Cementless threaded cups are commonly used in total hip arthroplasty. A method to match the elasticity of the cup to that of natural bone is reducing the wall thickness of the implant. Despite good results with this philosophy of implantation, we recently observed 3 cases of implant fractures after the implantation of such thin-walled cups called "Bicon." We performed a thorough analysis of 1 of these cases including a histological examination and a technical failure analysis (including scanning electron microscopy) to establish the chronology and cause of the failure. Multiple fractures of the thin-walled metal-back cup were determined to be caused by fatigue. We have concluded that due to the specific material and design parameters of this cup, under adverse circumstances such as the lack of primary or secondary osteointegration, there is a risk of failure due to fatigue.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/j.arth.2005.04.012 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Characteristics of 2D Ultrasonic Vibration Incremental Forming of a 1060 Aluminum Alloy Sheet.
Materials (Basel)
March 2024
College of Mechanical Engineering, Xi'an University of Science and Technology, Xi'an 710054, China.
Currently, 1060 aluminum alloy is widely applied in the electronics industry, construction, the aerospace field, traffic engineering, decorations, and the consumer goods market for its good chemical, physical, and mechanical properties. In general, excellent processing property is necessary and important for the manufacturing of complicated panels. In this paper, a special 2D ultrasonic vibration incremental forming method is designed to improve its plasticity and mechanical properties.
View Article and Find Full Text PDFInfluence of acetabular cup thickness on seating and primary stability in total hip arthroplasty.
J Orthop Res
September 2022
Institute of Biomechanics, Hamburg University of Technology, Hamburg, Germany.
Insufficient primary stability of acetabular hip cups is a complication resulting in early cup loosening. Available cup designs vary in terms of wall thickness, potentially affecting implant fixation. This study investigated the influence of different wall thicknesses on the implantation process and the resulting primary stability using excised human acetabula.
View Article and Find Full Text PDFResistance of a novel ceramic acetabular cup to critical impact loads.
Proc Inst Mech Eng H
October 2020
MatOrtho Limited, Leatherhead, UK.
A novel thin-walled direct-to-bone fixation ceramic cup was tested under critical impact loads simulating lateral fall and car crash scenarios. Three sizes of BIOLOX delta ceramic cups (total hip replacement cup with bearing diameter of 32 mm and two hip resurfacing cups with bearing diameters of 40 and 64mm) were implanted into reamed Sawbones blocks representing acetabulae. Three cups of each size were fully supported by the block and three were implanted with 15° of the cup's outer diameter unsupported by the block.
View Article and Find Full Text PDFHow screw connections influence the primary stability of acetabular cups under consideration of different bone models.
J Orthop
June 2020
Laboratory for Biomechanics, Justus Liebig University Giessen, Klinikstrasse 29, 35392, Giessen, Germany.
Introduction: Good osteointegration of implants requires sufficient primary stability. Aim of this study was to examine the influence of screw fixation on the primary stability of press-fit cups.
Methods: Two press-fit acetabular cups were tested with regard to the influence and number of screws and their primary stability.
Deformation of acetabular press-fit cups: Influence of design and surgical factors.
Clin Biomech (Bristol)
October 2019
Institute of Biomechanics, Hamburg University of Technology, Hamburg, Germany.
Background: Deformation of acetabular cups when press-fitted into an undersized cavity is inevitable due to the inhomogeneous stiffness of acetabular bone. Thinner cups or screw holes might increase the risk of high cup deformation. The aim of this study was to examine the influence of cup design and liner assembly on the deformation response during cup implantation.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!