Missed Monteggia Injuries in Children and Adolescents: A Treatment Algorithm

Abstract

Monteggia injuries are rare childhood injuries. In 25-50% of cases, however, they continue to be overlooked, leading to a chronic Monteggia injury. Initially, the chronic Monteggia injury is only characterized by a moderate motion deficit, which is often masked by compensatory movements. Later, however, there is a progressive valgus deformity, neuropathy of the ulnar nerve and a progressive deformity of the radial head ("mushroom deformity") with ultimately painful radiocapitellar arthrosis. In the early stages, when the radial head is not yet deformed and there is no osteoarthritis in the humeroradial joint, these injuries can be treated with reconstruction procedures. This can be achieved either by an osteotomy of the proximal ulna with or without gradual lengthening. If there is already a severe deformity of the radial head and painful osteoarthritis, only rescue procedures such as functional radial head resection or radial head resection with or without hemi-interposition arthroplasty can be used to improve mobility and, above all, to eliminate pain. In this review article, we provide an overview of the current treatment options of chronic Monteggia injury in children and adolescents and present a structured treatment algorithm depending on the chronicity and dysplastic changes.

Keywords: algorithms; children; missed Monteggia injury; radial head dislocation; ulnar osteotomy; upper extremity deformity.

Figure 1

Appropriate identification and treatment of acute Monteggia fracture-dislocations for Bado Typ I (a,c) and Typ III (e) in children with closed reduction and casting (b), intramedullary nailing (d) or plating (f).

Figure 2

Lateral radiograph of the elbow joint in an 8-year-old girl with a missed Monteggia fracture-dislocation. In preoperative planning, the Støeren line (red line) clearly deviates from the normal radiocapitellar line (black line) and does not intersect the humeral capitulum. Additionally, the ulna already shows plastic deformation, reflected in the ulnar bow sign (green line).

Figure 3

Treatment algorithm based on the chronicity and dysplastic changes (according to the literature).

Figure 4

This figure shows the treatment course for the reconstruction of two missed Monteggia fractures in 9-year-old children. Panels (a–d) depict an angulating proximal ulnar osteotomy with an external fixator and closed reduction of the radial head. This approach was undertaken after a failed external osteotomy at the CORA using plate osteosynthesis. Panels (e–h) illustrate an angulating proximal ulnar osteotomy with plate osteosynthesis combined with an open reduction of the radial head. In both cases, the far cortex of the osteotomy was left intact to promote faster and improved healing without bone grafting. Radiographs at 4 weeks (c,g) already demonstrate evidence of consolidation, with complete healing observed at 3 months (d,h) and no signs of nonunion.

Figure 5

Intraoperative images of the patient: Panels (a,b): Open reduction of the radial head and osteotomy of the proximal ulna with a temporary external fixator for alignment before definitive osteosynthesis using an advanced locking plate via an extended Kocher approach. Panels (c–e): Intraoperative fluoroscopy demonstrates correct reduction of the radial head in both planes and the proximal ulnar osteotomy with a remaining dorsal bony bridge. Image c corresponds to image a and image d to the intraoperative image b.

Figure 6

This figure demonstrates two salvage procedures for patients with advanced dysplastic changes of the radial head and proximal radioulnar joint (PRUJ) (a,b,e,f). Panels (a–d) depict a functional radial head resection according to Slongo. This procedure involves distalization of the radial head beyond the capitellum using a ring fixator and a proximal ulnar osteotomy (c,d). Panels (e–h) illustrate a radial head resection with hemi-interposition arthroplasty. In this approach, the radial head is resected distal to the coronoid process. A capsular flap is interposed between the humeral capitulum and the resected radial head to act as a spacer with small suture anchors. Additionally, the detached lateral ulnar collateral ligament is reattached to the bone with suture anchors.