Missed Monteggia fracture in children: Is annular ligament reconstruction always required?

Abstract

Background: Chronic (neglected) radiocapitellar joint dislocation is one of the feared complications of Monteggia fractures especially when associated with subtle fracture of the ulna bone. Many treatment strategies have been described to manage chronic Monteggia fracture and the need for annular ligament reconstruction is not always clear. The purpose of this study is to highlight the management of missed Monteggia fracture with particular emphasis on utility of annular ligament reconstruction by comparing the two groups of patients.

Materials and methods: In a prospective study 12 patients with mean age of 7.4 years, who presented with neglected Monteggia fractures, were studied. All children underwent open reduction of the radiocapitellar joint. Five children (Group A) were treated with angulation-distraction osteotomy of ulna and annular ligament reconstruction and six cases (Group B) required only angulation-distraction osteotomy of ulna without ligament reconstruction. In one case an open reduction of the radiocapitellar joint was sufficient to reduce the radial head and this was included in Group B. The gap between injury and presentation was from 3 months to 18 months (mean 9 months). Ten patients were classified as Bado I, and one each as Bado II and III respectively. We used the Kim's criteria to score our results.

Result: The mean follow-up period was 22 months. All ulna osteotomies healed uneventfully. The mean loss of pronation was 15 degree in Group A and 10 degree in Group B. Elbow flexion improved from the preoperative range and no child complained of pain, deformity and restriction of activity. The elbow score was excellent in 10 cases, and good in two cases.

Conclusion: Distraction-angulation osteotomy of the ulna suffices in most cases of missed monteggia fracture and the need for annular ligament reconstruction is based on intraoperative findings of radial head instability.

Keywords: Missed Monteggia fracture; annular ligament reconstruction; ulna osteotomy.

Figure 1A

Lateral and anteroposterior radiograph of right elbow of a seven year old girl showing missed Monteggia fracture of 18 months

Figure 1B

Lateral radiograph of elbow and forearm after open reduction, ulna osteotomy, bone grafing and annular ligament reconstruction

Figure 1C

Lateral radiograph of elbow at final follow-up of 24 months. She had no symptoms and the graft has healed well. The radial head is well maintained

Figure 2A

Lateral radiograph of elbow of 12 year old child showing missed Monteggia fracture

Figure 2B

Post-operative lateral radiograph of the elbow showing the angulation-distraction osteotomy of the ulna with bone grafting. Annular ligament reconstruction was not required (Group B)