Clinical reliability of closed techniques and comparison with open strategies to achieve union at the docking site

Docking site interventions following bone transport using external fixation: a systematic review of the literature

PURPOSE

Although bone transport is a well-recognised technique to address segmental bone defects, optimal management of docking sites is not absolutely determined. Some surgeons routinely intervene in all cases, and others prefer to observe and intervene only if spontaneous union does not occur. Primary aim of the study was to compare rates of docking site union between patients who underwent routine docking site intervention and those who did not.

METHODS

A systematic literature review using the keywords "bone transport", "docking", "tibia", and "femur" was performed in PubMed using PRISMA guidelines. Studies published in English from January 2000 to August 2022 were included and assessed independently by two reviewers. Pooled analysis was undertaken dividing patients into two groups: those managed by routine intervention and those initially observed.

RESULTS

Twenty-three clinical studies met the eligibility criteria for pooled analysis, including 1153 patients, 407 in the routine intervention and 746 in the observed group. The rate of union after initial treatment was 90% in the routine intervention group and 66% in the observed group (p < 0.0001). Overall union rates at the end of treatment were similar at 99% in both groups. Patients in the observed group required an average of 2.2 procedures to achieve union overall compared with 3.8 in the routine intervention group. Time in frame was similar between groups.

CONCLUSION

Based on the current literature, routine docking site interventions cannot be recommended, since this may lead to unnecessary interventions in two thirds of patients. Timely selective intervention in those at high risk or after a defined period of observation would appear to be a logical approach.

Predictive factors for docking site procedure in bone transport for large lower extremity segmental defects

BACKGROUND

Segmental bone transport is a common technique for treating large segmental bone defects. However, a docking site procedure is often necessary in segmental bone transport. To date, no prognostic factors for the need of docking site procedure have been reported. Thus, the decision is often made at random, based on the surgeon's subjective judgment and experience. The aim of this study was to identify prognostic factors for the need of docking site operation.

METHODS

Patients with segmental bone transport in lower extremity bone defects were included regardless of age, aetiology, and defect size. We excluded patients undergoing treatments that were not yet completed, and those who discontinued therapy by any reason. The need for docking site operation was modelled with logistical and linear regression as well as univariate analysis of variances (ANOVA). Receiver operating characteristics (ROC) curve analysis was also performed.

RESULTS

Twenty-seven patients from age 12 to 74 years (mean age: 39.07 ± 18.20 years) were included. The mean defect size was 76.39 ± 41.10 mm. The duration of transport (days) showed a significant influence (p = 0.049, 95%CI: 1.00-1.02) on the need for docking site operation. No other significant influences were detected.

CONCLUSION

A link between the duration of transport and the need for docking site operation was detected. Our data showed that if a threshold of about 188 days is exceeded, docking surgery should be considered.

Bone Transport with the Taylor Spatial Frame Technique: A Case Series

Aim

Bone transport is a beneficial reconstructive method for bone defects caused by infected non-unions or bone tumours. The Taylor Spatial Frame (TSF) is a three-dimensional corrective external fixator that can be used to achieve bone transport and correct any residual deformities easily at any time. This study reports the results of bone transport using TSF.

Materials and methods

This is a retrospective study of ten patients who underwent bone transport using the TSF. The mean age was 32.3 years; the femur was affected in one case and the lower leg in nine. Bone defects were due to infected non-unions in seven cases and bone tumours in three. The duration of external fixation, bone transport distance, distraction index (DI), alignment at the end of correction, leg length discrepancy, and complications were investigated.

Results

The average bone transport distance was 76.0 mm. The external fixation period averaged 367 days with the DI at 20.8 days/cm. Deformity at the docking site was assessed to have an average 2.6° deformity and 2.0 mm translation in the frontal view, as well as 3.3° deformity and 3.7 mm translation in the lateral view. The mean leg length discrepancy was 10.9 mm and the percentage of the mechanical axis (%MA) was 40.6%. Four patients underwent plate conversion after correction and two required additional surgery for non-union at the docking site. Bone union was achieved in all patients and there was no reaggravation of infection or tumour recurrence.

Conclusion

The TSF allowed for the correction of deformities and translations that occurred during bone transport giving excellent results. However, as with bone transport using this or other devices, additional procedures are often needed to obtain consolidation or docking site union.

How to cite this article

Shimokawa K, Matsubara H, Hikichi T, et al. Bone Transport with the Taylor Spatial Frame Technique: A Case Series. Strategies Trauma Limb Reconstr 2023;18(2):117-122.

Infected bone defects in the lower limb. Management by means of a two-stage distraction osteogenesis protocol

INTRODUCTION

Although bone transport is generally accepted as the gold standard for the treatment of segmental septic bone defects, some aspects of its practical application are still open to debate. We present our results in this field and compare them with the series published so far.

MATERIAL AND METHODS

We reviewed all our patients (2010-2018) that underwent a bone transport procedure in the lower limb due to a septic bone defect. We calculated the bone healing index (BHI), the external fixation index (EFI), the rate of complications and the clinical results. We statistically compared our results with 63 publications with a similar scope.

RESULTS

Thirty-five patients (30 M/5F) with a mean age of 40 years and a mean follow-up of 45 months were included. Bone segment was 24 T/11F and mean defect was 8.4 cm (7.34 T/ 10.73F). Mean global BHI was 45.62 days/cm (48.16 T/40.09F). Mean EFI was 2.37 months/cm. Results were excellent in 9 patients, good in 23 and bad in 3. Bone graft was used in 60% of the cases.

DISCUSSION

The size of our series is similar to previously published ones, although the mean age of our patients is higher and they present a larger bone defect. BHI of our series is similar to that of other series, although EFI is significantly higher. The number of complications is also in line with the existing literature.

CONCLUSION

The use of a two-stage technique for managing segmental bone defects of septic origin in the lower extremity is a valid alternative. Our series shows results comparable to the current literature.

Efficacy comparison of double-level and single-level bone transport with Orthofix fixator for treatment of tibia fracture with massive bone defects

PURPOSE

The aim of this study was to evaluate the clinical and functional outcomes of patients with large post-traumatic tibial bone defects managed by double-level bone transport using the Ilizarov technique and compare it with one-level bone transport technique.

METHODS

A retrospective cohort study was conducted on 26 patients with open tibial fracture from January 2010 to January 2017. All cases were Gustilo III. Depending on the site of osteotomy, the patients were divided into single-level (n = 13) and double-level groups (n = 13). The bone transport time, consolidation time of the distraction gap, docking site healing time, external fixation time, external fixation index, soft tissue defect area, soft tissue growth index, operating time, and surgical bleeding volume were recorded and compared between the two groups. Bone and functional results were evaluated according to the Association for the Study and Application of the Method of Ilizarov (ASAMI) criteria.

RESULTS

The mean duration of follow-up was 28.5 ± 5.8 months (range 13-38 months) since the Orthofix fixator was removed, all patients achieved complete union in the docking site and consolidation in the regenerate bone; moreover, the wound was closed The mean bone defect length after debridement was 7.2 cm (range 5.8-9.0 cm) in single-level group vs. 10.7 cm (range 7.5-15.0 cm) in the double-level group (P < 0.05). The mean docking site healing time was 10.85 ± 1.52 months in the single-level group vs. 8.93 ± 2.29 months in the double-level group (P < 0.05); external frame time was 18.06 months (range 15-20 months) in single-level group vs. 12.71 months (range 9.5-16.0 months) in the double-level group (P < 0.05); external fixation index was 2.52 months/cm (range 2.15-2.94 months/cm) versus 1.22 months/cm (range 0.96-1.67 months/cm) in double-level group (P < 0.01); and soft tissue growth index was 0.29 months/cm² (range 0.21-0.45 months/cm²) in the single-level group versus 0.62 months/cm² (range 0.47-0.86 months/cm²) in the double-level group (P < 0.01). According to the ASAMI classification, the clinical and functional results in the double-level group were better than in the single-level group.

CONCLUSION

The Ilizarov technique of double-level bone transport with Orthofix external fixator can be used successfully to repair and reconstruct the tibial bone loss and accompanying soft tissue defect.

Effect of Single Injection of Recombinant Human Bone Morphogenetic Protein-2-Loaded Artificial Collagen-Like Peptide in a Mouse Segmental Bone Transport Model

This study aimed to investigate whether a single injection of recombinant human bone morphogenetic protein-2-loaded artificial collagen-like peptide gel (rhBMP-2/ACG) accelerates consolidation at the bone defect site and bone union at the docking site in a mouse segmental bone transport (SBT) model. A critical sized bone defect (2 mm) was created in the femur of mice and subsequently reconstructed using SBT with an external fixator. Mice were divided into four treatment groups: Group CONT (immobile control), Group 0.2 (bone segments moved 0.2 mm/day for 10 days), Group 1.0 (bone segments moved 1.0 mm/day for 2 days), and Group 1.0/BMP-2 (rhBMP-2/ACG injected into the bone defect and segments moved 1.0 mm/day for 2 days). Consolidation at the bone defect site and bone union at the docking site was evaluated radiologically and histologically across eight weeks. Bone volume and bone mineral content were significantly higher in Group 0.2 than in Group 1.0. Group 0.2 showed evidence of rebuilding of the medullary canal eight weeks after surgery at the bone defect site. However, in Group 1.0, maturation of regenerative bone at the bone defect site was poor, with the central area between the proximal and distal bone composed mainly of masses of fibrous and adipose tissue. Group 1.0/BMP-2 had higher bone volume and bone mineral content compared to Group 1.0, and all mice achieved bone union at the bone defect and docking sites. Single injection of rhBMP-2/ACG combined with SBT may be effective for enhancing bone healing in large bone defects.

One-stage Surgical Treatment of Simultaneous Osteotomy and Asymmetric Lengthening on Short Femur with Severe Deformity of Genu Valgus

This study aimed to discuss the effects of one stage surgical treatment by simultaneous osteotomy and asymmetric lengthening by Ilizarov external fixator on short femur with severe deformity of genu valgus. A total of 12 cases with unilateral deformities treated by simultaneous osteotomy and Ilizarov asymmetric lengthening on short femur with severe deformity of genu valgus were retrospectively analyzed from January 2006 to April 2015. The affected limbs were 2.5–11 cm (5.2 cm on average) short, the femorotibial angle was 135°–158° (146.3° on average), and the ankle interval was 15–43 cm (24.7 cm on average). The Paley method was used to determine the osteotomy plane (distal femur) of genu valgus. According to this standard, the bone union results were as follows: 11 had excellent and 1 had good, where 7 patients had excellent and 5 had good functional outcomes. One stage surgical treatment by simultaneous osteotomy and asymmetric lengthening on short femur with severe deformity of genu valgus was considered to be an effective and reliable method with better osteotomy union, less trauma and fewer complications.

Histological study of the docking site after bone transport. Temporal evolution in a sheep model

INTRODUCTION

Bone transport appears to be a solution for segmental bone defects; specifically, the "docking site" is where the transported segment meets the target segment at the end of the process. A lack of its consolidation is one of the major causes of failure for this technique. Many studies have been performed in order to enhance the consolidation of the docking site, but histological changes occurring in it remain unknown. The aim of this study was to determine microscopic changes present in this area, from distraction to remodeling, in order to clarify the best options to facilitate the success of this technique.

MATERIALS AND METHODS

Ten adult sheep were submitted to bone transport using an Ilizarov external fixator. Histomorphometry and immunohistochemical studies were performed in the docking site to determine the main types of ossification, the evolutions of tissues and blood vessels and the distributions of collagen I and II.

RESULTS

Ossification was mainly intramembranous with some areas of endochondral ossification. Fibrous tissue was predominant until 98 days after surgery. The area occupied by blood vessels increased until 50 days after surgery, when it decreased slowly until the end of the study.

CONCLUSIONS

As far as the authors know, this is the first histological study performed in the docking site reporting the complete evolution of tissues until the end of remodeling, showing results contrary to those published by others authors. This could help to clarify information about its union and may be useful for future investigations about techniques for improving the consolidation of the docking site in humans.

Double-level bone transport for large post-traumatic tibial bone defects: a single centre experience of sixteen cases

PURPOSE

The aim of this study was to evaluate the clinical and functional outcomes of patients with large post-traumatic tibial bone defects managed by double-level bone transport using the Ilizarov technique.

METHODS

We retrospectively reviewed 16 patients of 39.1 years (range, 16.0-65.0 years). The bone defects averaged 10.9 ± 3.8 cm (range: 6.0 cm-20.0 cm) after radical resection and were managed by double-level bone transport. Bone and functional results were evaluated according to the ASAMI criteria.

RESULTS

The mean duration of follow-up after frame removal was 29.5 ± 1.8 months (range, 12.0-36.0 months). All patients achieved complete union in both the regenerates and the docking site and eradication of infection. The mean bone transport time was 55.6 ± 23.7 days (range, 30.0-125.0 days). The mean external fixation time was 12.0 ± 3.9 months (range, 5.0-18.0 months), and the mean external fixation index was 1.1 ± 0.3 months/cm (rang, 0.8-2.0 months/cm). The bone results were excellent in ten patients and poor in six patients. The functional results were excellent in 12 patients and good in four patients.

CONCLUSION

Double-level bone transport is a safe, reliable, and successful method for large post-traumatic tibial bone defects. Furthermore, this technique can reduce bone transport time, time in frame, and total treatment time in one stage.

Infected nonunion of tibia

Infected nonunions of tibia pose many challenges to the treating surgeon and the patient. Challenges include recalcitrant infection, complex deformities, sclerotic bone ends, large bone gaps, shortening, and joint stiffness. They are easy to diagnose and difficult to treat. The ASAMI classification helps decide treatment. The nonunion severity score proposed by Calori measures many parameters to give a prognosis. The infection severity score uses simple clinical signs to grade severity of infection. This determines number of surgeries and allows choice of hardware, either external or internal for definitive treatment. Co-morbid factors such as smoking, diabetes, nonsteroidal anti-inflammatory drug use, and hypovitaminosis D influence the choice and duration of treatment. Thorough debridement is the mainstay of treatment. Removal of all necrotic bone and soft tissue is needed. Care is exercised in shaping bone ends. Internal fixation can help achieve union if infection was mild. Severe infections need external fixation use in a second stage. Compression at nonunion site achieves union. It can be combined with a corticotomy lengthening at a distant site for equalization. Soft tissue deficit has to be covered by flaps, either local or microvascular. Bone gaps are best filled with the reliable technique of bone transport. Regenerate bone may be formed proximally, distally, or at both sites. Acute compression can fill bone gaps and may need a fibular resection. Gradual reduction of bone gap happens with bone transport, without need for fibulectomy. When bone ends dock, union may be achieved by vertical or horizontal compression. Biological stimulus from iliac crest bone grafts, bone marrow aspirate injections, and platelet concentrates hasten union. Bone graft substitutes add volume to graft and help fill defects. Addition of rh-BMP-7 may help in healing albeit at a much higher cost. Regeneration may need stimulation and augmentation. Induced membrane technique is an alternative to bone transport to fill gaps. It needs large amounts of bone graft from iliac crest or femoral canal. This is an expensive method physiologically and economically. Infection can resorb the graft and cause failure of treatment. It can be done in select cases after thorough eradication of infection. Patience and perseverance are needed for successful resolution of infection and achieving union.

Distraction osteogenesis for tibial nonunion with bone loss using combined Ilizarov and Taylor spatial frames versus a conventional circular frame

This retrospective review assesses 55 tibial nonunions with bone loss to compare union achieved with combined Ilizarov and Taylor spatial frames (I–TSF) versus a conventional circular frame with the standard Ilizarov procedure. Seventeen (31 %) of the 55 nonunions were infected. Thirty patients treated with I–TSF were compared with 25 patients treated with a conventional circular frame. In the I–TSF group, an average of 7.6 cm of bone was resected and the lengthening index (treatment time in months divided by lengthening amount in centimeters) was 1.97. In the conventional circular frame group, a mean of 6.5 cm was resected and the lengthening index was 2.1. Consolidation at the docking site and at the regenerate bone occurred in 49 (89 %) of 55 cases after the first procedure. No statistically significant difference was shown between the two groups. Superiority of one modality of treatment over the other cannot be concluded from our data. Application of combined Ilizarov and Taylor spatial frames for bone transport is useful for treatment of tibial nonunion with bone loss.

Level of evidence Case series, Level III.

Ilizarov bone transport combined with antibiotic cement spacer for infected tibial nonunion

PURPOSE

To evaluate the curative effect of Ilizarov bone transport combined with antibiotic cement spacer for infected tibial nonunion with bone defect.

METHODS

We retrospectively reviewed the outcomes of 58 patients with infected tibial nonunion from January 2008 to March 2011 at our institution. Patients were treated with complete debridement, radical sequestrectomy, antibiotic cement spacer implantation, bone transport using the Ilizarov external fixator, and soft tissue reconstruction. Clinical efficacy was assessed using Paley's grading system and patient satisfaction at the last follow-up.

RESULTS

Follow-up ranged from 24 to 63 months (average, 31.6 months). Mean size of the tibial defect was 9.2 cm (range, 6-15 cm). The soft tissue defect was closed successfully in all cases. Patients eventually achieved union with a mean bone union index of 1.2 months/cm at an average of 10.6 months (range, 8-31 months). In terms of Paley grade, 30 patients had excellent results, 23 good, and 5 fair. Functional results were excellent in 28 patients, good in 18, and fair in 12. Thirty-five patients felt extremely satisfied, 18 satisfied, and 5 acceptable with the functional outcome. Complications included pin site infection in 18 cases, limb length discrepancy less than 1.5 cm in 10, knee stiffness in 5, equinus deformity in 4, infectious recurrence in 1 and pin breakage in 1. There was no refracture at the reconstruction site.

CONCLUSION

Ilizarov bone transport combined with antibiotic cement spacer is a versatile and effective method for treatment of infected tibial nonunion.

Evaluation of an endoscopic procedure for the treatment of docking site nonunion

OBJECTIVE

To determine the effectiveness of an endoscopic docking site surgery during the use of a classic bone transport technique for dealing with bone loss.

DESIGN

Retrospective comparative study.

SETTING

Level I trauma center.

PATIENTS

Nine patients treated with endoscopic docking site surgery (group 1) were compared with 18 patients treated with standard open grafting of the docking site (group 2). All 27 bone transports with distraction osteogenesis were performed for the treatment of segmental tibial bone defects.

INTERVENTION

In group 1, 6 tibial and 3 tibiotalar docking sites were endoscopically treated. Anteromedial (instrumentation) and anterolateral (visualization) portals were used without a tourniquet, using a 30-degree arthroscope and a motorized 5-mm shaver/abrader. Fibrous tissue was removed, bone ends abraded, and the bone canal cleaned with bone grafting.

MAIN OUTCOME MEASURE

Clinical and radiographic.

RESULTS

Bone transport lengthening was 9.7 and 9.1 cm in groups 1 and 2, respectively. Consolidation at the docking site occurred in 8 patients (89%) in group 1. The docking site consolidation time and index lengthening were lower in group 1 (18 vs. 20 weeks for group 2 and 1.59 vs. 1.82 mo/cm in group 1 vs. group 2). Time in the external fixator was similar between the 2 groups (461 vs. 466 days in group 1 vs. group 2). Normal alignment was observed in both groups.

CONCLUSIONS

This study provides evidence that minimally invasive endoscopic docking site treatment during bone transport is a safe and viable technique using a common arthroscopic instrumentation.

Taylor spatial frame fixation in patients with multiple traumatic injuries: study of 57 long-bone fractures

OBJECTIVE

To evaluate the Taylor spatial frame (TSF) for primary and definitive fixation of lower limb long-bone fractures in patients with multiple traumatic injuries.

DESIGN

Retrospective.

SETTING

Level I trauma center.

PATIENTS

Consecutive series of 52 patients, 57 fractures (25 femoral and 32 tibial), treated between 2005 and 2009. Forty-nine fractures (86%) were open. Injury Severity Score ≥16 for all patients.

INTERVENTION

Fifty-four fractures (95%) underwent definitive fixation with the TSF and 3 were treated primarily within 48 hours of injury. In 22 cases (39%), fractures were acutely reduced with the TSF, fixed to bone and the struts in sliding mode without further adjustment, and in 35 cases (61%), the total residual deformity correction program was undertaken.

MAIN OUTCOME MEASURE

Clinical and radiological.

RESULTS

Complete union was obtained in 52 fractures (91%) without additional surgery at an average of 29 weeks. Four nonunions and 1 delayed union occurred. Results based on Association for the Study and Application of the Method of Ilizarov criteria: 74% excellent, 16% good, 4% fair, and 7% poor for bone outcomes and 35% excellent, 47% good, and 18% fair for functional outcomes. Eighty-eight percent of patients returned to preinjury work activities.

CONCLUSIONS

Primary and definitive fixation with the TSF is effective. Advantages include continuity of device until union, reduced risk of infection, early mobilization, restoration of primary defect caused by bone loss, easy and accurate application, convertibility and versatility compared with a monolateral fixator, and improved union rate and range of motion for lower extremity long-bone fractures in patients with multiple traumatic injuries.

Ilizarov non-free bone plasty for extensive tibial defects

PURPOSE

The purpose of this study was to present a retrospective comparative overview of the Ilizarov non-free bone plasty techniques of one-stage multilevel fragment lengthening and gradual tibilisation of the fibula used for extensive tibial defect management.

METHODS

Extensive tibial defects in 83 patients were managed either by multilevel fragment lengthening (group I, n = 41, mean defect size 13.1 ± 0.9 cm) or gradual tibilisation of the fibula (group II, n = 42, mean defect size 12.5 ± 1.2 cm) using the Ilizarov apparatus. The initial findings, treatment protocols and outcomes of those patients treated within the period 1972-2011 were studied retrospectively by medical records and radiographs, and statistically assessed with Microsoft Excel and Attestat software.

RESULTS

Group I had multilevel fragment lengthening over one stage that averaged 288.0 ± 14.4 days. The mean total period of gradual tibilisation of the fibula in group II was 316.0 ± 29.7 days. The patient's age in the latter group had an effect on the completeness of leg-length equalisation.

CONCLUSIONS

The techniques can be used to manage extensive tibial defects as all the defects bridged, leg-length discrepancy and deformity were corrected and patients were able to load their limbs.

Clinical strategies at the docking site of distraction osteogenesis: are open procedures superior to the simple compression of Ilizarov?

This retrospective review reports on forty-five tibial non-unions who underwent docking site treatment for non-union using closed versus open and endoscopic strategies. In this cohort of patients, all but twelve were infected non-unions. Sixteen patients initially treated with single compression were compared to twenty-three patients treated with open revision of the docking site, and six endoscopic procedures. In the single compression group, an average of 6.4 cm of bone was resected and index lengthening was 2.01. In the open revision group, a mean of 9.4 cm was resected and the index lengthening was 1.72. In the endoscopic group, an average of 8.6 cm of bone was resected and index lengthening was 1.71. Consolidation at the docking site occurred in 41 cases out of 45 following the first procedure. There was no statistical difference between the three groups. Conclusive evidence of superiority of one modality of treatment over the other cannot be drawn from our data. The simple compression procedure requires less invasive surgery and is probably less demanding and more cost-effective in short transports, although the two cases of failure due to recurrence of sepsis were observed after this procedure. Further studies are desirable to investigate the effectiveness of open docking site grating procedures.