Immediate mandibular reconstruction via patient-specific titanium mesh tray using electron beam melting/CAD/rapid prototyping techniques: One-year follow-up

2018 ◽  
Vol 14 (3) ◽  
pp. e1895
Author(s):  
Mohamed Farid Shehab ◽  
Nabila Mohammed Abdel Hamid ◽  
Nevien Abdullatif Askar ◽  
Ahmed Mokhtar Elmardenly
Keyword(s):  
Electron Beam ◽  
Rapid Prototyping ◽  
Electron Beam Melting ◽  
Mandibular Reconstruction ◽  
Patient Specific ◽  
Titanium Mesh ◽  
One Year

scholarly journals Custom-Made Titanium Mesh Tray for Mandibular Reconstruction Using an Electron Beam Melting System

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6556
Author(s):  
Isao Hoshi ◽  
Tadashi Kawai ◽  
Shingo Kurosu ◽  
Tadaharu Minamino ◽  
Kei Onodera ◽  
...  
Keyword(s):  
Electron Beam ◽  
Mechanical Strength ◽  
Electron Beam Melting ◽  
Maxillofacial Surgery ◽  
Honeycomb Structure ◽  
Mandibular Reconstruction ◽  
Titanium Mesh ◽  
Custom Made ◽  
Computer Aided ◽  
Sufficient Strength

Mandibular reconstruction using a titanium mesh tray and autologous bone is a common procedure in oral and maxillofacial surgery. However, there can be material problems—such as broken titanium mesh trays—which may undermine long-term functionality. This study was designed to investigate the optimal conditions for a titanium mesh tray with an ideal mandibular shape and sufficient strength, using computer-aided design, computer-aided manufacturing technology, and electron beam additive manufacturing. Specimens were prepared using Ti-6Al-4V extra low interstitial titanium alloy powder and an electron beam melting (EBM) system. The mechanical strength of the plate-shaped specimens was examined for differences in the stretch direction with respect to the stacking direction and the presence or absence of surface treatment. While evaluating the mechanical strength of the tray-shaped specimens, the topology was optimized and specimens with a honeycomb structure were also verified. Excellent mechanical strength was observed under the condition that the specimen was stretched vertically in the stacking direction and the surface was treated. The results of the tray-shaped specimens indicated that the thickness was 1.2 mm, the weight reduction rate was 20%, and the addition of a honeycomb structure could withstand an assumed bite force of 2000 N. This study suggests that the EBM system could be a useful technique for preparing custom-made titanium mesh trays of sufficient strength for mandibular reconstruction by arranging various manufacturing conditions.

Risk Forecast of In-Stent Restenosis by CFD Method

2014 ◽  
Vol 553 ◽  
pp. 235-239
Author(s):  
Chang Yan Lin ◽  
Xiu Jian Liu ◽  
Yu Yang Liu ◽  
Chuang Ye Xu ◽  
Guang Hui Wu
Keyword(s):  
Arterial Wall ◽  
Patient Specific ◽  
Stent Restenosis ◽  
Stent Treatment ◽  
Bifurcation Lesions ◽  
Risk Forecast ◽  
One Year ◽  
Cfd Method ◽  
In Stent Restenosis

The treatment of plaques near and involving coronary bifurcations (CB) is especially challenging, considering more plaques localized these regions and higher post-interventional in-stent restenosis (ISR) risk, mainly due to hemodynamic injury provoked on the arterial wall. Therefore optimization of stenting should begin with an understanding of how disease localized to these regions and why ISR formed associated with flow patterns. We chose four patients with bifurcation lesions, two patients with ISR and two without ISR according to the follow-up computed tomography angiography (CTA). Based on patient-specific pre-interventional and virtual stented geometries from CTA images, numerical simulation indicated that the wall shear stress (WSS) in stented segments, where the ISR occurred in one year, was lower than those without ISR, however. For bifurcation lesion, the stenting segments WSS is supposed a marker to forecast the ISR risk after stent treatment.

scholarly journals What are the Risk Factors for Worse Outcomes of Meniscus Surgery in 23-39-Year-Old Patients Ligamentously Stable Knees?

2020 ◽  
Vol 8 (7_suppl6) ◽  
pp. 2325967120S0046
Author(s):  
◽  
Megan Flynn ◽  
Anthony Egger ◽  
Yuxuan Jin ◽  
Elizabeth Sosic ◽  
...  
Keyword(s):  
Risk Factors ◽  
Young Adult ◽  
Patient Reported Outcomes ◽  
Meniscal Repair ◽  
Patient Specific ◽  
Lower Baseline ◽  
Patient Reported ◽  
Grade 3 ◽  
One Year

Objectives: Meniscus tears are a common and significant source of knee dysfunction in active young adult patients, and no high-quality prospective cohort or RCTs studies exist evaluating patient-reported outcomes in patients in this age group with ligamentously stable knees. Our objective was to identify patient-reported outcomes and patient-specific risk factors from a prospective cohort with a minimum of one-year follow-up following meniscal repair or excision in patients with ligamentously stable knees. We hypothesized that both groups would have significant improvement in outcomes; patients undergoing meniscal repair would have a higher reoperation rate; and articular cartilage injuries, subsequent knee surgery, and certain demographic characteristics would be significant risk factors to inferior outcomes at one year. Methods: Between February 2015 and December 2017, ligamentously stable meniscal procedures were enrolled and prospectively followed using the outcomes management evaluation system (OME) at Cleveland Clinic. Patients aged 23-39 preoperatively completed a series of validated outcome measurements including the Knee Injury and Osteoarthritis Outcome Score for both Pain (KOOS Pain) and Quality of Life (KOOS QoL). At the time of surgery, physicians documented all intra-articular findings, treatment, and surgical techniques utilized. Patients were followed at minimum of 1-year postoperatively through the OME platform and asked to complete the same outcome instruments done at baseline as well as a question designed to evaluate the Patient Acceptable Symptom State (PASS). The incidence and details of any subsequent knee surgeries were also obtained. Multivariable regression analysis was used to identify significant predictors of outcomes. Results: A total of 371 patients aged 23-39 underwent meniscus excision or repair during the study period. One hundred ninety-four met inclusion criteria, and one-year follow-up was obtained on 72% (n = 139) of the cohort (67% male; median age 32). Both KOOS Pain and KOOS QoL improved significantly at one-year for the entire cohort. Fourteen percent of the cohort (9% on the ipsilateral knee, 5% on the contralateral knee) underwent subsequent surgery at a minimum of one-year postoperatively. The patient-specific risk factors for worse one-year outcomes included preoperative baseline mental capacity score (VR-12 MCS), lower baseline KOOS QoL score, and the intraoperative finding of any grade 3 or 4 chondral changes. Conclusion: Young adult patients with ligamentously stable knees undergoing meniscal surgery have significantly improved patient-reported outcomes regardless of excision or repair; however, 14% of patients underwent additional knee surgery at a minimum of one-year postoperatively. The risk factors for worse outcomes include lower baseline mental health score, lower baseline KOOS QoL score, and any grade 3 or 4 chondromalacia scene.

scholarly journals Efficient hydrogen release from perhydro-N-ethylcarbazole using catalyst-coated metallic structures produced by selective electron beam melting

2015 ◽  
Vol 8 (2) ◽  
pp. 641-649 ◽  
Author(s):  
W. Peters ◽  
M. Eypasch ◽  
T. Frank ◽  
J. Schwerdtfeger ◽  
C. Körner ◽  
...  
Keyword(s):  
Electron Beam ◽  
Rapid Prototyping ◽  
Continuous Flow ◽  
Electron Beam Melting ◽  
Hydrogen Release ◽  
Metallic Structures ◽  
Selective Electron Beam Melting

Perhydro-N-ethyl carbazole is dehydrogenated in continuous flow using a reactor produced by rapid prototyping, releasing hydrogen equivalent to 4.32 kWel L−1.

scholarly journals Early experience and patient-reported outcomes of 503 INFINITY total ankle arthroplasties

2021 ◽  
Vol 103-B (7) ◽  
pp. 1270-1276
Author(s):  
David N. Townshend ◽  
Andrew J. F. Bing ◽  
Timothy M. Clough ◽  
Ian T. Sharpe ◽  
Andy Goldberg ◽  
...  
Keyword(s):  
Functional Outcome ◽  
Early Experience ◽  
Outcome Data ◽  
Patient Specific ◽  
Patient Specific Instrumentation ◽  
Significant Difference ◽  
Patient Reported ◽  
The Mean ◽  
One Year

Aims This is a multicentre, non-inventor, prospective observational study of 503 INFINITY fixed bearing total ankle arthroplasties (TAAs). We report our early experience, complications, and radiological and functional outcomes. Methods Patients were recruited from 11 specialist centres between June 2016 and November 2019. Demographic, radiological, and functional outcome data (Ankle Osteoarthritis Scale, Manchester Oxford Questionnaire, and EuroQol five-dimension five-level score) were collected preoperatively, at six months, one year, and two years. The Canadian Orthopaedic Foot and Ankle Society (COFAS) grading system was used to stratify deformity. Early and late complications and reoperations were recorded as adverse events. Radiographs were assessed for lucencies, cysts, and/or subsidence. Results In all, 500 patients reached six-month follow-up, 420 reached one-year follow-up, and 188 reached two-year follow-up. The mean age was 67.8 years (23.9 to 88.5). A total of 38 patients (7.5%) presented with inflammatory arthritis. A total of 101 (20.0%) of implantations used patient-specific instrumentation; 167 patients (33.1%) underwent an additional procedure at the time of surgery. A total of seven patients died of unrelated causes, two withdrew, and one was lost to follow-up. The mean follow-up was 16.2 months (6 to 36). There was a significant improvement from baseline across all functional outcome scores at six months, one, and two years. There was no significant difference in outcomes with the use of patient-specific instrumentation, type of arthritis, or COFAS type. Five (1.0%) implants were revised. The overall complication rate was 8.8%. The non-revision reoperation rate was 1.4%. The 30-day readmission rate was 1.2% and the one-year mortality 0.74%. Conclusion The early experience and complications reported in this study support the current use of the INFINITY TAA as a safe and effective implant in the treatment of end-stage ankle arthritis. Cite this article: Bone Joint J 2021;103-B(7):1270–1276.

scholarly journals Mechanical Evaluation of Collapse Risk for Osteonecrosis of Femoral Head Post-Medical Treatment

2021 ◽  
Author(s):  
Yuqian Mei ◽  
Qi Tang ◽  
Songhao Chen ◽  
Duanduan Chen
Keyword(s):  
Femoral Head ◽  
Medical Treatment ◽  
Early Stage ◽  
Equivalent Stress ◽  
Stress Index ◽  
Patient Specific ◽  
Relative Stress ◽  
The Mean ◽  
One Year

Abstract Background: Early-stage osteonecrosis of the femoral head can progressively induce the bone collapse and the accuracy of the collapse risk evaluation is limited. This study aims to propose a potential collapse indicator by biomechanical evaluating the treatment effectiveness. Methods: Six patient-specific models pre- (initial presentation) and post- medical treatment were established and elastic properties of the bone were assigned with a function of spatial-variant Hounsfield unit values. Morphological and mechanical analyses were compared between pre- and post-treatment models. Results: In the morphological study, four cases show the reduced ratio of low-density necrotic volume, but not consistent with one-year follow-up results. In the mechanical analysis, the equivalent stress variation near the Ward triangle shows consistency in the one-year outcome. Moreover, a parameter - relative stress index, the ratio between the mean volume stress index and the mean volume equivalent stress, is proposed. A smaller value of the relative stress index indicates stronger bone compressive strength and its variation is consistent with the follow-up results. Conclusions: Results implicate that to evaluate the effectiveness of medical treatments, the morphologic analysis should be considered but the mechanical capability and the loading transfer path through the necrotic and viable bone play a more important role.

Abstract 16230: Pulmonary Autograft Wall Stresses One Year After Ross Operation

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Edgardo Alonso ◽  
Yue XUAN ◽  
Alexander Emmott ◽  
Zhongjie Wang ◽  
Shalni Kumar ◽  
...  
Keyword(s):  
Ascending Aorta ◽  
Patient Specific ◽  
Principal Stresses ◽  
Ross Operation ◽  
Children And Young Adults ◽  
Specific Material ◽  
One Year ◽  
Patients Experience

Introduction: The Ross procedure is an excellent option for children and young adults who need aortic valve replacement as this surgery can restore patient survival to that of a normal sex and aged-matched population. However, some patients experience aneurysmal formation during autograft remodeling and require reoperation. As the underlying biomechanics of autograft remodeling are unknown, we investigated patient-specific wall stresses in pulmonary autografts one year post-operatively to better understand systemic pressure-driven early autograft wall stresses. Methods: Ross patients (n=16) who underwent intraoperative collection of pulmonary root/aortic specimen, and subsequent one-year MRI follow-up were recruited. Patient-specific material properties from their tissue were experimentally determined and incorporated into autograft ± Dacron and ascending aorta finite element models. A multiplicative approach was used to account for pre-stress geometry from in-vivo MRI. Physiologic pressure loading was simulated with LS-DYNA software. Results: At systemic systole, first principal stresses were 567kPa (25-75% IQR, 485-675kPa), 809kPa (691-1219kPa), and 382kPa (334-413kPa) at autograft sinuses, sinotubular junction (STJ), and ascending aorta, respectively. Second principal stresses were 355kPa (320-394kPa), 360kPa (310-426kPa), and 184kPa (147-222kPa) at autograft sinuses, STJ, and ascending aorta, respectively. Mean autograft diameters were 38.3±5.3mm, 29.9±2.7mm, and 26.6±4.0mm at sinuses, STJ, and annulus, respectively. Conclusions: First principal stresses were mainly located at STJ, particularly when Dacron reinforcement was applied to constrain STJ dilatation. However, at one-year after the Ross operation, autograft dilatation was not seen despite elevated autograft wall stresses compared to their internal controls, the lower wall stresses in corresponding native distal ascending aorta. In this group of patients, higher risk of dilatation is expected in the sinuses and STJ if not constrained by Dacron than the corresponding ascending aorta. Future follow-up will elucidate the biomechanics of long-term autograft remodeling to develop predictive models for autograft dilatation.

scholarly journals Next Generation Orthopaedic Implants by Additive Manufacturing Using Electron Beam Melting

2012 ◽  
Vol 2012 ◽  
pp. 1-14 ◽  
Author(s):  
Lawrence E. Murr ◽  
Sara M. Gaytan ◽  
Edwin Martinez ◽  
Frank Medina ◽  
Ryan B. Wicker
Keyword(s):  
Mechanical Properties ◽  
Electron Beam ◽  
Additive Manufacturing ◽  
Electron Beam Melting ◽  
Stress Shielding ◽  
Bone Cell ◽  
Cellular Structures ◽  
Patient Specific ◽  
Porous Structures ◽  
Orthopaedic Implants

This paper presents some examples of knee and hip implant components containing porous structures and fabricated in monolithic forms utilizing electron beam melting (EBM). In addition, utilizing stiffness or relative stiffness versus relative density design plots for open-cellular structures (mesh and foam components) of Ti-6Al-4V and Co-29Cr-6Mo alloy fabricated by EBM, it is demonstrated that stiffness-compatible implants can be fabricated for optimal stress shielding for bone regimes as well as bone cell ingrowth. Implications for the fabrication of patient-specific, monolithic, multifunctional orthopaedic implants using EBM are described along with microstructures and mechanical properties characteristic of both Ti-6Al-4V and Co-29Cr-6Mo alloy prototypes, including both solid and open-cellular prototypes manufactured by additive manufacturing (AM) using EBM.

Sign in / Sign up

Export Citation Format

Share Document