Posterolateral instability of the elbow in an adolescent boy with a lateral epicondyle fracture: a case report

Abstract

Background

Posterolateral rotatory instability of elbow is considered to be due to the disruption of the ulnar part of the lateral collateral ligament (LUCL). This instability pattern may also be induced by a fracture of components of the lateral column.

Results

We present the case of a 16-year-old boy who fell on his left outstretched arm as he attempted to jump over a tennis net. On initial physical examination, the elbow had instability found on varus stress and the radial head could be felt posteriorly. With attempted valgus and supination force combined with axial loading, the elbow gapped open and the patient had a sense of increased instability. X-rays showed a fracture of the lateral humeral epicondyle and posterolateral subluxation of the elbow. In the operating room, the patient was found to have reproducible posterolateral instability of the elbow. The lateral epicondyle was found to be fractured off the humerus with the LUCL still attached to the fragment. The elbow was reduced, and the injury was stabilized with small screws and suture anchors. At 6-month follow-up, the patient was pain-free, and physical examination revealed 170° of flexion, full extension, 90° of pronation, and 65° of supination. X-rays showed healing of the fracture with concentric reduction of the elbow joint.

Conclusion

In lateral epicondyle fractures, the affected elbow should be assessed for any signs of associated instability. If signs of clear instability are seen that would prohibit proper postinjury rehabilitation, then surgical reduction and fixation of the epicondyle with reinforcement of the LUCL is an effective method of treatment.