Hexapod Stacked Transport for Tibial Infected Nonunions With Bone Loss: Long-Term Functional Outcomes

OBJECTIVES: To analyze long-term functional outcomes in patients with posttraumatic infected tibial nonunions having undergone bone transport with hexapod external fixator. DESIGN: Retrospective cohort study. SETTING: Level 1 trauma center. PATIENTS/PARTICIPANTS: Thirty-eight patients with infected nonunions of the tibia. INTERVENTION: Resection of nonunion with application of stacked hexapod external fixator for bone transport. MAIN OUTCOME MEASUREMENTS: Functional outcome was measured using the short Musculoskeletal Functional Assessment (sMFA). Parameters measured included age, sex, presence of diabetes, smoking, use of a free flap, bone defect size, length in frame, external fixation index, and direction of lengthening. RESULTS: The mean sMFA score for the entire group was 27.1. Average patient age was 46.8 ± 12.7 years, 74% patients were male, 8% were diabetic, and 29% were smokers. Seventeen patients had soft-tissue defects that required a free flap. Smokers had higher degrees of disability compared with nonsmokers (39 ± 16 vs. 22 ± 14, P = 0.011). Patients requiring adjunctive stabilization had worse functional scores compared with those who did not receive adjunctive stabilization (33 ± 17 vs. 22 ± 15, P = 0.049). Sixteen patients returned 2 sMFA surveys at different time points after completion of bone transport. Initial average sMFA score was 26.5 at a mean of 25.3 months; subsequent sMFA scores averaged 19.4 at a mean of 98.8 months. CONCLUSIONS: Stacked hexapod external fixator bone transport is a reliable technique for infected nonunion of the tibia with bone loss. Improved sMFA scores can be expected from 2 to 8 years, suggesting full recovery takes longer than previously anticipated. Limb salvage with hexapod bone transport is justified over time. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.