Management of traumatic bone defects: Metaphyseal versus diaphyseal defects

Novel Bone Void Filling Cement Compositions Based on Shell Nacre and Siloxane Methacrylate Resin: Development and Characterization

Shell nacre from Pinctada species has been extensively researched for managing bone defects. However, there is a gap in the research regarding using shell nacre powder as a cement with improved biological and physicochemical properties. To address this, bone void filling cement was formulated by incorporating shell nacre powder and an organically modified ceramic resin (ormocer). The shell nacre powder was specifically processed from the shells of Pinctada fucata and analysed using thermogravimetric analysis (TGA), X-ray diffraction spectroscopy, Fourier transform infrared (FTIR), and Raman spectroscopy, confirming the presence of organic constituents and inorganic aragonite. Trace element analysis confirmed the eligibility of shell nacre powder for biomedical applications. Next, the ormocer SNLSM2 was synthesized through a modified sol-gel method. FTIR, Raman, TGA, and transmission electron microscopy studies revealed the presence of a ladder-structured siloxane backbone and methacrylate side chain. To develop chemical curable composite shell nacre cement (SNC), different amounts of shell nacre (24%, 48%, and 72%) were added to the SNLSM2 resin, and the impact on the physicochemical properties of the cement was studied. Among the compositions, SNC 72 exhibited significantly lower linear polymerization shrinkage (0.4%) and higher compressive (>100 MPa) and flexural strength (>35 MPa). SNC 72 was radiopaque, and the exotherm generated during the cement curing was minimal. Cytotoxicity studies with L929 cells revealed the non-cytotoxic nature of the cement. Overall, the findings of this study prove that the shell nacre cement is a promising candidate for managing bone voids.

Mechanical Distribution and New Bone Regeneration After Implanting 3D Printed Prostheses for Repairing Metaphyseal Bone Defects: A Finite Element Analysis and Prospective Clinical Study

Critical metaphyseal bone defects caused by nonunion and osteomyelitis are intractable to repair in clinical practice owing to the rigorous demanding of structure and performance. Compared with traditional treatment methods, 3D printing of customized porous titanium alloy prostheses offer feasible and safe opportunities in repairing such bone defects. Yet, so far, no standard guidelines for optimal 3D printed prostheses design and fixation mode have been proposed to further promote prosthesis stability as well as ensure the continuous growth of new bone. In this study, we used a finite element analysis (FEA) to explore the biomechanical distribution and observed new bone regeneration in clinical practice after implanting 3D printed prostheses for repairing metaphyseal bone defects. The results reflected that different fixation modes could result in diverse prosthesis mechanical conductions. If an intramedullary (IM) nail was applied, the stress mainly conducted equally along the nail instead of bone and prosthesis structure. While the stress would transfer more to the lateral bone and prosthesis’s body when the printed wing and screws are selected to accomplish fixation. All these fixation modes could guarantee the initial and long-term stability of the implanted prosthesis, but new bone regenerated with varying degrees under special biomechanical environments. The fixation mode of IM nail was more conducive to new bone regeneration and remodeling, which conformed to the Wolff’s law. Nevertheless, when the prosthesis was fixed by screws alone, no dense new callus could be observed. This fixation mode was optional for defects extremely close to the articular surface. In conclusion, our innovative study could provide valuable references for the fixation mode selection of 3D printed prosthesis to repair metaphyseal bone defect.

Technique and results after immediate orthotopic replantation of extracorporeally irradiated tumor bone autografts with and without fibular augmentation in extremity tumors

Background

Reconstruction of the skeletal defects resulting from the resection of bone tumors remains a considerable challenge and one of the possibilities is the orthotopic replantation of the irradiated bone autograft. One technical option with this technique is the addition of a vital autologous fibular graft, with or without microvascular anastomosis. The aim of our study was to evaluate the clinical results of the treatment of our patient cohort with a specific view to the role of fibular augmentation.

Methods

Twenty-one patients with 22 reconstructions were included. In all cases, the bone tumor was resected with wide margins and in 21 of them irradiated with 300 Gy. In the first case, thermal sterilization in an autoclave was used. The autograft was orthotopically replanted and stabilized with plates and screws. Fifteen patients underwent an additional fibular augmentation, 8 of which received microvascular anastomoses or, alternatively, a locally pedicled fibular interposition.

Results

the most common diagnosis was a Ewing sarcoma (8 cases) and the most common location was the femur (12 cases). The mean follow-up time was 70 months (16–154 months). For our statistical analysis, the one case with autoclave sterilization and 3 patients with tumors in small bones were excluded. During follow-up of 18 cases, 55.6% of patients underwent an average of 1.56 revision surgeries. Complete bony integration of the irradiated autografts was achieved in 88.9% of cases after 13.6 months on average. In those cases with successful reintegration, the autograft was shorter (n.s.). Microvascular anastomosis in vascularized fibular strut grafts did not significantly influence the rate of pseudarthrosis.

Conclusions

the replantation of extracorporeally irradiated bone autografts is an established method for the reconstruction of bone defects after tumor resection. Our rate of complications is comparable to those of other studies and with other methods of bone reconstruction (e.g. prosthesis). In our opinion, this method is especially well suited for younger patients with extraarticular bone tumors that allow for joint preservation. However, these patients should be ready to accept longer treatment periods.

S53P4 bioactive glass scaffolds induce BMP expression and integrative bone formation in a critical-sized diaphysis defect treated with a single-staged induced membrane technique

Critical-sized diaphysis defects are complicated by inherent sub-optimal healing conditions. The two-staged induced membrane technique has been used to treat these challenging defects since the 1980's. It involves temporary implantation of a membrane-inducing spacer and subsequent bone graft defect filling. A single-staged, graft-independent technique would reduce both socio-economic costs and patient morbidity. Our aim was to enable such single-staged approach through development of a strong bioactive glass scaffold that could replace both the spacer and the graft filling. We constructed amorphous porous scaffolds of the clinically used bioactive glass S53P4 and evaluated them in vivo using a critical-sized defect model in the weight-bearing femur diaphysis of New Zealand White rabbits. S53P4 scaffolds and standard polymethylmethacrylate spacers were implanted for 2, 4, and 8 weeks. Induced membranes were confirmed histologically, and their osteostimulative activity was evaluated through RT-qPCR of bone morphogenic protein 2, 4, and 7 (BMPs). Bone formation and osseointegration were examined using histology, scanning electron microscopy, energy-dispersive X-ray analysis, and micro-computed tomography imaging. Scaffold integration, defect union and osteosynthesis were assessed manually and with X-ray projections. We demonstrated that S53P4 scaffolds induce osteostimulative membranes and produce osseointegrative new bone formation throughout the scaffolds. We also demonstrated successful stable scaffold integration with early defect union at 8 weeks postoperative in critical-sized segmental diaphyseal defects with implanted sintered amorphous S53P4 scaffolds. This study presents important considerations for future research and the potential of the S53P4 bioactive glass as a bone substitute in large diaphyseal defects. STATEMENT OF SIGNIFICANCE: Surgical management of critical-sized diaphyseal defects involves multiple challenges, and up to 10% result in delayed or non-union. The two-staged induced membrane technique is successfully used to treat these defects, but it is limited by the need of several procedures and bone graft. Repeated procedures increase costs and morbidity, while grafts are subject to donor-site complications and scarce availability. To transform this two-staged technique into one graft-independent procedure, we developed amorphous porous scaffolds sintered from the clinically used bioactive glass S53P4. This work constitutes the first evaluation of such scaffolds in vivo in a critical-sized diaphyseal defect in the weight-bearing rabbit femur. We provide important knowledge and prospects for future development of sintered S53P4 scaffolds as a bone substitute.

Sol-Gel Synthesis, in vitro Behavior, and Human Bone Marrow-Derived Mesenchymal Stem Cell Differentiation and Proliferation of Bioactive Glass 58S

Background:

Bioactive glasses 58S, are silicate-based materials containing calcium and phosphate, which dissolved in body fluid and bond to the bone tissue. This type of bioactive glass is highly biocompatible and has a wide range of clinical applications.

Methods:

The 58S glass powders were synthesized via sol-gel methods, using tetraethyl orthosilicate, triethyl phosphate, and calcium nitrate, as precursors. Upon the analyses of phase and chemical structures of bioactive glass in different gelation times (12, 48, and 100 h), the appropriate heat treatment (at 525, 575, and 625 °C) was performed to eliminate nitrate compounds and stabilize the glass powder samples. The in vitro assay in SBF solution revealed the bioactivity of the synthesized 58S glass through the morphological (SEM), chemical structure (FTIR), release of calcium, phosphorous and silicon elements, pH variations, and weight loss measurements. The behavior of MSCs in the presence of bioactive glass powders was studied by MTT cytotoxicity, cell staining, ALP activity and biomineralization tests, as well as by the evaluation of ALP, osteocalcin, osteonectin, collagenI, and RUNX2 gene expression.

Results:

The results confirmed a gelation time of 100 h and a calcination temperature of 575 °C at optimal conditions for the synthesis of nitrate-free bioactive glass powders.

Conclusion:

The glass spherical nanoparticles in the range of 20-30 nm possess the improved bioactivity and osteogenic properties as demanded for bone tissue engineering.

Sol-Gel Synthesis, in vitro Behavior, and Human Bone Marrow-Derived Mesenchymal Stem Cell Differentiation and Proliferation of Bioactive Glass 58S

Background

Bioactive glasses 58S, are silicate-based materials containing calcium and phosphate, which dissolved in body fluid and bond to the bone tissue. This type of bioactive glass is highly biocompatible and has a wide range of clinical applications.

Methods

The 58S glass powders were synthesized via sol-gel methods, using tetraethyl orthosilicate, triethyl phosphate, and calcium nitrate, as precursors. Upon the analyses of phase and chemical structures of bioactive glass in different gelation times (12, 48, and 100 h), the appropriate heat treatment (at 525, 575, and 625 °C) was performed to eliminate nitrate compounds and stabilize the glass powder samples. The in vitro assay in SBF solution revealed the bioactivity of the synthesized 58S glass through the morphological (SEM), chemical structure (FTIR), release of calcium, phosphorous and silicon elements, pH variations, and weight loss measurements. The behavior of MSCs in the presence of bioactive glass powders was studied by MTT cytotoxicity, cell staining, ALP activity and biomineralization tests, as well as by the evaluation of ALP, osteocalcin, osteonectin, collagen I, and RUNX2 gene expression.

Results

The results confirmed a gelation time of 100 h and a calcination temperature of 575 °C at optimal conditions for the synthesis of nitrate-free bioactive glass powders.

Conclusion

The glass spherical nanoparticles in the range of 20-30 nm possess the improved bioactivity and osteogenic properties as demanded for bone tissue engineering.

[Bone transplantation or biomaterials? : An analysis of 99,863 surgical procedures in orthopedic and trauma surgery in Germany from 2018]

BACKGROUND

The aims of this study were (1) to analyze the total number of interventions with autologous or allogeneic bone transplantation as well as biomaterials, (2) to investigate the different types of biomaterials, autologous and allogeneic bone transplantations and (3) to analyze the additional use of an antibiotic additive in biomaterials.

METHODS

Data were obtained from the Federal Statistical Office for the year 2018. The surgery and procedure codes 5‑784 "bone transplantation and transposition" and 5‑785 "implantation of alloplastic bone substitutes" were used to analyze the procedure frequency of implantation of biomaterials, such as calcium phosphate ceramics, calcium sulphate, calcium phosphate cements and polymethyl methacrylate as well as autologous and allogeneic bone for defect reconstruction of the extremities and pelvis.

RESULTS

In 2018 a total of 99,863 procedures were performed using autografts (54,784, 55%), biomaterials (23,838, 24%) and allografts (21,241, 21%). For both autografts and allografts cancellous bone grafting was used most frequently (77% and 79%, respectively). For biomaterials, ceramics (42%) were used more frequently than bone cements (37%, other biomaterials 21%). In 16,027 cases (67%) with biomaterials no antibiotic supplement was used. Antibiotic supplementation was mainly used for bone cements (6612 cases, 75%).

CONCLUSION

In 2018 bone transplants or biomaterials were used in a considerable number of the 99,863 bone defect reconstruction procedures. Autologous bone was used in more than half of the cases (55%), biomaterials in approximately one quarter (24%) and allogenic bone in approximately one fifth (21%). Ceramics (42%) were more often used as biomaterials than cements (37%). The addition of antibiotics was mainly used with cements (75%).

Management of acute bone loss following high grade open tibia fractures

INTRODUCTION

Optimal treatment for acute post-traumatic bone loss in the tibia remains unclear. Distraction osteogenesis (DO) and induced membrane technique (IM) have been established as the mainstays of treatment. Aim of this article is to review the current evidence regarding the use of these two methods.

METHODS

A review of the MEDLINE database was performed with strict inclusion and exclusion criteria focusing on treatment of the acute bone loss after open tibia fractures with DO and IM. Bone union rate was taken as the primary outcome and infection rate as secondary outcome.

RESULTS

Four studies out of 78 on the use of the DO and three studies out of 18 on the use of the IM technique matched the inclusion criteria. Union rate in the DO group ranged between 92% and 100%, with infection rates between 0 and 4%. In the IM group, union was reached in 42% to 100% of cases, with septic complications occurring in 12% to 43%. Differences in union rate and infection rate reached statistical significance.

DISCUSSION

We found a considerable evidence gap regarding treatment of bone loss in high grade open tibia fractures. The limitations of our study prevented us from drawing clear causative conclusions on the results. Although our study points to higher union rates and lower infection rate with the use of the DO technique, the results remain preliminary and further high-level evidence is needed to establish the roles of DO and IM in treatment of acute bone loss in open tibia fractures.

Saving the lower limb with GlassBONE™ - Successful surgical revision of pseudarthrosis after infected open proximal tibia fracture type IIIC with bioactive glass grafting - A case report

Background

The management of bone defect due to trauma or surgical debridement is a current problem in orthopedic trauma surgery, often complicated by infection and bone nonunion. The graft is one of the most challenging variables in surgical treatment. Bioactive Glass (BAG) as a biocompatible and osteogenic product is a promising bone substitute showing good results in maxillo-facial-, spine surgery and treatment of osteomyelitis. Surprisingly, there is very little data on BAG use in trauma surgery.

Case presentation

A 51-year-old male patient, involved in a motorcycle accident, suffered an open proximal tibia fracture, type IIIC, of the left leg. Patient was admitted in January of 2013 to a general orthopedic department for surgical treatment. After several surgical revisions due to infection, vascular damage, and bone nonunion, the patient was successfully treated with Masquelet therapy followed by GlassBONE™ grafting (GlassBONE™ 45S5; Norarker). The patient demonstrated excellent results over the course of a two-year follow-up.

Conclusions

In our experience, GlassBONE™ 45S5 has proven to be an effective bone substitute even in difficult grafting conditions, including multiple surgical revisions for bone nonunion and infection. In our case, at the end of 2 years and 3 months of follow-up, the patient reported no pain, and had no signs of infection. Bone union and full weight bearing was achieved.

This case report is oriented by the CARE guidelines for clinical case reports; the patient gave consent for publication.

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GlassBONE™ 45S5 has proven to be an effective bone substitute even in difficult grafting conditions.

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Bone nonunion was successfully treated with Masquelet therapy followed by GlassBONE™ grafting.

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Bone loss due to fracture or surgical debridement is a current problem in orthopedic trauma surgery.

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Bone fractures are the most widespread trauma in humans.