Comparison of ten-year survivorship of hip prostheses with use of conventional polyethylene, metal-on-metal, or ceramic-on-ceramic bearings.

Background: To improve the long-term performance of hip prostheses, alternative bearings with metal-on-metal (MoM) and ceramic-on-ceramic (CoC) couples have been introduced. Although currently the results from the use of these bearings are in the midterm stage, there have been few comparative studies of these different bearings.

Methods: From 2000 to 2002, 487 total hip replacements were performed with use of a BICON-PLUS acetabular cup and an SL-PLUS femoral stem (Plus Orthopedics, Rotkreuz, Switzerland, now Smith & Nephew Orthopaedics).

Survivorship and retrieval analysis of Sikomet metal-on-metal total hip replacements at a mean of seven years.

Background: Second-generation metal-on-metal total hip replacements were introduced in the early 1990s with the aim of eliminating polyethylene wear and the resulting complications of osteolysis and aseptic loosening. The goal of the present study was to evaluate the intermediate-term results in a series of patients who were managed with one of these implants.

Methods: Between 1994 and 2002, we performed 640 total hip replacements in 591 patients with use of a Bicon-Plus cementless threaded cup with a polyethylene liner housing a metal inlay made of Sikomet low-carbon cobalt-chromium-molybdenum alloy that articulates with a Sikomet metal femoral head.

Poor results from the isoelastic total hip replacement: 14-17-year follow-up of 149 cementless prostheses.

Background: To overcome the mismatch between a stiff stem and the more elastic bone, the concept of isoelasticity was introduced in the 1970s. This concept was based on the assumption that the implant and the bone should deform as one unit to avoid stress shielding. The Robert Mathys (RM) cementless total hip replacement (THR) was one of the earliest isoelastic designs.

Serum levels of cobalt and chromium in patients with Sikomet metal-metal total hip replacements.

Metal/metal total hip replacements (M/M THRs) made of CoCr-based alloys were reintroduced in hip arthroplasty in order to avoid the problem of polyethylene wear and consequently to diminish the wear debris-related osteolysis. Emerging concerns accompanying the reintroduction of M/M THRs are related to the possibility increase of Co and Cr serum levels and, therefore, a careful surveillance of M/M patients is recommended. In the present work three groups of patients with Sikomet SM21 low-carbon alloy were investigated: retrospective group, prospective group and revision group.

Fifty-one-year survival of a Judet polymethylmethacrylate hip prosthesis.

Revision arthroplasty of a Judet polymethylmethacrylate (PMMA) hip hemiprosthesis was performed 51 years after implantation. This makes it the first implant to have survived for longer than 50 years. No signs of aggressive osteolysis were found on histologic analysis, which confirms good tissue tolerance for PMMA.

Determination of trace cobalt concentrations in human serum by adsorptive stripping voltammetry.

The goal of our study was to develop an accurate and reliable method for determining trace cobalt concentrations in human serum. The method was used to determine cobalt in the sera of healthy persons and patients with orthopaedic implants containing cobalt - a possible source of systemic release of cobalt into the human body. This goal is of vital interest since cobalt and its compounds are classified by IARC as potentially carcinogenic to humans.