Heterodyne holographic contouring for wear measurement of orthopedic implants

Cobalt-base alloys (Co-Cr-Mo) are widely employed in dentistry and orthopedic implants due to their biocompatibility, high mechanical strength and wear resistance. The osseointegration of implants can be improved by surface modification techniques. However, complex geometries obtained by additive manufacturing (AM) limits the efficiency of mechanical-based surface modification techniques. Therefore, plasma immersion ion implantation (PIII) is the best alternative, creating nanotopography even in complex structures. In the present study, we report the osseointegration results in three conditions of the additively manufactured Co-Cr-Mo alloy: (i) as-built, (ii) after PIII, and (iii) coated with titanium (Ti) followed by PIII. The metallic samples were designed with a solid half and a porous half to observe the bone ingrowth in different surfaces. Our results revealed that all conditions presented cortical bone formation. The titanium-coated sample exhibited the best biomechanical results, which was attributed to the higher bone ingrowth percentage with almost all medullary canals filled with neoformed bone and the pores of the implant filled and surrounded by bone ingrowth. It was concluded that the metal alloys produced for AM are biocompatible and stimulate bone neoformation, especially when the Co-28Cr-6Mo alloy with a Ti-coated surface, nanostructured and anodized by PIII is used, whose technology has been shown to increase the osseointegration capacity of this implant.

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Microstructural Analysis of Fractured Orthopedic Implants

Materials ◽

10.3390/ma14092209 ◽

2021 ◽

Vol 14 (9) ◽

pp. 2209

Author(s):

Mateusz Kopec ◽

Adam Brodecki ◽

Grzegorz Szczęsny ◽

Zbigniew L. Kowalewski

Keyword(s):

Physical Activity ◽

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Fracture Behavior ◽

Locking Plate ◽

Microstructural Analysis ◽

Pure Titanium ◽

Orthopedic Implants ◽

Mechanical Loads ◽

Scanning Electron

In this paper, fracture behavior of four types of implants with different geometries (pure titanium locking plate, pure titanium femoral implant, Ti-6Al-4V titanium alloy pelvic implant, X2CrNiMo18 14-3 steel femoral implant) was studied in detail. Each implant fractured in the human body. The scanning electron microscopy (SEM) was used to determine the potential cause of implants fracture. It was found that the implants fracture mainly occurred in consequence of mechanical overloads resulting from repetitive, prohibited excessive limb loads or singular, un-intendent, secondary injures. Among many possible loading types, the implants were subjected to an excessive fatigue loads with additional interactions caused by screws that were mounted in their threaded holes. The results of this work enable to conclude that the design of orthopedic implants is not fully sufficient to transduce mechanical loads acting over them due to an increasing weight of treated patients and much higher their physical activity.

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Injection process parameter analysis of metal injection molding for green part orthopedic implants

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/1034/1/012177 ◽

2021 ◽

Vol 1034 (1) ◽

pp. 012177

Author(s):

Haruman Wiranegara ◽

Donny Syahputra ◽

Tria Mariz Arief

Keyword(s):

Injection Molding ◽

Orthopedic Implants ◽

Process Parameter ◽

Parameter Analysis ◽

Metal Injection Molding ◽

Injection Process ◽

Green Part

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Nano-scale coating wear measurement by introducing Raman-sensing underlayer

Journal of Material Science and Technology ◽

10.1016/j.jmst.2021.04.031 ◽

2021 ◽

Author(s):

Nan Xu ◽

Chun Wang ◽

Liuquan Yang ◽

Eric Kumi Barimah ◽

Gin Jose ◽

...

Keyword(s):

Nano Scale ◽

Wear Measurement

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