Comparison of intramedullary nail, plate, and external fixation in the treatment of distal tibia nonunions

Purpose The purpose of this study was to examine time to union of extra-articular distal tibia nonunions based on fracture type and fixation methods: intramedullary nail (IMN), plate osteosynthesis (PO), and external fixation (EF). Methods This retrospective chart review included all patients who presented at a Level I trauma center with AO/OTA 43A & distal third 42A-C fracture nonunions between 2008 and 2014. Fixation methods were recorded and patient course was followed until nonunion had healed clinically. Results Thirty-three distal tibia nonunions were included, and 29 reached eventual union (88%). Five AO/OTA fracture types were present. Mean times to union from nonunion diagnosis between original fracture types were compared ( p = 0.203). Comminuted fracture types had longer times to union from nonunion diagnosis compared to simple fracture types (78 vs. 46 weeks, p = 0.051) and more revision fixations (1.5 vs. 0.5, p = 0.037). Mean time to union from nonunion diagnosis was shorter when no revision fixation was done compared to revisions (15 vs. 42 weeks, p = 0.102). Times to union from nonunion diagnosis without revision fixation were: IMN (12 weeks), PO (27 weeks), and EF (13 weeks) ( p = 0.202). Times to union from definitive revision fixation were: IMN (17 weeks), PO (21 weeks), and EF (66 weeks) ( p = 0.009), with EF taking significantly longer than both other methods. 21 patients (64%) underwent revision fixation. Revision fail rates were: IMN (0/6, 0%), PO (2/8, 25%), and EF (15/21, 71%). Time to union was longer in revisions that changed fixation method compared to revisions that used the same method (51 vs. 18 weeks, p = 0.030). Deep infections were also associated with longer union times (81 vs. 47 weeks, p = 0.040). Conclusions In this nonunion population, comminuted fracture types needed more time and revisions to reach union. Time to union was only clinically shorter when revision fixation was not performed, but IMN and PO were both successful fixation options with significantly shorter times to union than EF. Mean time to union increased even more when revision of fixation method was performed vs. exchange revision, as did nonunions with deep infections.