1319 patients with open or closed tibial shaft fractures were included in this trial to compare the effects of reamed and unreamed intramedullary nailing approaches (Study to Prospectively Evaluate Reamed Intramedullary Nails in Patients with Tibial Fractures (SPRINT)). Patients were randomized to treatment with either reamed or unreamed intramedullary nails. The results at the 12 month follow up period indicated that fewer patients with closed fractures, treated with reamed intramedullary nailing, experienced the primary composite outcome (bone grafting, implant exchange or dynamization in patients with a fracture gap greater <1cm). However, this significant result was due to differences in autodynamization. In patients with open fractures, there was an increase in the primary composite outcome associated with reamed nailing, but this finding was not significant.