https://www.thelancet.com/pdfs/journals/lancet/PIIS0140673607604577.pdf

The operation of the century: total hip replacement

Objectives- T identify the literature on primary total hip replacement(THR) surgery that is relevant to the question of whether prostheses differ in their medium to longer term outcomes, and to synthesise this evidence. To use evidence regarding both costs and outcomes of primary THR to model how much more effective newer prostheses must be to justify higher costs

Primary total hip replacement surgery: a systematic review of outcomes and modelling of cost-effectiveness associated with different prostheses.

Advances in the processing, sterilization, and crosslinking of ultra-high molecular weight polyethylene for total joint arthroplasty.

Recent studies have generated considerable information that reveals substantial support for major change in the understanding of total hip arthroplasty and its current state. Although some of these observations appear unrelated at first glance, they can be drawn together to support the thesis that osteolysis is the dominant problem in total hip arthroplasty. These observations are as follows: (1) Five-year followup data are required for a minimum assessment of a new concept in total hip design and material because osteolysis is uncommon before that time. (2) Excellent fixation can be achieved on the femoral side with good cementing and good cementless techniques. Thus, femoral component loosening is less of an issue currently. (3) Many acetabular components become loose because of the ingress of particulate debris that leads to linear bone loss at the interface with the pelvis, a process that is biologically akin to the more florid forms of osteolysis. Thus, much acetabular component loosening represents a form of osteolysis. (4) Many cementless femoral reconstructions have developed a high incidence of femoral osteolysis. (5) Many cementless sockets have developed a high incidence of pelvic osteolysis. Taken in conjunction, these observations suggest that periprosthetic osteolysis is the leading problem in contemporary total hip replacement.

The problem is osteolysis

Early failure associated with adverse reactions to metal debris is an emerging problem after hip resurfacing but the exact mechanism is unclear. We analysed our entire series of 660 metal-on-metal resurfacings (Articular Surface Replacement (ASR) and Birmingham Hip Resurfacing (BHR)) and large-bearing ASR total hip replacements, to establish associations with metal debris-related failures. Clinical and radiological outcomes, metal ion levels, explant studies and lymphocyte transformation tests were performed. A total of 17 patients (3.4%) were identified (all ASR bearings) with adverse reactions to metal debris, for which revision was required. This group had significantly smaller components, significantly higher acetabular component anteversion, and significantly higher whole concentrations of blood and joint chromium and cobalt ions than asymptomatic patients did (all p < 0.001). Post-revision lymphocyte transformation tests on this group showed no reactivity to chromium or cobalt ions. Explants from these revisions had greater surface wear than retrievals for uncomplicated fractures. The absence of adverse reactions to metal debris in patients with well-positioned implants usually implies high component wear. Surgeons must consider implant design, expected component size and acetabular component positioning in order to reduce early failures when performing large-bearing metal-on-metal hip resurfacing and replacement.

Early failure of metal-on-metal bearings in hip resurfacing and large-diameter total hip replacement: A CONSEQUENCE OF EXCESS WEAR

This information is current as of September 30, 2010 Supplementary Material http://www.ejbjs.org/cgi/content/full/87/4/781/DC1 Reprints and Permissions Permissions] link. article, or locate the article citation on jbjs.org and click on the [Reprints andClick here to order reprints or request permission to use material from thisPublisher Information www.jbjs.org 20 Pickering Street, Needham, MA 02492-3157The Journal of Bone and Joint Surgery

Thomas P. Schmalzried

Papers

Metal-on-Metal Bearing Hip Prostheses The Relationship Between Activity and Ions in Patients with