Radiological findings in posteromedial rotatory instability of the elbow and their application to treatment

There are distinct patterns of radiological injury in the subtypes of posteromedial instability. Subtype 2-1 is primarily associated with substantial lateral ligamentous injury, whereas subtype 2-3 features larger coronoid fractures and an increased rate of associated injury to the posterior bundle of the ulnar ligament; subtype 2-2 is intermediate. These findings inform a proposed algorithm for the surgical treatment: lateral ligamentous repair is key for 2-1, and fixation of the coronoid fracture fixation is key for 2-3, with intraoperative assessment guiding further steps. This observational study establishes a theoretical framework for the management of these patients, which will require validation in the future.