The Adult Monteggia Fracture: Patterns and Incidence of Annular Ligament Incarceration Among 121 Cases at a Single Institution Over 19 Years.

PURPOSE: The purposes of this study were to identify the relative frequency of Monteggia fracture patterns and to investigate the required frequency of open reduction of the proximal radiocapitellar joint.

METHODS: We identified 121 Monteggia fractures at a Level I trauma center from 1996 to 2015 and included 119 in this study. These fractures were identified using a database search for the appropriate International Classification of Diseases, Ninth Revision and Current Procedural Terminology codes as well as individual surgeons' logs. Two fellowship-trained hand surgeons reviewed the identified patients' x-rays and operative notes. Each fracture was classified using Bado's original description, excluding transolecranon and Monteggia variants.

RESULTS: Bado I lesion represented 68% (81 of 119) of Monteggia fractures. Annular ligament incarceration preventing radial head reduction occurred in approximately 17% (14 of 81) of this Bado type. Revision fixation of the ulna was not necessary (none of 119 cases) and functional range of motion (average arc, 117°) was recovered in most patients. The reoperation rate of 20% (23 of 119) was related to the severity of the presenting injury and hardware prominence.

CONCLUSIONS: Most radial head dislocations associated with Monteggia fractures occur anteriorly and will reduce with anatomic plating of the ulna. In cases where the radial head fails to reduce, entrapment of the annular ligament can be expected and open reduction is required. Revision fixation of the ulna to achieve reduction of the radial head is uncommon in our experience.

TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic IV.