Lateral compression type 1 (LC1) pelvic ring injuries: a spectrum of fracture types and treatment algorithms

Lateral compression type 1 (LC1) fractures are the commonest pelvic ring injury. However, they represent a heterogenous spectrum of injury mechanisms and fracture patterns, resulting in a lack of strong evidence for a universally agreed treatment algorithm. Although consensus exists that LC1 fractures have a preserved posterior ligamentous complex and are vertically stable, controversy persists around defining internal rotational instability. As such, treatment strategies extend from routine non-operative management through to dynamic imaging such as examination under anaesthetic (EUA) or stress radiographs to guide fixation algorithm. Multiple protocols sit between these two, all with slightly different thresholds for advocating surgery or otherwise, exemplifying a broad lack of consensus that is not seen for other, more severe, grades of pelvic ring injury. In the following review we discuss the evolving concepts of pelvic ring instability and management, starting from a historical perspective, through to current trends and controversies in LC1 fracture treatment. Emerging directions for research and emerging pharmacological and surgical treatments/technologies are also considered and expert commentary from 3 leading centres provided. The distinction is made between LC1 fracture arising from high-energy trauma and those following low-energy falls from standing height (so-called fragility fractures of the pelvis-FFP), since these two patient groups have different functional requirements and medical vulnerabilities. Issues pertaining to FFP are considered separately.