| CASE REPORT |
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| Year : 1991 | Volume
: 37
| Issue : 4 | Page : 221-2,222A |
Divergent dislocation of the elbow in a child (a case report).
Hemmadi SS, Trivedi JM
Department of Orthopaedic Surgery, Seth G. S. Medical College, Parel.
Correspondence Address:
Department of Orthopaedic Surgery, Seth G. S. Medical College, Parel.
A rare case of simultaneous disruption of superior radio-ulnar joint and posterior dislocation of the same elbow in a 6 year old boy is presented. It was possible to achieve the stable reduction by means of closed manipulation, restoring normal function in 6 weeks time. The possible mode of injury is discussed. There are only 4 cases reported of such a divergent elbow dislocation in modern literature.
How to cite this article:
Hemmadi S S, Trivedi J M. Divergent dislocation of the elbow in a child (a case report). J Postgrad Med 1991;37:221-2,222A |
Dislocation of the elbow in children is rare. It comprises only 6% of an children's fractures and dislocations involving the elbow[1]. Most pure dislocation is posterior but they can occur anteriorly, medially, or laterally. Further rare proximal radio-ulnar joint disruption (dibergent dislocation) can occur either in the antero posterior or medial transverse planes. We present here a case of disruption of superior radio-ulnar joint and posterior dislocation of the same elbow.
A 6-year-old boy was brought to the out patient department of our hospital with a painful deformity and swelling of the right elbow following an accidental fall in school while playing. The elbow was held in 30? flexion. The three bony point relationship was found to be disturbed suggesting posterior and proximal displacement of the olecranon. The elbow was severely tender all around and the radial head was distinctly palpable on the lateral side, somewhat away from the olecranon. Both flexion-extension and supination-pronation of the elbow were painful and limited. There was no associated neurovascular injury. Radiological examination of the right elbow and forearm showed disruption, of the superior radio-ulnar joint alongwith posterior dislocation of the elbow. (See [Figure - 1]) The forearm bones did not show any fracture.
Under general anaesthesia, longitudinal traction was applied to reduce the humero-ulnar dislocation. The radial head was then pushed medially in alignment with the capitallum of the humerus and the elbow was gently flexed to 900 with the forearm fully supinated. The reduction was checked radiologically. (See [Figure - 2]) There was no clinical eidence of instability. The extremity was then immobilised above elbow slab for three weeks. Active mobilisation of the extremity was encouraged. Painless function of the extremity was restored in 6 weeks.
The probable mechanism of injury is a fall on a pronated hand with the elbow in full or nearly full extension, the resultant axial force acting on the radial shaft leading to first a radial head dislocation followed by posterior dislocation of the humero-ulnar joint[3].
The final position of the radial head being determined by the instant at which posterior dislocation occurs in relation to the continuing movement of pronation[2].
The structures most likely to be damaged in this injury resulting in disruption of the superior radio-ulnar joint with posterior dislocation of the elbow will be the capsule, collateral ligament of the elbow joint and the annular ligament. This would also have damaged the supinator muscle and the interosscous membrane. However, it is not possible to ascertain the extent of damage as the case was managed conservatively. The major tear of the interosseous membrane and the muscles of the forearm would be a potential cause of compartment syndrome, and should be carefully watched for.
We believe that closed reduction would succeed in such an injury except when the reduction of the radial head gets obstructed by the infolding of the annular ligament. The latter situation would necessitate open reduction.
| 1. |
Carey RPL. Simultaneous dislocation of the elbow and the proximal radio-ulnar joint. J Bone A Surg 1989; 66B:254-258.  |
| 2. | Holbrook JL, Green NE. Divergent paediatric elbow dislocation. A case report. Clin Orthop Rel Res 1988; 234: 72-73. |
| 3. | Vesely DG. Isolated traumatic dislocations of the radial head in children. Clin Orthop 1967; 50:31-36.
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