The long-term wear of retrieved McKee-Farrar metal-on-metal total hip prostheses (original) (raw)

Long-duration metal-on-metal total hip arthroplasties with low wear of the articulating surfaces

The Journal of Arthroplasty, 1996

The 20-year performance of metal-on-metal hip articulations has not been reported. Five McKee-Farrar total hip prostheses and one Sivash prosthesis were obtained at revision surgery after a mean implantation time of 21.3 years. A radiographic, histologic, implant, and wear analysis was performed on these total hip implants with cobalt-chrome metal-on-metal articulations. All cases were associated with femoral component loosening, but the bearing surfaces performed remarkably well. The worst case estimate of combined femoral and acetabular linear wear was 4.2 gm per year, about 25 times less than that typically seen with polyethylene. Metal particles and foreign-body inflammation were seen in all cases, but the volume of reactive tissue was small compared with what is generally seen at revision of hips with a polyethylene acetabular bearing. This may be due to a reduced particle burden or a decreased inflammatory reaction to particulate metal, or both. In addition to articular wear, other sources of metal particles included femoral neck impingement on the acetabular rim, stem burnishing, and corrosion. Prosthetic hip reconstructions can fail for many reasons, including suboptimal femoral stem and/or acetabular cup design and/or fixation. By today's standards, the McKee-Farrar and Sivash stem and acetabular component designs are suboptimal; however, after more than 20 years of use, the metal-on-metal bearing surfaces in these cases demonstrated low wear and do not appear to be the cause of failure. Recent advances in total hip arthroplasty, which include improved implant design, materials, manufacturing, and fixation, combined with a better understanding of the mechanisms of implant loosening and failure, suggest that the cobalt-chrome metal-on-metal bearing be reexamined as an alternative to polyethylene when exceptional durability is required.

Wear and Lubrication of Metal-on-Metal Hip Implants

Clinical Orthopaedics and Related Research, 1999

The implication of polyethylene wear particles as the dominant cause of periprosthetic osteolysis has created a resurgence of interest in metalon-metal implants for total hip arthroplasty because of their potential for improved wear performance. Twenty-two cobalt chromium molybdenum metal-on-metal implants were custom-manufactured and tested in a hip simulator. Accelerated wear occurred within the first million cycles followed by a marked decrease in wear rate to low steady-state values. The volumetric wear at 3 million cycles was very small, ranging from 0.15 to 2.56 mm3 for all implants tested. Larger head-cup clearance and increased surface roughness were associated with increased wear. Independent effects on wear of From the

A finite element method comparison of wear in two metal-on-metal total hip prostheses

Proceedings of The Institution of Mechanical Engineers Part H-journal of Engineering in Medicine, 2006

The contact mechanics of two metal-on-metal (MOM) total hip prostheses was studied by means of the finite element method (FEM). The purpose of the work was to compare two total hip replacements (DuromTM and MetasulTM) with regard to the amount of wear debris released. Wear on the bearing surfaces was evaluated following Reye hypotheses from the pressure distribution, computed by means of three-dimensional FEM models; an approximate analytical model based on Hertz contact theory has also been developed and discussed. The results show that in the dry friction condition the DuromTM joint releases almost twice as much wear volume as produced by the MetasulTM joint. Therefore, while DuromTM implants can improve hip stability by increasing the prosthetic impingement-free range of motion (PIF-ROM), MetasulTM prostheses can be a valuable solution whenever wear represents a critical choice factor. could be attributed to the larger bearing diameter but also to the elasticity of the underlying bone

Volumetric wear assessment of failed metal-on-metal hip resurfacing prostheses

Wear, 2011

Recent advancements in hip arthroplasty have allowed the operation to boast excellent results and high survivorship. However, failures do still occur and a major cause is complications arising from wear debris. It is essential therefore that debris is minimized by reducing wear at the bearing surface. One proposed method of achieving this wear reduction is through the use of metal-on-metal articulations. One of the latest manifestations of this biomaterial combination is in designs of hip resurfacing which are aimed at younger, more active patients who might wear out a conventional metal-on-polymer hip prosthesis. However, do these metal-on-metal hip resurfacings show less wear when implanted into patients?

Analysis of failed metal-on-metal hip prostheses

Replacement joints, or prostheses, are an important tool for reducing pain and restoring functionality to patients with diseases such as arthritis. However, even the most modern prostheses have a limited life span and a major cause of failure is wear.

Which Factors Determine the Wear Rate of Large-Diameter Metal-on-Metal Hip Replacements?

The Journal of Bone and Joint Surgery (American), 2013

Background: Determining the relationship between clinical factors and engineering analysis of retrieved hip implants can help our understanding of the mechanism of device failure. This is particularly important for metal-on-metal hip arthroplasties because the most common cause of failure is unexplained. We sought to understand the variation in wear rates in a large series of retrieved metal-on-metal hip arthroplasty components.

Failure Modes of 433 Metal-on-Metal Hip Implants: How, Why, and Wear

Orthopedic Clinics of North America, 2011

Modern metal on metal hip replacement bearings are often seen as a durable option for younger patients because they are stronger and considered to produce lower rates of wear and osteolysis. 1 The use of metal-on-metal bearings has increased since the introduction of largediameter components for hip replacements and hip resurfacings, which offer protection against dislocation. Consequently, metal-on-metal bearings are reported to be second in popularity to polyethylene-on-metal bearings. 2 However, concerns remain regarding the potential biologic reactivity and long-term effects of cobaltchromium alloy metal particles and ions, particularly in light of recent reports of soft tissue masses, 3,4 necrosis, 5,6 and systemic effects 7 of elevated ion levels. Although the incidence of these problems is thought to be relatively low, 8 there have been calls to severely limit the use of metal-on-metal bearings. Our research center has collected a large number of failed metal-on-metal implants, including firstgeneration McKee-Farrar total hip replacements (THRs), early generation hip resurfacings (McMinn; Corin Group, PLC, Cirencester, UK and Wagner; Sulzer, Winterthur, Switzerland), 11 and a range of contemporary large-diameter modular THRs and hip resurfacings. In 2006, we published a retrieval study of implant failure modes in metal-on-metal surface arthroplasties and reported that aseptic loosening and femoral neck fracture comprised most failures. We also reported that revision directly attributed to wear of the bearings was relatively rare.

Wear evaluation of cobalt–chromium alloy for use in a metal‐on‐metal hip prosthesis

Journal of Biomedical …, 2004

Wear of the polyethylene in total joint prostheses has been a source of morbidity and early device failure, which has been extensively reported in the last 20 years. Although research continues to attempt to reduce the wear of polyethylene joint-bearing surfaces by modifications in polymer processing, there is a renewed interest in the use of metal-on-metal bearing couples for hip prostheses. Wear testing of total hip replacement systems involving the couple of metal or ceramic heads on polymeric acetabular components has been performed and reported, but, until recently, there has been little data published for pin-on-disk or hip-simulator wear studies involving the combination of a metallic femoral head component with an acetabular cup composed of the same or a dissimilar metal. This study investigated the in vitro wear resistance of two cobalt/chromium/molybdenum alloys, which differed primarily in the carbon content, as potential alloys for use in a metal-on-metal hip-bearing couple. The results of pin-on-disk testing showed that the alloy with the higher (0.25%) carbon content was more wear resistant, and this alloy was therefore chosen for testing in a hip-simulator system, which modeled the loads and motions that might be exerted clinically. Comparison of the results of metal-on-polyethylene samples to metal-on-metal samples showed that the volumetric wear of the metal-on-polyethylene bearing couple after 5,000,000 cycles was 110 -180 times that for the metal-bearing couple. Polyethylene and metal particles retrieved from either the lubricant for pin-on-disk testing or hip simulator testing were characterized and compared with particles retrieved from periprosthetic tissues by other researchers, and found to be similar. Based upon the results of this study, metal-on-metal hip prostheses manufactured from the high carbon cobalt/chromium alloy that was investigated hold sufficient promise to justify human clinical trials.

A lexicon for wear of metal-on-metal hip prostheses

Journal of Orthopaedic Research, 2014

Research on metal-on-metal (MoM) hip bearings has generated an extensive vocabulary to describe the wear processes and resultant surface damage. However, a lack of consistency and some redundancy exist in the current terminology. To facilitate the understanding of MoM tribology and to enhance communication of results among researchers and clinicians, we propose four categories of wear terminology: wear modes refer to the in vivo conditions under which the wear occurred; wear mechanisms refer to fundamental wear processes (adhesion, abrasion, fatigue, and tribochemical reactions); wear damage refers to the resultant changes in the morphology and/or composition of the surfaces; and wear features refer to the specific wear phenomena that are described in terms of the relevant modes, mechanisms, and damage. Clarifying examples are presented, but it is expected that terms will be added to the lexicon as new mechanisms and types of damage are identified. Corrosion refers to electrochemical processes that can remove or add material and thus also generate damage. Corrosion can act alone or may interact with mechanical wear. Examples of corrosion damage are also presented. However, an in-depth discussion of the many types of corrosion and their effects is beyond the scope of the present wear lexicon. ß