Background High-energy tibial plateau and tibial plafond fractures have a high complication rate and are frequently treated with a staged approach of spanning external fixation followed by definitive internal fixation after resolution of soft tissue swelling. A theoretical advantage to early spanning external fixation is that earlier fracture stabilization could prevent further soft tissue damage and potentially reduce the occurrence of subsequent infection. However, the relative urgency of applying the external fixator after injury is unknown, and whether delay in this intervention is correlated to subsequent treatment complications has not been examined. Questions/purposes Is delay of more than 12 hours to spanning external fixation of high-energy tibial plateau and plafond fractures associated with increased (1) infection risk; (2) compartment syndrome risk; and (3) time to definitive fixation, length of hospitalization, or risk of secondary surgeries? We further stratified our results based on injury site: plateau and plafond. In practical clinical terms, many of these high-energy C-type articular fractures will arrive at the regional trauma center in the evening and this investigation attempted to explore if these injuries need to be placed in temporizing fixators that evening or if they may be safely addressed in a dedicated trauma room the next morning. Methods We performed a retrospective review of all patients at a Level I university trauma center with highenergy tibial plateau and plafond fractures who underwent staged treatment with a spanning external fixation followed by subsequent definitive internal fixation between 2006 and 2012. Patients who received a fixator within 12 hours of recorded injury time were classified as early external fixation; those who received a fixator greater than 12 hours from injury were classified as delayed external fixation. There were 80 patients (42 plateaus and 38 plafonds) in the early external fixation cohort and 79 patients (45 plateaus and 34 plafonds) in the delayed external fixation cohort. Deep infection rate was 13% in plateau fractures and 18% in plafond fractures. Rates of infection, compartment One of the authors (ENK) has received research support funding from the Department of Defense Congressionally Directed Medical Research Program and VA Early Feasibility Program. One of the authors (TFH) lists the following relevant financial activities outside of this work and/or any other relationships or activities that readers could perceive to have influenced, or that give the appearance of potentially influencing, this manuscript: DePuy Synthes (West Chester, PA, USA) in the amount of less than USD 10,000. One of the authors (ENK) lists the following relevant financial activities outside of this work and/or any other relationships or activities that readers could perceive to have influenced, or that give the appearance of potentially influencing, this manuscript: CoNextions (Sandy, UT, USA) in the amount of more than USD 10,000, OrthoGrid (Salt Lake City...