Additive manufactured metallic implants for orthopaedic applications

Abstract

Metallic implants are commonly used in various orthopaedic surgeries, like fracture fixation, spinal instrumentation, joint replacement and bone tumour surgery. Patients may need to adapt to the fixed dimensions of the standard implants. It may result in suboptimal fit to the host bones and possible adverse clinical results. The standard traditional implants may not address the reconstructive challenges such as severe bone deformity or bone loss after implant loosening and bone tumour resection. With the advent of digital technologies in medical imaging, computer programming in three-dimensional (3D) modelling and computer-assisted tools in precise placement of implants, patient-specific implants (PSI) have gained more attention in complex orthopaedic reconstruction. Additive manufacturing technology, in contrast to the conventional subtractive manufacturing, is a flexible process that can fabricate anatomically conforming implants that match the patients' anatomy and surgical requirements. Complex internal structures with porous scaffold can also be built to enhance osseointegration for better implant longevity. Although basic studies have suggested that additive manufactured (AM) metal structures are good engineered biomaterials for bone replacement, not much peer-reviewed literature is available on the clinical results of the new types of implants. The article gives an overview of the metallic materials commonly used for fabricating orthopaedic implants, describes the metal-based additive manufacturing technology and the processing chain in metallic implants; discusses the features of AM implants; reports the current status in orthopaedic surgical applications and comments on the challenges of AM implants in orthopaedic practice.

Current Trends in Improving of Artificial Joints Design and Technologies for Their Arthroplasty

“…The methods of 3D printing of orthopedic products made of polymers by the Fused Deposition Modeling (FDM) method and metals using Direct Metal Laser Sintering (DMLS), developed in recent years, have opened up new possibilities for creating personalized implants (Wong and Scheinemann, 2018;Dall'Ava et al, 2019;Timercan et al, 2019), which, moreover, can be very effective from the point of view of drug delivery to the area of their implantation (Benmassaoud et al, 2019). Despite the fact that additive manufacturing techniques for implants are in the initial stage of development, it can be argued that in the future they will be a powerful means of creating structures with a porous structure, optimal not only in relation to mechanical properties, but also to biocompatibility, bioactivity, and, if necessary and biodegradability (Yuan et al, 2018).…”

Exploring Macroporosity of Additively Manufactured Titanium Metamaterials for Bone Regeneration with Quality by Design: A Systematic Literature Review

“…This capability permits the fabrication of hierarchical structures at the microscale and the manipulation of material properties to create metamaterials. In terms of implant design, this advance means that products can be designed with a biomimetic approach according to the patient's anatomy and the bone tissue's mechanical properties [21]. The design freedom of AM allows its use in difficult clinical scenarios in which bone diseases, deformities, and trauma usually necessitate the reconstruction of bone defects with complex anatomical shapes, which is extremely difficult even for the most skilled surgeon [22].…”

3D Printed Acetabular Cups for Total Hip Arthroplasty: A Review Article

“…At the end of the manufacturing process, the as-fabricated part needs to be cleaned from the residual unmolten powder [43]. The complex porous structures that can be produced with 3D printing have made this cleaning process challenging [35,65,66].…”

“…3D printed acetabular cup designs currently on the market (custom designs are specified)[65,[70][71][72][73][74][75][76][77][78][79][80].…”