PEDIATRIC MONTEGGIA FRACTURES

Anterior, posterior, or lateral dislocation of the radial head together with an ulna fracture was first described by Giovanni Batista Monteggia in 1814. When a child falls on his/her arm in extension and pronation, the body weight exerts a torsional force on the elbow joint, forcing the humerus and ulna into external rotation. When the ulna is deformed, the radial head continues to be forced into hyperpro-nation. If the torsional force is great enough, the radial head dislocates, and if the plastic deformation of the ulna also exceeds the ulna fractures. Although anterior dislocation of the radial head and an ulna fracture can rarely be seen due to trauma from the dorsal side to the proximal ulna shaft, this mechanism is uncommon in children. Clinically, a child with a Monteggia fracture may hold his/her arm in flexion and pronation to reduce pain. An ulna fracture, seen on anteroposterior (AP) and lateral radiographs, may attract all attention and prevent radial head dislocation from being noticed. Since anterior and posterior dislocations may be missed on AP radiographs, lateral radiographs are essential for determining the dislocation. Monteggia lesions are divided into four groups. Regardless of the fracture characteristics on the ulna, the ulna shaft is always angular to the side where the radial head is dislocated. Type 1; extension type ulna fracture and anterior radial head dislocation (60-85%); Type 2: flexion type ulna shaft fracture with posterior radial head dislocation (10-15%); Type 3: ulna shaft angular laterally, radial head dislocation laterally (5%), Type 4; Type 1 with radial head fracture (5%). Neurovascular structures should be carefully evaluated during diagnosis. Although examining a pain-ful elbow in a child is complex, indirect neurovascular findings such as skin color and hand and finger functions should be carefully evaluated. The main goal in treating Monteggia fractures is to reduce the radial head. Straightening the ulna shaft is vital for reduction. Open reduction is rarely necessary. In incomplete fractures such as greenstick fractures, the bending of the ulna may naturally prevent the reduction of the radial head. It may be required to create a complete fracture. The most essential step in preventing complications is correct diagnosis. After improperly treated Monteggia fractures, elbow movement restriction, instability, and valgus deformity may develop. If there is a fracture dislocation of the radial head, radicapitellar incongruity may be seen after the radial head malformation. Hetero-topic ossification may also be seen after Monteggia fractures. Periarticular ossification, myositis ossifi-cans, and radioulnar synostosis may occur. In a child diagnosed with a Monteggia fracture, it should be confirmed that the radial head is not dislocated after closed or open reduction. Associated pathologies should be carefully evaluated.