Adverse reactions of artificial bone graft substitutes: lessons learned from using tricalcium phosphate geneX®

Limitations and modifications in the clinical application of calcium sulfate

Calcium sulfate and calcium sulfate-based biomaterials have been widely used in non-load-bearing bone defects for hundreds of years due to their superior biocompatibility, biodegradability, and non-toxicity. However, lower compressive strength and rapid degradation rate are the main limitations in clinical applications. Excessive absorption causes a sharp increase in sulfate ion and calcium ion concentrations around the bone defect site, resulting in delayed wound healing and hypercalcemia. In addition, the space between calcium sulfate and the host bone, resulting from excessively rapid absorption, has adverse effects on bone healing or fusion techniques. This issue has been recognized and addressed. The lack of sufficient mechanical strength makes it challenging to use calcium sulfate and calcium sulfate-based biomaterials in load-bearing areas. To overcome these defects, the introduction of various inorganic additives, such as calcium carbonate, calcium phosphate, and calcium silicate, into calcium sulfate is an effective measure. Inorganic materials with different physical and chemical properties can greatly improve the properties of calcium sulfate composites. For example, the hydrolysis products of calcium carbonate are alkaline substances that can buffer the acidic environment caused by the degradation of calcium sulfate; calcium phosphate has poor degradation, which can effectively avoid the excessive absorption of calcium sulfate; and calcium silicate can promote the compressive strength and stimulate new bone formation. The purpose of this review is to review the poor properties of calcium sulfate and its complications in clinical application and to explore the effect of various inorganic additives on the physicochemical properties and biological properties of calcium sulfate.

Biological Properties and Medical Applications of Carbonate Apatite: A Systematic Review

Bone defects represent an everyday challenge for clinicians who work in the fields of orthopedic surgery, maxillofacial and oral surgery, otorhinolaryngology, and dental implantology. Various bone substitutes have been developed and utilized, according to the needs of bone reconstructive surgery. Carbonate apatite has gained popularity in recent years, due to its excellent tissue behavior and osteoconductive potential. This systematic review aims to evaluate the role of carbonate apatite in bone reconstructive surgery and tissue engineering, analyze its advantages and limitations, and suggest further directions for research and development. The Web of Science, PubMed, and Scopus electronic databases were searched for relevant review articles, published from January 2014 to 21 July 2023. The study was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Eighteen studies were included in the present review. The biological properties and medical applications of carbonate apatite (CO3Ap) are discussed and evaluated. The majority of articles demonstrated that CO3Ap has excellent biocompatibility, resorbability, and osteoconductivity. Furthermore, it resembles bone tissue and causes minimal immunological reactions. Therefore, it may be successfully utilized in various medical applications, such as bone substitution, scaffolding, implant coating, drug delivery, and tissue engineering.

Crystalline Micro-Sized Carbonated Apatites: Chemical Anisotropy of the Crystallite Surfaces, Biocompatibility, Osteoconductivity, and Osteoinductive Effect Enhanced by Poly(ethylene phosphoric acid)

Carbonated hydroxyapatites (CAp) are very close to natural bone apatite in chemical composition and are regarded as a prospective bone mineral substitute for bone surgery and orthopedics. However, until now, the studies and applications of CAp were limited because of the amorphous nature of the synthetic CAp. In the present work, microsized highly crystalline carbonated apatites with uniform hexagonal (hCAp) or platelike (pCAp) morphology have been studied for the first time in vitro and in vivo, comparing against commercial hydroxyapatite (HAp) and β-tricalcuim phosphate (βTCP). In vitro experiments on dissolution of those calcium phosphate ceramics (CPCs) in acetate (pH 5.5) and Tris (pH 7.3) buffer solutions showed the following rank order of the dissolution rates: βTCP > hCAp > pCAp > HAp. The higher dissolution rate of hCAp in comparison with pCAp is explained by chemical anisotropy of the crystallite surfaces, which was proven by SEM studies of the changes in the morphology of hCAp and pCAp crystallites during hydrolysis. A 5-week experiment on subcutaneous implantation of CPC species showed the following rank order of bioresorption rates: βTCP > pCAp > hCAp > HAp. pCAp matrixes exhibited the highest biocompatibility, confirmed by histomorphological analysis. Three-month bone regeneration experiments involving a rat tibial defect model were conducted with 250-500 μm granules of pCAp and pCAp-PEPA [pCAp, pretreated with 2 wt % poly(ethylene phosphoric acid)]. Notably, pCAp-PEPA implants were resorbed at higher rates and induced the formation of more mature osseous tissue, a compact bone with Haversian systems.

Artificial Bone Graft Substitutes for Curettage of Benign and Low-Grade Malignant Bone Tumors: Clinical and Radiological Experience with Cerasorb

Background

Artificial bone graft substitutes (ABGS) for curettage of bone tumors are becoming increasingly popular. The aim of this retrospective analysis was to determine the efficacy of the ABGS Cerasorb (Curasan-AG, Kleinostheim, Germany), a beta-tricalcium phosphate (beta-TCP), concerning resorption profile, bone healing, and remodeling after surgery and to evaluate potential complications.

Methods

Forty-three patients suffering from benign and low-grade malignant bone tumors were treated with curettage and refilling of the bony cavity using the ABGS Cerasorb between 2018 and 2021 and included in the final analysis. Clinical follow-up exams with X-rays in two planes were performed 6 weeks, 3 months, 6 months, and 1 year after surgery.

Results

After a mean follow-up period of 14.6 months, radiological consolidation following curettage was observed in all patients. Total resorption was observed in 16.3% of patients; in the other 83.7%, resorption was partial. In four patients, of whom two had a tumor in the distal femur and two in the humeral diaphysis, fractures occurred within 6 weeks after primary surgery.

Conclusion

In conclusion, the beta-TCP Cerasorb seems to be a reliable bone graft substitute with low complication rates and is a suitable alternative to autologous bone grafts or allografts. Nonetheless, it shows a tendency of delayed resorption.

Level of Evidence

III; retrospective cohort study.

Injectable Synthetic Beta-Tricalcium Phosphate/Calcium Sulfate (GeneX) for the Management of Contained Defects Following Curettage of Benign Bone Tumours

Benign and low-grade malignant bone tumours are often treated with curettage and filling of the resultant defect using any of a number of materials, including autologous bone grafts, allografts, or synthetic materials. The objective of this study was to report our experience using a synthetic bone graft substitute in these patients. Ten consecutive cases (four males, six females; mean age, 36 years) of benign bone tumours were treated surgically at a tertiary musculoskeletal oncology centre, between 2019 and 2021. Following curettage, the contained defects were managed with injectable beta-tricalcium phosphate/calcium sulfate (GeneX; Biocomposites Ltd., Keele, UK). The desired outcomes were early restoration of function and radiographic evidence of healing. No other graft materials were used in any of the patients. The mean follow-up was 24 months (range, 20–30 months). All patients in this series (100%) demonstrated radiographic evidence of healing and resumed their daily living activities. There were no tumour recurrences and no complications were encountered with the use of GeneX. In patients with contained defects following curettage of benign bone tumours, we found GeneX to be a safe and effective filling agent. These findings contrast with some existing studies that have reported local complications with the use of injectable beta-tricalcium phosphate/calcium sulfate.

Injection of a Bone Substitute in the Treatment of Unicameral Bone Cysts

Background

Simple bone cysts are benign bony lesions. Treatment strategies are varied for this particular pathology. It remains controversial as to what the ideal treatment strategy is. Recently, bony substitute injections have emerged as a potential option for treatment. This paper aimed to describe our institution's experience in using bony substitute injections to treat unicameral bone cysts.

Methods

A retrospective review of consecutive patients over an 84-month period at a tertiary paediatric hospital was performed. Information regarding patients' presentation, diagnosis, and management was recorded and summarised.

Results

A total of 15 patients were included in our study, with a mean follow-up of 118 weeks. 86.7% of patients demonstrated clinical resolution (absence of pain at the latest follow-up) and 80% of patients demonstrated radiographic resolution. Only one patient sustained a subtrochanteric fracture post-index operation, whilst two others demonstrated redevelopment of cystic architecture on follow-up.

Conclusion

This study demonstrates that bone substitute injection is potentially a minimally invasive and seemingly successful technique in the treatment of unicameral bone cysts and other simple bone lesions. Further randomised and comparative studies are required to confirm and validate our findings.

Calcium Orthophosphate (CaPO4)-Based Bioceramics: Preparation, Properties, and Applications

Various types of materials have been traditionally used to restore damaged bones. In the late 1960s, a strong interest was raised in studying ceramics as potential bone grafts due to their biomechanical properties. A short time later, such synthetic biomaterials were called bioceramics. Bioceramics can be prepared from diverse inorganic substances, but this review is limited to calcium orthophosphate (CaPO4)-based formulations only, due to its chemical similarity to mammalian bones and teeth. During the past 50 years, there have been a number of important achievements in this field. Namely, after the initial development of bioceramics that was just tolerated in the physiological environment, an emphasis was shifted towards the formulations able to form direct chemical bonds with the adjacent bones. Afterwards, by the structural and compositional controls, it became possible to choose whether the CaPO4-based implants would remain biologically stable once incorporated into the skeletal structure or whether they would be resorbed over time. At the turn of the millennium, a new concept of regenerative bioceramics was developed, and such formulations became an integrated part of the tissue engineering approach. Now, CaPO4-based scaffolds are designed to induce bone formation and vascularization. These scaffolds are usually porous and harbor various biomolecules and/or cells. Therefore, current biomedical applications of CaPO4-based bioceramics include artificial bone grafts, bone augmentations, maxillofacial reconstruction, spinal fusion, and periodontal disease repairs, as well as bone fillers after tumor surgery. Prospective future applications comprise drug delivery and tissue engineering purposes because CaPO4 appear to be promising carriers of growth factors, bioactive peptides, and various types of cells.

Multi-stage controllable degradation of strontium-doped calcium sulfate hemihydrate-tricalcium phosphate microsphere composite as a substitute for osteoporotic bone defect repairing: degradation behavior and bone response

Various requirements for the repair of complex bone defects have motivated to development of scaffolds with adjustable degradation rates and biological functions. Tricalcium phosphate (TCP) and calcium sulfate are the most commonly used bone repair materials in the clinic, how to better combine TCP and calcium sulfate and play their greatest advantages in the repair of osteoporotic bone defect is the focus of our research. In this study, a series of scaffolds with multistage-controlled degradation properties composed of strontium-doped calcium sulfate (SrCSH) and strontium-doped tricalcium phosphate (Sr-TCP) microspheres scaffolds were prepared, and their osteogenic activity,in vivodegradation and bone regeneration ability in tibia of osteoporotic rats were evaluated.In vitrostudies revealed that different components of SrCSH/Sr-TCP scaffolds significantly promoted the proliferation and differentiation of MC3T3-E1 cells, which showed a good osteogenic induction activity.In vivodegradation results showed that the degradation time of composite scaffolds could be controlled in a large range (6-12 months) by controlling the porosity and phase composition of Sr-TCP microspheres. The results of osteoporotic femoral defect repair showed that when the degradation rate of scaffold matched with the growth rate of new bone, the parameters such as bone mineral density, bone volume/total volume ratio, trabecular thickness, angiogenesis marker platelet endothelial cell adhesion molecule-1 and new bone formation marker osteocalcin expression were higher, which promoted the rapid repair of osteoporotic bone defects. On the contrary, the slow degradation rate of scaffolds hindered the growth of new bone to a certain extent. This study elucidates the importance of the degradation rate of scaffolds for the repair of osteoporotic bone defects, and the design considerations can be extended to other bone repair materials, which is expected to provide new ideas for the development of tissue engineering materials in the future.

Usefulness of Synthetic Osteoconductive Bone Graft Substitute with Zeta Potential Control for Intramedullary Fixation with Proximal Femur Nail Antirotation in Osteoporotic Unstable Femoral Intertrochanteric Fracture

Purpose

This study was conducted in order to examine the usefulness of osteoconductive bone substitutes with zeta potential control (geneX® ds; Biocomposites, England) by comparing the complications and radiographic evaluation with or without geneX® ds augmentation for internal fixation with proximal femur nail antirotation (PFNA) for treatment of osteoporotic unstable intertrochanteric fractures.

Materials and Methods

A retrospective study of 101 patients who underwent fixation with PFNA in osteoporotic unstable intertrochanteric fractures was conducted from December 2015 to August 2020. The radiographic evaluation and complication rates were compared between patients with geneX® ds (Group A: 41 cases) and those without geneX® ds (Group B: 60 cases).

Results

In radiological valuation, the degree of blade sliding from the time immediately after surgery to one year after surgery was 1.4±1.2 mm and 5.8±2.7 mm in Group A and Group B, respectively (P<0.001). During the same time frame, a significant difference of 2.3±2.2° and 7.4±3.1° , respectively (P<0.001), in varus collapse, was observed for Group A and Group B.

Conclusion

Among patients fixed with PFNA for treatment of unstable intertrochanteric fractures, less blade sliding and varus collapse was observed for those with geneX® ds augmentation compared to those without it. In addition, there was no increase in the incidence of complications. The authors believe it can be regarded as a safe and effective additive for intramedullary fixation for treatment of unstable intertrochanteric fractures.

Progressive Osteolysis After Use of Synthetic Bone Graft Substitute

Benign bone tumors are commonly treated with intralesional curettage and bone graft, with autogenous bone graft being the gold standard. However, autogenous bone graft has its limitation, and artificial bone graft substitutes were developed as an alternative. PRO-DENSE™ (Wright Medical Technology, Arlington, Tennessee) is a calcium sulfate and calcium phosphate mixed bone graft substitute that is biodegradable and osteoconductive, which has made them a popular choice among surgeons. However, long-term studies of this treatment method for benign tumors are still limited.

In this report, we present a case of progressive femoral neck osteolysis caused by an inflammatory reaction to PRO-DENSE™ two years after intralesional curettage and bone grafting of a benign bone tumor. 

A twenty-one-year-old female with fibrous dysplasia underwent intralesional curettage with the use of PRO-DENSE™ bone substitute to fill the cavitary defect. She developed an inflammatory reaction to the bone graft substitute leading to increasing pain and osteolysis requiring a reoperation.

Bone graft substitute has many advantages; however, they should be used with discretion due to many unknown regarding their safety and long-term outcomes.

Improved Anti-Washout Property of Calcium Sulfate/Tri-Calcium Phosphate Premixed Bone Substitute with Glycerin and Hydroxypropyl Methylcellulose

Calcium sulfate/calcium phosphate (CS-CP)-based bone substitutes have been developed in premixed putty for usage in clinical applications. However, it is difficult to completely stop the bleeding during an operation because premixed putty can come into contact with blood or body fluids leading to disintegration. Under certain conditions depending on particle size and morphology, collapsed (washed) particles can cause inflammation and delay bone healing. In this context, anti-washout premixed putty CS-CP was prepared by mixing glycerin with 1, 2, and 4 wt% of hydroxypropyl methylcellulose (HPMC), and the resultant anti-washout properties were evaluated. The results showed that more than 70% of the premixed putty without HPMC was disintegrated after being immersed into simulated body fluid (SBF) for 15 min. The results demonstrated that the more HPMC was contained in the premixed putty, the less disintegration occurred. We conclude that CS-CP pre-mixed putty with glycerin and HPMC is a potential bone substitute that has good anti-washout properties for clinical applications.

Efficacy of bone formation of microporous sphere-shaped biphasic calcium phosphate in a rabbit skull bone defect model

Bone graft is required in various surgical procedures. Although autograft is the gold standard, it has limited availability. Various compounds have been proposed as alternatives such as biphasic calcium phosphate (BCP), which is the most widely used compound. The newly synthesized microporous sphere-shaped BCP has the advantage of increasing contact surface, and it can induce the formation of microbone structures. A putty-type contains the addition of a fluid carrier to the sphere-shaped BCP and can be easily used for a small orifice large bone defect. To compare the widely used BCP products, new bone formation and residual graft materials (RGM) were evaluated for 6 and 12 weeks in a rabbit calvarial bone defect model. Although existing BCP products and the microporous sphere-type product did not differ significantly with respect to new bone formation and RGM, the putty-type product was largely washed out and had low new bone formation at 6 and 12 weeks. Overall, the results suggest that microporous sphere-shaped BCP showed similar bone formation capability to existing products and was able to maintain higher initial mechanical stability.

New Strategies in Enhancing Spinal Fusion

The biologic steps involved in creating a bony fusion between adjacent segments of the spine are a complex and highly coordinated series of events. There have been significant advancements in bone grafts and bone graft substitutes in order to augment spinal fusion. While autologous bone grafting remains the gold standard, allograft bone grafting, synthetic bone graft substitutes, and bone graft enhancers are appropriate in certain clinical situations. This article provides an overview of the basic biology of spinal fusion and strategies for enhancing fusion through innovations in bone graft material.

Effect of a synthetic osteoconductive bone graft substitute with zeta potential control (geneX®ds) in the treatment of intertrochanteric fracture: A single center experience of 115 consecutive proximal femoral nail antirotations

INTRODUCTION

Although various clinical applications of geneX^®ds have been reported, no study has reported the clinical application of geneX^®ds in osteoporotic hip fracture. The present study aimed to identify the clinical effect of the application of geneX^®ds in elderly patients with intertrochanteric fracture treated using proximal femoral nail antirotation (PFNA).

MATERIALS AND METHODS

From March 2014 to October 2017, 233 patients with intertrochanteric fracture (65 men and 168 women) were enrolled in this study. All patients received surgical treatment using PFNA. Patients were classified into two groups: those in whom geneX^®ds which is synthetic osteoconductive bone graft substitute with the unique property of Zeta Potential Control (ZPC^®), was use, and those in whom it was not. We compared the preoperative details and surgical outcomes, including radiologic outcome (postoperative reduction, tip apex distance, sliding distance of the helical blade, union, and union time) and clinical outcomes (Harris Hip Score and the walking ability at the last follow-up) between the groups.

RESULTS

In patients with unstable fracture who achieved anatomical or extramedullary type of reduction, the average sliding distance at 1, 3, and 12 months was 4.9 mm, 7.5 mmm and 8.1 mm in the geneX^®ds group and 7.5 mm, 10.8 mm, and 12.1 mm in the no geneX^®ds group, respectively. There were significant differences in the sliding distance at 1, 3, and 12 months between these two groups.

CONCLUSION

The use of this synthetic osteoconductive bone graft substitute with zeta potential control may have positive effect on the controlled sliding of the helical blade and the healing of intertrochanteric fracture.

Early postoperative compilations of bone filling in curettage defects

Background

Curettage is widely used in orthopedic oncology; the defect created frequently requires filling for mechanical and functional stability for the bones and adjacent joint. Allograft, bone graft substitute, and polymethyl methacrylate (PMMA) are the most common substances used each with their benefits and drawbacks. The aim of the study is to show that good functional result can be achieved with curettage and bone filler, regardless of type.

Methods

A series of 267 cases were reviewed between 1994 and 2015 who received curettage treatment and placement of a bone filler. Endpoints included fracture, infection, cellulitis, pulmonary embolism, and paresthesia. Complication rates at our single institution were compared against literature values for three study cohorts: allograft, bone graft substitute, and PMMA bone fillers. Friedman test, Wilcoxon test, and Z-score for two populations were used to compare our subset against literature values and between different bone filling types.

Results

Our cases included 18 autografts, 74 allografts, 121 bone graft substitute, and 54 PMMA of which the bulk of complications occurred. Our overall complication rate was 3.37%. Allograft has a complication rate of 1.35%, bone graft substitute of 4.13%, and PMMA of 5.56%. Other techniques did not yield any complications. Combination filling techniques PMMA + allograft and PMMA + bone graft substitute had sample sizes too small for statistical comparison. Statistical comparison yielded no significant difference between complications in any of the filling groups (P = 0.411).

Conclusions

Some has even argued that bone defects following curettage do not require bone filling for good outcome. However, many structural or biologic benefits that aid in earlier return to functionality can be conferred by filling large bone defects. There was no significant difference in postoperative complication rates between allograft, bone graft substitute, and PMMA when compared at our institution and with literature values. Nevertheless, one complication with a large defect filled with allograft, requiring a subsequent reconstruction using vascularized fibular graft. Taking everything into account, we see bone graft substitute as a suitable alternative to other bone filling modalities.

The potential of carbonate apatite as an alternative bone substitute material

Bone reconstructive surgery has become a common procedure, and bone transplantation has become the second most frequently performed tissue transplantation procedure worldwide. Therefore, the need for bone substitute materials has increased. Artificial bone substitutes exhibit osteoconductive properties and feature several advantages, including abundant resources, low cost, and low donor site morbidity. Carbonate apatite (CO3Ap) is a calcium phosphate ceramic that can be used as a synthetic bone graft. The carbonate content of this ceramic is similar to that of bone apatite. In this review, we show that carbonate apatite can be degraded given its chemical reactivity in a weakly acidic environment and through osteoclast resorption. Moreover, it is osteoconductive and promotes bone tissue formation without fibrotic tissue formation. Additionally, microstructural analysis revealed that new bone tissue is formed within the bone graft itself.

Sinus Tract Formation with Chronic Inflammatory Cystic Mass after Beta Tricalcium Phosphate Insertion

Beta tricalcium phosphate (β-TCP) is one of allogenic bone substitute which is known to have interconnected pores that draws cell and nutrients for bone generation. It has been resulted in good outcomes for bone defect coverage or augmentation. However, several studies have also reported negative outcomes and associated complications including unexpected formation of cystic mass, continuous pain and secretion. We present the case of a 36-year-old man with a right cheek cystic mass who had a history of right zygomaticomaxillary (ZM) complex fracture and surgical correction with β-TCP powder insertion to ZM bone defect. Excisional biopsy under local anesthesia revealed calcified mass in a sinus tract which was found to be connected to the ZM bone defect site in postoperative computed tomography image. Further excision under general anesthesia was performed to remove the sinus tract and fine granules which filled the original defect site. Pathologic report revealed bony spicules and calcification materials with chronic foreign body reaction. Postoperative complications and recurrence were not reported.

Clinical experience with the artificial bone graft substitute Calcibon used following curettage of benign and low-grade malignant bone tumors

Artificial bone graft substitutes, such as Calcibon, are becoming increasingly interesting as they do not cause donor site morbidity which is an advantage compared to autologous bone grafts. The aim of this study was to evaluate the efficacy and potential complications associated with the use of Calcibon. Twenty-seven patients with benign and low-grade malignant bone tumors were treated with curettage and refilling of the bony cavity. Based on the radiological classification system of Neer, these lesions only comprised Grade I lesions, describing cysts that only require curettage and filling, but no additional treatment. At a mean follow up of six months we observed radiological consolidation without resorption of the bone graft substitute. These observations were also made at a mean follow-up of 13 and 32 months, respectively. According to the classification system of Goslings and Gouma we observed six surgical complications. Summing up, Calcibon seems to be a reliable bone graft substitute with low complication rates. However, delayed resorption should be expected. Calcibon seems to be an alternative to autologous bone grafts or allografts in adequate indications.

Reconstruction of mandibular defects with autogenous bone and decellularized bovine bone grafts with freeze-dried bone marrow stem cell paracrine factors

The gold standard following segmental mandibulectomy is vascularized autologous bone graft in the form of the fibula flap. However, in bone reconstruction the use of autogenous bone does not always guarantee a successful outcome. The aim of the present investigation was to develop a novel biologically active bone (BAB) graft, and to use it for the reconstruction of large size defects of the mandible bone following tumor resection. In the first part of the present study, biologically active bone graft was developed by using human freeze-dried bone marrow stem cells (BMSCs) paracrine factors and three-dimensional bone scaffold derived from cancellous bovine bone following decellularization. In the second part of the research, one male and three female patients with primary tumors of the mandible underwent hemimandibulectomy. The mandibular bone defects following tumor resection were reconstructed with autogenous rib grafts in three patients and BAB graft was used in one patient. The graft-host interfaces were covered with decellularized human amnion/chorion membrane graft. All patients were followed-up every five months following the reconstruction of the mandible, with no complications observed. Preliminary clinical investigations demonstrated that a BAB graft containing freeze-dried BMSC paracrine factors may be used for the reconstruction of large mandibular bone defects following tumor resection.

Treatment of cystic lesion of mandible using combination of modified bone granules and calcium phosphate bone cement: A preliminary report

AIMS

This study was conducted to evaluate healing of bony cavity in mandible following enucleation of cystic lesion by obliterating the cavity using modified natural bone granules (G Graft) and calcium phosphate bone cement (G Bone).

MATERIALS AND METHOD

In this technique, after enucleation of cystic lesion, peripheral ostectomy using No. 702 fissure bur and perforation of the inferior cortex using 1.5 mm drill bits were performed. Modified hydroxyapatite granules were used to fill the defect while calcium hydroxide bone cement was used to seal the cavity opening. Thirty-seven patients were treated using this technique. In 30 patients, quality and quantity of bone were within acceptable limits, and in 7 patients, there was extrusion of graft material and post-operative infection.

CONCLUSION

Treatment of cystic lesion of mandible using combination of modified bone granules and calcium phosphate cement is good alternative to other treatment methods. Long-term and comparative studies are required to evaluate its advantage over the other methods of treatment.

Adverse effect of beta-tricalcium phosphate with zeta potential control in repairing critical defects in rats' calvaria

Objective

To evaluate whether a new biphasic cement composed of calcium sulfate and beta tricalcium phosphate with zeta potential control could induce or lead to bone neoformation in critical defects.

Methods

A critical defect of diameter 8 mm was made in the calvaria of forty male Wistar rats. In the Test Group (n = 20), the defects were filled with cement. In the Control Group (n = 20), the defect was not filled and only coagulum was present. The animals were sacrificed 7, 14, 21 and 42 days after the operation. Calvaria specimens were subjected to microtomography and were then prepared for histological analysis. The analyses included morphological assessment on the histopathology of the repair; comparative morphometric evaluation of the area of formation of bone trabeculae between the groups; and histochemical staining by means of tartrate-resistant phosphatase (TRAP) in order to identify osteoclasts.

Results

Microtomographic images of the defects filled by the cement did not show any decrease in area over the course of postoperative evolution. In the Test Group, the material continued to present a foreign-body response until the last observational periods. Histomorphological analysis showed that there were more significant groupings of giant cells in the Test Group and greater maturity of neoformed bone in the Control Group. Exogenous material was also present. Histomorphometric analysis showed that in the Control Group, the total area of bone neoformation was significantly greater (p = 0.009) and grew progressively. The giant cells presented a positive reaction to TRAP but no osteoclasts were observed.

Conclusion

The ceramic cement did not induce or lead to bone neoformation from the microtomographic or histological point of view.

Lytic Complications after Skull Reconstruction Using GeneX®

Multiple methods and materials are available for bone defect reconstruction. Bone graft substitute is one of the materials used for reconstruction of bone defect and have been widely used recently. This report describes some cases about complications related to GeneX® which is introduced as mixture of calcium sulfate and β-tricalcium phosphate at manufacturer's official web site. It informed of 3 patients who suffered wound inflammation, serous cyst after using GeneX® for reconstructing skull defect.

Complete twelve month bone remodeling with a bi-phasic injectable bone substitute in benign bone tumors: a prospective pilot study

Background

Benign primary bone tumors are commonly treated by surgery involving bone grafts or synthetic bone void fillers. Although synthetic bone grafts may provide early mechanical support while minimizing the risk of donor-site morbidity and disease transmission, difficult handling properties and less than optimal transformation to bone have limited their use.

Methods

In a prospective series, patients with benign bone tumors were treated by minimal invasive intervention with a bi-phasic and injectable ceramic bone substitute (CERAMENT™ BONE VOID FILLER, BoneSupport, Sweden) with the hypothesis that open surgery with bone grafting might be avoided. The defects were treated by either mini-invasive surgery (solid tumors) or percutaneous injection (cysts) and followed clinically and radiologically for 12 months. CT scan was performed after 12 months to confirm bone remodeling of the bone substitute. All patients were allowed full weight bearing immediately after surgery.

Results

Fourteen patients with a median age of 13 years (range 7–75) were consecutively recruited during 11 months. Eleven lesions were bone cysts (eight unicameral and three post-traumatic) and three were solid benign tumors. The median size of the lesions was 40 mL (range 1–152). The most common location was humerus (n = 10). After 12 months the defects completely or partially filled with median 18 mL (range 5–28) of bone substitute demonstrated full resolution (Neer Classification grade I) in 11 patients, partial resolution (Neer II) in 2 patients and in 1 patient the cyst persisted (Neer III).

No lesions required recurrent surgery during the observation period. No post-operative fracture or infection was recorded.

Conclusions

Minimal invasive treatment with a bi-phasic and injectable ceramic bone substitute might offer an alternative to regular bone grafting due to convenient handling properties and rapid bone remodeling.

Trial Registration

ClinicalTrials NCT02567084 Release Date 10/01/2015

Porous titanium granules are better than autograft bone as a bone void filler in lateral tibial plateau fractures: A randomised trial

A total of 20 patients with a depressed fracture of the lateral tibial plateau (Schatzker II or III) who would undergo open reduction and internal fixation were randomised to have the metaphyseal void in the bone filled with either porous titanium granules or autograft bone. Radiographs were undertaken within one week, after six weeks, three months, six months, and after 12 months. The primary outcome measure was recurrent depression of the joint surface: a secondary outcome was the duration of surgery. The risk of recurrent depression of the joint surface was lower (p < 0.001) and the operating time less (p < 0.002) when titanium granules were used. The indication is that it is therefore beneficial to use porous titanium granules than autograft bone to fill the void created by reducing a depressed fracture of the lateral tibial plateau. There is no donor site morbidity, the operating time is shorter and the risk of recurrent depression of the articular surface is less.