Monteggia like or Monteggia Associated with a Terrible Triad: How far the Spectrum of that Lesion Extends (A Case Report)

The Monteggia lesion, first described in 1814, is defined as a fracture of the proximal ulna associated with dislocation of the radial head [4]. Monteggia lesions account for 2 to 5% of fractures of the proximal end of the two bones of the forearm. In 1967, Bado spoke of Monteggia lesions and established a classification of 4 types. Type I corresponds to an anterior dislocation of the radial head, type II is a posterior dislocation of the head, type III is a lateral dislocation, and type IV is defined by a fracture of both forearm bones with dislocation of the radial head [5].

Jupiter et al.further classified type II lesions according to the location of the fracture line and the type of fracture of the radial head [5]. The monteggia lesion may be associated with fractures of the radial head or coronoid process described by Bado, under the equivalent name of Monteggia lesions [6].

However, the Monteggia lesion may be associated with a group of lesions that are not included in the Bado and Jupiter classification. Giannicolla et al [7] identified six elements of a Monteggia Like lesion, the combination of which explains the complexity of treatment:

• Ulnar fracture
• Radio-humeral dislocation
• Ulno-huméral dislocation
• Proximal radioulnar dislocation
• Radial fracture
• Distal radioulnar disjunction/interosseous membrane lesion

The coexistence of dislocation and associated fracture of the coronoid process or radial head exposes the patient to a risk of reoperability, which remains high in the various series. Ring et al reported 48 patients with monteggia lesions, and 6 of the 8 patients with poor results had an associated fracture of the coronoid process or of the radial head [6]. Jupiter et al [8], in a series of 11 patients with a monteggia lesion, noted an excellent result, according to the Broberg Morrey score, in three patients, an average to good result in seven patients and a poor result in one patient.

Strauss et al [9] studied 28 patients admitted for a Monteggia type II lesion (with posterior displacement of the head). In 6 of these patients, there was an association with a posterior dislocation of the elbow. The association of a posterior dislocation is thought to result in a greater loss of mobility of the elbow, particularly with regard to extension. Of the six patients operated on for this association, 3 needed repeat surgery [9].

The mechanism of injury for a type II monteggia lesion associated with a dislocation of the elbow suggests a first dislocation due to a fall on a limb in extension and abduction. The alternative explanation would be a monteggia lesion following direct trauma with the elbow in flexion, with dislocation occurring as a second stage [9]. Nadeem et al. speak of injuries that occur in extension with varus forces that fracture the ulna, and the energy released crosses the interosseous membrane and annular ligament to rupture it. With the continuing traumatic force and the existence of a pivot within the fracture site of the ulna, lateral dislocation of the head will occur [10]. The mean revision rate in the review by Weber et al [4] was 23%, which proves that the difficulties still posed by these lesions, nonunion of the ulna, failure of osteosynthesis (28%) and posterolateral instability of the radial head (12%) were the main reasons. Locked plates showed better results than reconstruction plates or 1/3-tube plates [4].

When the monteggia lesion is associated with a fracture of the coronoid process, there is a high risk of anteroposterior huméroulnar instability. It is also important to reconstruct fractures of the radial head using mini screws in the case of Mason II fractures. In the case of Mason III fractures, arthroplasty or resection should be considered if there is integrity of the medial ligament, the coronoid process and the interosseous membrane (Essex Lopresti lesion) [9].

The management of the terrible triad is currently codified [11,12] and is based on the following principles:

• Transform the dislocation fracture into a simple fracture and then keep the elbow reduced
• The risk of reluxation is reduced by fixation or replacement of the radial head, reinsertion of the external collateral ligament on the epicondyle and, if necessary, repair of the coronoid process.
• Restoring capitulo-radial contact is a key element in restoring elbow stability
• As long as the elbow remains reduced, the ulnar collateral ligament will be able to heal.
• If repair of the coronoid, radial head and external collateral ligament does not prevent redislocation, repair of the medial collateral ligament will be considered.

For our patient, the initial treatment was osteosynthesis by intramedullary K-wire fixation, necessitated by the open nature of the lesions and the patient's emergency care. Repair of the annular ligament was reinforced by arthrodesis of the proximal radioulnar joint, which was maintained for 15 days. Then, there was a combination of injuries to the elbow, the management of which was based on the principle of repairing a terrible triad from medial to lateral: a Morrey type I coronoid process fracture that did not require fixation, resection of the fragment of the head that could not be fixed, and repair of the lateral ligament plane. The elbow was stable and free of laxity. The criticisms of our management were unstable osteosynthesis, which meant that rehabilitation was not started.