Distraction osteogenesis and nonunion of the docking site: is there an ideal treatment option?

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.

Bone Transport Through Induced Membrane Versus Conventional Bone Transport in Management of Infected Long-Bone Defects of Lower Limbs: A Randomized Controlled Trial

OBJECTIVES

To compare bone transport through induced membrane (BTM) and conventional bone transport (BT) regarding docking site union and infection recurrence in the management of infected long-bone defects.

DESIGN

Prospective, randomized, controlled study.

SETTING

Tertiary-level center.

PARTICIPANTS

Thirty patients with infected nonunited long-bone fractures of lower limbs were included.

INTERVENTION

Fifteen patients were treated by BTM in group A, and 15 patients were treated by BT in group B.

OUTCOME MEASUREMENTS

The outcome measures were external fixation time, external fixation index, and docking time. Bone and functional outcomes were evaluated by the Association for the Study and Application of the Method of Ilizarov scoring system. Postoperative complications were evaluated according to the Paley classification.

RESULTS

The mean docking time was significantly lower in the BTM group than in the BT group (3.6 ± 0.82 months vs. 4.8 ± 0.86 months, respectively; P value 0.001). Docking site nonunion and infection recurrence were significantly lower in the BTM group than in the BT group (0% vs. 40%; P value 0.02 and 0% vs. 33.3%; P value 0.04, respectively), with no significant difference in the external fixation index ( P value 0.08).

CONCLUSIONS

This is the first prospective, randomized, controlled study comparing BTM and BT techniques, showing that BTM had significantly faster docking site union, lower incidence of postoperative complications including docking site nonunion and infection recurrence rates, and lower number of additional procedures needed at the expense of 2-staged operation in comparison with BT.

LEVEL OF EVIDENCE

Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Ilizarov technique in the treatment of bone defects of the radius and ulna: a systematic review and meta-analysis

PURPOSE

The objective of this systematic review and meta-analysis was to assess the efficacy of the Ilizarov method in the treatment of radius and ulna bone defects.

METHODS

The PubMed, Embase, Web of Science, Cochrane Library, Ovid MEDLINE, and Scopus databases were searched for articles published up to May 2023. The quality of the studies was evaluated using a modified version of the Newcastle-Ottawa scale. The effect size and confidence intervals at 95% for the main results were calculated. The heterogeneity was evaluated. The demographic data, defect size (DS), external fixation time (EFT), external fixation index (EFI), and complications were extracted and analyzed using the Stata version 16.

RESULTS

This meta-analysis identified and included seven studies involving 98 patients. The union rate of 100% was reported in all studies. According to the findings of the single-arm meta-analysis, the pooled DS was 3.42 cm (95% CI [2.64, 4.21], I2 = 53.5%, P = 0.045), EFT was 148.43 days (95% CI [97.49, 199.38], I2 = 91.9%, P = 0.000), and EFI was 41.32 days/cm (95% CI [35.72, 46.91], I2 = 62.2%, P = 0.021). Pin tract infection was the most common complication, as reported in six studies.

CONCLUSION

The findings of the present meta-analysis indicate that the Ilizarov technique is a successful treatment option for bone defects in the radius and ulna. This method has demonstrated efficacy in achieving expected clinical outcomes.

New insights in lower limb reconstruction strategies

High Energy Musculoskeletal Traumas (HEMTs) represent a relevant problem for healthcare systems, considering the high social costs, and both the high morbidity and mortality. The poor outcomes associated with HEMT are related to the high incidence of complications, including bone infection, fracture malunion and non-union. The treatment of each of these complications could be extremely difficult. Limb reconstruction often needs multiple procedures, rising some questions on the opportunity in perseverate to try to save the affected limb. In fact, theoretically, amputation may guarantee better function and lower complications. However, amputation is not free of complication, and a high long-term social cost has been reported. A comprehensive literature review was performed to suggest possible ways to optimize the limb preservation surgeries of HEMT's complications in order to ameliorate their management.

An osteoinductive and biodegradable intramedullary implant accelerates bone healing and mitigates complications of bone transport in male rats

Bone transport is a surgery-driven procedure for the treatment of large bone defects. However, challenging complications include prolonged consolidation, docking site nonunion and pin tract infection. Here, we develop an osteoinductive and biodegradable intramedullary implant by a hybrid tissue engineering construct technique to enable sustained delivery of bone morphogenetic protein-2 as an adjunctive therapy. In a male rat bone transport model, the eluting bone morphogenetic protein-2 from the implants accelerates bone formation and remodeling, leading to early bony fusion as shown by imaging, mechanical testing, histological analysis, and microarray assays. Moreover, no pin tract infection but tight osseointegration are observed. In contrast, conventional treatments show higher proportion of docking site nonunion and pin tract infection. The findings of this study demonstrate that the novel intramedullary implant holds great promise for advancing bone transport techniques by promoting bone regeneration and reducing complications in the treatment of bone defects.

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.

Treatment of tibial large bone defects: A comparative study of bone transport over an intramedullary nail in combination with antibiotic-impregnated calcium sulphate versus bone transport alone with antibiotic-impregnated calcium sulphate

PURPOSE

To compare the bone transport over an intramedullary nail in combination with antibiotic-impregnated calcium sulphate versus bone transport alone with antibiotic-impregnated calcium sulphate for the treatment of tibial large bone defects.

METHODS

A retrospective analysis was conducted by enroling 33 surgically treated patients with tibial large bone defects after the debridement for tibial infection or osteomyelitis who were admitted in Lower Limb Surgery Ward of Traumatic orthopaedic Department, Xi'an Honghui Hospital from January 2018 to January 2021. All the patients were categorized in Group A (transport over intramedullary nail, 12 cases) and Group B (transport alone, 21 cases) based on the surgery strategy. The collected clinical materials and data included gender, age, injury mechanism, smoking habits, comorbidity diseases, initial fracture type (open or close), bone defect size, surgical duration, intraoperative bleeding loss, resorption time of calcium sulphate, bone transport time, external fixation time, external fixation index, weight bearing time, complications and Paley bone and functional criteria.

RESULTS

Thirty-three patients were enroled and successfully followed up with an average time of 15.25±4.31 months ranged from 8 to 21 months in Group A and an average time of 17.09±5.64 months ranged from 9 to 31 months in Group B. No significantly statistical differences of the demographic data were discovered between the two groups. There were no significantly statistical differences of the average bone defect size, intraoperative bleeding loss, resorption time of calcium sulphate and bone transport time between the two groups. However, the average surgical duration (P = 0.002) was significantly longer in Group A than Group B and the average external fixation time (P<0.001), external fixation index(P = 0.002) and weight bearing time (P = 0.030) were significantly shorter in Group A than Group B. No significantly statistical difference of excellent and good rate of bone outcomes and complication rate was observed, however, the excellent and good rate of functional outcomes (P = 0.041) was significantly higher in Group A than Group B.

CONCLUSION

Compared with the conventional Ilizarov technique combining with antibiotic-impregnated calcium sulphate for large tibial bone defects, bone transport over an intramedullary nail in combination with antibiotic-impregnated calcium sulphate had favourable external fixation time, external fixation index, weight bearing time and clinical functional outcomes which effectively suppressed the infection and allowed patients earlier removal of the external fixator and weight bearing for rehabilitation.

Tetrafocal (three osteotomies) and pentafocal (four osteotomies) bone transport using Ilizarov technique in the treatment of distal tibial defect-preliminary outcomes of 12 cases and a description of the surgical technique

OBJECTIVE

To evaluate the preliminary outcomes of tetrafocal (three osteotomies) and pentafocal (four osteotomies) bone transport using Ilizarov technique for the treatment of distal tibial defect and describe the surgical technique.

METHODS

A total of 12 eligible patients with distal tibial defect > 6 cm caused by direct trauma or posttraumatic osteomyelitis who were admitted to our institution from January 2017 to January 2019 were treated by tetrafocal or pentafocal bone transport using Ilizarov technique. Detailed demographic data, including age, sex, etiology, defect size, number of osteotomies (three or four), external fixation time (EFT) and external fixation index (EFI), were collected, and the bone and functional outcomes were evaluated by the Association for the Study and Application of the Method of Ilizarov (ASAMI) scoring system. Complications during the surgery and the follow-up period were recorded and evaluated by the Paley classification at a minimum follow-up of two years after removal of the fixator.

RESULTS

There were 9 men and 3 women with an average age of 37.4±7.8 years. The etiology included posttraumatic osteomyelitis in 8 cases and posttraumatic bone loss in 4 cases. The mean bone defect after radical debridement was 7.1±0.6 cm. Tetrafocal bone transport was applied in 9 cases, and pentafocal bone transport was applied in 3 cases. The average EFT and EFI were 5.2±0.8 months and 0.7±0.2 months/cm, respectively. The average time of follow-up after removal of the external fixator was 28.5±3.3 months without recurrence of osteomyelitis. The bone results were good in 7 cases, fair in 4 cases, and poor in 1 case, and the functional results were good in 5 cases, fair in 6 cases, and poor in 1 case. The most common complication was pin tract infection, which occurred in all cases, but there were no major complications, such as nerve or vascular injury.

CONCLUSION

Tetrafocal and pentafocal bone transport using Ilizarov technique could be an alternative treatment option in selected cases with distal tibial defect > 6 cm. It could shorten the distraction period, fasten regeneration, and reduce the associated complications.

Current Perspectives on the Management of Bone Fragments in Open Tibial Fractures: New Developments and Future Directions

Open tibial fractures may be associated with bone loss at the time of the injury or following surgical debridement of the fracture. This article discusses the various treatment options available and the latest developments surrounding the management of free bone fragments in open tibial fractures.

Matched comparative study of trifocal bone transport versus induced membrane followed by trifocal bone transport in the treatment of segmental tibial defects caused by posttraumatic osteomyelitis

Objectives

To compare the efficacy and clinical outcomes of trifocal bone transport (TBT) versus induced membrane followed by trifocal bone transport (IM + TBT) in the treatment of tibial defects > 6 cm caused by posttraumatic osteomyelitis.

Methods

A total of 69 eligible patients with tibial defects > 6 cm who were treated between January 2010 and January 2018 were retrospectively reviewed. Overall, 18 patients treated by IM + TBT and 18 treated by TBT were matched by propensity score analysis. The mean tibial defect after radical debridement was 6.97 ± 0.76 cm (range, 6.0 to 8.9 cm). The measurements, including demographic data, external fixation index (EFI), external fixation time (EFT), duration of docking union, bone and functional outcomes evaluated by the Association for the Study and Application of the Method of Ilizarov (ASAMI) scoring system, and postoperative complications evaluated by Paley classification during follow-up were recorded.

Results

Age, gender, injury mechanism, affected side, defect size, previous operation time, and follow-up time were not significantly different between the two groups (P > 0.05). The mean EFT was 293.8 ± 12.1 days in the TBT group vs. 287.5 ± 15.3 days in the IM + TBT group. The mean EFI was 36.02 ± 2.76 days/cm vs. 34.69 ± 2.83 days/cm, respectively. The mean duration of docking union was 210.7 ± 33.6 days vs. 179.7 ± 22.9 days, respectively. There was no significant difference in postoperative bone and functional results between the two groups. Delayed union or nonunion and soft tissue incarceration were significantly reduced in the IM + TBT group compared to those in the TBT group.

Conclusion

Both TBT and IM + TBT achieved satisfactory postoperative bone and functional outcomes in patients with segmental tibial defects > 6 cm following posttraumatic osteomyelitis, while IM + TBT had a significantly lower incidence of postoperative complication in delayed union or nonunion and soft tissue incarceration, as well as faster docking union.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05501-8.

Technical considerations for the management of segmental osseous defects with an internal bone transport nail

INTRODUCTION

Traditionally, distraction osteogenesis has been accomplished with an external fixator. All internal transport utilizing magnetic intramedullary nails is a newer technique for bone reconstruction. The Precice Bone Transport Nail is a new implant that allows for noninvasive transport via a magnetically driven motor.

AREAS COVERED

This report describes the function of the Bone Transport Nail along with the technical considerations on how to successfully manage bone defects with this new technology. Appropriate use of the nail, preoperative planning, intraoperative considerations, and postoperative management are discussed in detail.

EXPERT OPINION

The Precice Bone Transport Nail utilizes the technology of the original Precice nail to provide an all-internal option for reconstruction of intercalary defects. This obviates the need for an additional plate with a standard Precice nail when performing bone transport and allows for a less invasive option that decreases operating room time. It provides a more cosmetic result than external fixation and avoids the risks of pin tract infection. Preoperative planning is essential to appropriate execution of the operative procedure and to perform a successful transport. A thorough understanding of the nail design and limitations are a prerequisite as this implant is significantly different from a standard intramedullary nail.

Analysis of bone transport for ankle arthrodesis as a limb salvage procedure for the treatment of septic pilon fracture nonunion

Septic nonunion of the pilon region with ankle joint infection is challenging for orthopedic surgeons to treat and is associated with a high risk of limb loss. Therefore, the aim of this study was to evaluate the effectiveness of bone transport for ankle arthrodesis in salvaging the limp after septic ankle destruction of the pilon region. We conducted a single-center, retrospective study including 21 patients treated for septic pilon nonunion with accompanying septic ankle destruction via Ilizarov bone transport between 2004 and 2018. In all cases, the complete excision of the nonunion and the resection of the ankle joint were carried out, followed by treating the bone and joint defect with a bone transport into the ankle arthrodesis. In 12/21 patients an additional flap transfer was required due to an accompanying soft tissue lesion. The overall healing and failure rate, final alignment and complications were recorded by the patients’ medical files. The bone-related and functional results were evaluated according to the Association for the Study and Application of Methods of Ilizarov (ASAMI) scoring system and a modified American Orthopedic Foot and Ankle Society (AOFAS) scale. After a mean follow-up of 30.9 ± 15.7 months (range 12–63 months), complete bone and soft tissue healing occurred in 18/21 patients (85.7%). The patients had excellent (5), good (7), fair (4), and poor (3) results based on the ASAMI functional score. Regarding bone stock, 6 patients had excellent, 7 good, and 6 fair results. The modified AOFAS score reached 60.6 ± 18 points (range, 29–86). In total, 33 minor complications and 28 major complications occurred during the study period. In 2 cases, a proximal lower leg amputation was performed due to a persistent infection and free flap necrosis with a large soft tissue defect, whereas in one case, persistent nonunion on the docking side was treated with a carbon orthosis because the patient refused to undergo an additional surgery. Bone transport for ankle arthrodesis offers the possibility of limb salvage after septic ankle destruction of the pilon region, with acceptable bony and functional results. However, a high number of complications and surgical revisions are associated with the treatment of this severe complication after pilon fracture.

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.

Segmental Bone Defects and the History of Bone Transport

This article describes the etiology of segmental bone defects and reviews the options of care, past and present. A brief description of distraction osteogenesis and how the Ilizarov method was used to treat bone defects with circular external fixation leading to the latest method of transport with motorized internal lengthening nails is presented.

Treatment for postoperative infection of pathological femoral fracture after radiotherapy: two case reports and review of the literature

INTRODUCTION

Radiation-induced pathological fractures show high nonunion and infection rates. Successful treatment of postoperative infections of these fractures without limb amputation is extremely rare.

METHODS

We report two cases of postoperative infection of pathological femoral fracture after radiation therapy for soft tissue tumors. Considering the poor condition of the irradiated site, a two-staged operation was selected to create the optimal situation for bone union. The treatment involved the Masquelet technique, latissimus dorsi (LD) flap, and a free vascularized fibula graft (FVFG). In the first stage, we drastically resected the necrotic bone and the surrounding infected tissue and placed antibiotic polymethylmethacrylate space on the bone gap according to the Masquelet technique. Next, we used an Ilizarov external fixator as a temporizing stabilizer and performed the LD flap. Six weeks later, in the second stage, we changed the external fixation to plate fixation; packed the artificial bone (β-TCP) and autograft bone to the induced membrane; and performed FVFG on the other side of the plate. As postoperative therapy, toe touch was allowed immediately, and partial weight bearing was started 2 months after second surgery.

RESULTS

Both patients achieved bone union and were able to walk without postoperative complications. At the 2-year follow-up, there was no recurrence of infection.

CONCLUSION

Our treatment is effective for controlling postoperative infection of radiation-induced pathological fracture.

Ilizarov bone transport using an intramedullary cable transportation system in the treatment of tibial bone defects

INTRODUCTION

Segmental tibia defects remain challenging for orthopedic surgeons to treat. The aim of this study was to demonstrate bone-related and functional outcomes after treatment of complex tibial bone defects using Ilizarov bone transport with a modified intramedullary cable transportation system (CTS).

PATIENTS AND METHODS

We conducted a single-center, retrospective study including all 42 patients treated for tibial bone loss via Ilizarov bone transport with CTS between 2005 and 2018. Bone-related and functional results were evaluated according to the Association for the Study and Application of Methods of Ilizarov (ASAMI) scoring system. Complication and failure rates were determined by the patients' medical files.

RESULTS

Patients had a mean age of 45.5 ± 15.1 years. The mean bone defect size was 7.7 ± 3.4 cm, the average nonunion scoring system (NUSS) score was 59 ± 9.5 points, and the mean follow-up was 40.8 ± 24.4 months (range, 13-139 months). Complete bone and soft tissue healing occurred in 32/42 patients (76.2%). These patients had excellent (10), good (17), fair (2), and poor (3) results based on the ASAMI functional score. Regarding bone stock, 19 patients had excellent, 10 good, and 3 fair results. In total, 37 minor complications and 62 major complications occurred during the study. In 7 patients, bone and soft tissue healing occurred after CTS failure with either an induced membrane technique or classic bone transport; 3 patients underwent lower leg amputation. Patients with treatment failure were significantly older (57.6 vs. 41.8 years; p = 0.003). Charlson score and treatment failure had a positive correlation (Spearman's rho 0.43; p = 0.004).

CONCLUSION

Bone transport using both intramedullary CTS and Ilizarov ring fixation is viable for treating patients with bone loss of the tibia and complex infection or soft tissue conditions. However, a high number of complications and surgical revisions are associated with the treatment of this severe clinical entity and should be taken into account.

Role of Primary Autologous Bone Graft at Docking Site in the Treatment of Infected Non-union Tibia Using Rail Fixation System

Introduction:

Distraction osteogenesis has been used effectively in the management of tibia non-unions with skeletal defect. A retrospective case series study of the infected non-union tibia managed with acute docking in a rail fixation system was conducted at a tertiary care hospital in South India. It was designed to evaluate the use of autologous bone graft at the docking site in achieving an early union with a seven years follow-up period.

Materials and Methods:

From 2010 to 2017, a total of 19 patients with infected tibia non-union and a bone defect less than 3cm, were treated with debridement and a monolateral frame fixation with acute shortening and lengthening. The patients were divided into two groups: one in which no bone graft was used at the docking site during early years of the study; and a later group in which autologous bone graft was used at the acute docking site primarily in addition to compression. Consolidation at the docking site was assessed both radiographically and clinically, and the results were statistically analysed.

Results:

There were 12 patients in Group I without bone graft, where consolidation at the docking site was noted after a mean duration of 22.08 ± 3.87 weeks. There were seven patients in Group II with bone graft, where the mean time for docking site consolidation was significantly lower at 16.57 ± 3.82 weeks. No docking site complications were noted in either group.

Conclusion:

Primary autologous bone graft enhances docking site consolidation in acute shortening. The routine use of bone graft at the docking site in acute shortening will expedite the docking site union with reduction of treatment time.

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.

Clinical feasibility of fracture healing assessment through continuous monitoring of implant load

Current fracture fixation follow-up is based on subjective radiological and clinical examination. Efforts to objectify the procedure have been undertaken since decades. Assessment of implant load as an indirect predictor of callus maturity has so far failed to enter clinical routine due to limited practicability, technical obstacles and its snap-shot nature. We recently introduced the concept of continuous implant load monitoring to aid in diagnosing fracture healing progression. This study aimed at investigating the feasibility of the system in a clinical context. Ten patients treated with Taylor-Spatial-Frame external fixators following pathological tibia fractures were equipped with a Fracture Monitor device attached to a fixator-strut and were monitored until hardware removal. Two patients were excluded due to technical issues. Implant load and fracture activity was continuously and autonomously measured for 139 ± 89 days (mean ± SD). Data was wirelessly collected with consumer smartphones. Relative implant load initially rose for 34.1 ± 22.2 days and finally declined to a level of 45.0 ± 33.8% of the maximum implant load. In five patients the load dropped below 50% of the maximum load. These patients underwent hardware removal according to the clinical assessment. In three patients, whose external fixators were exchanged to internal fixation at the end of the study, implant load did not drop below the 50% margin. The continuous measurement principle allows resolving implant load progression and appears indicative for the bone healing status. Data can be acquired in a homecare setting and is believed to provide valuable information to support timely healing assessment and enable patient specific after-care.

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.

Comparison of the use of antibiotic-loaded calcium sulphate and wound irrigation-suction in the treatment of lower limb chronic osteomyelitis

AIMS

We sought to compare the efficacy of antibiotic-loaded calcium sulphate with wound irrigation-suction in patients with lower limb chronic osteomyelitis.

PATIENTS AND METHODS

Adult patients with lower limb chronic osteomyelitis treated at our hospital by means of segmental bone resection, antibiotic-loaded calcium sulphate implantation or wound irrigation-suction, followed by bone transport with external fixator from January 2011 to July 2015 were retrospectively evaluated. The clinical presentation, laboratory results, complications, docking obstruction, infection recurrence were compared.

RESULTS

There were totally 74 patients met the inclusion criteria. Docking obstruction rate and infection recurrence were higher in the irrigation group with significant difference. The success rate of the first operation was 90.74% in the calcium sulphate group compared with 45% in the irrigation group. Postoperaton leakage of the incision happened more in the calcium sulphate group, but it wasn't a risk factor for docking obstruction and infection recurrence. Patients in the calcium sulphate group had shorter hospital stay and systemic antibiotic treatment, also with less external fixator index.

CONCLUSIONS

The findings of our study suggest that antibiotic-loaded calcium sulphate implantation for lower chronic limb osteomyelitis was a more successful method than wound irrigation-suction, it greatly decreased infection recurrence and docking obstruction. Postoperative leakage after implantation didn't worsen patient's outcome.

Horizontal alveolar transport distraction osteogenesis followed by implant placement

Alveolar transport distraction osteogenesis (ATDO) is an alternative treatment method to vertical alveolar distraction osteogenesis in cases of large bony defects, especially when the bone is limited in size. ATDO was performed in 10 patients with 12 defects. The mean age of the patients was 39.1years. The average bone length gain was 18.2mm. Implants were inserted following a 3-month consolidation period. Three patients needed additional bone grafting for horizontal widening. Final prosthetic rehabilitation was performed at least 3 months following implant insertion. The mean follow-up period was 63 months and the survival rate of the 25 implants placed was 92%. All failures (n=2) occurred during the early healing period. Although the results are not totally predictable, it can be concluded that ATDO can be effective in the reconstruction of the alveolar crest prior to implant placement.

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.

Femoral nonunion with segmental bone defect treated by distraction osteogenesis with monolateral external fixation

BACKGROUND

Currently, the common treatment for femoral nonunion with large segmental bone defect is difficult and complex. The effective surgical methods are rare, include vascularized bone grafting, Masquelet technique and Ilizarov distraction osteogenesis. The objective of this study is to investigate the outcomes of segmental femoral defects treated with monolateral external fixation using the distraction osteogenesis.

METHODS

We retrospectively analyzed patients with femoral nonunion with segmental bone defects (> 6 cm) between January 2010 and January 2014 in our single trauma center. All patients were treated by distraction osteogenesis with monolateral external fixation. All surgeries were performed by the same surgeon. Bone union, duration of distraction osteogenesis in days, time to consolidation in months, external fixation index (EFI), complications, and additional surgical interventions were recorded postoperatively. The modified Application of Methods of Illizarov (ASAMI) criteria were used to evaluate the operative effectiveness.

RESULTS

Forty-one patients were enrolled in this study for analysis. The length of the bone defect ranged from 6 to 17 cm. All patients eventually achieved healing, and no patient experienced recurrence of infection or newly developed infection. The average time needed for healing was 13 months. In terms of the incidence of complications, 3 cases axial deviations, 5 cases docking site nonunion, 23 cases pin-tract infection, 14 cases knee joint stiffness or their joint mobility declined, 2 cases osteogenesis insufficient in the distraction area,1 case refracture, and 2 cases loose external fixation pins. In terms of the evaluations of fracture healing and function, 30 patients excellent, 6 patients good, 5 patients fair, and 0 patient poor. In terms of postoperative function evaluations, 21 patients excellent, 9 patients good, 7 patients fair, and 4 patients poor.

CONCLUSION

For patients with femoral nonunion with large segmental bone defects, the monolateral external fixation can provide effective stability, improve compliance, and reduce complications.

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.

Accordion technique combined with minimally invasive percutaneous decortication for the treatment of bone non-union

BACKGROUND

A variety of approaches have been used to treat oligotrophic or atrophic non-union. Conventional methods are often associated with great operative trauma, increased blood loss, a risk of re-infection, higher medical costs, and complications at the donor site. This study aimed to assess the clinical efficacy of the accordion technique combined with Minimally Invasive Percutaneous Decortication (MIPD) for these types of bone non-union.

METHODS

From January 2010 to December 2015, 20 patients with long bone aseptic non-unions of the lower extremities without bone defects who were treated with the accordion technique combined with MIPD. The limb-length discrepancy (LLD) was less than 2cm in all patients. None of the patients received autogenous bone grafts during follow-up. All surgeries were performed by the same surgeon, and the modified Application of methods of Ilizarov (ASAMI) criteria were used to evaluate the operative effectiveness.

RESULTS

A total of 20 patients were included in this study, and 1 patient was lost during follow-up. Fifteen of these patients presented with oligotrophic non-unions, and 5 patients presented with atrophic non-unions. The average follow-up period in these patients was 12.1 months (range: 8-42 months). The alternative compression and distraction procedure was repeated 1-3 times. Blood loss was 30 to 250ml during surgery. Ultimately, bone union was achieved in 19 patients and failed in 1 patient. The fractures healed within 4-8 months (average time: 5.9 months), and fracture healing was considered excellent in 19 patients and poor in 1 patient. Postoperative function was evaluated as excellent in 9 patients, good in 6 patients, fair in 4 patients, and poor in 1 patient.

CONCLUSION

The accordion technique combined with MIPD, which is a simple, minimally invasive procedure that does not require autologous bone grafting, resulted in a high bone union rate and good postoperative function.

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.

Treatment of post-traumatic chronic osteomyelitis of lower limbs by bone transport technique using mono-lateral external fixator: Follow-up study of 18 cases

PURPOSE

To review the results of the treatment of post-traumatic chronic osteomyelitis of lower limbs by bone transport technique using mono-lateral external fixator.

PATIENTS AND METHODS

A total of 18 patients with post-traumatic chronic osteomyelitis of lower limbs were treated by bone transport technique using mono-lateral external fixator in this study. Seven cases (patients No. 1-7) were performed early BGPO (autologous ilium bone grafting and plate osteosynthesis) intervention after BT (bone transport). The end results were assessed by the criteria of ASAMI and Paley et al. Some data between the cases with and without the intervention of early BGPO were subjected to statistical analysis of Student's t-test.

RESULTS

The overall average time for union was 10.8 months. The average union time of the non-early BGPO cases was 52.27 ± 7.82 weeks while the early BGPO cases took a shorter time of 36.86 ± 5.34 weeks (P < 0.001). The overall average duration from bone transport to removal of external fixator was 10.0 months. The average duration from bone transport to removal of external fixator in the non-early BGPO cases was 51.55 ± 7.45 weeks while the early BGPO cases took a shorter time of 29.29 ± 5.47 weeks (P < 0.001). The overall average of BHI was 1.77 months cm(-1). The average of BHI in the non-early BGPO cases was 2.25 ± 0.25 months cm(-1) and the average BHI of the early BGPO cases was 1.22 ± 0.114 months cm(-1) (P < 0.001). There were 31 additional surgeries and 38 complications in total after bone transport treatment. The bone results were excellent in 15 cases, good in 3 cases. The functional results were excellent in 9 cases, good in 6 cases and fair in 3 cases.

CONCLUSIONS

1. Bone transport technique using mono-lateral external fixator is an effective method for the treatment of post-traumatic chronic osteomyelitis. 2. Early BGPO intervention after bone transport is a feasible method to shorten the external fixation time and the total duration of treatment.

The treatment of femoral bone loss by axial external fixation and susbequent locking plate application: a case report

A 20-year-old man was admitted to our hospital having sustianed bilateral high-energy femoral fractures. The right femoral fracture was an open grade 3B with OTA grade 3 bone loss. The patient had also a brain contusion with a subdural haematoma and a closed fracture of the left clavicle. Initial management included temporarily stabilisation of the femoral fractures wth external fixators and prompt transfer to the intensive care unit. Three weeks later the external fixator of the right femur was converted to an hybrid system, and the fixator of the left side was removed and a reamed intramedullary locking nail was applied. Two months after the accident the patient underwent bone transport (11 cm long) of the right femur with an monolateral external fixation. When the final length was achieved there were knee stiffness (ROM 0° to 30°) and non-union of the docking site. Therefore, the patient underwent a Judet's procedure to treat the knee stiffness and stabilisation of the non united femur with a locking plate (LISS). After the operation the patient started progressive weight bearing. A year after trauma and following union of the femur, the patient underwent soft tissue reconstruction of the anterior side of the thigh with a free vascularised flap. At final follow upo the patient had a good functional recovery with return to his previous occupation.

Induction of bone formation in abdominal implants constituted by collagen sponges embedded with plant-based human transforming growth factor family proteins in ectopic dog model

Background

Trauma, osteomyelitis, bone tumour resections and congenital deformities are the main causes of bone deficiency in which autologous graft is the preferred treatment, but usually the bone supplies are limited.

Methods

An experimental model of heterotopic bone formation in the subcutaneous abdominal area of dogs was developed. This model consists in omentum wrapped implants constituted by collagen type 1 sponges embedded with demineralized bone powder, calcium cloride, thrombin and platelet rich plasma; the implant is totally converted in trabecular bone after four months of implantation. This model was improved by accelerating bone production, after the isolation of the most conspicuous histological constituents (inflammatory, bone and adipose tissues) by laser microdisection and purified from them RNA that was used to determine by RT-PCR the gene expression kinetics of the most important growth bone factors. Then, the most abundant and rapidly synthesized factors were produced by genetic engineering in tobacco plants.

Results

Bone morphogenetic proteins 2 and 7 and transforming growth factor-β1were the most rapidly and highly synthesized factors, and they were efficiently produced in a genetic engineering plant based system in tobacco leaves. Their incorporation as recombinant proteins in the scaffold collagen sponge induced in just one month mature heterotopic bone.

Conclusion

This study demonstrates for the first time that this plant system is able to produce recombinant bone growth factors in high amount and at low cost, and they were highly efficient to rapidly induce bone formation in abdominal implants potentially useful for autotransplantation.

Bone transport with an external fixator and a locking plate for segmental tibial defects

Although gradual bone transport may permit the restoration of large-diameter bones, complications are common owing to the long duration of external fixation. In order to reduce such complications, a new technique of bone transport involving the use of an external fixator and a locking plate was devised for segmental tibial bone defects. A total of ten patients (nine men, one woman) with a mean age at operation of 40.4 years (16 to 64) underwent distraction osteogenesis with a locking plate to treat previously infected post-traumatic segmental tibial defects. The locking plate was fixed percutaneously to bridge proximal and distal segments, and was followed by external fixation. After docking, percutaneous screws were fixed at the transported segment through plate holes. At the same time, bone grafting was performed at the docking site with the external fixator removed. The mean defect size was 5.9 cm (3.8 to 9.3) and mean external fixation index was 13.4 days/cm (11.8 to 19.5). In all cases, primary union of the docking site and distraction callus was achieved, with an excellent bony result. There was no recurrence of deep infection or osteomyelitis, and with the exception of one patient with a pre-existing peroneal nerve injury, all achieved an excellent or good functional result. With short external fixation times and low complication rates, bone transport with a locking plate could be recommended for patients with segmental tibial defects.

The Ilizarov paradigm: thirty years with the Ilizarov method, current concerns and future research

The Ilizarov method of bone lengthening, reconstruction and osteosynthesis has developed immensely since its introduction by G.A. Ilizarov in the Soviet Union in the 1960s and in the Western countries in the early 1980s. It has become an integral part of the arsenal used by the orthopaedic community worldwide. The evolutionary development of the method and its current role has considerably improved the quality of life for millions of people around the whole world. Despite the great versatility of its possible applications for bone injuries and diseases, the Ilizarov method could not and cannot be the alternative to a range of other methods that are applied for some specific bone conditions, but rather is a method of choice. Its combination with the current methods of internal fixation or the means of internal fixation that use the biological principles that were laid down by G.A. Ilizarov have demonstrated the importance of tension stress, blood supply, functional loading, and fragment control during bone treatment. The objective of this study was to present an overview of the current state and concerns in the application of the Ilizarov method and define the prospective research trends aimed at regeneration stimulation, better control of treatment, infection barriers and patient comfort.

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.

Methods to shorten the duration of an external fixator in the management of tibial infections

Massive segmental bone loss due to chronic osteomyelitis represents a considerable challenge to orthopedic surgeons and is a limb threatening condition. The only option available in such a clinical situation is segment transport using the Ilizarov technique of distraction osteogenesis; yet the most common problem in cases of bone transport with the Ilizarov technique in massive bone loss, is the long duration of the fixator. In addition to autologous bone grafting, several mechanical, biologic, and external physical treatment modalities may be employed to promote bone formation and maturation during segment transport in osteomyelitis patients. Mechanical approaches include compressive loading of the distraction regenerate, increased frequency of small increments of distraction, and compression-distraction. Intramedullary nailing and hemicorticotomy can reduce the time in external fixation; however, these techniques are associated with technical difficulties and complications. Exogenous application of low-intensity pulsed ultrasound or pulsed electromagnetic fields may shorten the duration of external fixation. Other promising modalities include diphosphonates, physician-directed use (off-label use) of bone morphogenetic proteins, and local injection of bone marrow aspirate and platelet gel at the osteotomy site. Well-designed clinical studies are needed to establish safe and effective guidelines for various modalities to enhance new bone formation during distraction osteogenesis after segment transfer.

The role of stem cells in fracture healing and nonunion

Nonunion and large bone defects present a therapeutic challenge to the surgeon and are often associated with significant morbidity. These defects are expensive to both the health care system and society. However, several surgical procedures have been developed to maximise patient satisfaction and minimise health-care-associated and socioeconomic costs. Integrating recent evidence into the diamond concept leads to one simple conclusion that not only provides us with answers to the "open questions" but also simplifies our entire understanding of bone healing. It has been shown that a combination of neo-osteogenesis and neovascularisation will restore tissue deficits, and that the optimal approach includes a biomaterial scaffold, cell biology techniques, a growth factor and optimisation of the mechanical environment. Further prospective, controlled, randomised clinical studies will determine the effectiveness and economic benefits of treatment with mesenchymal stem cells, not in comparison to other conventional surgical approaches but in direct conjunction with them.

Pseudoaneurysm of the peroneal artery: an unusual complication of open docking site procedure in bone transport with Taylor Spatial Frame

A docking site is the terminus of travel of two segments of bone that are gradually brought into approximation, normally associated with the bone transport technique in limb reconstruction. Traumatic pseudoaneurysm of the peroneal artery have been reported following different types of trauma and orthopedic procedures performed in the distal leg. One uncommon case of delayed peroneal artery pseudoaneurysm following surgical docking site is described. The diagnosis was supported by angiography. Embolization with coil was a successful method of treatment. We recommend a safe method of osteotomy with good bone exposure and adequate soft tissue protection.

Bone regeneration and docking site healing after bone transport distraction osteogenesis in the canine mandible

PURPOSE

Bone transport distraction osteogenesis provides a promising alternative to traditional grafting techniques. However, existing bone transport distraction osteogenesis devices have many limitations. The purpose of this research was to test a new device, the mandibular bone transport reconstruction plate, in an animal model with comparable mandible size to humans and to histologically and mechanically examine the regenerate bone.

MATERIALS AND METHODS

Eleven adult foxhounds were divided into an unreconstructed control group of 5 animals and an experimental group of 6 animals. In each animal, a 34-mm segmental defect was created in the mandible. The defect was reconstructed with a bone transport reconstruction plate. Histologic and biomechanical characteristics of the regenerate and unrepaired defect were analyzed and compared with bone on the contralateral side of the mandible after 4 weeks of consolidation.

RESULTS

The reconstructed defect was bridged with new bone, with little bone in the control defect. Regenerate density and microhardness were 22.3% and 42.6%, respectively, lower than the contralateral normal bone. Likewise, the anisotropy of the experimental group was statistically lower than in the contralateral bone. Half the experimental animals showed nonunion at the docking site.

CONCLUSION

The device was very stable and easy to install and activate. After 1 month of consolidation, the defect was bridged with new bone, with evidence of active bone formation. Regenerate bone was less mature than the control bone. Studies are underway to identify when the regenerate properties compare with normal bone and to identify methods to augment bone union at the docking site.

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

PURPOSE

This retrospective review follows 31 tibial nonunions to compare union at the docking site using closed versus open strategies. In this cohort of patients, all but five were infected nonunions.

METHODS

Thirteen patients initially treated with single compression were compared with 18 patients treated by open revision of the docking site. In the single compression group, an average of 6.5 cm of bone was resected and index lengthening was 2.04. In the open revision group, a mean of 9.4 cm was resected and the index lengthening was 1.73.

RESULTS

Consolidation at the docking site occurred in all subjects in both groups. There was no statistical difference between the two groups. Conclusive evidence of superiority of one modality of treatment over the other cannot be drawn from our data.

CONCLUSIONS

The simple compression procedure requires less invasive surgery and is probably less demanding and more cost-effective in short transports.

Bone transport for postinfectious segmental tibial bone defects with a combined ilizarov/taylor spatial frame technique

OBJECTIVE

To assess and compare the results of trifocal (two-level bone lengthening with compression at the nonunion site) and bifocal (one-level bone lengthening with compression at the nonunion site) bone transport using the Taylor Spatial Frame (TSF; Smith and Nephew, Inc, Memphis, TN) for postinfectious segmental tibial bone defects.

DESIGN

Retrospective study of 12 patients with atrophic tibial nonunions. These patients were treated with resection of the nonunion followed by bone transport using the TSF for the segmental tibial bone defects. All patients were treated by the same surgeon (F.S.).

SETTING

Level I trauma center.

PATIENTS/PARTICIPANTS

Twelve consecutive patients treated for postinfectious segmental tibial bone defects between November 2004 and September 2007.

INTERVENTION

All patients were treated using the TSF for a trifocal or bifocal technique of bone transport along with associated soft tissue reconstructive surgeries. All patients were additionally treated with 45 days of culture-specific antibiotics.

OUTCOME MEASUREMENT

All patients were evaluated by the guidelines of the Association for the Study of the Method of Ilizarov.

RESULTS AND CONCLUSION

All patients achieved complete union and eradication of infection. The results were evaluated according to Association for the Study of the Method of Ilizarov criteria: 83% were excellent and 17% were good in terms of bony outcomes; functional results were excellent in 50%, good in 42%, and fair in 8%. Combined Ilizarov/TSF trifocal and bifocal techniques for the treatment of segmental tibial bone defects achieve union without malalignment of the mechanical axis.

Enhancement of bone formation during distraction osteogenesis: pediatric applications

Delayed bone healing during distraction osteogenesis negatively affects clinical outcome. In addition to autologous bone grafting, several mechanical, chemical, biologic, and external treatment modalities may be employed to promote bone growth during distraction osteogenesis in the pediatric patient. Mechanical approaches include compressive loading of the distraction regenerate, increased frequency of small increments of distraction, and compression-distraction. Intramedullary nailing and submuscular plating can reduce the time in external fixation; however, these techniques are associated with technical difficulties and complications. Exogenous application of low-intensity pulsed ultrasound or pulsed electromagnetic fields may shorten the duration of external fixation. Other promising modalities include diphosphonates, physician-directed use (off-label use) of bone morphogenetic proteins, and local injection of bone marrow aspirate and platelet gel at the osteotomy site. Well-designed clinical studies are needed to establish safe and effective guidelines for various modalities to enhance new bone formation during distraction osteogenesis in children.

Autologous bone graft: when shall we add growth factors?

Although the unquestionable value of autologous bone grafting and the analogous value of the reaming by-products in nonunion treatment have been mentioned extensively in the literature, there is ongoing vivid discussion for the treatment of those case scenarios where the fracture nonunion is complicated by other local environment adverse circumstances. The graft expansion with growth factors as the bone morphogenetic proteins (BMPs) offers the possibility to reduce the number of operative procedures, complications, length of hospital stay, and time to union. In this article, we consider the potential clinical scenarios for graft expansion with BMPs.

Bone transport and compression-distraction in the treatment of bone loss of the lower limbs

A clinical series of 17 adult patients operated due to significant by bone loss of the long bones of the lower extremity (3 femurs and 11 tibias), is presented. Their management consisted of 6 bone transports (6 tibias) and 11 compression distraction procedures (3 femurs and 8 tibiae) using monolateral external fixators. Bone loss ranged from 3.9 cm to 14.7 cm. Mean healing time was 301 days with a mean healing index of 45.6 days for cm of lengthening achieved. The clinical and radiological results were excellent in 9, good in 6 and fair in 2 patients according to the utilised criteria of assessment. Consolidation was achieved in all but one patient who developed an aseptic stiff non-union. Two patients developed residual limb-length discrepancy less than 1.5 cm, three tibias ended up with less than 5° of valgus deviation. In two cases the half-pins were re-inserted due to early loosening. In two cases reoperation was needed for late bending of the callus after fixator removal. Three cases of bone transport and 1 case of compression distraction needed bone grafting at the docking site. Bone transport and compression-distraction are effective methods for treating bone loss in the lower extremity. It is suggested that the compression-distraction technique is preferable, since this is associated with a lower incidence of complications than bone transport procedures. The deciding factor, however, is the actual extent of the bone loss.

Autologous bone graft: when shall we add growth factors?

Although the unquestionable value of autologous bone grafting and the analogous value of the reaming by-products in nonunion treatment have been mentioned extensively in the literature, there is ongoing vivid discussion for the treatment of those case scenarios where the fracture nonunion is complicated by other local environment adverse circumstances. The graft expansion with growth factors as the bone morphogenetic proteins (BMPs) offers the possibility to reduce the number of operative procedures, complications, length of hospital stay, and time to union. In this article, we consider the potential clinical scenarios for graft expansion with BMPs.