Elbow instability following lateral collateral ligament complex avulsion fracture and joint interposition: an uncommon presentation.

The lateral collateral ligament (LCL) complex of the elbow is a capsuloligamentous structure, critical for elbow stability. Though isolated ligamentous injuries have been reported in literature, there are no studies reporting avulsion fractures of the lateral ligamentous complex of the elbow with joint incarceration in a child. An 11-year-old boy presented to the emergency department after a fall from height, with pain and swelling to the lateral side of his left elbow. Radiographs established a fracture of the lateral condyle and CT imaging confirmed an avulsion of the lateral ligamentous complex, with fragments in the inferior radiocapitellar joint. Examination under anaesthesia revealed an unstable elbow with restricted extension, and the child underwent joint debridement and open reduction internal fixation of LCL complex with cannulated screws. At the final follow-up at 15 months, the child regained preinjury level of function.