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.