Distraction osteogenesis in management of composite bone and soft tissue defects

An unusual case of traumatic injury to the first metatarsal a case report

A 44-year-old male sustained trauma to his foot leading to a 5-cm defect of the first metatarsal bone and infection of the bone by Staphylococcus aureus. Osteotomy is the most suitable method for treating large metatarsal defects complicated with osteomyelitis, however few reports have been published on this challenging approach. In this case, osteotomy and external fixation for distraction were performed. Finally, the osteomyelitis of the patient was well controlled, the bone length was restored, and the patient could carry weight completely, and the treatment effect was satisfactory.

Long Bone Defect Filling with Bioactive Degradable 3D-Implant: Experimental Study

Previously, 3D-printed bone grafts made of titanium alloy with bioactive coating has shown great potential for the restoration of bone defects. Implanted into a medullary canal titanium graft with cellular structure demonstrated stimulation of the reparative osteogenesis and successful osseointegration of the graft into a single bone-implant block. The purpose of this study was to investigate osseointegration of a 3D-printed degradable polymeric implant with cellular structure as preclinical testing of a new technique for bone defect restoration. During an experimental study in sheep, a 20 mm-long segmental tibial defect was filled with an original cylindrical implant with cellular structure made of polycaprolactone coated with hydroxyapatite. X-ray radiographs demonstrated reparative bone regeneration from the periosteum lying on the periphery of cylindrical implant to its center in a week after the surgery. Cellular structure of the implant was fully filled with newly-formed bone tissue on the 4th week after the surgery. The bone tissue regeneration from the proximal and distal bone fragments was evident on 3rd week. This provides insight into the use of bioactive degradable implants for the restoration of segmental bone defects. Degradable implant with bioactive coating implanted into a long bone segmental defect provides stimulation of reparative osteogenesis and osseointegration into the single implant-bone block.

Skeletal regeneration for segmental bone loss: Vascularised grafts, analogues and surrogates

Massive segmental bone defects (SBD) are mostly treated by removing the fibula and transplanting it complete with blood supply. While revolutionary 50 years ago, this remains the standard treatment. This review considers different strategies to repair SBD and emerging potential replacements for this highly invasive procedure. Prior to the technical breakthrough of microsurgery, researchers in the 1960s and 1970s had begun to make considerable progress in developing non autologous routes to repairing SBD. While the breaktthrough of vascularised bone transplantation solved the immediate problem of a lack of reliable repair strategies, much of their prior work is still relevant today. We challenge the assumption that mimicry is necessary or likely to be successful and instead point to the utility of quite crude (from a materials technology perspective), approaches. Together there are quite compelling indications that the body can regenerate entire bone segments with few or no exogenous factors. This is important, as there is a limit to how expensive a bone repair can be and still be widely available to all patients since cost restraints within healthcare systems are not likely to diminish in the near future. STATEMENT OF SIGNIFICANCE: This review is significant because it is a multidisciplinary view of several surgeons and scientists as to what is driving improvement in segmental bone defect repair, why many approaches to date have not succeeded and why some quite basic approaches can be as effective as they are. While there are many reviews of the literature of grafting and bone repair the relative lack of substantial improvement and slow rate of progress in clinical translation is often overlooked and we seek to challenge the reader to consider the issue more broadly.

An alternative therapeutic strategy for infected large bone defect and massive soft-tissue loss of leg-is free flap reconstruction inevitable?

PURPOSE

This study aims to report the clinical and radiographic outcomes of a non-flap therapeutic strategy for the limb salvage of infected composite bone and soft-tissue defects of a leg, attempting to describe some new techniques regards the docking of bone ends.

METHODS

Twelve patients with infected large tibial bone defect (mean size 12.1 ± 2.8 cm) and massive soft-tissue loss (mean size 254.5 ± 60.2 cm²) who were treated with the non-flap therapeutic strategy between 2014 and 2019 were retrospectively reviewed. Clinical and radiographic results were evaluated and analyzed. The results of bone and function were assessed by the Paley criteria. The exercise capacity of patients was evaluated based on the following four aspects: walking, running, jumping, squatting, and going up/down the stairs.

RESULTS

During the treatment, shortening and re-lengthening technique was applied in six patients, bone transport technique in 12, submarine technique (SMT) in six, balloon dilatation technique (BDT) in seven, and soft-tissue incarceration creating technique (SICT) in seven. The mean external fixation time (EFT) and external fixation index (EFI) were 675.6 ± 179.2 days (range, 366-1040 days) and 60.1 ± 13.9 days/cm (range, 47.0-95.5 days/cm), respectively. Soft-tissue defect was successfully repaired for all patients. After a mean follow-up of 43.5 ± 23.2 months (range, 13-103 months), bone result was classified as "excellent" in ten patients, as "good" in one and "poor" in one, while functional result was graded as "excellent" in four patients and "good" in eight.

CONCLUSIONS

The non-flap therapeutic strategy could be cautiously considered as an alternative treatment for the large lower limb composite defects.

Adrenomedullin 2 improves bone regeneration in type 1 diabetic rats by restoring imbalanced macrophage polarization and impaired osteogenesis

Background

Both advanced glycation end products (AGEs) and AGE-mediated M1 macrophage polarization contribute to bone marrow mesenchymal stem cell (BMSC) dysfunction, leading to impaired bone regeneration in type 1 diabetes mellitus (T1DM). Adrenomedullin 2 (ADM2), an endogenous bioactive peptide belonging to the calcitonin gene-related peptide family, exhibits various biological activities associated with the inhibition of inflammation and reduction of insulin resistance. However, the effects and underlying mechanisms of ADM2 in AGE-induced macrophage M1 polarization, BMSC dysfunction, and impaired bone regeneration remain poorly understood.

Methods

The polarization of bone marrow-derived macrophages was verified using flow cytometry analysis. Alkaline phosphatase (ALP) staining, ALP activity detection, and alizarin red staining were performed to assess the osteogenesis of BMSCs. Quantitative real-time polymerase chain reaction, enzyme-linked immunosorbent assay, western blotting, and immunofluorescence staining were used to assess polarization markers, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling, and osteogenic markers. In vivo, a distraction osteogenesis (DO) rat model with T1DM was established, and tibia samples were collected at different time points for radiological, biomechanical, and histological analyses, to verify the effects of ADM2 on bone regeneration and M2 polarization under diabetic conditions.

Results

ADM2 treatment reversed AGE-induced M1 macrophage polarization towards the M2 phenotype, which was partially achieved by the peroxisome proliferator-activated receptor γ (PPARγ)-mediated inhibition of NF-κB signaling. The PPARγ inhibitor GW9662 significantly attenuated the effects of ADM2. Besides, ADM2 treatment improved the AGE-impaired osteogenic potential of BMSCs in vitro. Furthermore, ADM2 accelerated bone regeneration, as revealed by improved radiological and histological manifestations and biomechanical parameters, accompanied by improved M2 macrophage polarization in diabetic DO rats, and these effects were partially blocked by GW9662 administration.

Conclusions

These results indicate that ADM2 enhances diabetic bone regeneration during DO, by attenuating AGE-induced imbalances in macrophage polarization, partly through PPARγ/NF-κB signaling, and improving AGE-impaired osteogenic differentiation of BMSCs simultaneously. These findings reveal that ADM2 may serve as a potential bioactive factor for promoting bone regeneration under diabetic conditions, and imply that management of inflammation and osteogenesis, in parallel, may present a promising therapeutic strategy for diabetic patients during DO treatment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-021-02368-9.

Overview of methods for enhancing bone regeneration in distraction osteogenesis: Potential roles of biometals

BACKGROUND

Distraction osteogenesis (DO) is a functional tissue engineering approach that applies gradual mechanical traction on the bone tissues after osteotomy to stimulate bone regeneration. However, DO still has disadvantages that limit its clinical use, including long treatment duration.

METHODS

Review the current methods of promoting bone formation and consolidation in DO with particular interest on biometal.

RESULTS

Numerous approaches, including physical therapy, gene therapy, growth factor-based therapy, stem-cell-based therapy, and improved distraction devices, have been explored to reduce the DO treatment duration with some success. Nevertheless, no approach to date is widely accepted in clinical practice due to various reasons, such as high expense, short biologic half-life, and lack of effective delivery methods. Biometals, including calcium (Ca), magnesium (Mg), zinc (Zn), copper (Cu), manganese (Mn), and cobalt (Co) have attracted attention in bone regeneration attributed to their biodegradability and bioactive components released during in vivo degradation.

CONCLUSION

This review summarizes the current therapies accelerating bone formation in DO and the beneficial role of biometals in bone regeneration, particularly focusing on the use of biometal Mg and its alloy in promoting bone formation in DO. Translational potential: The potential clinical applications using Mg-based devices to accelerate DO are promising. Mg stimulates expression of multiple intrinsic biological factors and the development of Mg as an implantable component in DO may be used to argument bone formation and consolidation in DO.

Reconstruction of massive tibial bone and soft tissue defects by trifocal bone transport combined with soft tissue distraction: experience from 31 cases

BACKGROUND

Large post-traumatic tibial bone defects combined with soft tissue defects are a common orthopedic clinical problem associated with poor outcomes when treated using traditional surgical methods. The study was designed to investigate the safety and efficacy of trifocal bone transport (TFT) and soft-tissue transport with the Ilizarov technique for large posttraumatic tibial bone and soft tissue defects.

METHODS

We retrospectively reviewed 31 patients with massive posttraumatic tibial bone and soft tissue defects from May 2009 to May 2016. All of the eligible patients were managed by TFT and soft-tissue transport. The median age was 33.4 years (range, 2-58 years). The mean defect of bone was 11.87 cm ± 2.78 cm (range, 8.2-18.2 cm) after radical resection performed by TFT. The soft tissue defects ranged from 7 cm × 8 cm to 24 cm × 12 cm. The observed results included bone union time, wound close time and true complications. The Association for the Study and Application of the Method of Ilizarov (ASAMI) scoring system was used to assess bone and functional results and postoperative complications were evaluated by Paley classification.

RESULTS

The mean duration of follow-up after frame removal was 32 months (range, 12-96 months). All cases achieved complete union in both the elongation sites and the docking sites, and eradication of infection. The mean bone transport time was 94.04 ± 23.33 days (range, 63.7-147 days). The mean external fixation time was 22.74 ± 6.82 months (range, 14-37 months), and the mean external fixation index (EFI) was 1.91 ± 0.3 months/cm (range, 1.2-2.5 months/cm). The bone results were excellent in 6 patients, good in 14 patients, fair in 8 patients and poor in 3 patients. The functional results were excellent in 8 patients, good in 15 patients, fair in 5 patients and poor in 3 patients.

CONCLUSION

TFT, in conjunction with soft tissue transport technique, can give good results in most patients (in this article, good and excellent results were observed in 64% of patients). Soft tissue transport is a feasible method in providing good soft tissue coverage on the bone ends. Although it has no advantages over microvascular techniques, it might be an good alternative in the absence of an experienced flap surgeon. Nonetheless, high-quality controlled studies are needed to assess its long-term safety and efficacy.

Bone Transport for Treatment of Traumatic Composite Tibial Bone and Soft Tissue Defects: Any Specific Needs besides the Ilizarov Technique?

Objective

To evaluate the surgical efficacy of bone transport (Ilizarov technique) plus “shortening-lengthening,” “flap surgery,” and “open bone transport” as individualized treatments for traumatic composite tibial bone and soft tissue defects.

Methods

We retrospectively analyzed sixty-eight cases (mean age: 35.69 years, (range, 16–65)) treated from July 2014 to June 2017, including 29 middle, 18 distal, and 21 proximal tibial bone defects (4–18 cm, mean: 7.97 cm) with soft tissue defects (2.5 cm × 4.0 cm to 30.0 cm × 35.0 cm after debridement). We adopted the bone transport external fixator to fix the fracture after debriding the defect parts. In the meantime, we adopted the “shortening-lengthening technique,” “flap surgery,” and “open bone transport” as individualized treatment based on the location, range, and severity of the composite tibial bone and soft tissue defects. Postoperative follow-up was carried out. Surgical efficacy was assessed based on (1) wound healing; (2) bone defect healing rate; (3) external fixation time and index; (4) incidence/recurrence of deep infection; (5) postoperative complications; and (6) Association for the Study and Application of the Methods of Ilizarov (ASAMI) score.

Results

The mean duration from injury to reconstruction was 22 days (4–80 d), and the mean postoperative follow-up period was 30.8 months (18–54 m). After the repair and reconstruction, 2 open bone transport patients required infected bone removal first before continuing the bone transport treatment. No deep infection (osteomyelitis) occurred or recurred in the remaining patients, and no secondary debridement was required. Some patients had complications after surgery. All the postoperative complications, including flap venous crisis, nail channel reaction, bone nonunion, mechanical axis deviation, and refracture, were improved or alleviated. External fixation time was 12.5 ± 3.41 months, and the index was 1.63 ± 0.44. According to the ASAMI score, 76.47% of the outcomes were good/excellent.

Conclusion

The Ilizarov technique yields satisfactory efficacy for composite tibial bone and soft tissue defects when combined with “shortening-lengthening technique,” “flap surgery,” and “open bone transport” with appropriate individualized treatment strategies.

Similarities and Differences of Induced Membrane Technique Versus Wrap Bone Graft Technique

BACKGROUND

There are no reports on the similarities and differences between induced membrane (IM) technique and wrap bone graft(WBG) technique.

OBJECTIVE

The aims of this study are to investigate the effects of IM technique and WBR technique in repairing segmental bone defects, and to analyze the similarities and differences between them.

MATERIALS AND METHODS

66 patients of tibial segmental bone defects treated by IM technique and WBG technique were retrospectively analyzed. Aged 13-69 years old with an average of 35.3 years old. IM technique was divided into early IM group (bone grafting at 6-8 weeks of bone cement filling) and late IM group (bone grafting after 8 weeks of bone cement filling). WBG was divided into titanium mesh group and line suturing cortical bone blocks group. There were 11 cases, 25 cases, 10 cases and 20 cases in the early IM group, late IM group, titanium mesh group and line suturing group, respectively. Bone healing, complications and functional recovery (Paley's method) were observed, the causes of nonunion and delayed union and factors affecting bone healing were analyzed.

RESULTS

There were no significant differences in terms of age, sex, defect length, course, fixation method, defect location and preoperative function of adjacent joints among the 4 groups. All patients were followed up for 12-50 months, with an average of 20.1 months. The clinical healing time of early IM group, late IM group, titanium mesh group and line suturing group were (5.81 ± 0.75) months, (7.56 ± 1.66) months, (7.50 ± 0.70) months and (7.81 ± 1.81) months, respectively, showing significant differences among the 4 groups (P = 0.005). However, only early IM group had significant difference with other groups (P < 0.05), while no significance was found between late IM group and WBR group, between titanium mesh group and suture group (P > 0.05). There were no significant differences in healing ration, complications and functional recovery of adjacent joints among the 4 groups (P > 0.05). There were 4 cases of nonunion and delayed union, all of which were caused by poor quantity or quality of bone graft or unstable bone graft or internal fixation.

CONCLUSION

Both IM technique and WBG technique are effective method for repairing segmental bone defects. In addition to mechanical encapsulation, early IM has biological osteogenesis. However, mechanical encapsulation is a common basis for repairing bone defects, and biological osteogenesis can enhance bone healing.

Bifocal Compression-Distraction for Combined Bone and Soft-Tissue Defects in Post-traumatic Tibial Nonunion

OBJECTIVE

To compare 2 distraction osteogenesis techniques in post-traumatic tibial nonunion patients with composite bone and soft-tissue defects.

DESIGN

Nonrandomized prospective, case series, single-center study.

SETTING

Department of Orthopaedics and Traumatology, Limb Reconstruction Unit, El-Helal hospital, Cairo, Egypt.

PARTICIPANTS

Fifty post-traumatic tibial nonunion patients with composite bone and soft-tissue defects.

INTERVENTION

Twenty-five patients were treated using bone transport (BT) technique, and 25 patients were treated using acute shortening (AS) and distraction technique.

OUTCOME MEASUREMENTS

The external fixation index (EFI); functional and bone results; and complication rates.

RESULTS

All patients were followed for a minimum of 18 months after removal of their Ilizarov frame. AS and BT groups were followed up for a mean of 19.7 and 20.3 months, respectively. The mean bone gap after resection and debridement was 4 cm in AS group and 5.9 cm in BT group (P = 0.06). The mean EFI was statistically significant and lower in the AS group compared with BT group (P = 0.03). There were no other statistically significant differences between either intervention groups.

CONCLUSIONS

Both techniques achieved comparable good to excellent results, and the differences in number of complications and ASAMI scores for bone or function were not statistically significant. Yet, it appears that the AS technique may be superior because it has a significantly lower EFI. This may not be feasible in all cases, however, because the AS technique is limited by the defect size and the condition of the surrounding soft tissues.

LEVEL OF EVIDENCE

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

All-Trans Retinoic Acid Promotes Osteogenic Differentiation and Bone Consolidation in a Rat Distraction Osteogenesis Model

Distraction osteogenesis (DO) is used to treat specific disorders associated with growth abnormalities and/or loss of bone stock secondary to trauma or disease. However, a high rate of complications and discomfort hamper its further application in clinical practice. Here, we investigated the effects of all-trans retinoic acid (ATRA) on osteogenic differentiation of rat bone marrow-derived mesenchymal stem cells (rBMSCs) and bone consolidation in a rat DO model. Different doses of ATRA were used to treat rBMSCs. Cell viability and osteogenic differentiation were assessed using CCK-8 and alkaline phosphatase staining, respectively. The mRNA expression of osteogenic differentiation-genes (including ALP, Runx2, OCN, OPN, OSX, and BMP2) and angiogenic genes (including VEGF, HIF-1, FLK-2, ANG-2, and ANG-4) were determined by quantitative real-time PCR analysis. Further, we locally injected ATRA or PBS into the gap in the rat DO model every 3 days until termination. X-rays, micro-computed tomography (Micro-CT), mechanical testing, and immunohistochemistry stains were used to evaluate the quality of the regenerates. ATRA promoted osteogenic differentiation of rBMSCs. Moreover, ATRA elevated the mRNA expression levels of osteogenic differentiation-genes and angiogenic genes. In the rat model, new bone properties of bone volume/total tissue volume and mechanical strength were significantly higher in the ATRA-treatment group. Micro-CT examination showed more mineralized bone after the ATRA-treatment, and immunohistochemistry demonstrated more new bone formation after ATRA-treatment than that in the PBS group. In conclusion, as a readily available and very cost effective bio-source, ATRA may be a novel therapeutic method to enhance bone consolidation in the clinical setting.

A Successful Limb Salvage of an Electrical Burned Patient With Extensive Soft Tissue and Femoral Bone Necrosis

Severe electrical injury presents a formidable therapeutic challenge for surgeons because of the requirement for complex soft tissue and bony reconstruction to restore functionality of the injured area. The authors report on the limb salvage procedure for a patient with extensive soft tissue and femoral bone necrosis from a high-voltage electrical burn. The right thigh and knee were burned, resulting in large areas of muscle necrosis and a long segment of distal femur exposure and necrosis. Complete debridement of the area resulted in a 20 × 35 cm soft tissue defect and an 18-cm long distal femoral bone defect. The wound was repaired through latissimus dorsi muscle transplantation and bony reconstruction using the sequential Ilizarov osteogenesis method. The injured limb was retained, and the functional recovery of the patient's leg was satisfactory. This experience indicates that the combination of flap transplantation and the Ilizarov osteogenesis method are good options for the treatment of large soft tissue and huge segmental bony defects.

[Discussion on dealing skills of complex soft tissue problems in osteomyelitis treated by Ilizarov technique]

Objective

To discuss skills for the treatment of complex soft tissue problems in osteomyelitis using Ilizarov techniques.

Methods

The clinical data of 31 patients with complex soft tissue problems during the treatment of osteomyelitis with Ilizarov technique between January 2015 and June 2017 were retrospectively analyzed. There were 23 males and 8 females, with an age of 14-67 years (mean, 37.8 years). All the patients were post-traumatic chronic osteomyelitis, the disease duration was 12 days to 16 months (mean, 6.3 months). They went through 2-8 times surgeries (mean, 3.8 times). There were 29 cases of soft tissue insertion after bone grafting; 1 case of strephopodia and calcaneal osteomyelitis with plantar skin infection defect; 1 case of the open tibial fracture postoperative infection, the skin defect of infection was more than that of bone defect. The soft tissue defect area was 4.5 cm×4.0 cm to 16.5 cm×8.5 cm. Soft tissue depression and insertion was corrected by subcutaneous insertion of Kirschner wire after slow elastic retraction. Soft tissue defects were gradually resolved through slow traction.

Results

All patients were followed up 6-24 months (mean, 11.5 months). All wounds healed by first intention, and skin graft and flap repair were not performed in the two stage. One case of strephopodia and calcaneal osteomyelitis with plantar skin infection defect was treated with slow skin traction, no secondary suture was performed; no skin ulceration was found after walking for 3 months, and the feeling was slightly lower than normal. One case of soft tissue transverse traction wound completely covered, with no bone exposure and no obvious pigmentation of local soft tissue, the feeling was slightly lower than normal, the skin elasticity was worse than normal, and the color, temperature had no obvious abnormalities. There was no severe needle eye reactions in 29 patients with skin depressions corrected by Kirschner wire. Six cases of Kirschner wire showed elastic retraction and lacerate skin; 1 case of plantar skin traction had 2 times of exudation of the needle eye and local skin reddish phenomenon; the symptoms relieved when the traction needle was changed once, the traction was stopped for 1 week, the dressing was changed and antibiotics were used once. One patient with transverse traction had 3 times of pin-eye infection, and the treatment was completed after adjusting the traction device and symptomatic treatment.

Conclusion

For most of the complex soft tissue problems in osteomyelitis, early and effective intervention with Ilizarov technique can be easily, economically, and effectively solved, which provides a new way for clinical treatment.

Management of extra-articular segmental defects in long bone using a titanium mesh cage as an adjunct to other methods of fixation

Aims

This study reviews the use of a titanium mesh cage (TMC) as an adjunct to intramedullary nail or plate reconstruction of an extra-articular segmental long bone defect.

Patients and Methods

A total of 17 patients (aged 17 to 61 years) treated for a segmental long bone defect by nail or plate fixation and an adjunctive TMC were included. The bone defects treated were in the tibia (nine), femur (six), radius (one), and humerus (one). The mean length of the segmental bone defect was 8.4 cm (2.2 to 13); the mean length of the titanium mesh cage was 8.3 cm (2.6 to 13). The clinical and radiological records of the patients were analyzed retrospectively.

Results

The mean time to follow-up was 55 months (12 to 126). Overall, 16 (94%) of the patients achieved radiological filling of their bony defect and united to the native bone ends proximally and distally, resulting in a functioning limb. Complications included device failure in two patients (12%), infection in two (12%), and wound dehiscence in one (6%). Four patients (24%) required secondary surgery, four (24%) had a residual limb-length discrepancy, and one (6%) had a residual angular limb deformity.

Conclusion

A titanium mesh cage is a useful adjunct in the treatment of an extra-articular segmental defect in a long bone. Cite this article: Bone Joint J 2018;100-B:646–51.

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.

Porcine brain extract promotes osteogenic differentiation of bone marrow derived mesenchymal stem cells and bone consolidation in a rat distraction osteogenesis model

Distraction osteogenesis (DO) is the gold standard to treat large bone defects, but long consolidation period is a major limitation. Innovative efforts to promote osteogenesis are needed. Porcine brain extract (PBE) was reported to enhance the proliferation and differentiation of multiple primary cells. In this study, we aimed to develop a method for collecting PBE and investigate its effects on osteogenic differentiation of rat bone marrow derived mesenchymal stem cells (rBMSCs) and bone consolidation in a rat DO model. The PBE was collected from neonatal brain tissues of porcine fetus and was used to treat rBMSCs. Following PBE treatment (700 ng/ml), osteogenic differentiation was assessed. Further, we locally injected PBE (7 μg/ml, 100μl) or PBS (100μl) into the gap in a Sprague-Dawley (SD) male rat DO model every three days till termination. X-rays, micro-computed tomography, mechanical testing, histology and immunohischemistry examinations were used to exam the quality of the regenerates. The alkaline phosphatase, calcium deposits, and steogenic markers in the PBE treated rBMSCs were significantly increased. In the rat model, new bone properties of bone volume/total tissue volume and mechanical strength were higher in the PBE treated group. Histological analysis also confirmed more mineralized bone after PBE treatment. The current study reports a standard protocol for PBE collection and demonstrated its positive effects on osteogenic differentiation and bone consolidation in DO. Since the PBE is readily available and very cost effective, PBE may be a potential new bio-source to promote bone formation in patients undergo DO treatment.

Treatment Options for Nonunion With Segmental Bone Defects: Systematic Review and Quantitative Evidence Synthesis

OBJECTIVES

To determine which reconstruction treatment of long bones nonunion with segmental bone defects (SBDs) is effective to restore bone length and union with good function.

DATA SOURCES

PubMed was used to identify published literature on treatment of SBD caused by fracture nonunion regardless of infection between January 1975 and December 2014.

STUDY SELECTION

We included retrospective cohort studies with a minimum sample size of 10 consecutive patients with minimum follow-up of 18 months and available data on radiographic and functional outcomes.

DATA EXTRACTION

Literature review revealed 24 publications with a sample size of 504 patients (395 males, 109 females). Data on bone union and functional outcome and complications were collected and analyzed based on validated classification systems.

DATA SYNTHESIS

Two outcome groups were categorized for bone union and functional outcome, success, and failure. We then performed heterogeneity test to examine the variability or differences in the methods used by these studies and based on that we determined whether the fixed effect or random effect method is appropriate in examining the summary or pool estimate. Pool estimate was examined for bone union and functional outcome in each surgical modality and in each anatomic location when data were available.

CONCLUSIONS

Treatment of SBD can be challenging. This quantitative evidence synthesis shows that bone union was achieved by different procedures with variable bone union and functional outcomes.

LEVEL OF EVIDENCE

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

Unhappy triad in limb reconstruction: Management by Ilizarov method

AIM

To evaluate the results of the Ilizarov method in management of cases with bone loss, soft tissue loss and infection.

METHODS

Twenty eight patients with severe leg trauma complicated by bone loss, soft tissue loss and infection were managed by distraction osteogenesis in our institution. After radical debridement of all the infected and dead tissues the Ilizarov frame was applied, corticotomy was done and bone transport started. The wounds were left open to drain. Partial limb shortening was done in seven cases to reduce the size of both the skeletal and soft tissue defects. The average follow up period was 39 mo (range 27-56 mo).

RESULTS

The infection was eradicated in all cases. All the soft tissue defects healed during bone transport and plastic surgery was only required in 2 cases. Skeletal defects were treated in all cases. All patients required another surgery at the docking site to fashion the soft tissue and to cover the bone ends. The external fixation time ranged from 9 to 17 mo with an average of 13 mo. The complications included pin tract infection in 16 cases, wire breakage in 2 cases, unstable scar in 4 cases and chronic edema in 3 cases. According to the association for study and application of methods of Ilizarov score the bone results were excellent in 10, good in 16 and fair in 2 cases while the functional results were excellent in 8, good in 17 and fair in 3 cases.

CONCLUSION

Distraction osteogenesis is a good method that can treat the three problems of this triad simultaneously.

Clinical evaluation of patients submitted to osteogenic distraction in the lower limb at a university hospital

Objective

To evaluate the clinical characteristics from patients submitted to osteogenic distraction to correct bone gap at a university hospital.

Methods

Retrospective transversal study, with a convenience sample, from 2000 to 2012, evaluating clinical aspects of patients treated, submitted to osteogenic distraction (bone transport) with Ilizarov's external fixation device. The chi-squared, Fisher's, and Mann–Whitney's U tests were used with a 5% level of significance (p < 0.05).

Results

33 patients were studied, of whom 28 men (84.8%). The more frequent age was from 21 to 40 years. Most patients were from the metropolitan region of the capital (57.6%). The leg was the most affected limb (75.8%), and the left side was the most affected (66.7%). The most common cause was infected pseudoarthrosis (75.8%). The most common bone transportation type was bifocal (75.8%). Mean previous surgery at others institutions were 2.62 (1.93 standard deviation), and mean surgeries after treatment were 1.89 (1.29 standard deviation). Ilizarov's external fixation device was used for 1.94 years (1.34 mean deviation), from one to six years. The most common complications were pin infection (57.6%), equinus (30.3%), deep infection (24.2%), and shortening (21.2%).

Conclusion

Osteogenic distraction for bone gaps were more frequent in young adults, men, in the leg, with bifocal transportation, after several previous surgeries, treated for a mean of two years, with many complications (infections were the most common).

Placement-induced effects on high tibial osteotomized construct - biomechanical tests and finite-element analyses

BACKGROUND

High tibial osteotomy (HTO) with a medially opening wedge has been used to treat osteoarthritic knees. However, the osteotomized tibia becomes a highly unstable structure and necessitates the use of plate and screws to stabilize the medial opening and enhance bone healing. A T-shaped plate (e.g. TomoFix) with locking screws has been extensively used as a stabilizer of the HTO wedge. From the biomechanical viewpoint, however, the different plate sites and support bases of the HTO plate should affect the load-transferring path and wedge-stabilizing ability of the HTO construct. This study uses biomechanical tests and finite-element analyses to evaluate the placement- and base-induced effects of the HTO plates on construct performance.

METHODS

Test-grade synthetic tibiae are chosen as the standard specimens of the static tests. A medial wedge is created for each specimen and stabilized by three plate variations: hybrid use of T- and I-shaped plates (TIP), anteriorly placed TomoFix (APT), and medially placed TomoFix (MPT). There are five tests for each variation. The failure loads of the three constructs are measured and used as the load references of the fatigue finite-element analysis. The residual life after two hundred thousand cycles is predicted for all variations.

RESULTS

The testing results show no occurrence of implant back-out and breakage under all variations. However, the wedge fracture consistently occurs at the opening tip for the APT and MPT and the medially resected plateau for the TIP, respectively. The testing results reveal that both failure load and wedge stiffness of the TIP are the highest, followed by the MPT, while those of the APT are the least (P < 0.05). The fatigue analyses predict comparable values of residual life for the TIP and MPT and the highest value of damage accumulation for the APT. Both experimental and numerical tests show the biomechanical disadvantage of the APT than their counterparts. However, the TIP construct without locking screws shows the highest stress at the plate-screw interfaces.

CONCLUSIONS

This study demonstrates the significant effect of placement site and support base on the construct behaviors. The TIP provides a wider base for supporting the HTO wedge even without the use of locking screws, thus significantly enhancing construct stiffness and suppressing wedge fracture. Compared to the APT, the MPT shows performance more comparable to that of the TIP. If a single plate and a smaller incision are considered, the MPT is recommended as the better alternative for stabilizing the medial HTO wedge.

Segmental bone loss in pediatric lower extremity fractures: indications and results of bone transport

BACKGROUND

In this study, we evaluated the results of external bone transport, which was applied to 11 patients with traumatic bone loss who had not completed their bone development.

METHODS

The average age of the 9 male and 2 female patients was 10.6 (range, 8 to 16) years. Eight of the defects were located in the tibia, whereas the other 3 were in the femur. The average defect was 5.4 (range, 4.5 to 8.5) cm. External bone transport was applied in the early period in 7 patients, whereas in 4 patients it was performed due to nonunion. Bifocal osteosynthesis and single osteotomy were performed in 2 patients with type B2 nonunion. Compression to the nonunion region and lengthening in the osteotomy region were applied. In 2 patients with type B1 nonunion, and the other 9 patients who had external bone transport, the gap was eliminated by bifocal osteosynthesis, single osteotomy, and bone transport to the osteotomy line.

RESULTS

The mean follow-up period was 21 (range, 13 to 48) months. Complete union was achieved in all patients without any bone operation or graft application. No refracture was observed after the removal of the external fixator, and the average hospitalization time was 16 (range, 7 to 65) days. The average external fixation time was 4.2 (range, 3.5 to 5.5) months, and the mean external fixator index was 0.8 months (23 d/cm). The mean bone healing time was 5.1 (range, 4.6 to 6) months.

CONCLUSIONS

To initially consider the open fractures with true or in situ bone loss in children as "anticipated nonunion," and determine the treatment strategies regarding this fact, may prevent nonunion and shorten the healing period. Bone transport in the treatment of traumatic bone defects in children is an easy biological procedure, with lower complications but higher success ratios.

LEVEL OF EVIDENCE

Level IV-therapeutic.

Stress and stability comparison between different systems for high tibial osteotomies

BACKGROUND

High tibial osteotomy (HTO) with a medial opening wedge has been used to treat medial compartment osteoarthritis. However, this makes the proximal tibia a highly unstable structure and causes plate and screws to be the potentials sources for mechanical failure. Consequently, proper design and use of the fixation device are essential to the HTO especially for overweight or full weight-bearing patients.

METHODS

Based on the CT-based images, a tibial finite-element model with medial opening was simulated and instrumented with one-leg and two-leg plate systems. The construct was subjected to physiological and surgical loads. Construct stresses and wedge micromotions were chosen as the comparison indices.

RESULTS

The use of locking screws can stabilize the construct and decrease the implant and bone stresses. Comparatively, the two-leg design provides a wider load-sharing base to form a force-couple mechanism that effectively reduces construct stresses and wedge micromotions. However, the incision size, muscular stripping, and structural rigidity are the major concerns of using the two-leg systems. The one-leg plates behave as the fulcrum of the leverage system and make the wedge tip the zone of tension and thus have been reported to negatively affect the callus formation.

CONCLUSIONS

The choice of the HTO plates involved the trade-off between surgical convenience, construct stability, and stress-shielding effect. If the stability of the medial opening is the major concern, the two-leg system is suggested for the patients with heavy load demands and greater proximal tibial size. The one-leg system with locking screws can be used for the majority of the patients without heavy bodyweight and poor bone quality.

WITHDRAWN: Distraction osteogenesis using monolateral external fixator for post-traumatic skeletal defects of the femur

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Long bone reconstruction using multilevel lengthening of bone defect fragments

PURPOSE

This paper presents experimental findings to substantiate the use of multilevel bone fragment lengthening for managing extensive long bone defects caused by diverse aetiologies and shows its clinical introduction which could provide a solution for the problem of reducing the total treatment time.

METHODS

Both experimental and clinical multilevel lengthening to bridge bone defect gaps was performed with the use of the Ilizarov method only.

RESULTS

The experimental findings and clinical outcomes showed that multilevel defect fragment lengthening could provide sufficient bone formation and reduction of the total osteosynthesis time in one stage as compared to traditional Ilizarov bone transport. The method of multilevel regeneration enabled management of critical-size defects that measured on average 13.5 ± 0.7 cm in 78 patients.

CONCLUSIONS

The experimental and clinical results proved the efficiency of the Ilizarov non-free multilevel bone plasty that can be recommended for practical use.

Bone transport techniques in posttraumatic bone defects

INTRODUCTION

The treatment of posttraumatic diaphyseal bone defects (BD) calls on a number of techniques including bone transport techniques: isolated shortening, compression-distraction at the fracture site, shortening followed by lengthening in a corticotomy distant from the site and segmental bone transport.

PATIENTS AND METHODS

The multicenter retrospective study combined 38 cases: 22 cases of initial diaphyseal bone defect and 16 cases of secondary diaphyseal BD, sometimes associated with metaphyseal or metaphyseal-epiphyseal BD, involving the humerus, the forearm, the femur and the tibia. These techniques were mainly used on the lower extremity (33 cases), for the most part on the tibia (22 cases) in young men.

RESULTS

Bone healing was acquired in 37 cases out of 38 after a mean 14.9 months (range, 6-62 months). A mean 4.3 secondary interventions were required to obtain final union; most notably, a bone graft was necessary at the docking site for the segmental bone transport procedures.

DISCUSSION

Many reconstruction techniques can be proposed to treat posttraumatic BD. None responds to all situations. Bone transport techniques have their place and their indications. Isolated shortening is intended for bone loss not exceeding 3cm, notably in the humerus and to a lesser degree in the lower extremity. Shortening associated with lengthening is valuable in the femur and the tibia for bone loss up to 6cm. Segmental bone transport is the only technique that can treat bone defects associated with shortening in the lower limb. For substantial bone loss beyond 10cm, segmental bone transport is particularly indicated. However, these cases of substantial bone loss tend to be resolved by a hybridization of the procedures. The distraction gap of a bone segment can, for example, be prepared using an induced-membrane technique.

LEVEL OF EVIDENCE

Level IV. Retrospective study.

Transport distraction osteogenesis for maxillomandibular reconstruction: current concepts and applications

Reconstruction of the facial skeleton remains a herculean task for a reconstructive surgeon, even with the availability of ample reconstructive options. Transport distraction osteogenesis is a novel reconstructive modality in the armamentarium of a maxillofacial reconstructive surgeon with obvious advantages of osteogenesis and histogenesis from the residual host tissues after tumor ablative surgeries or trauma and also, precludes donor site morbidity. This paper reviews the current concepts, principles involved and applications of transport distraction osteogenesis in maxillomandibular reconstruction.

Enhancing bone healing during distraction osteogenesis with platelet-rich plasma

Gradual limb lengthening with external fixators using distraction osteogenesis principles is the gold standard for treatment of limb-length discrepancy. However, long treatment time is a major disadvantage of the current lengthening procedures. Efforts to decrease the treatment include biological and biomechanical factors. Injection of platelet-rich plasma (PRP) is a biological method to enhance bone healing during distraction osteogenesis. We hypothesised that PRP can enhance bone healing during limb lengthening. We report our experience with the use of PRP during distraction osteogenesis. This retrospective study included 19 patients divided into the standard group of 10 patients who did not receive PRP and the PRP group of nine patients who received PRP at the end of the distraction phase. The study variables included external fixator time, external fixation index, and complications during treatment. The PRP group had statistically significantly shorter treatment time (p=0.0412). Injection of PRP into regenerate bone might be an effective method to shorten treatment time during limb lengthening and lead to better functional outcomes and improved patient satisfaction.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

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.

Comparison of 39 post-traumatic tibia bone transports performed with and without the use of an intramedullary rod: the long-term outcomes

Bone transport can be performed with an external fixator alone or with the monorail technique which entails the combination of a fixator and an intramedullary nail. The purpose of this study was to compare the complication rates and long-term outcomes of these methods. Two groups of patients, the external fixator (n = 21) and the monorail group (n = 18), were compared. The average follow-up period was 7.9 ± 5.6 years and the mean defect length 8.3 ± 3.1 cm. Healing was achieved in 19 (90%) and 13 (72%) of the fixator and monorail patients, respectively. Six patients underwent amputations because of persistent infections (two in the fixator and four in the monorail group). The rate of deformities was significantly higher in the fixator group (p = 0.049). No statistically significant difference was found when comparing categories of the SF-36 test or the ability to work or do sports. The main advantages of the monorail method are reduction of the external fixation time and the lower rate of deformities. However, the authors recommend segmental transport with external fixator in patients with chronic infections.

Osteocutaneous thermal necrosis of the leg salvaged by TSF/Ilizarov reconstruction. Report of 7 patients

Injudicious reaming of the tibial shaft can lead to extreme local hyperthermia, which in turn can result in the rare but catastrophic complication of segmental bone and soft tissue necrosis (osteocutaneous thermal necrosis). This is a retrospective study showing osteocutaneous thermal necrosis occurring after tibial intramedullary reaming salvaged by Ilizarov reconstruction in seven patients from the collective experience of four limb reconstruction centres. All patients were males, with an average age of 51.8 years (range, 30-70 years), who had undergone intramedullary reaming during the treatment of closed tibial fractures. In all patients, circumferential bone and variable contiguous soft tissue necrosis developed a few days after reaming. Bone and soft tissue reconstruction was subsequently performed using a circular external fixator (Ilizarov apparatus or Taylor spatial frame) a mean of four months after injury in six patients; in one case, reconstruction was undertaken four years after the original injury. Two complications (secondary tissue breakdown at a bone transport site; premature consolidation) necessitated cessation of bone transport at one of two bone transport levels in two patients. All patients eventually healed with a good functional result after an average of 11.5 months in the fixator (range, 10-13 months).