Elbow Varus posteromedial rotatory instability: Reflections from a multidimensional perspective

Varus posteromedial rotatory instability (VPMRI) is one of the types of complex elbow instability, which was initially proposed by O 'Driscoll in 2003. Its typical clinical manifestations are anteromedial coronoid fracture (AMCF), injury of lateral collateral ligament complex (LCL), widening of the lateral humeroradial space, and subluxation of the coronoid process relative to the medial edge of the humeral trochlea. However, it presents diagnostic challenges due to its low incidence, complex mechanisms of injury, and radiography reveals only isolated coronoid process fractures without obvious joint space mismatch. In addition to this, the current best treatment plan for VPMRI is still controversial. Misdiagnosis and mistreatment may lead to complications such as post-traumatic arthritis, heterotopic ossification, and joint stiffness. Therefore, enhancing recognition and suspicion of VPMRI and investigating its injury mechanism, treatment strategies, surgical approaches, and internal fixation methods are essential. This narrative review conducts retrospective analysis from different perspectives, and provides imaging examples and related schematic diagrams, aiming to provide a certain reference for the precise diagnosis and treatment of VPMRI.