14-3) is normal as opposed to subtle plastic deformation of the ulna which will have a concave ulnar bow and can be misdiagnosed as a type I equivalent when the injury is really a Bado I lesion. In type I equivalent lesions, the radial head is malaligned in its relationship to the capitellum and proximal ulna. In nursemaid’s elbow cases, the radiographs are normal. This subclassification includes a “pulled elbow” or “nursemaid’s elbow” because the mechanism of longitudinal traction, pronation, and hyperextension is similar to a true type I lesion. 14-2) include isolated anterior dislocations of the radial head without ulnar fracture. Since his original publication, the list of equivalent lesions has expanded case report by case report.īado type I equivalents ( Fig. Type IV lesions are relatively rare in children.Įxpansion of the Bado Classification: Monteggia Equivalent Lesionsīado 8, 10 classified certain injuries as equivalents to true Monteggia lesions because of their similar mechanisms of injury, radiographic appearance, or treatment methods. The original description was of a radial fracture at the same level or distal to the ulna fracture. 63, 118, 146Ī Bado type IV lesion is an anterior dislocation of the radial head associated with fractures of both the ulna and the radius. 13, 48, 98, 103, 160 When an injury is characterized by an olecranon fracture and a lateral or anterolateral radiocapitellar dislocation but no radioulnar dissociation, the injury is not a true Monteggia lesion. This is the second most common pediatric Monteggia lesion. 41, 116, 117Ī Bado type III lesion is a lateral dislocation of the radial head associated with a varus (apex lateral) fracture of the proximal ulna. 105, 106, 119 Type II lesions account for 6% of Monteggia lesions in children, 77 and are usually found in older patients 105 who have sustained significant trauma. This pattern is the most common Monteggia lesion in adults, but is relatively rare in children. 38, 53, 81, 119, 156Ī Bado type II lesion is a posterior or posterolateral dislocation of the radial head associated with an apex posterior ulnar diaphyseal or metaphyseal fracture. This is the most common Monteggia lesion in children and represents approximately 70% to 75% of all injuries. The key to a good outcome after a Monteggia-type fracture-dislocation of the forearm remains early recognition of proximal radioulnar dissociation.A Bado type I lesion is an anterior dislocation of the radial head associated with an apex anterior ulnar diaphyseal fracture at any level.
Late reconstruction of chronic Monteggia lesions in children can be complicated and unpredictable. Unstable (complete) ulnar fractures are prone to residual or recurrent displacement and may require operative fixation. The relatively good results associated with nonoperative treatment of pediatric Monteggia injuries reflect the prevalence of stable (incomplete) fractures in children. The notoriously poor results of treatment of Monteggia fractures in adults improved dramatically after the development of modern techniques of plate-and-screw fixation, which facilitate early mobilization by ensuring anatomic reduction. Stable anatomic reduction of the ulnar fracture results in anatomic reduction of the radial head.
It is the character of the ulnar fracture, rather than the direction of radial head dislocation, that is useful in determining the optimal treatment of Monteggia fractures in both children and adults. The eponymous term "Monteggia fracture" is most precisely used to refer to dislocation of the proximal radioulnar joint in association with a forearm fracture.