Fracture–dislocations of the forearm joint: a systematic review of the literature and a comprehensive locker-based classification system

Background: Monteggia, Galeazzi, and Essex-Lopresti injuries are the most common types of fracture–dislocation of the forearm. Uncommon variants and rare traumatic patterns of forearm fracture–dislocations have sometimes been reported in literature. In this study we systematically review the literature to identify and classify all cases of forearm joint injury pattern according to the forearm joint and three-locker concepts. Methods: A comprehensive search of the PubMed database was performed based on major pathological conditions involving fracture–dislocation of the forearm. Essex-Lopresti injury, Monteggia and Galeazzi fracture–dislocations, and proximal and/or distal radioulnar joint dislocations were sought. After article retrieval, the types of forearm lesion were classified using the following numerical algorithm: proximal forearm joint 1 [including proximal radioulnar joint (PRUJ) dislocation with or without radial head fractures], middle radioulnar joint 2, if concomitant radial fracture R, if concomitant interosseous membrane rupture I, if concomitant ulnar fracture U, and distal radioulnar joint 3 [including distal radioulnar joint (DRUJ) dislocation with or without distal radial fractures]. Results: Eighty hundred eighty-four articles were identified through PubMed, and after bibliographic research, duplication removal, and study screening, 462 articles were selected. According to exclusion criteria, 44 full-text articles describing atypical forearm fracture–dislocation were included. Three historical reviews were added separately to the process. We detected rare patterns of two-locker injuries, sometimes referred to using improper terms of variant or equivalent types of Monteggia and Galeazzi injuries. Furthermore, we identified a group of three-locker injuries, other than Essex-Lopresti, associated with ulnar and/or radial shaft fracture causing longitudinal instability. In addition to fracture–dislocations commonly referred to using historical eponyms (Monteggia, Galeazzi, and Essex-Lopresti), our classification system, to the best of the authors’ knowledge, allowed us to include all types of dislocation and fracture–dislocation of the forearm joint reported in literature. According to this classification, and similarly to that of the elbow, we could distinguish between simple dislocations and complex dislocations (fracture–dislocations) of the forearm joint. Conclusions: All injury patterns may be previously identified using an alphanumeric code. This might avoid confusion in forearm fracture–dislocations nomenclature and help surgeons with detection of lesions, guiding surgical treatment. Level of evidence: V.