EPIPHYSIOLYSIS OF THE CAPITELLUM HUMERI - rbrs

JBR–BTR, 2005, 88: 184-186. 

EPIPHYSIOLYSIS OF THE CAPITELLUM HUMERI 

T. Lauwers 1 , E. Geusens 1 , S. Pans 1 , S. Nijs 2 

A four-year-old girl presents at the emergency department with left elbow pain after a fall. X-ray demonstrated an 

epiphysiolysis of the capitellum humeri, without a bony fragment, the so-called Salter Harris Type 1 fracture. 

The fracture was treated by open reduction and internal fixation. This case is unusual because avulsions of the 

capitellum are usually associated with a bony fracture. 

Key-words: Elbow, fractures – Children, skeletal system. 

Pure chondral fractures of the 

capitellum are unusual. These 

lesions are usually associated with a 

radiological visible bony fragment. 

We present a displaced avulsion of 

the capitellum, the so-called Salter 

Harris Type 1 fracture (SH1). 

Case history 

A four-year-old girl with a medical 

history of left plexus brachialis 

injury after shoulder dystocia due to 

birth trauma presented at the emergency 

department with left elbow 

pain. She had fallen from a slide. 

Fig. 1. — AP and lateral view of the left elbow: there is a 

moderate to large extracapsular soft tissue swelling. The 

capitellum is displaced (arrow) but without a bony chip 

fracture. The absent displacement of the fat planes is due 

to capsular rupture. 

Clinical examination demonstrated 

deformity and swelling of 

her left elbow, suggestive for fracture 

or dislocation of the elbow. 

There was a reduced mobility due to 

the pain. 

X-ray showed displacement of 

the capitellum humeri without a 

bony fragment (Fig. 1). The normal 

side was taken for comparison 

and for better evaluation of 

the displacement of the fracture 

(Fig. 2). 

The fracture was treated by open 

reduction and internal fixation 

(Fig. 3). 

From: Department of 1. Radiology, 2. Trauma Surgery, University Hospitals Leuven, 

Leuven, Belgium. 

Address for correspondence: Dr E. Geusens, Dept. of Radiology, UZ Gasthuisberg 

Herestraat 49, B-3000 Leuven, Belgium. 

Discussion 

Fractures around the elbow are 

commonly missed or misdiagnosed 

because of a poor appreciation of 

the anatomy and development of 

the normal elbow. In the young 

child, some of the structures may 

not yet have ossified and are therefore 

not visible on plain radiographs 

(1). 

Most long bones have one epiphyseal 

growth centre and one 

physis at each end. The distal 

humerus, however, has four ossification 

centres and in older children 

Fig. 2. — Normal right side for comparison 

two separate physes. The normal 

ossification stadia in the elbow are 

illustrated in figure 4. Initially the 

distal humeral epiphysis is one 

large mass of cartilage. The epiphyseal 

growth plate is transverse at 

birth, which contributes to a predis-

position to total separation of the 

epiphysis if significant trauma 

occurs. During maturation, separate 

ossification centres develop for the 

capitellum, the medial epicondyle, 

the trochlea and the lateral epicondyle. 

In early youth, the growth 

plate gradually extends obliquely 

downward and medially from a 

point just above the lateral epicondyle 

to below the medial epicondyle 

(Fig. 4). 

By age 4, the growth plate becomes 

more irregular and metaphyseal 

bone begins to project between 

the medial epicondyle and the capitellum, 

dividing the physis into two 

separate physes. Both of these factors 

aid stability and total separation 

of the epiphyses becomes more difficult. 

Anatomic peculiarities of the distal 

humerus may therefore explain 

the differences in age distribution of 

these injuries (2). 

Many classifications of physeal 

injuries have been proposed. The 

classification of Salter and Harris 

(Fig. 5) is the most commonly used: 

type 1: a fracture that involves epiphyseal 

separation because of a 

fracture through the physis only, 

type 2: a fracture through the physis 

and metaphysis, with a fragment of 

the metaphysis remaining attached 

to the epiphysis, type 3: a fracture 

that begins intra-articularly and travels 

through the epiphysis into the 

physis, type 4: a fracture that begins 

intra-articularly and travels through 

the epiphysis, physis and the metaphysis, 

and type 5: the physis is 

crushed (3). 

Anteroposterior and lateral radiographs 

of the injured elbow are 

EPIPHYSIOLYSIS OF THE CAPITELLUM HUMERI — LAUWERS et al 185 

Fig. 3. — Image during open reduction and internal fixation: 

note the displaced capitellum (arrow). 

essential for evaluation. Views of the 

opposite elbow in the same position 

provide a valuable basis for comparison 

in assessing injury, but should 

not be taken on a routine base. Intraarticular 

haematoma may displace 

the posterior fat pad of the distal 

humerus (the “fat pad sign”), which 

may be the only demonstrable sign 

in an undisplaced or spontaneously 

reduced fracture. But in case of capsular 

rupture, the intra-articular 

blood or fluid can leak in the sur- 

Fig. 4. — Schematic drawing of the normal age of ossification 

of the elbow. Numbers indicate the approximate age in years at 

which the centre begins to ossify. 

Fig. 5. — Schematic drawing of the Salter-Harris classification 

of physeal injuries. 

rounding tissues, and the fat pad 

sign can disappear. So, a normal fat 

pad does not exclude a fracture of 

the elbow. 

Because the epiphysis is primarily 

cartilaginous in young children, 

epiphyseal separation may be difficult 

to diagnose by routine radiographs. 

Ultrasound has gained an 

increasing role in the diagnosis of 

musculo-skeletal pathology (3). It is 

non-invasive, and does not require 

sedation. High resolution real-time

186 JBR–BTR, 2005, 88 (4) 

sonography of the musculo-skeletal 

system of infants and young children 

is being used with increasing 

frequency, in part because of the 

inability of plain film radiography to 

visualize unossified cartilage (4). 

Reasons to examine a patient with 

sonography include pain, limitation 

of motion, soft tissue swelling and 

clinical suspicion of joint abnormality 

when findings on plain films are 

inconclusive. Because we had a 

diagnosis on plain films alone, we 

did no perform ultrasound before 

surgery. MRI can also be of 

value (5), but anaesthesia is often 

needed in young children. 

Because this fracture involves 

both the articular surface and the 

physis, anatomic reduction is necessary 

and must be held until the fracture 

has united. This usually 

requires internal fixation. 

Malunion and non-union are frequent 

complications in untreated 

cases. These can cause deformity, 

loss of motion and degenerative 

arthrosis. 

In conclusion, we do not advocate 

the systematic use of comparative 

views, but in doubtful cases, the 

comparative view can be helpful in 

making the correct diagnosis. 

This case is unusual because 

avulsions of the capitellum are usually 

associated with a bony fracture. 

Pure chondral fractures of the 

capitellum are very unusual. 

References 

1. Paterson J.M.H.: Children’s fractures 

“not to be missed”. Hospital 

Medicine, 2002, 63: 426-428. 

2. Peterson H.A.: Physeal injuries of the 

distal humerus. Orthopedics, 1992, 

15: 799-808. 

3. Bar-On E., Howard C.B., Porat S.: The 

use of ultrasound in the diagnosis of 

atypical pathology in the unossified 

skeleton. J Paediatr Ortho, 1995, 15: 

817-820. 

4. Markowitz R.I., Davidson R.S., 

Harty M.P., et al.: Sonography of the 

elbow in infants and children. AJR, 

1992, 159: 829-833. 

5. Della-Giustina K., Della-Giustina D.A.: 

Emergency department evaluation 

and treatment of pediatric orthopaedic 

injuries. Emerg Med Clin 

North Am, 1999, 17: 895-923.

EPIPHYSIOLYSIS OF THE CAPITELLUM HUMERI - rbrs

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