Titanium Alloy Mesh Research Articles

Reconstruction of the chest wall in locally advanced breast cancer with multi-disciplinary cooperation: a case report of mesh repair plus TRAM combined with DIEP chest wall reconstruction

Locally advanced breast cancer, which is defined as a malignant breast tumor that invades or adheres to the surrounding tissue, is characterized by the invasion of the chest wall and the skin surface by the tumor. Multiple lymph nodes are invaded and fuse into a mass, causing extensive axillary lymph node metastasis. However, locally advanced breast cancer does not exhibit distant metastasis. At present, in most hospitals in China and the rest of the world, this type of breast cancer is primarily managed through systematic and local treatments. However, a consensus concerning the optimal surgical method for chest wall reconstruction, which for many surgeons is a difficult and confusing procedure, has not been reached. In the past, many breast centers had used skin flap combined with hard mesh titanium alloy plate to repair the large chest wall defects. Although titanium alloy plate can maintain the stability of the chest wall, it may have a negative effect on the follow-up radiotherapy of breast cancer patients, which is a controversial method. In addition, titanium alloy mesh also has the risk of deformation and fracture. These factors will cause some hidden dangers to patient safety. According to the research, the soft mesh not only has the characteristics of satisfactory compatibility and robustness for maintaining the stability of chest wall, but also does not affect the postoperative radiotherapy of patients. Combined with the advantages of soft mesh, Our department treated a case of locally advanced breast cancer with chest wall invasion. Through cooperation between the breast surgery and thoracic surgery departments, a mesh repair plus transverse rectus abdominis myocutaneous (TRAM) combined with deep inferior epigastric perforator (DIEP) procedure was performed to remove the breast tumor and repair the large area of skin defect after surgery, and a relatively satisfactory therapeutic effect was achieved. In this case, we took two novel approaches: first, a 4-layer high-density polyethylene mesh was used to repair the defect; secondly, the inferior epigastric artery perforation was anastomosed with the thoracoacromial artery (end-to-end anastomosis) and the inferior epigastric vein perforation was anastomosed with the axillary vein (end-to-side anastomosis).

Biomechanical Evaluation and the Assisted 3D Printed Model in the Patient-Specific Preoperative Planning for Thoracic Spinal Tuberculosis: A Finite Element Analysis.

Posterior fixation is superior to anterior fixation in the correction of kyphosis and maintenance of spinal stability for the treatment of thoracic spinal tuberculosis. However, the process of selecting the appropriate spinal fixation method remains controversial, and preoperative biomechanical evaluation has not yet been investigated. In this study, we aimed to analyze the application of the assisted finite element analysis (FEA) and the three-dimensional (3D) printed model for the patient-specific preoperative planning of thoracic spinal tuberculosis. An adult patient with thoracic spinal tuberculosis was included. A finite element model of the T7−T11 thoracic spine segments was reconstructed to analyze the biomechanical effect of four different operative constructs. The von Mises stress values of the implants in the vertical axial load and flexion and extension conditions under a 400-N vertical axial pre-load and a 10-N⋅m moment were calculated and compared. A 3D printed model was used to describe and elucidate the patient’s condition and simulate the optimal surgical design. According to the biomechanical evaluation, the patient-specific preoperative surgical design was prepared for implementation. The anterior column, which was reconstructed with titanium alloy mesh and a bone graft with posterior fixation using seven pedicle screws (M+P) and performed at the T7–T11 level, decreased the von Mises stress placed on the right rod, T7 pedicle screw, and T11 pedicle. Moreover, the M+P evaded the left T9 screw without load bearing. The 3D printed model and preoperative surgical simulation enhanced the understanding of the patient’s condition and facilitated patient-specific preoperative planning. Good clinical results, including no complication of implants, negligible loss of the Cobb angle, and good bone fusion, were achieved using the M+P surgical design. In conclusion, M+P was recommended as the optimal method for preoperative planning since it enabled the preservation of the normal vertebra and prevented unnecessary internal fixation. Our study indicated that FEA and the assisted 3D printed model are tools that could be extremely useful and effective in the patient-specific preoperative planning for thoracic spinal tuberculosis, which can facilitate preoperative surgical simulation and biomechanical evaluation, as well as improve the understanding of the patient’s condition.

Application of 3D printing technology to thoracic wall tumor resection and thoracic wall reconstruction.

Thoracic wall tumors can leave large defects in the thoracic wall after tumor resection. Currently, the shape of the materials commonly used for thoracic wall repair, including dacron mesh and titanium alloy mesh, cannot readily conform to the shapes of defect sites. In this study, we aimed to retrospectively review and evaluate the outcomes of applying three-dimensional (3D) printing technology in assisting in thoracic wall tumor resection and thoracic wall construction. Six patients with thoracic wall tumors underwent thin-slice CT scanning. We 3D reconstructed pleural tumors and adjacent structures with Amira software and 3D printed them. Preoperative simulation, surgical rehearsal, and surgical planning were performed, and 3D conformal titanium plates were created based on 3D reconstruction models and sutured to the defect sites of the thoracic wall. We also retrospectively reviewed 10 patients who underwent this surgery with conventional methods. All of the demographic data, clinical data, and laboratory findings (non-normally distributed variables) were compared between these two groups. 3D reconstructions of the tumors and their adjacent structures were successfully performed, and 3D printing physical models and conformal titanium plates were also successfully obtained. The plate afforded accurate matching, less bleeding, fewer postoperative complications, and less pain. This 3D printing technology can aid in preoperative rehearsal, surgical planning, and the manufacturing of 3D implants. The 3D titanium plate has such advantages over traditional implants as having good fit and hardness, improving the surgical accuracy and curative effect, and reducing complications, such as bleeding and pain.

Interplay of topographical and biochemical cues in regulating osteoblast cellular activity in BMP-2 eluting three-dimensional cellular titanium alloy mesh structures.

The objective of this study is to elucidate the elution response of bone morphogenetic protein (BMP-2) in tuning cellular functions on 3D-printed titanium alloy mesh scaffolds subjected to microarc/plasma electrolytic oxidation process. The microtopographical cues enabled strong interaction with BMP-2 protein, which led to controlled release. Furthermore, the interaction of BMP-2 with the surface microtopographical cue regulated osteoblast cellular activity by contributing to the early phase differentiation and mineralization of osteoblasts. The in vitro BMP-2 release kinetics showed an initial burst of BMP-2 after day 1, followed by a controlled release on plasma electrolytic oxidized mesh structure. The profile represented that the rate of release decreased with increase in time on both as-fabricated and plasma electrolytic oxidized mesh structures after 24 h, with relatively higher degree on plasma electrolytic oxidized mesh structure. Furthermore, the in vitro osteoblast cellular activity indicated enhanced osteogenic induction on BMP-2 adsorbed plasma electrolytic oxidized mesh structure. Cells penetrated into micropores through several filopodia-like cellular extensions by increasing the area of contact, leading to stronger cell adhesion on BMP-2 adsorbed plasma electrolytic oxidized mesh structure. The up-regulation of biochemical markers and quantification of the expression level of cell secreted proteins underscored the determining role of BMP-2 eluting 3D mesh structure in modulating osteoblasts functions. The study emphasizes the potential of BMP-2 in rendering plasma electrolytic oxidized 3D-printed titanium alloy mesh structure osteoinductive and controlled delivery of BMP-2. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 49-60, 2019.

A minimum 20-year outcome of 100 consecutive alumina-on-alumina arthroplasties performed by a single surgeon.

Ceramic-on-ceramic (CoC) is currently a viable bearing combination in primary total hip arthroplasty (THA) and, due to its mechanical properties, it can be used in young patients requiring a long-lasting implant. The aim of this study is to report the results of a series of CoC THAs at a minimum 20 years follow-up. A retrospective study was conducted on the 1st 100 consecutive alumina-on-alumina arthroplasties performed by a single surgeon on 51 females and 40 males with an average age of 60.7 years. The mean preoperative Harris Hip Score was 35. The press-fit cup consisted of a pure titanium core with a titanium alloy mesh. Both the inlay and the head were made of dense polycrystalline surgical-grade alumina. The 32-mm femoral head was anchored on 3 different femoral components. 19 patients with 22 THAs were died or lost, 2 anatomic cementless stems were revised due to sinking, 1 THA was revised for periprosthetic infection. 2 patients sustained a Vancouver B1 periprosthetic femoral fracture. None of the 78 THAs eligible for this study were revised for wear, breakage, noise of the ceramic components. None of the cups, none of the cemented stems, none of the cementless straight stems failed. HHS raised up to a mean value of 95. The present report demonstrates that CoC coupling offers minimal wear at a long-term follow-up. Further studies are needed to evaluate whether the modern ceramic composites will confirm such excellent results in total hip replacement.

Copper-modified Ti6Al4V alloy fabricated by selective laser melting with pro-angiogenic and anti-inflammatory properties for potential guided bone regeneration applications

Custom-made biocompatible titanium alloy mesh can be designed to facilitate the regeneration of alveolar bone defects by supporting a protected space and inhibiting bacterial infections. Copper ions are often incorporated into titanium alloy due to their high bioactivity and outstanding antibacterial properties. However, the impacts of copper-bearing alloys on peri-implanted cell behaviors have rarely been systematically explored. In the present study, a copper-bearing alloy (Ti6Al4V-6Cu) was fabricated by selective laser melting (SLM) technology. The characterization of Ti6Al4V-6Cu alloy and its effects on the behaviors of gingival fibroblasts (HGFs), human umbilical vein endothelial cells (HUVECs), osteoblasts and macrophages were evaluated and compared with Ti6Al4V. The diffraction peaks of the Ti2Cu intermetallic phase were observed in the Ti6Al4V-6Cu alloy. Adding Cu enhanced the release of Ti and Al ions. The chemical state of Cu in the Ti6Al4V-6Cu alloy may exist predominantly in Cu2O or TiCuOx. Ti6Al4V-6Cu did not affect the attachment of HGFs or the osteogenic activity of osteoblasts. Furthermore, it inhibited the activation, proliferation, and pro-inflammatory cytokine secretion of macrophages and upregulated angiogenesis-related gene expression and VEGF-A secretion of HUVECs. These results demonstrate that a Ti6Al4V-6Cu alloy was successfully fabricated that did not negatively impact the cell viability of gingival fibroblasts and osteoblasts, inhibited the inflammatory response of macrophages, and increased the angiogenesis of HUVECs. Thus, Ti6Al4V-6Cu has potential applications for the fabrication of titanium alloy mesh to promote alveolar bone regeneration.

Surface nanotopography-induced favorable modulation of bioactivity and osteoconductive potential of anodized 3D printed Ti-6Al-4V alloy mesh structure.

The objective of the study described here is to fundamentally elucidate the biological response of 3D printed Ti-6Al-4V alloy mesh structures that were surface modified to introduce titania nanotubes with an average pore size of ∼80 nm via an electrochemical anodization process from the perspective of enhancing bioactivity. The bioactivity of the mesh structures were analyzed through immersion test in simulated body fluid, which confirmed the nucleation and growth of fine globular nanoscale apatite on the nanoporous titania-modified (anodized) mesh structure surface, and agglomerated apatite with fine flakes of apatite crystals on as-fabricated mesh structure surface, that were rich in calcium and phosphorous. The cellular activity of bioactive anodized mesh structure was explored in terms of cell-material interactions involving adhesion, proliferation, synthesis of extracellular and intracellular proteins, differentiation, and mineralization. Cells adhered with a sheet-like morphology on as-fabricated mesh structure, whereas, on anodized mesh structure, numerous filopodia-like cellular extensions interacting with nanotube pores were observed. The formation of a bioactive nanoscale apatite, cell-nanotube interactions as imaged via electron microscopy, higher expression of proteins (actin, vinculin, fibronectin, and alkaline phosphatase (ALP)), and calcium content points toward the determining role of anodized mesh structure in modulating osteoblasts functions. The unique combination of nanoporous bioactive titania and interconnected porous architecture of anodized titanium alloy mesh structure provided a multimodal roughness surface ranging from nano to micro to macroscale, which helps in attaining strong primary and secondary fixation of the implant device along with the pathway for supply of nutrients and oxygen to cells and tissue.

Advancements in three-dimensional titanium alloy mesh scaffolds fabricated by electron beam melting for biomedical devices: mechanical and biological aspects

We elucidate here the process-structure-property relationships in three-dimensional (3D) implantable titanium alloy biomaterials processed by electron beam melting (EBM) that is based on the principle of additive manufacturing. The conventional methods for processing of biomedical devices including freeze casting and sintering are limited because of the difficulties in adaptation at the host site and difference in the micro/macrostructure, mechanical, and physical properties with the host tissue. In this regard, EBM has a unique advantage of processing patient-specific complex designs, which can be either obtained from the computed tomography (CT) scan of the defect site or through a computeraided design (CAD) program. This review introduces and summarizes the evolution and underlying reasons that have motivated 3D printing of scaffolds for tissue regeneration. The overview comprises of two parts for obtaining ultimate functionalities. The first part focuses on obtaining the ultimate functionalities in terms of mechanical properties of 3D titanium alloy scaffolds fabricated by EBM with different characteristics based on design, unit cell, processing parameters, scan speed, porosity, and heat treatment. The second part focuses on the advancement of enhancing biological responses of these 3D scaffolds and the influence of surface modification on cell-material interactions. The overview concludes with a discussion on the clinical trials of these 3D porous scaffolds illustrating their potential in meeting the current needs of the biomedical industry.

Partial resection and reconstruction of the sternum for treatment of metachronous sternal metastasis of thyroid carcinoma

Rationale:Metachronous sternal metastasis of thyroid carcinoma was a rare disease. There was no consensus in the treatment for bone metastasis after the initial thyroid carcinoma surgery.Patient concerns:A 53-year-old female patient was hospitalized due to recurrent dull chest pains, with a history of radical right side thyroid carcinoma 4 years ago. On examination, there was an irregular mass on the lower left half of the sternum. Computerized tomography scan showed sternal bone destruction with a soft tissue mass.Diagnoses:Metachronous sternal metastasis of thyroid carcinoma.Interventions:Partial resection of the sternum and reconstruction with a titanium alloy mesh were performed.Outcomes:After a 3-year follow-up, the patient had no recurrence.Lessons:Surgical resection may be a sufficient treatment for metachronous sternal metastasis of thyroid carcinoma. Biosynthesis material mesh is preferred to be used.

Functional response of osteoblasts in functionally gradient titanium alloy mesh arrays processed by 3D additive manufacturing

We elucidate here the osteoblasts functions and cellular activity in 3D printed interconnected porous architecture of functionally gradient Ti-6Al-4V alloy mesh structures in terms of cell proliferation and growth, distribution of cell nuclei, synthesis of proteins (actin, vinculin, and fibronectin), and calcium deposition. Cell culture studies with pre-osteoblasts indicated that the interconnected porous architecture of functionally gradient mesh arrays was conducive to osteoblast functions. However, there were statistically significant differences in the cellular response depending on the pore size in the functionally gradient structure. The interconnected porous architecture contributed to the distribution of cells from the large pore size (G1) to the small pore size (G3), with consequent synthesis of extracellular matrix and calcium precipitation. The gradient mesh structure significantly impacted cell adhesion and influenced the proliferation stage, such that there was high distribution of cells on struts of the gradient mesh structure. Actin and vinculin showed a significant difference in normalized expression level of protein per cell, which was absent in the case of fibronectin. Osteoblasts present on mesh struts formed a confluent sheet, bridging the pores through numerous cytoplasmic extensions. The gradient mesh structure fabricated by electron beam melting was explored to obtain fundamental insights on cellular activity with respect to osteoblast functions.

The application of computer-aided designated titanium mesh in repairing skull defects

Objective To explore the clinical value of repairing skull defects with titanium alloy-mesh of computer-aided design. Methods A retrospective analysis was done on clinical data of 86 cases with skull defects who underwent repairing using titanium mesh with two-dimensional or three-dimensional computer-aided design. Results All the incisions achieved primary healing other than one case conducting reoperation due to exposed titanium mesh. Two cases got subcutaneous exudate, one obtained painful mastication and one experienced proliferation of scalp scar. Conclusions With the computer-aided designated titanium mesh, relevant operation can resume the original state to maximum extent, lower surgical risk, decrease post-operational complications and then obtain satisfying clinical effect. DOI: 10.3969/j.issn.1672-6731.2015.01.015

In vitro evaluation of a low-modulus mesh canine prosthetic hip stem

To compare an electron beam melting-processed (EBMP) low-modulus titanium alloy mesh stem with a commercial cobalt-chromium (CC) stem in a canine cadaver model. 9 pairs of cadaver femora. EBMP stems of 3 sizes were placed in randomly chosen sides of femora (left or right) and CC stems in opposite sides. Stem impaction distances were recorded. Five strain gauges were attached to the femoral surface to record transverse tensile (hoop) strains in the femur during axial loading. Constructs were axially loaded 4 times to 800 N and 4 times to 1,600 N in a materials testing machine. Axial stiffness of constructs and bone surface strains were compared between EBMP and CC constructs. Stems were impacted without creating femoral fissures or fractures. Stem impaction distances were larger for EBMP stems than for CC stems. Mean axial stiffness of EBMP constructs was lower than mean axial stiffness of CC constructs. Subsidence did not differ between groups. Bone strains varied among strain gauge positions and were largest at the distal aspect of the stems. At a load of 1,600 N, bones strains were higher in CC constructs than in EBMP constructs for 2 of 4 medial strain gauges. EBMP stems were successfully impacted and stable and led to a focal decrease in bone strain; this may represent an acceptable option for conventional or custom joint replacement.

Effects of estrogen deficiency on the growth of tissue into porous titanium implants.

The effect of systemic deficiency of estrogen on the growth of tissue into porous titanium-fiber implants was studied in ovariectomized Beagle dogs. Five dogs were ovariectomized and five dogs had a sham operation. After waiting four months to allow the levels of circulating estrogen to decline, a titanium-alloy implant that contained four surface pads of titanium-alloy mesh was implanted in the proximal part of the humerus of each dog bilaterally. Two months later, the implants were harvested and subjected to a mechanical push-out test and quantitative histological study. The push-out strength of the implants from the ovariectomized dogs was 31 per cent less than in the control animals. Ovariectomy caused no difference in the amount of ingrowth of bone but resulted in a significant increase in the amount of fibrous connective tissue within the porous pads. The presence of this fibrous tissue appeared to have an important effect on bone-implant fixation: in the control dogs, strength correlated positively with ingrowth of bone and negatively with ingrowth of fibrous tissue, whereas in the ovariectomized dogs, strength correlated positively with ingrowth of fibrous tissue and not at all with ingrowth of bone.