Tratamiento quirúrgico de la lesión crónica de Monteggia en niños…(Inglés)

Operative treatment of chronic Monteggia lesion in younger children: A report of three cases

T.C. Koslowsky MD, K. Mader MD, A.P. Wulke MD, T. Gausepohl MD and D. Pennig MD

Department of Trauma Surgery, Hand and Reconstructive Surgery, St Vinzenz-Hospital, Cologne, Germany

The Monteggia lesion, first described by Giovanni Monteggia in 1814, is a severe injury of the forearm, defined as a fracture of the ulna with a dislocation of the radiohumeral joint. Bado and Boals3 classified the Monteggia lesion into 4 subtypes by describing the different positions of the radial head.

Unreduced dislocation of the radial head for more than 4 weeks is considered to be chronic. The missed dislocation of the radial head in children leads to significant impairment of elbow function. Late sequelae of chronic Monteggia lesions include skeletal deformity, pain, instability, and loss of motion of the elbow joint, as well as subluxation of the distal radioulnar joint.10, 11 and 14

The treatment of chronic radial head dislocation appears to be difficult, because there is no reliable technique available to maintain reduction of the radial head. High complication rates in the previously published cases indicate that the treatment of choice is still a matter of discussion.4 and 14

In these patients we present encouraging results using a 2-step procedure in missed radial head dislocations.

Persistent malangulation of the ulna was considered to be an obstacle to adequate reduction of the radial head. As the first step, an external mini-fixator was applied to the ulna (Orthofix Srl, Bussolengo, Italy), by use of a 2.2-mm pin size and a standard body with a 3-dimensional joint. This technique provides the ability to rotate about the ulnar axis. After that, a percutaneous osteotomy of the ulna, as described by Küntscher10 in 1964, was performed. The ulna was held by the fixator, and the angulation was corrected by manipulating the fixator joint and the length of the fixator rail. This maneuver can lead to spontaneous reduction of the radial head. If spontaneous reduction did not occur, open reduction was performed via a small open approach. An open reduction of the radial head included removal of interposed tissue and retention of the radial head with an absorbable Maxon suture around the radial neck and the ulna.

Patients were seen 26 to 30 months after surgery. For evaluation, the standard rating system of Morrey13 was used.

Case reports

Case 1

A 6-year-old girl was referred to us 1 month after initial trauma. An ulnar fracture was recognized in another institution and treated by closed reduction and an above-elbow cast. A Bado type II radial head dislocation was missed. After removal of the cast, the patient was referred to us with limited range of motion of the left elbow and a severe loss of forearm rotation. Ulnar osteotomy, 3-dimensional angulation, and closed reduction of the radial head were performed 30 days after the initial trauma. The postoperative course was uneventful, and the fixator was removed 6 weeks after surgery. Plain radiographs at a follow-up of 26 months showed an anatomic position of the radial head.

Case 2 A 5-year-old girl was treated 4 months after a fracture of the forearm (Bado type IV) with a persistent radial head dislocation. Clinically, she presented with a valgus deformity and limited flexion and extension, as well as pronation and supination. First, an open reduction of the radial head and reconstruction of the annular ligament were performed. The position of the radial head was maintained with K-wire fixation. This operation failed, and redislocation occurred a few days after surgery, so a second operation was necessary.

In a second attempt, the index operation was performed. The radial head was reduced via a small open approach. Scar tissue was removed from the radiohumeral joint, and the radial head was fixed to the ulna with a Maxon (B. Braun-Dexon GmbH, Spangenberg, Germany) suture around its neck. The postoperative course was uneventful, and the fixator was removed 6 weeks after surgery. Plain radiographs at a follow-up of 30 months demonstrated an anatomic position of the radial head.

Case 3 A 7-year-old girl presented with increased cubitus valgus, a slight limitation of elbow flexion and extension, and pain during elbow movement. There was a healed fracture of the ulna, and the radial head was dislocated for 7 months (Bado type I). An ulnar osteotomy and 3-dimensional correction were performed. Intraoperatively, closed reduction failed and the radial head was reduced via a small incision. It was fixed with a Maxon suture around its neck. Radiographs at the 26-month follow-up visit demonstrated an anatomic reduction. On examination, radiographs showed bony union with normal anatomy of the elbow joint in all cases. All patients had no pain and a full range of motion in flexion, extension, pronation, and supination compared with the uninjured side. There was no restriction in daily life or sport activities. In all 3 cases, the result was excellent based on the Morrey score without any complications.

Discussion Rodgers et al14 described 14 complications in 7 patients after operative treatment in chronic missed Monteggia lesions. These ranged from radial head redislocation, malunion of the ulnar shaft, and compartment syndrome of the forearm to nerve palsy of the ulnar and radial nerves. With regard to the high failure rate, it is evident that the treatment of chronic Monteggia lesions requires further attention. Treatment recommendations include a wait-and-see policy, as well as various operative procedures.1, 6, 7, 9, 10 and 15

Two different protocols are described in the literature. One group of authors prefers a radial head reduction as the key procedure. These authors recommend an ulnar osteotomy as the second step only if reduction fails.5

The other group of authors considers the ulnar malunion to be the main cause of the persistent dislocation of the radial head and, therefore, recommends correcting the ulnar malunion before radial head reduction. The first description of an ulnar osteotomy combined with open reduction of the radial head was published by Judet et al8 in 1962. Mandaba et al12 and, later, Hirayama et al7 described an osteotomy with overcorrection of the angular deformity of the ulna pointing to the interosseous membrane as a primary stabilizer of the radial head. In those cases, an open reduction of the radial head was needed to remove scar tissue from the radiohumeral joint.

External fixation of the ulna in missed Monteggia lesions was described by Exner4 for gradual lengthening and dorsal angulation of the ulna to achieve closed reduction of the radial head. We are, however, concerned about the unpredictable response of the interosseous membrane, possible fibrous tissue interposition as a result of the annular ligament,2 and the distal radioulnar joint, which might ultimately compromise pronation and supination.

The extensive operative approach with ulnar osteotomy, plate fixation, and open radial head reduction is accompanied by a high complication rate.14 This may partly be because of the difficulties in planning and performing a 2-step correction of the ulnar malunion, as the degree and direction of the necessary correction frequently are 3-dimensional and unpredictable. In our cases the use of a multidirectional external fixator helped to facilitate reduction. It allowed changing of the alignment of the ulna until the tendency of redislocation in the radiohumeral joint was minimized during forearm rotation. The osteotomy in this series was performed percutaneously as described by Küntscher.10 Open radial head reduction is performed if a closed reduction after osteotomy and ulnar alignment cannot be achieved.

In these rather recent injuries, without the added difficulty of longitudinal growth changes, percutaneous osteotomy wi
th external fixation to correct the malalignment of the ulna may be a helpful technique. An open reduction of the radial head is only required if closed reduction after ulnar osteotomy does not lead to radioulnar and humeroradial congruency.16.