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.

Hexapod Frame Stacked Transport for Tibial Infected Nonunions With Bone Loss: Analysis of Use of Adjunctive Stability.

OBJECTIVES: The stacked hexapod bone transport technique is an effective treatment for infected tibial nonunions with bone loss. The purpose of this study was to evaluate the patients' risk factors and timing for requiring adjunctive stabilization. DESIGN: Retrospective cohort study. SETTING: Level 1 trauma center. PATIENTS/PARTICIPANTS: Seventy-five patients with infected posttraumatic nonunions of the tibia. INTERVENTION: Resection of nonunion with application of stacked hexapod frame for bone transport. MAIN OUTCOME MEASUREMENTS: Parameters measured included age, sex, diabetes, smoking, use of a free flap, bone defect size, length in frame, external fixation index, and direction of lengthening. Outcomes recorded: removal of frame, below knee amputation, or adjunctive stability. Further analysis evaluated location of nonunion, timing of adjunctive stabilization, and type of fixation. RESULTS: The average patient age was 45.7 ± 12.5 years, 76% patients were men, 11% were diabetic, and 44% were smokers. Forty two percent had soft tissue defects that required a free flap. Thirty-eight patients had removal of frame, whereas 36 patients required adjunctive stability of the hexapod frame. Patient receiving adjunctive stabilization had a longer length of time in the hexapod frame (P = 0.026) and were more likely to require a free flap (P = 0.053). Ninety-three percent docking site nonunions occurred after the removal of the frame (P = 0.032); whereas 79% regenerate nonunions occurred before the hexapod frame was removed (P = 0.029). CONCLUSIONS: The use of a hexapod frame for the infected tibial nonunions with bone loss is an effective method for achieving union and eradicating infection in a difficult orthopaedic patient population. Use of adjunctive stabilization is a reasonable technique to address delayed regenerate and docking site nonunions. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.