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

Bone Transport for Large Segmental Tibial Defects Using Taylor Spatial Frame versus the Ilizarov Circular Fixator

OBJECTIVE

Bone transport has become the gold standard for treating large segmental tibial bone defects. The technique for application the Ilizarov circular fixator (ICF) has a long learning curve and is associated with many complications. There are few clinical studies on bone transport via the Taylor spatial frame (TSF). The main purpose of this study was to compare the radiological and clinical and outcomes of bone transport by using the TSF and the ICF.

METHODS

There were 62 patients included in this retrospective study from June 2011 to June 2021 and distributed to two groups according to the fixation method: a TSF group consisting of 30 patients and an ICF group consisting of 32 patients. Demographic information, surgical duration, external fixation times, external fixation index, final radiographic results, complications, and clinical outcomes were recorded and examined. The clinical outcomes were assessed using the ASAMI criteria during the most recent clinical visit. Then, statistical analysis such as independent-samples t tests or chi-Square test was performed.

RESULTS

The mean surgical duration in the TSF group was 93.8 ± 7.3 min, which was shorter than that in the ICF group (109.8 ± 1.4 min) (p < 0.05). Compared to the ICF group (10.2 ± 2.0 months), the TSF group (9.7 ± 1.8 months) had a shorter average external fixation time (p > 0.05). The external fixation index was 1.4 ± 0.2 m/cm and 1.5 ± 0.1 m/cm in the two groups. Moreover, there was no significant difference between the two groups. At the last follow-up visit, the medial proximal tibial angle (MPTA) and posterior proximal tibial angle (PPTA) in the TSF group were 88.1 ± 12.1° and 80.9 ± 1.3°, respectively. The MPTA and PPTA in the ICF group were 84.4 ± 2.4° and 76.2 ± 1.9°, respectively. There were statistically significant differences between the two groups (all p < 0.05). The complication rate was 50% in the TSF group and 75% in the ICF group. Moreover, the ASAMI score between the two groups was no statistically significant difference (p > 0.05).

CONCLUSION

No statistically significant difference was found in clinical outcomes between the use of Taylor spatial frame and Ilizarov circular fixator for treating large segmental tibial bone defects. However, TSF is a shorter and simpler procedure that causes fewer complications and improves limb alignment.

The Management of Tibial Bone Defects: A Multicenter Experience of Hexapod and Ilizarov Frames

INTRODUCTION

Bone defects may be managed with bone transport or acute shortening and lengthening using circular external fixation devices. We performed a multicenter retrospective cohort study to compare the outcomes between the Ilizarov frames and hexapod frames for the management of bone defects.

METHODS

Patients treated for bone defects using either Ilizarov or hexapod frames were included for analysis in two specialist institutions. Primary outcomes were time to consolidation, bone healing index (BHI), and external fixator index (EFI). Radiographic parameters included the medial proximal tibial angle, lateral distal tibial angle, posterior proximal tibial angle, and anterior distal tibial angle.

RESULTS

There were 137 hexapods and 90 Ilizarov frames in total. The mean time to follow-up was 3.7 years in the hexapod group and 4.0 years in the Ilizarov group. Hexapods had a significantly lower time to consolidation (253 days versus 449 days) (P < 0.0001) and BHI (59.1 days/cm versus 87.5 days/cm) (P < 0.0001). Hexapods had a significantly better EFI (72.3 days/cm versus 96.1 days/cm) (P = 0.0009).

CONCLUSION

Hexapods may confer a significant advantage over Ilizarov frames in the management of bone defects. Time to consolidation, radiographic parameters, BHI, and EFI are all superior in hexapods.

Salvage of Bone Transport with the Induced Membrane Technique in an Open Tibia Fracture with a Segmental Defect: A Case Report

CASE

A 29-year-old man with an open tibia fracture and a 15-cm bone defect was treated with irrigation, debridement, intramedullary nailing, soft-tissue flap, and bone transport with a frame over the nail. He developed osteomyelitis of his bone transport segment close to docking, which required bone resection and an induced membrane technique to salvage his transport segment and achieve union.

CONCLUSIONS

This report illustrates the combined use of bone transport and induced membrane technique to achieve union in a 15-cm tibial defect. It demonstrates the use of the Masquelet technique to salvage an infected bone transport segment.

Management of critical-sized bone defects in the treatment of fracture-related infection: a systematic review and pooled analysis

PURPOSE

This systematic review determined the reported treatment strategies, their individual success rates, and other outcome parameters in the management of critical-sized bone defects in fracture-related infection (FRI) patients between 1990 and 2018.

METHODS

A systematic literature search on treatment and outcome of critical-sized bone defects in FRI was performed. Treatment strategies identified were, autologous cancellous grafts, autologous cancellous grafts combined with local antibiotics, the induced membrane technique, vascularized grafts, Ilizarov bone transport, and bone transport combined with local antibiotics. Outcomes were bone healing and infection eradication after primary surgical protocol and recurrence of FRI and amputations at the end of study period.

RESULTS

Fifty studies were included, describing 1530 patients, the tibia was affected in 82%. Mean age was 40 years (range 6-80), with predominantly male subjects (79%). Mean duration of infection was 17 months (range 1-624) and mean follow-up 51 months (range 6-126). After initial protocolized treatment, FRI was cured in 83% (95% CI 79-87) of all cases, increasing to 94% (95% CI 92-96) at the end of each individual study. Recurrence of infection was seen in 8% (95% CI 6-11) and amputation in 3% (95% CI 2-3). Final outcomes overlapped across treatment strategies.

CONCLUSION

Results should be interpreted with caution due to the retrospective and observational design of most studies, the lack of clear classification systems, incomplete data reports, potential underreporting of adverse outcomes, and heterogeneity in patient series. A consensus on classification, treatment protocols, and outcome is needed to improve reliability of future studies.

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.