Synthetic Graft Research Articles

Advances in Bioceramics for Bone Regeneration: A Narrative Review

Large osseous defects resulting from trauma, tumor resection, or fracture render the inherent ability of the body to repair inadequate and necessitate the use of bone grafts to facilitate the recovery of both form and function of the bony defect sites. In the United States alone, a large number of bone graft procedures are performed yearly, making it an essential area of investigation and research. Synthetic grafts represent a potential alterative to autografts due to their patient-specific customizability, but currently lack widespread acceptance in the clinical space. Early in their development, non-autologous bone grafts composed of metals such as stainless steel and titanium alloys were favorable due to their biocompatibility, resistance to corrosion, mechanical strength, and durability. However, since their inception, bioceramics have also evolved as viable alternatives. This review aims to present an overview of the fundamental prerequisites for tissue engineering devices using bioceramics as well as to provide a comprehensive account of their historical usage and significant advancements over time. This review includes a summary of commonly used manufacturing techniques and an evaluation of their use as drug carriers and bioactive coatings—for therapeutic ion/drug release, and potential avenues to further enhance hard tissue regeneration.

Advancing Adult-Acquired Flatfoot Deformity Treatment: Enhanced Biomechanical Support Through Graphene Oxide-Integrated Bioengineered Grafts Tested In Silico

Adult-Acquired Flatfoot Deformity (AAFD) is a progressive orthopedic condition causing the collapse of the foot’s medial longitudinal arch, often linked with injuries to the plantar arch’s passive stabilizers, such as the spring ligament (SL) and plantar fascia. Conventional treatment typically involves replacing the SL with synthetic material grafts, which, while providing mechanical support, lack the biological compatibility of native ligaments. In response to this shortcoming, our study developed an electrospun, twisted polymeric graft made of polycaprolactone (PCL) and type B gelatin (GT), enhanced with graphene oxide (GO), a two-dimensional nanomaterial, to bolster biomechanical attributes. The addition of GO aimed to match the native ligamentous tissue’s mechanical strength, with the PCL-GT-GO 2.0% blend demonstrating an optimal Young’s modulus of 240.75 MPa. Furthermore, the graft showcased excellent biocompatibility, evidenced by non-hemolytic reactions, suitable wettability and favorable platelet aggregation—essential features for promoting cell adhesion and proliferation. An MTT assay revealed cell viability exceeding 80% after 48 h of exposure, highlighting the potential of the graft as a regenerative scaffold for affected ligaments. Computational modeling of the human foot across various AAFD stages assessed the graft’s in situ performance, with the PCL-GT-OG 2.0% graft efficiently preventing plantar arch collapse and offering hindfoot pronator support. Our study, based on in silico simulations, suggests that this bioengineered graft holds significant promise as an alternative treatment in AAFD surgery, marking a leap forward in the integration of advanced materials science for enhanced patient care.

An in-silico protocol to predict the pelvic-status post harvesting the bone for auto-grafting procedure using finite element analysis

In bone grafting surgery, autograft, allograft, xenograft, and synthetic graft are the choices of materials used to fill the voids. Because of the risk of infection cautioned during bone grafting surgery, the bone harvested from patient’s own body is widely used to fill the damaged/diseased bone-site. In this study, the voids created post harvesting the bones from iliac-crest of a 40-years-old male patient was considered in-silico. Bone harvested in different geometric patterns by window and trapdoor techniques are considered, and a series of finite element analyses was conducted to evaluate the pelvis status pre and post extraction of bone graft under a single-leg stance loading condition. The results of the study revealed that the maximum of 20 cm3 volume of cortico-cancellous bone in the form of circular pattern harvested from the iliac-crest using a trapdoor technique as the best. To validate the result, the displacements obtained post the extraction of different volumes of cortico-cancellous bone was analyzed, and found that 20 cm3 volume of cortico-cancellous bone harvested using a circular trapdoor technique was ideal choice, considering the pelvis fragility as a major concern. The outcomes of the study can be used to noninvasively predict the pelvis status before harvesting the bone.

USO DE ENXERTOS EM CIRURGIAS RECONSTRUTIVAS APÓS TRAUMAS GRAVES: UMA REVISÃO INTEGRATIVA

This article provides a comprehensive review of the use of grafts in reconstructive surgeries for patients with severe trauma, highlighting the differences among autologous, allogeneic, and synthetic grafts and their efficacy in specific contexts. Autologous grafts are known for their high integration rates and low immune rejection, while allogeneic and synthetic grafts expand therapeutic options, albeit with higher risks of complications. Technological advances, such as 3D bioprinting, allow for the customization of grafts, enhancing aesthetic and functional outcomes. However, these methods still face limitations, such as vascularization issues and immune rejection risks. This study emphasizes the importance of a careful and personalized selection of graft type to maximize patient quality of life and satisfaction. In conclusion, while autologous grafts remain the gold standard, the development of synthetic and bioprinted materials represents a promising frontier for reconstructive medicine.

Decellularized Extracellular Matrix Scaffolds: Recent Advances and Emerging Strategies in Bone Tissue Engineering.

Bone tissue engineering (BTE) is a complex biological process involving the repair of bone tissue with proper neuronal network and vasculature as well as bone surrounding soft tissue. Synthetic biomaterials used for BTE should be biocompatible, support bone tissue regeneration, and eventually be degraded in situ and replaced with the newly generated bone tissue. Recently, various forms of bone graft materials such as hydrogel, nanofiber scaffolds, and 3D printed composite scaffolds have been developed for BTE application. Decellularized extracellular matrix (DECM), a kind of natural biological material obtained from specific tissues and organs, has certain advantages over synthetic and exogenous biomaterial-derived bone grafts. Moreover, DECM can be developed from a wide range of biological sources and possesses strong molding abilities, natural 3D structures, and bioactive factors. Although DECM has shown robust osteogenic, proangiogenic, immunomodulatory, and bone defect healing potential, the rapid degradation and limited mechanical properties should be improved for bench-to-bed translation in BTE. This review summarizes the recent advances in DECM-based BTE and discusses emerging strategies of DECM-based BTE.

Successful management of mycotic anastomotic pseudoaneurysm of interposition vein graft following a carotid endarterectomy: a case report

BackgroundAnastomotic pseudoaneurysms of interposition vein grafts are a rare entity that requires urgent management to prevent life-threatening complications, such as rupture and thromboembolism, especially when involving the carotid arteries. As these are rare complications and literature is sparse, we believe that this case report can aid the decision-making process in similar circumstances.Case presentationA 49-year-old Ukrainian male patient presented with a false aneurysm of both distal and proximal anastomosis of an interposition vein graft between the common carotid artery and the internal carotid artery, which was previously performed as a bailout procedure after the patient developed a complication of carotid surgery. The patient was successfully treated with extra-anatomical interposition of a vein graft from the subclavian artery to the remnant of extracranial internal carotid artery and en bloc excision of the previous vein graft with the false aneurysms.ConclusionMycotic anastomotic pseudoaneurysms following carotid endarterectomy represent a rare yet serious complication in vascular surgery that requires urgent treatment. While endovascular techniques could represent an alternative option, open surgical repair is still the standard of care for this pathology, offering advantages in preventing postoperative ischemic complications and ensuring optimal long-term outcomes. The open approach provides direct visualization of the pseudoaneurysm. It allows the meticulous debridement of the infected tissues and an accurate reconstruction of the arterial wall with autologous or synthetic grafts. In light of the substantial evidence supporting its superiority, open surgical repair should remain the preferred approach in addressing mycotic anastomotic pseudoaneurysms following carotid endarterectomy. Future research should continue to explore advancements in other surgical techniques and refine treatment strategies to enhance patient outcomes in this challenging clinical scenario.

Evaluation of efficacy of open thrombectomy for recently thrombosed arteriovenous fistulae and synthetic grafts for hemodialysis

Evaluation of efficacy of open thrombectomy for recently thrombosed arteriovenous fistulae and synthetic grafts for hemodialysis

Biological knee joint reconstruction using patella following giant cell tumor excision: a case report

A 20-year-old female patient presented to us with a large expansile swelling over right knee diagnosed clinically and confirmed histopathological and radiologically to be Giant Cell Tumor of upper end of Tibia involving both condyles with a breach in the posterior cortex. In this case report we tried to retain the joint function by biological reconstruction using the Patella after the wide excision of the tumor mass. A radical excision of the upper end of the Tibia was done. The Patella was used as an articular surface supported by ipsilateral Fibula and cortico-cancellous bone chips from the ipsilateral iliac crest as struts and complemented with synthetic bone graft pieces. Thus, the joint was reconstructed biologically. The case was followed for 1 year. The tumor was excised in toto, the knee joint was restored by the Patella and the bone graft struts. The results were discussed in detail.

The Benefits of a Rehabilitation Program Following Medial Patellofemoral Ligament Reconstruction

The medial patellofemoral ligament (MPFL) is critical for patellar stability. This study investigates the efficacy of a one-year physical therapy rehabilitation program following MPFL reconstruction using Synthetic Graft (SG) and Quadriceps Tendon Autograft (QTA). Thirty-five patients aged 18–38 underwent MPFL reconstruction (20 SG, 15 QTA). They participated in a structured rehabilitation program to improve their range of motion (ROM), muscle strength, pain management, and overall quality of life (QoL). The program included physiotherapy and MLS laser, Game Ready Therapy, EMS, TENS, TECAR, and lymphatic drainage. Before and after the program, assessments included knee flexion and extension using goniometry, muscle strength via the Medical Research Council (MRC) scale, knee circumference, pain intensity on the Visual Analogue Scale (VAS), and QoL with the EQ-5D instrument. Significant improvements were observed in knee flexion (37.57° vs. 114.71°, p < 0.001), muscle strength (MRC scale 1–4 points vs. 4–5 points, p < 0.001), and pain reduction (VAS 6.66 vs. 0.46, p < 0.001). The functional coefficient of mobility and QoL scores also markedly increased. Patients with QTA improved some parameters better than those with SG. These findings support the effectiveness of a comprehensive rehabilitation program in enhancing knee functionality, reducing pain, and improving QoL post-MPFL reconstruction. Personalized rehabilitation protocols are recommended to optimize recovery outcomes.

Investigation on structurally reinforced synthetic bone grafts via tricalcium silicate

AbstractTricalcium silicate (C3S) is one of the main components of mineral trioxide aggregates, which is used in dental endodontic treatment. C3S provides workable viscosity itself and fast hydration when water is added, and it is known to be nontoxic, noncarcinogenic, nongenotoxic, biocompatible, and insoluble in tissue fluids. In this study, C3S is added to synthetic bone‐graft materials from 30% to 60% to deliver viscosity to increase workability in the early stage of implant surgical procedure and to attain some degree of compressive strength after the hydration. Additionally, the porosity is not overly reduced to maintain the ability for bone regeneration. The porosity of the samples was confirmed to be 40%–50% with the formation of the C3S matrices. Simultaneously, the maximum compressive strength was ensured at 14.9 MPa within 24 h of curing time. The radiopacity required for post‐procedural diagnosis was evaluated. The radiopacity of the samples with 50% and 60% C3S was 1.0 mm Al and 1.1 mm Al, respectively. When ZrO2 was added, the radiopacity was enhanced to 1.6 mm Al. Overall, the experimental results showed that the bone‐graft added C3S would be suitable for alveolar bone support and rigid matrix formation in implant surgery.

Non-tuberculous mycobacterial bone and joint infections - a case series from a tertiary referral centre in Australia.

Non-tuberculous mycobacteria (NTM) are rare causes of bone and joint infection (BJI) and there is limited evidence on which to base management decisions. This study describes 1 year of experience from a multi-disciplinary BJI team which collects data on all cases reviewed at a tertiary referral centre in Queensland, Australia. The database was interrogated for all cases in which NTM were recovered from operative samples. Individual chart review was performed to collect the details of each case. A total of seven cases were managed between 1st February 2021 and 28th February 2022, comprising one patient with chronic osteomyelitis, three with fracture-related infections, two with prosthetic joint infections, and one with infection of a synthetic ligament graft. In contrast to pulmonary NTM infections, most patients were clinically well and immunocompetent, and most infections were propagated by direct inoculation. Time to diagnosis was unknown in three patients, with 1, 2, 2, and 5 months for the remaining four. Rapid growing NTM were diagnosed on routine cultures and specific mycobacterial cultures were confirmatory. Management was characterized by multiple stage surgical procedures and prolonged antimicrobial regimens. Antimicrobial complications were common; however, all patients were infection free at their latest follow up. Despite the inherent limitations, these results suggest that routinely ordering mycobacterial culture is of low yield. There is potential for shorter-term oral antimicrobial treatments. Prospective research is required to optimize treatment regimens and durations.

Highly porous polycaprolactone microspheres for skeletal repair promote a mature bone cell phenotype in vitro.

Improving our ability to treat skeletal defects is a critical medical challenge that necessitates the development of new biomaterials. One promising approach involves the use of degradable polymer microparticles with an interconnected internal porosity. Here, we employed a double emulsion to generate such round microparticles (also known as microspheres) from a polycaprolactone-based polymerised high internal phase emulsion (polyHIPE). These microspheres effectively supported the growth of mesenchymal progenitors over a 30-day period, and when maintained in osteogenic media, cells deposited a bone-like extracellular matrix, as determined by histological staining for calcium and collagen. Interestingly, cells with an osteocyte-like morphology were observed within the core of the microspheres indicating the role of a physical environment comparable to native bone for this phenotype to occur. At later timepoints, these cultures had significantly increased mRNA expression of the osteocyte-specific markers dentin matrix phosphoprotein-1 (Dmp-1) and sclerostin, with sclerostin also observed at the protein level. Cells pre-cultured on porous microspheres exhibited enhanced survival rates compared to those pre-cultured on non-porous counterparts when injected. Cells precultured on both porous and non-porous microspheres promoted angiogenesis in a chorioallantoic membrane (CAM) assay. In summary, the polycaprolactone polyHIPE microspheres developed in this study exhibit significant promise as an alternative to traditional synthetic bone graft substitutes, offering a conducive environment for cell growth and differentiation, with the potential for better clinical outcomes in bone repair and regeneration.

Biomechanical evaluation of healing of critical-sized long bone defects in rats treated with biphasic hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP) bioceramic scaffolds

Critical-sized bone defects are those that would not heal spontaneously despite surgical stabilisation. These defects are treated using autografts, allografts, xenografts and synthetic bone grafts. The present study was undertaken to evaluate the efficacy of biphasic hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP) bioceramic scaffolds in treating critical-sized segmental bone loss in rats. The study was conducted in sixty male Wistar rats aged between 8-12 weeks, weighing 200-250 g body weight with critical-sized defects in the right femur. A six-mm segmental mid-diaphyseal femoral defect was created under general anaesthesia. The bone defect was bridged with biphasic hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP) bioceramic scaffolds and retained in position with microplate and screws. Fifteen rats were sacrificed as per the guidelines of CCSEA during the 4th, 8th, 12th and 16th week post-surgery. The treated bone and contralateral femur were harvested and subjected to a three-point bending test, torsion test and compression test to compare the regained strength of the repaired right femur with that of the intact contralateral left femur. From the present study, it was observed that the use of biphasic hydroxyapatite and β-tricalcium phosphate bioceramic scaffolds in the treatment of critical-sized long bone defects in rats resulted in biomechanical properties of the healed right femur greatly superior to the femur with untreated critical-sized diaphyseal defect by sixteenth week post-surgery and was only slightly inferior to the normal intact left femur. The results were suggestive of using biphasic hydroxyapatite and β-tricalcium phosphate bioceramics scaffolds as a safe and promising alternative for the treatment of critical-sized bone defects Keywords: Beta-tricalcium phosphate, bioceramic scaffold, compression test, hydroxyapatite, three-point bending test and torsion test

Distraction osteogenesis application in bone defect caused by osteomyelitis following mandibular fracture surgery: a case report and literature review

BackgroundOsteomyelitis secondary to mandibular fracture surgery is rare and complete surgical debridement of necrotic infected tissues is an optimal treatment for it. Subsequent reconstruction is required for bone defect caused by operation. Autogenous, allograft and synthetic bone graft substitutes have become widespread in bone defect treatment. Distraction osteogenesis (DO) was also applied in bone defect reconstruction, even it wasn’t conventional therapy in jaw.Case presentationHere we report a case of a 40-year-old aged man who presented with chronic swelling and pain on the right mandibular masseteric region after mandibular angle and Le Fort II fracture surgery. In six weeks after surgery, CBCT images showed that the fracture ends hadn’t heal and the fracture gap had widened significantly. The clinical diagnosis of the patient was right mandibular angle osteomyelitis. After controlling the symptoms of pain and infection with local rinses and systemic antibiotic therapy, the patient underwent segmental resection of the infected bone and DO reconstruction for bone defect simultaneously. Encouragingly, well bone healing and normal occlusion restoration was observed finally.ConclusionsDO could be a valuable alternative therapy to bone grafts for bone defect, even in the case of infection.

Treatment with a self-expanding endoprosthesis in patients with stenosis or occlusion at the arteriovenous graft: 6-Month outcomes of a post-marketing surveillance study.

To assess 6-month safety and efficacy of a self-expanding stent graft placement to treat stenotic or thrombosed synthetic arteriovenous access graft at the venous anastomoses. This prospective, multicenter, post-market surveillance study assessed the GORE® VIABAHN® Endoprosthesis (stent graft) in Japanese patients with stenotic or thrombosed vascular access grafts. Key efficacy and safety outcomes were primary patency (PP) and secondary patency (SP) of the target lesion and the vascular access circuit, repeat interventions, technical and clinical success, incidence of adverse and serious adverse events, and device deficiencies through 6 months. The 103 enrolled patients (mean age 71.8 years; 57.3% female) had stent grafts placed in the venous anastomosis of arteriovenous access grafts (on-label). The majority of lesions were stenotic (77.1%) and located in the upper arm (91.4%). Mean lesion length was 42.9 ± 23.6 mm and diameter was 6.7 ± 1.9 mm; 28 patients (27.2%) had elephant trunk placements. Technical and clinical success rates were 100%. At 6 months, Kaplan-Meier estimates of target lesion and circuit PP were 75.1% (95% CI: 65.2, 82.6) and 66.8% (95% CI: 56.4, 75.3), and SP rates were 93.8% (95% CI: 86.7, 97.2) and 93.8% (95% CI: 86.7, 97.2), respectively. Mean cumulative number of reinterventions (0.36; 95% CI: 0.20, 0.51) and incidence of device- or procedure-related adverse events were low (⩽3%). No device deficiencies were reported. The 6-month outcomes of the self-expanding stent graft to treat thrombosed venous anastomoses of synthetic hemodialysis vascular access grafts with stenosis demonstrated safety and effectiveness.

Patellar Tendon Ruptures after Total Knee Arthroplasty.

Patellar tendon (PT) rupture following total knee arthroplasty (TKA) is a rare, but devastating complication. These injuries occur most frequently in the acute period following TKA due to trauma to the knee. PT ruptures that disrupt the extensor mechanism create a marked functional deficit, impacting every facet of daily life. In complete ruptures of the PT, repair or reconstruction is typically indicated; however, complication rates following intervention remain high. Operative intervention remains the mainstay of treatment, with only certain specific situations where nonoperative intervention is appropriate. Operative techniques are chosen based on the acuity, location of disruption, and status of the residual soft tissues. Treatment options include repair with or without augmentation or reconstruction. Augmentation does reduce the high risk of complications, bringing rates down from 63 to 25%. Augmentation options include autografts, allografts, synthetic grafts, or synthetic meshes. Despite advancements, outcomes are unpredictable and complications are common, highlighting the need for further research to improve treatment protocols. This article provides an overview of PT ruptures following TKA, the various treatment options, and the recommendations of the M.M., R.D., G.S. for each common type of PT injury encountered.

Regional Differences in Vascular Graft Degradation and Regeneration Contribute to Dilation.

Severe coronary artery disease is often treated with a coronary artery bypass graft using an autologous blood vessel. When this is not available, a commercially available synthetic graft can be used as an alternative but is associated with high failure rates and complications. Therefore, the research focus has shifted toward the development of biodegradable, regenerative vascular grafts that can convert into neoarteries. We previously developed an electrospun tropoelastin (TE)-polyglycerol sebacate (PGS) vascular graft that rapidly regenerated into a neoartery, with a cellular composition and extracellular matrix approximating the native aorta. We noted, however, that the TE-PGS graft underwent dilation until sufficient neotissue had been regenerated. This study investigated the mechanisms behind the observed dilation following TE-PGS vascular graft implantation in mice. We saw more pronounced dilation at the graft middle compared with the graft proximal and graft distal regions at 8 weeks postimplantation. Histological analysis revealed less degradation at the graft middle, although the remaining graft material appeared pitted, suggesting compromised structural and mechanical integrity. We also observed delayed cellular infiltration and extracellular matrix (ECM) deposition at the graft middle, corresponding with the area's reduced ability to resist dilation. In contrast, the graft proximal region exhibited greater degradation and significantly enhanced cellular infiltration and ECM regeneration. The nonuniform dilation was attributed to the combined effect of the regional differences in graft degradation and arterial regeneration. Consideration of these findings is crucial for graft optimization prior to its use in clinical applications.

Urgent hybrid repair of a symptomatic dissection-related type ii thoracoabdominal aortic aneurysms.

Emergency repair of type II thoraco-abdominal aortic aneurysms is burdened by high perioperative morbidity and mortality. We report the case of a symptomatic type II post-dissection thoraco-abdominal aortic aneurysm that was treated by mean of a hybrid technique. The repair was carried out through two stages. In the first stage, we deployed two imbricated stent grafts in the descending thoracic aorta. A left carotid to left subclavian artery by-pass was preemptively performed in order to obtain a proper proximal landing zone and as part of the spinal cord protective maneuvers. The endovascular first stage was effective in obtaining proximal sealing but, as expected, did not prevent distal reperfusion of the aneurysmatic false lumen. Few hours later, we moved on to the second stage in which we repaired the aneurysmal distal thoracic and abdominal aortic segment by mean of a multibranched synthetic graft. The repair was carried out through a left thoracophrenolaparotomy in the VII intercostal space. A left passive arterial by-pass and selective cold renal and warm visceral perfusion were adopted in order to provide organ protection. Technical success was achieved and radiologically confirmed. The patient experienced a mild postoperative paraplegia, which almost completely regressed after a neuro-motor rehabilitation program.

THE EFFECTIVENESS OF THE FUNCTIONING OF RECONSTRUCTED HEPATIC VEINS USING VARIOUS TYPES OF MATERIALS IN TRANSPLANTATION OF THE RIGHT LOBE OF THE LIVER FROM A LIVING DONOR

Background. In adult living donor liver transplantation with the right lobe, the venous outflow of the anterior sector is typically restored during the procedure to form a neo-middle hepatic vein. Restoring the middle hepatic vein for the drainage of the anterior sector is critically important for achieving optimal graft function. Various conduits are used for this reconstruction, such as synthetic and biological grafts (e.g., the recipient's portal vein, vessels from a deceased donor, and modified great saphenous vein). However, the selection of the best option remains a topic of discussion. This study evaluates the effectiveness of using biological and synthetic grafts for MHV reconstruction. Materials and methods. A retrospective analysis of outcomes was conducted in patients who underwent transplantation of a modified right liver lobe due to end-stage liver disease from 2011 to 2024. Results. A transplantation of modified right liver lobes was performed on 80 patients. In 69 cases, the reconstruction of the hepatic veins was carried out using a biological graft, while in 11 cases, a synthetic graft was used. Statistically significant differences were noted in mortality and the postoperative period. No significant differences were found in the frequency of intraoperative complications. Conclusion. Our study demonstrates that the use of a biological graft for the reconstruction of the hepatic veins of segments 5 and 8 is more effective than the application of a vascular prosthesis.

Acute lower limb ischemia caused by repeat deployment of vascular closure device.

Vascular closure devices are used to facilitate faster hemostasis and earlier ambulation, improve patient comfort, and reduce length of hospital stay after percutaneous endovascular procedures. However, their use may rarely be associated with limb ischemia due to endothelial damage and arterial thrombosis. This report illustrates the case of a patient who experienced acute lower limb ischemia due to superficial femoral artery occlusion caused by repeat closure with Angio-Seal vascular closure device within 30 days in a small-caliber superficial femoral artery. The patient was surgically treated by vascular repair with a synthetic graft, and remains symptom-free in 3-year follow-up. Repeat deployment of vascular closure devices in the same access site within a period of 30 days may cause acute limb ischemia due to arterial thrombosis, especially in patients with small-caliber arteries, even in the absence of evident risk factors.