How to Measure Wear following Total Hip Arthroplasty

Abstract

Total hip arthroplasty has yielded excellent results in decreasing pain and enhancing function in patients with hip degenerative disease. However, the problems associated with prosthetic failure and the consequent need for revision surgery still represent a major clinical issue. The most common reasons for revision surgery include implant loosening, periprosthetic osteolysis, infection, malalignment, stiffness, implant failure or fracture, and wear. The need for eliminating or reducing wear plays a crucial role in refining prosthesis composition and design. In this regard, it is important to develop new techniques for more accurate and reproducible measurement of wear. This should allow earlier detection of increased wear and thus permit earlier identification of patients who are at risk, and also help to identify faulty implant designs. This work is aimed at discussing the most common in vivo and in vitro methods used for evaluating the wear of hip prosthesis components.

Quantification of Wear and Deformation in Different Configurations of Polyethylene Acetabular Cups Using Micro X-ray Computed Tomography

“…Numerous techniques have been developed to assess PE wear of hip components during simulator tests [30,31,32,33,34,35]. Recently, the use of μCT has become widespread in the wear assessment of knee tibial liner [36].…”

Development of a Novel in Silico Model to Investigate the Influence of Radial Clearance on the Acetabular Cup Contact Pressure in Hip Implants

“…Wear tests are performed on materials and designs used in prosthetic implants [1,2,3] to obtain quality control and acquire further knowledge on the tribological behavior in joint prostheses. To gain realistic results, a wear test should replicate the in vivo working conditions of the artificial implants [4]. However, it is well known that wear tests have a long duration and are expensive [1,5,6].…”

“…The running-in period encompasses approximately the first half a million cycles [10]; therefore, the steady-state wear is assessed by measuring the wear when the running-in period is over. Wear is measured either gravimetrically, measuring the weight loss of the component, or through a direct analysis of the volume that has been removed, optically or by coordinate-measuring [4,11,12,13]. …”

New Challenges in Tribology: Wear Assessment Using 3D Optical Scanners

“…The study and monitoring of wear progression is a topic of great significance since the result of the analysis of surfaces’ modifications can lead to the definition of optimized profiles in terms of wear resistance and useful-life. However, it is difficult to assess the surface topography of an object with a complex shape—as for example teeth, knees, bones, or freeform mechanical components—due to the various irregularities and geometric configurations that are unique for each component [1]. …”