Technical Overview of Osseointegrated Transfemoral Prostheses: Orthopedic Surgery and Implant Design Centered

2018 ◽  
Vol 1 (2) ◽  
Author(s):  
Andrii Maryniak ◽  
Brock Laschowski ◽  
Jan Andrysek
Keyword(s):  
Bacterial Infections ◽  
Implant Design ◽  
Medical Complication ◽  
Cobalt Chromium ◽  
Coagulase Negative Staphylococci ◽  
Postoperative Rehabilitation ◽  
Intraoperative Procedures ◽  
Osseointegrated Implants ◽  
Transfemoral Prosthesis ◽  
Cobalt Chromium Molybdenum

Bone-anchored prostheses represent a promising solution to numerous medical complications associated with conventional socket-suspended prostheses. The following technical overview was constructed for engineers and orthopedic surgeons interested in osseointegrated implants for transfemoral prosthesis-residuum interfacing. Existing osseointegrated implants comprise different biomaterial compositions (i.e., titanium alloy versus cobalt-chromium-molybdenum alloy) and mechanical designs (i.e., screw-fixated versus press-fixated devices). Perioperative systems of osseointegration surgery include preoperative assessments (i.e., alongside inclusion and exclusion criteria), intraoperative procedures, and postoperative rehabilitation (i.e., static loading and dynamic gait rehabilitation). The intraoperative procedures involve transecting and reorganizing the residual musculature, embedding the implant into the femoral intramedullary cavity, and coupling the osseointegrated implant to an external prosthesis. Postoperative clinical evaluations have demonstrated significant biomechanical, psychological, and physiological improvements in patients using bone-anchored prostheses compared to conventional socket-suspended prostheses. Nevertheless, bacterial infections surrounding the skin-implant bio-interface, often resulting from Staphylococcus aureus or other coagulase-negative staphylococci, remain a relatively frequent medical complication, which can culminate in periprosthetic osteomyelitis and/or implant extraction. The technical overview concludes with discussing the recent Food and Drug Administration humanitarian use device designations, financial analyses between bone-anchored prostheses and socket-suspended prostheses, and applications of vibrotactile osseoperception for augmenting walking and balance feedback control.

UGI KC35N

Alloy Digest ◽  
2014 ◽  
Vol 63 (12) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Shear Strength ◽  
Physical Properties ◽  
Heat Treating ◽  
Molybdenum Alloy ◽  
Cobalt Chromium ◽  
Austenitic Structure ◽  
Nickel Cobalt ◽  
Cobalt Chromium Molybdenum

Abstract UGI KC35N is a nonmagnetic nickel-cobalt-chromium-molybdenum alloy with a fully austenitic structure. This datasheet provides information on composition, physical properties, elasticity, and shear strength. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Co-124. Producer or source: Schmolz + Bickenbach USA Inc..

#53: High Burden of Serious Bacterial Infections in African Children Treated for Cancer

2021 ◽  
Vol 10 (Supplement_1) ◽  
pp. S6-S6
Author(s):  
G Naidu ◽  
A Izu ◽  
R Wainwright ◽  
S Poyiadjis ◽  
D MacKinnon ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Case Fatality ◽  
Morbidity And Mortality ◽  
Coagulase Negative Staphylococci ◽  
Children With Cancer ◽  
Indwelling Catheter ◽  
High Burden ◽  
African Children ◽  
Serious Bacterial Infections ◽  
Living With Hiv

Abstract Background Infectious complications in children treated for cancer contribute to their morbidity and mortality. There is a paucity of studies on the incidence, microbiological etiology, risk factors, and outcome of serious bacterial infections in African children treated for cancer. Aim The aim of the study was to delineate the epidemiology of infectious morbidity and mortality in South African children with cancer. Methods This prospective, single-center, longitudinal-cohort study enrolled children one-19 years old hospitalized for cancer treatment at the Paediatric Oncology Unit, Chris Hani Baragwanath Academic Hospital, Soweto, South Africa. Children were investigated for infection as part of the standard of care. Results In total, 169 children were enrolled, 82 with hematological malignancy (HM), 87 with a solid tumor (ST), median age was 68.5 months and 10.7% were living with HIV. The incidence (per 100 child-years) of septic episodes (SE) and microbiologically confirmed SE (MSCE) was 101 (138 vs. 70, P < 0.001) and 70.9 (99.1 vs. 47.3; P < 0.001), respectively; higher in children with HM than ST. The incidence of MCSE in children with high-risk HM (137.7) was 4.32-fold greater compared with those with medium-risk HM (30.3; P < 0.001). Children with metastatic ST had a higher incidence (84.4) of MSCE than those with localized ST (33.6; aOR: 2.52; P < 0.001). The presence of an indwelling catheter was 3-fold (P < 0.001) more likely to be associated with MCSE compared with those without. There was no association for age group, nutritional status or HIV-status, and incidence of MCSE. The incidence of gram-positive (GPB) and gram-negative (GNB) SEs was 48.5 and 37.6, respectively, and higher in children with an HM. The most commonly identified GPB were Coagulase-negative Staphylococci, Streptococcus viridans and Enterococcus faecium; while the most common GNB were Escherichia coli, Acinetobacter baumannii, and Pseudomonas species. The median CRP was higher in children with MSCE compared with those with culture-negative SE (CNSE) (116.5 vs. 92; P < 0.001) in both HM (132.5 vs. 117; P < 0.001) and ST (87.5 vs. 46; P < 0.001). The procalcitonin was higher in those with MSCE compared with those with CNSE (2.30 vs. 1.40; P < 0.001) in both HM (2.95 vs. 1.60; P = 0.002) and ST (2.10 vs. 1.20; P < 0.001). The case fatality risk was 40.4%; 80% was attributed to sepsis. Of these, 35 (72.92%) had HM and 34 of the 35 (97.14%) had HR-HM. Children with HM had an overall sepsis CFR of 42.68%. Four (30.77%) of the 13 sepsis-related deaths in STs had metastatic disease and 8 (16.67%) of the total number of sepsis-related deaths were in children living with HIV. There was no association between malnutrition or HIV-positivity and death. The odds of dying from sepsis were higher in children with profound (aOR 3.96; P = 0.004) and prolonged (aOR 3.71; P = 0.011) neutropenia. Pneumonia (58.85% vs. 29.23%; aOR 2.38; P = 0.025) and tuberculosis (70.83% vs. 34.91%; aOR 4.3; P = 0.005) were independently associated with a higher CFR. Conclusion The current study emphasizes the high burden of sepsis in African children treated for cancer, and especially HM, and highlights the association of tuberculosis and pneumonia as independent predictors of death in children with cancer.

scholarly journals Prediction of tool-wear in turning of medical grade cobalt chromium molybdenum alloy (ASTM F75) using non-parametric Bayesian models

2017 ◽  
Vol 30 (3) ◽  
pp. 1259-1270 ◽  
Author(s):  
Damien McParland ◽  
Szymon Baron ◽  
Sarah O’Rourke ◽  
Denis Dowling ◽  
Eamonn Ahearne ◽  
...  
Keyword(s):  
Tool Wear ◽  
Bayesian Models ◽  
Molybdenum Alloy ◽  
Cobalt Chromium ◽  
Astm F75 ◽  
Cobalt Chromium Molybdenum ◽  
Medical Grade ◽  
Non Parametric

scholarly journals Surface treatment on cobalt and titanium alloys using picosecond laser pulses in burst mode

2020 ◽  
Vol 127 (1) ◽  
Author(s):  
Daniel Metzner ◽  
Peter Lickschat ◽  
Steffen Weißmantel
Keyword(s):  
Surface Treatment ◽  
Picosecond Laser ◽  
Laser Pulses ◽  
Laser Source ◽  
Time Interval ◽  
Cobalt Chromium ◽  
Burst Mode ◽  
Self Organized ◽  
Implant Alloys ◽  
Cobalt Chromium Molybdenum

AbstractThe authors report on the results of surface treatment experiments using a solid-state amplified laser source emitting laser pulses with a pulse duration of 10 ps. The laser source allows the generation of pulse trains (bursts) with an intra-burst pulse repetition rate of 80 MHz (pulse-to-pulse time interval about 12.5 ns) with up to eight pulses per burst. In this study a wavelength of 1064 nm was used to investigate both ablation of material and laser-induced surface modifications occuring in metallic implant alloys CoCrMo (cobalt-chromium-molybdenum) and TiAlV (titanium-aluminum-vanadium) in dependence of the number of pulses and fluences per pulse in the burst. By using the burst mode, a smoothing effect occurs in a certain parameter range, resulting in very low surface roughness of the generated microstructures. It is demonstrated that at fluences per pulse which are smaller than the material-specific ablation threshold, a self-organized pore formation takes place if a defined number of pulses per burst is used. Thus, the advantage of the MHz burst mode in terms of a possible surface modification is established.

scholarly journals Peri-implant cartilage and bone histological changes following treatment of focal osteochondral defects in the femoral head with polyether ether ketone implants versus cobalt chromium molybdenum alloy implants: assessment in a goat model

2020 ◽  
Author(s):  
Zhiguo Yuan ◽  
Wei Zhang ◽  
Xiangchao Meng ◽  
Jue Zhang ◽  
Teng TengLong ◽  
...  
Keyword(s):  
Femoral Head ◽  
Osteochondral Defect ◽  
Osteochondral Defects ◽  
Cobalt Chromium ◽  
Cocrmo Alloy ◽  
Polyether Ether Ketone ◽  
Histological Score ◽  
Ether Ketone ◽  
Cobalt Chromium Molybdenum

Abstract Objective: This study aimed to quantitatively investigate the peri-implant histology of applying defect-size polyether ether ketone (PEEK) implant for the treatment of localized osteochondral defects in the femoral head and compared it with cobalt chromium molybdenum (CoCrMo) alloy implant.Methods: A femoral head osteochondral defect model was created in the left hips of goats (n=12). Defects were randomly treated by immediate placement of a PEEK (n=6) or CoCrMo implant (n=6). The un-operated right hip joints served as a control. Goats were sacrificed at 12 weeks. Periprosthetic cartilage quality was semi-quantitatively analyzed macroscopically and microscopically. Implant osseointegration was measured by micro-CT and histomorphometry.Results: The modified macroscopic articular evaluation score in the PEEK group was lower than that in the CoCrMo group (p<0.05), and the histological score of the periprosthetic and acetabular cartilage in the PEEK group was lower than that in the CoCrMo group (P<0.05). The mean bone-implant contact for PEEK implants was comparable with that for CoCrMo alloy implants at 12 weeks.Conclusions: A PEEK implant for the treatment of local osteochondral defect in the femoral head demonstrated effective fixation and superior in vivo cartilage protection compared with an identical CoCrMo alloy implant.

Microstructure and Mechanical Properties Study of CoCrMo Parts Sintered under Control Atmosphere

2016 ◽  
Vol 1133 ◽  
pp. 85-89
Author(s):  
Mohamad Azmirruddin Ahmad ◽  
Fazira Suriani Mohamed Fadzil ◽  
Mazlan Mohamad ◽  
Mohamad Hasnan Abdul Hamid ◽  
Mohd Asri Selamat
Keyword(s):  
Mechanical Properties ◽  
Sintering Temperature ◽  
Inert Gases ◽  
Cobalt Chromium ◽  
Sintered Compact ◽  
Sintering Atmosphere ◽  
Knee Replacements ◽  
Powder Pressing ◽  
Cobalt Chromium Molybdenum ◽  
Bio Compatibility

Their excellent properties, such as corrosion resistance, fatigue strength and bio-compatibility, made Cobalt-chromium-molybdenum (CoCrMo) were used in total hip and knee replacements and dental devices. The green CoCrMo compacts specimens in rectangle shape were fabricated by powder pressing technique. The effects of sintering temperature and atmosphere on the mechanical properties and microstructure of the CoCrMo compacts which is sintered at 1300°C-1400°C under two different inert gases sintering atmosphere (Ar2/N2H2) were investigated. The experimental results show that the grain boundaries sizes of CoCrMo compact sintered specimen were increased with increasing sintering temperature. The CoCrMo compacts specimens sintered at 1350°C under inert gases N2H2 atmosphere possess highest density (8.096 g/cm3) and hardness (327.1Hv). However, when the compacts specimens are sintered at 1400°C, the density (7.596 g/cm3) and hardness (320 Hv) properties of sintered compact were decreased.

High speed end milling of cobalt chromium molybdenum alloy using solid carbide tool under MQL condition

2019 ◽  
Author(s):  
H. A. Zaman ◽  
S. Sharif ◽  
M. H. Idris ◽  
A. S. Mohruni ◽  
P. Y. M. W. Ndaruhadi ◽  
...  
Keyword(s):  
High Speed ◽  
End Milling ◽  
Molybdenum Alloy ◽  
Carbide Tool ◽  
Cobalt Chromium ◽  
Solid Carbide ◽  
Cobalt Chromium Molybdenum

Surface Formation Mechanisms in Selective Laser Melting of Cobalt-Chromium-Molybdenum Powder

2020 ◽  
Vol 839 ◽  
pp. 73-78
Author(s):  
Alexander A. Saprykin ◽  
Yuriy P. Sharkeev ◽  
Natalya A. Saprykina ◽  
Egor A. Ibragimov
Keyword(s):  
Selective Laser Melting ◽  
Marangoni Effect ◽  
Powdered Material ◽  
Formation Mechanisms ◽  
Cobalt Chromium ◽  
Laser Melting ◽  
Movement Velocity ◽  
Surface Formation ◽  
Preheating Temperature ◽  
Cobalt Chromium Molybdenum

Selective laser melting (SLM) is a manufacturing technology of metal parts of any shapes with target mechanical properties by means of laser melting. This paper discusses the effect of SLM parameters: laser output power, laser movement velocity, scanning pitch and preheating temperature of a powdered material on surface formation mechanism, namely, its physical configuration when melting cobalt-chromium-molybdenum powdered material Со28Cr3Mo. The study points at structural differences of melted surfaces even under identical process parameters. Several types of surface formation are identified, e.g. homogenous melt, coagulated particles, and shapeless particles. Vapor pressure, Marangoni effect, and heat effect of a melted powder are stated to be key reasons for rough surface. This research is of high importance for understanding the effect of SLM parameters on formation of a target quality surface, positive stability and repeatable accuracy of the process.

High lubricious surface of cobalt–chromium–molybdenum alloy prepared by grafting poly(2-methacryloyloxyethyl phosphorylcholine)

Biomaterials ◽  
2007 ◽  
Vol 28 (20) ◽  
pp. 3121-3130 ◽  
Author(s):  
Masayuki Kyomoto ◽  
Yasuhiko Iwasaki ◽  
Toru Moro ◽  
Tomohiro Konno ◽  
Fumiaki Miyaji ◽  
...  
Keyword(s):  
Molybdenum Alloy ◽  
Cobalt Chromium ◽  
Cobalt Chromium Molybdenum
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