Transposition of radius and ulna associated with dislocation of the elbow in a child

314

Injury, 10, 314-316

Printed in Great Britain

Transposition of radius and ulna associated with dislocation of the elbow in a child W. A. MacSween Leicester Royal Infirmary Summary

A case of transposition of the radius and ulna associated with posterior dislocation of the elbow in a child is reported.

INTRODUCTION CAREFUL examination of radiographs is necessary in order to determine the exact nature of injury in all cases. This is particularly true in the management of childhood injuries when comparison with the reversed radiograph of the normal limb may be helpful. It is important to take radiographs following reduction while the child remains under anaes-

Fig. 1. Anteroposterior

thesia in order to confirm reduction and demonstrate associated fractures or other abnormality. Dislocation of the elbow accompanied by severe soft tissue disruption may, and usually does, have an excellent prognosis in the young child.

CASE REPORT A healthy 6-year-old boy fell from a swing onto his outstretched left hand. He complained of pain in his left elbow which on examination was swollen, deformed and bruised. The forearm lay in the midprone position. Anteroposterior and lateral radiographs of the elbow were thought to show a simple posterior dislocation associated with minimal fracture of the radial neck (Fig. 1).

and lateral radiographs

of the elbow on admission.

MacSween

: Elbow

Dislocation

Fig. 2. Anteroposterior

and lateral radiographs

of the elbow after initial attempt

at reduction.

Fig. 3. Anteroposterior

before application

and lateral radiographs of plaster.

Under general anaesthesia traction was applied to the elbow and there was audible evidence of reduction of the dislocation. Flexion, however, was not possible beyond 90” and the forearm remained fixed in the mid-prone position. Further radiographs taken under anaesthesia revealed that the ulna articulated with the capitellum and that the radius lay to the medial side (Fig. 2). Review of the original radiographs showed this transposition to be present on admission. It was

of the elbow after reduction and

possible to relocate the radial head by supination of the wrist and direct pressure over the ulna and radius (Fig. 3). Full flexion was then possible and a normal range of pronation and supination was present while maintaining the elbow in 100” flexion. The elbow was immobilized in a plaster-of-Paris back slab in 100” flexion and full supination of the forearm for 3 weeks (Fig. 4). The patient was then instructed in active mobilization of his elbow. Seven weeks after injury he lacked

Injury: the British Journal of Accident

316

Fig. 4. Anteroposterior

and lateral

radiographs

20” of extension and 30” of pronation,

but flexion and supination were full; 5 months after injury the elbow was functionahy normal. When examined one year after injury, hyperextension of 25” was present, compared to 15” on the normal side. There was an increase of 5” in the valgus angle; pronation lacked 10”. At no stage was there evidence of neurovascular damage.

DISCUSSION Dislocation

of the elbow is a relatively

common

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4

of the elbow in plaster.

injury in children resulting usually from a fall on the outstretched hand. The excellent functional result one year after injury suggests that in young children, severe soft tissue damage associated with dislocation of the elbow may carry a very good prognosis. Disruption of the superior radio-ulnar joint may be present, but as far as the author is aware no case has been described in which the upper ends of the radius and ulna are transposed following this disruption.

Requesls for reprints should be addressed lo: Mr W. A. MacSween, L&ester

Royal Infirmary, L&ester.