Missed Monteggia injuries.

The classical Monteggia injury comprises a dislocation of the radial head with an associated fracture of the ulna. In the variant type, there is no ulnar fracture merely plastic deformation. We performed a retrospective study of all Monteggia injuries from 1992 to 2001. A total of 39 were reviewed, of which 8 were missed (1 classical and 7 variant). Of those, five were male and three female with a mean age of 6.3 years. The mean follow-up was 2.5 years, with a mean interval between injury and diagnosis of 33.5 weeks. Two Monteggia injuries diagnosed within 4 weeks were successfully treated by closed manipulation. The other six required ulnar osteotomy, repair of the annular ligament and stabilisation of the radial head with a transcapitellar pin. A protocol for the diagnosis of Monteggia injuries is described. Doubtful cases require an immediate review since early treatment improves the outcome. Acceptable clinical and radiological results in late diagnosed Monteggia injuries can result from ulnar osteotomy, open reduction of the radial head with repair of the annular ligament and transcapitellar pin stabilisation of the reduced radial head.