Comparison of two hydroxyapatite-coated femoral components: a randomized clinical trial using radiostereometric analysis.

Aims: The primary aim of this trial was to compare the subsidence of two similar hydroxyapatite-coated titanium femoral components from different manufacturers. Secondary aims were to compare rotational migration (anteversion/retroversion and varus/valgus tilt) and patient-reported outcome measures between both femoral components.

Methods: Patients were randomized to receive one of the two femoral components (Avenir or Corail) during their primary total hip arthroplasty between August 2018 and September 2020.

Radiostereometric analysis and clinical outcomes of a novel reverse total hip system at two years.

Aims: Instability is a common cause of failure after total hip arthroplasty. A novel reverse total hip has been developed, with a femoral cup and acetabular ball, creating enhanced mechanical stability. The purpose of this study was to assess the implant fixation using radiostereometric analysis (RSA), and the clinical safety and efficacy of this novel design.

Modes of failure of hip hemiarthroplasty for femoral neck fracture.

Background: Hemiarthroplasty is a common treatment for displaced femoral neck fractures, but limited Canadian data are available about hemiarthroplasty failure. We evaluated the frequency and predictors of hemiarthroplasty failure in Manitoba.

Methods: In this retrospective multicentre province-wide study, billing and joint registry databases showed 4693 patients who had hemiarthroplasty for treatment of femoral neck fracture in Manitoba over an 11-year period (2005-2015), including 155 hips with subsequent reoperations (open or closed) for treatment of hemiarthroplasty failure.

Does oxidized zirconium make a difference? Midterm cohort survivorship of symmetric posterior condyle posterior-stabilized total knee arthroplasty.

Background: A novel symmetric posterior condylar design and option of a femoral component with an outer zirconium oxide layer were introduced to a successful asymmetric condylar total knee arthroplasty system in 2005. Given the paucity of information on this modified design, we performed a study to determine its early to midterm survivorship and performance.

Methods: Patients who received the Genesis II Symmetric Posterior Condyle or Legion Primary total knee (cobalt–chromium [CoCr] or oxidized zirconium–niobium [OxZr]) (Smith & Nephew) implanted at the study centre between March 2007 and December 2013 were enrolled into a prospective database.

Retrieval Analysis of Large-Head Modular Metal-on-Metal Hip Replacements of a Single Design.

Background: There are limited publications examining modular metal-on-metal (MoM) total hip implants in which a comprehensive analysis of retrieved components is performed. This study examines 24 retrieved modular MoM implants from a single manufacturer and compares retrieval analytics; bearing surface damage, wear, and modular taper corrosion against patient, surgical and implant characteristics to elucidate significant associations.

Methods: Clinical, patient, and surgical data were collected including age, body mass index, blood metal ion levels, and cup inclination.

In Vivo Wear Performance of Cobalt-Chromium Versus Oxidized Zirconium Femoral Total Knee Replacements.

This study examines the damage and wear on the polyethylene (PE) inserts from 52 retrieved Genesis II total knee replacements to identify differences in tribological performance between matched pairs of cobalt-chromium (CoCr) and oxidized zirconium (OxZr) femoral components. Observer damage scoring and microcomputed tomography were used to quantify PE damage and wear, respectively. No significant differences were found between CoCr and OxZr groups in terms of PE insert damage, surface penetration, or wear.

Corrosion on the acetabular liner taper from retrieved modular metal-on-metal total hip replacements.

Eight retrieved metal-on-metal total hip replacements displayed corrosion damage along the cobalt-chromium alloy liner taper junction with the Ti alloy acetabular shell. Scanning electron microscopy indicated the primary mechanism of corrosion to be grain boundary and associated crevice corrosion, which was likely accelerated through mechanical micromotion and galvanic corrosion resulting from dissimilar alloys. Coordinate measurements revealed up to 4.

Abrasive wear and metallosis associated with cross-linked polyethylene in total hip arthroplasty.

A 34-year-old female patient received a cobalt-chromium (CoCr) alloy femoral head on cross-linked polyethylene total hip replacement for the revision of her fractured ceramic-on-ceramic total hip replacement. The CoCr alloy femoral head became severely worn due to third-body abrasive wear by ceramic particles that could not be removed by synovectomy or irrigation at revision surgery. Ceramic particles were found embedded in the cross-linked polyethylene liner.

Randomized trial of computer-assisted knee arthroplasty: impact on clinical and radiographic outcomes.

Computer-assisted surgery in knee arthroplasty is gaining popularity; however, the resulting outcome improvement is controversial. A double-blinded trial was performed with subjects randomized to undergo surgery with either computer-assisted or nonassisted instruments. Postoperatively, limb and implant alignment and rotation were assessed using both full-length radiographs and computed tomography in addition to clinical scores.

Posterior condyle surface damage on retrieved femoral knee components.

Twenty-two retrieved femoral knee components were identified with posterior condyle surface damage on average at 99° flexion (range, 43°-135° flexion). Titanium alloy material transfer and abrasive surface damage were evident on cobalt-chromium alloy femoral components that were in contact with titanium alloy tibial trays. Surface damage on the retrieved Oxinium femoral components (Smith and Nephew, Inc, Memphis, Tenn) that were in contact with titanium alloy tibial trays showed gouging, associated with the removal and cracking of the oxide and exposure of the zirconium-niobium alloy substrate.

Paraneoplastic Clostridium septicum infection of a total knee arthroplasty.

We describe a case of a well-functioning total knee arthroplasty acutely infected with Clostridium septicum. This is the first reported infection of a prosthetic joint with this organism. A search for the source of this infection uncovered a colonic malignancy.