OBJECTIVES: To evaluate rates of nonunion repair, osseous healing, and outcomes in femoral nonunions with contemporary healing. DESIGN: Retrospective review. SETTING: Five academic level 1 trauma centers. PATIENTS/PARTICIPANTS: This study includes adult patients (age older than 18) seen at one of the participating institutions between 2012 and 2019 who sustained a femur fracture (OTA/AO 31, 32, 33) initially treated with intramedullary fixation that developed nonunion and were treated with exchange nailing for the index nonunion surgery. Seventy-nine patients with femoral nonunion met inclusion criteria. INTERVENTION: Exchange nailing for treatment of femoral nonunion. MAIN OUTCOME MEASUREMENTS: The primary outcome measure was radiographic osseous union. We further analyzed union rates by OTA/AO classification, nonunion type, implants used, graft used, time from the initial procedure, and infection status. RESULTS: Seventy-nine patients met inclusion criteria. Rates of osseous union were similar by OTA/AO classification ( CONCLUSIONS: This large, multicenter study with modern implants, instruments, and techniques for exchange nailing of femoral nonunions demonstrates high rates of reoperation (n = 30
38%), but higher rates of osseous healing (n = 68
86% healed) than previously reported data in the literature. LEVEL OF EVIDENCE: III.