Imaging of total hip arthroplasty: Part I – Implant design, imaging techniques, and imaging of component wear and fracture

Updates on Biomaterials Used in Total Hip Arthroplasty (THA)

“…Hip arthroplasties vary in terms of component design and biomaterials used [ 45 ]. An important characteristic of the prosthesis is the bearing surface and, in modern times, it can be made of metal-on-metal (MoM), metal-on-polyethylene (MoP), ceramic-on-ceramic (CoC), or ceramic-on-polyethylene (CoP) materials, where the polyethylene can be ultra-high molecular weight polyethylene (UHMWPE) or highly cross-linked polyethylene [HXLPE] [ 45 , 46 ]. The most often utilized bearing surfaces for THA are highly cross-linked polyethylene (HXLPE), ceramic, ultra-high molecular weight polyethylene (UHMWPE), and metal.…”

“…Until now, the most-used bearing coupling is the cobalt-chromium femoral head that articulates with an HXLPE liner, since it shows extended durability and reduced wear rates with good safety in various longitudinal inspections [ 45 , 81 ].…”

“…Metals are used in THA both for the fixed components (femoral stem and acetabular component) as well as for the mobile components (femoral head and liner). It should be mentioned that MoM THA is no longer utilized [ 45 , 46 , 95 ], because metal wear debris may increase metal ion levels in serum and can generate hypersensitivity responses in the soft tissues, with harmful systemic consequences [ 96 ] such as pseudotumor formation and aseptic lymphocyte-dominated vasculitis-associated lesions (ALVAL), leading to eventual soft tissue and bone destruction [ 97 ]; due to this, MoM implants have been replaced more and more with metal-with-polymer (MoP) THA implants [ 11 ].…”

“…Ceramic materials can be used for making mobile components, the prosthetic head, and the acetabular liner, thus resulting in two ceramic-on-ceramic or ceramic-on-polyethylene friction couples, each with its advantages and disadvantages. Component fracture risk was a worry in CoC arthroplasties; however, with the newer generations of implants, when the complication rates were reduced, the use of CoC has not considerably decreased [ 45 , 95 ] and remains one of the most effective ways to prevent liner wear with wear rates of less than 0.001 mm/year compared to 0.072 mm/year in ceramic-on-UHMWPE (CoUHMWPE), 0.30 mm/year in ceramic-on-HXLPE (CoHXLPE), and 0.042 mm/year in metal-on-HXLPE (MoHXLPE) [ 129 ]. Furthermore, a very recent study from 2023 found the Delta ceramic bearing to be a viable alternative for primary and revision THA, with favourable mid-term outcomes, satisfactory survival, and a low complication rate [ 130 ].…”