyle; surgical reduction is usually
required [5].
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Fig. 2A. —Diagram shows types of fractures involving medial epicondyle in
children. (Reprinted and modified with permission from
[4]) Normal right elbow. MCL =
medial collateral ligament, M = medial, L = lateral.
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Fig. 2C. —Diagram shows types of fractures involving medial epicondyle in
children. (Reprinted and modified with permission from
[4]) Avulsion with entrapment
of medial epicondyle between ulna and trochlea.
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Diagnosis of medial epicondylar fractures is readily made on radiography if
this growth center has begun to ossify. This process typically occurs between
the ages of 4 and 6 years [4,
5]. In younger children
(typically age 5 years old or younger) as in our patient neither the medial
epicondyle nor the trochlea is ossified. Physical examination and radiographic
findings may strongly suggest a medial epicondyle injury, but they may not
distinguish between a simple avulsion and avulsion with entrapment
[5]. For example, a torn joint
capsule will allow a hemarthrosis to decompress, so a fat pad sign may not be
present [3]. Both arthrography
and MR imaging can reliably characterize medial elbow injuries in children
[5,
6]. However, these tests are
expensive and frequently require sedation, and arthrography is invasive.
Neither test can be performed as readily as sonography.
Real-time sonography of the pediatric elbow to locate the cartilaginous
medial epicondyle apophysis is relatively easy and rapid. Successful
sonography of the elbow (or any other joint) requires knowledge of anatomy and
reasonable skill in scanning. Specific elbow scanning protocols have been
suggested [3]. However,
directing the examination to address a specific question allows a shorter
examination time and enhances patient tolerance. Sonography of the uninjured
side for the purpose of comparison is frequently useful, as it was in our
patient in showing the healthy appearance of the contralateral medial
epicondyle.
In summary, we present a case of simple avulsion of the medial epicondyle
in a 5-year-old boy that could not be diagnosed by clinical or radiographic
features but was seen on sonography. Sonography permitted initiation of
appropriate therapy in the emergency department.
References
-
Markowitz RI, Davidson RS, Harty MP, Bellah RD, Hubbard AM,
Rosenberg HK. Sonography of the elbow in infants and children.
AJR
1992;159: 829
-833[Abstract/Free Full Text]
-
Davidson RS, Markowitz RI, Dormans J, Drummond DS. Ultrasonographic
evaluation of the elbow in infants and young children after suspected trauma.
J Bone Joint Surg Am
1994;76-A: 1804
-1813[Abstract/Free Full Text]
-
Bouffard A, Cho KH, Cardinal E, Chhem RK. Elbow. In: Chhem RK,
Cardinal E, eds. Guidelines and gamuts in musculoskeletal
ultrasound. New York: Wiley-Liss, 1999: 82
-84
-
Rogers LF. Radiology of skeletal trauma.
New York: Churchill Livingstone, 1992: 772
-779
-
Chambers HG, Wilkins KE. Apophyseal injuries of the distal humerus.
In: Rockwood CA, Wilkins KE, Beaty JH, eds. Fractures in
children. Philadelphia: Lippincott-Raven,
1996: 800-819
-
Kerr R. Diagnostic imaging of upper extremity trauma.
Radiol Clin North Am
1989;27: 891
-908[Medline]
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Introduction
Case Report
