BACKGROUND: All orthopaedic procedures, comprising foot and ankle surgeries, seemed to show a positive trend, recently. Bone grafts are commonly employed to fix bone abnormalities resulting from trauma, disease, or other medical conditions. This study specifically focuses on reviewing the safety and efficacy of various bone substitutes used exclusively in foot and ankle surgeries, comparing them to autologous bone grafts.
METHODS: The systematic search involved scanning electronic databases including PubMed, Scopus, Cochrane online library, and Web of Science, employing terms like \'Bone substitute,\' \'synthetic bone graft,\' \'Autograft,\' and \'Ankle joint.\' Inclusion criteria encompassed RCTs, case-control studies, and prospective/retrospective cohorts exploring different bone substitutes in foot and ankle surgeries. Meta-analysis was performed using R software, integrating odds ratios and 95% confidence intervals (CI). Cochrane\'s Q test assessed heterogeneity.
RESULTS: This systematic review analyzed 8 articles involving a total of 894 patients. Out of these, 497 patients received synthetic bone grafts, while 397 patients received autologous bone grafts. Arthrodesis surgery was performed in five studies, and three studies used open reduction techniques. Among the synthetic bone grafts, three studies utilized a combination of recombinant human platelet-derived growth factor BB homodimer (rhPDGF-BB) and beta-tricalcium phosphate (β-TCP) collagen, while four studies used hydroxyapatite compounds. One study did not provide details in this regard. The meta-analysis revealed similar findings in the occurrence of complications, as well as in both radiological and clinical evaluations, when contrasting autografts with synthetic bone grafts.
CONCLUSIONS: Synthetic bone grafts show promise in achieving comparable outcomes in radiological, clinical, and quality-of-life aspects with fewer complications. However, additional research is necessary to identify the best scenarios for their use and to thoroughly confirm their effectiveness.
METHODS: Level II.

BACKGROUND: This study aims to evaluate the optimal ratio of synthetic bone graft (SBG) material and platelet rich fibrin (PRF) mixed in a metal 3D-printed implant to enhance bone regeneration.
METHODS: Specialized titanium hollow implants (5 mm in diameter and 6 mm in height for rabbit; 6 mm in diameter and 5 mm in height for pig) were designed and manufactured using 3D printing technology. The implants were divided into three groups and filled with different bone graft combinations, namely (1) SBG alone; (2) PRF to SBG in 1:1 ratio; (3) PRF to SBG in 2:1 ratio. These three groups were replicated tightly into each bone defect in distal femurs of rabbits (nine implants, n = 3) and femoral shafts of pigs (fifteen implants, n = 5). Animal tissue sections were obtained after euthanasia at the 8th postoperative week. The rabbit specimens were stained with analine blue, while the pig specimens were stained with Masson-Goldner\'s trichrome stain to perform histologically examination. All titanium hollow implants were well anchored, except in fracture specimens (three in the rabbit and one fracture in the pig).
RESULTS: Rabbit specimens under analine blue staining showed that collagen tissue increased by about 20% and 40% in the 1:1 ratio group and the 2:1 ratio group, respectively. Masson-Goldner\'s trichrome stain results showed that new bone growth increased by 32% in the 1:1 ratio PRF to SBG, while - 8% in the 2:1 ratio group.
CONCLUSIONS: This study demonstrated that placing a 1:1 ratio combination of PRF and SBG in a stabilized titanium 3D printed implant resulted in an optimal increase in bone growth.

UNASSIGNED: This study compared the effect of various grafting materials on the area and volume of minerals attached to dental implants.
UNASSIGNED: In this animal study, 13 dogs were divided into three groups according to the time of sacrificing (2 months, 4 months, or 6 months). The implants were placed in oversized osteotomies, and the residual defects were filled with autograft, bovine bone graft (Cerabone), or a synthetic substitute (Osteon II). At the designated intervals, the dogs were sacrificed and the segmented implants underwent micro-computed tomography analysis. The bone-implant area (BIA) and bone-implant volume (BIV) of bone and graft material were calculated in the region of interest around the implant. The data were analyzed by two-way analysis of variance (ANOVA) at P < 0.05.
UNASSIGNED: There was no significant difference in BIA and BIV between the healing intervals for any of the grafting materials (P > 0.05). ANOVA exhibited comparable BIA and BIV between the grafting materials at 2 and 4 months after surgery (P > 0.05), although a significant difference was observed after 6 months (P < 0.05). Pairwise comparisons revealed that BIA was significantly greater in the autograft-stabilized than the synthetic-grafted sites (P = 0.035). The samples augmented with autograft also showed significantly higher BIV than those treated by the xenogenic (P = 0.017) or synthetic (P = 0.002) particles.
UNASSIGNED: All graft materials showed comparable performance in providing mineral support for implants up to 4 months after surgery. At the long-term (6-month) interval, autogenous bone demonstrated significant superiority over xenogenic and synthetic substitutes concerning the bone area and volume around the implant.

We examine the range of available bone graft substitutes often used in nonunion and malunion surgery of the upper extremity. Synthetic materials such as calcium sulfate, beta-calcium phosphate ceramics, hydroxyapatite, bioactive glass, and 3D printed materials are discussed. We delve into the advantages, disadvantages, and clinical applications for each, considering factors such as biocompatibility, osteoconductivity, mechanical strength, and resorption rates. This review provides upper extremity surgeons with insights into the available array of bone graft substitutes. We hope that the reviews helps in the decision-making process to achieve optimal outcomes when treating nonunion and malunion of the upper extremity.

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.

A biphasic calcium phosphate with submicron needle-shaped surface topography combined with a novel polyethylene glycol/polylactic acid triblock copolymer binder (BCP-EP) was investigated in this study. This study aims to evaluate the composition, degradation mechanism and bioactivity of BCP-EP in vitro, and its in vivo performance as an autograft bone graft (ABG) extender in a rabbit Posterolateral Fusion (PLF) model. The characterization of BCP-EP and its in vitro degradation products showed that the binder hydrolyses rapidly into lactic acid, lactide oligomers and unaltered PEG (polyethylene glycol) without altering the BCP granules and their characteristic submicron needle-shaped surface topography. The bioactivity of BCP-EP after immersion in SBF revealed a progressive surface mineralization. In vivo, BCP-EP was assessed in a rabbit PLF model by radiography, manual palpation, histology and histomorphometry up to 12 weeks post-implantation. Twenty skeletally mature New Zealand (NZ) White Rabbits underwent single-level intertransverse process PLF surgery at L4/5 using (1) autologous bone graft (ABG) alone or (2) by mixing in a 1:1 ratio with BCP-EP (BCP-EP/ABG). After 3 days of implantation, histology showed the BCP granules were in direct contact with tissues and cells. After 12 weeks, material resorption and mature bone formation were observed, which resulted in solid fusion between the two transverse processes, following all assessment methods. BCP-EP/ABG showed comparable fusion rates with ABG at 12 weeks, and no graft migration or adverse reaction were noted at the implantation site nor in distant organs.

Due to high demand but limited supply, there has been an increase in the need to replace autologous bone grafts with alternatives that fulfill osteogenic requirements. In this study, two different types of bone grafts were tested for their drug carrying abilities along with their osteogenic properties. Two different types of alendronate-loaded bone grafts, Bio-Oss (bovine bone graft) and InRoad (biphasic synthetic bone graft) were observed to see how different concentrations of alendronate would affect the sustained release to enhance osteogenesis. In this study, defected ovariectomize-induced osteoporotic rat calvarias were observed for 28 days with three different concentrations of alendronate (0 mg, 1 mg, 5 mg) for both Bio-Oss and InRoad. A higher concentration (5 mg) allowed for a more controlled and sustained release throughout the 28-day comparison to those of lower concentrations (0 mg, 1 mg). When comparing Bio-Oss and InRoad through histology and Micro-CT, InRoad showed higher enhancement in osteogenesis. Through this study, it was observed that alendronate not only brings out robust osteogenesis with InRoad bone grafts, but also enhances bone regeneration in an alendronate-concentration-dependent manner. The combination of higher concentration of alendronate and multiple porous bone graft containing internal micro-channel structure of InRoad resulted in higher osteogenesis with a sustained release of alendronate.

OBJECTIVE: The aim of this research was to determine the osseointegration of two presentations of biphasic calcium phosphate (BCP) biomaterial-one untreated and another submitted to biofunctionalization with a TGF-β1 inhibitor peptide, P144, on dental alveolus. Materials and Methods: A synthetic bone graft was used, namely, (i) Maxresorb® (Botiss Klockner) (n = 12), and (ii) Maxresorb® (Botiss Klockner) biofunctionalized with P144 peptide (n = 12). Both bone grafts were implanted in the two hemimandibles of six beagle dogs in the same surgical time, immediately after tooth extraction. Two dogs were sacrificed 2, 4, and 8 weeks post implant insertion, respectively. The samples were submitted to histomorphometrical and histological analyses. For each sample, we quantified the new bone growth and the new bone formed around the biomaterial\'s granules. After optical microscopic histological evaluation, selected samples were studied using backscattered scanning electron microscopy (BS-SEM). Results: The biofunctionalization of the biomaterial\'s granules maintains a stable membranous bone formation throughout the experiment timeline, benefitting from the constant presence of vascular structures in the alveolar space, in a more active manner that in the control samples. Better results in the experimental groups were proven both by quantitative and qualitative analysis. Conclusions: Synthetic bone graft biofunctionalization results in slightly better quantitative parameters of the implant\'s osseointegration. The qualitative histological and ultramicroscopic analysis shows that biofunctionalization may shorten the healing period of dental biomaterials.

UNASSIGNED: The main objective is to evaluate the quantity and quality of bone formed after use of bioactive synthetic bone graft putty in sinus augmentation and to radiographically and histologically evaluate increase in alveolar bone height in augmented sinus.
UNASSIGNED: It is a pre- and post-intervention study of 15 patients (present at both baseline and at 6 months) with 80% power and 95% confidence level.
UNASSIGNED: The mean increase in alveolar bone height is 7.08 ± 1.42 mm ranging from 5.6 mm to 10.7 mm. It is evident from the data that there has been increase in alveolar bone height postbone graft augmentation. P < 0.001 shows that increase in alveolar bone height is highly significant as compared to preoperative bone height. The mean postoperative density is 525.43 ± 104.18 hounsfield unit ranging from 649 HU to 350 HU. This is also a D3 quality bone as per Misch classification. The mean difference in alveolar bone density is 104 ± 125.16 HU. P = 0.0053 shows that increase in alveolar bone density is significant as compared to preoperative bone density.
UNASSIGNED: Bioactive synthetic bone graft putty yields sufficient quantity of mineralized tissue for implant placement in patients with 2-6 mm of alveolar bone height before grafting. Histologically, it has shown that it has good osteoconductive properties and good quality of bone is formed within 6 months of its augmentation.

Autologous bone remains the gold standard grafting substrate for bone fusions used for small gaps and critical defects. However, significant morbidity is associated with the harvesting of autologous bone grafts and, for that reason, alternative bone graft substitutes have been developed. In the present case series, a glass-reinforced hydroxyapatite synthetic bone substitute, with osteoinductive and osteoconductive proprieties, was applied. This synthetic bone substitute comprises the incorporation of P2O5-CaO glass-based system within a hydroxyapatite matrix, moulded into spherical pellets with 250-500 μm of diameter. A total of 14 veterinary clinical cases of appendicular bone defects and maxillary / mandibular bone defects are described. In all clinical cases, the synthetic bone substitute was used to fill bone defects, enhancing bone regeneration and complementing the recommended surgical techniques. Results demonstrated that it is an appropriate synthetic bone graft available to be used in veterinary patients. It functioned as a space filler in association with standard orthopaedic and odontological procedures of stabilization, promoting a faster bone fusion without any local or systemic adverse reactions. This procedure improves the animals\' quality of life, decreasing pain and post-operative recovery period, as well as increasing bone stability improving positive clinical outcomes.