During total hip arthroplasty, both the femoral and acetabular bearing surfaces are surgically replaced with metallic, polymeric, and/or ceramic components. Throughout the twentieth century, many different combinations of these materials have been proposed and examined as bearing surfaces for total hip arthroplasty. Metal-on-metal total hip replacements were first implanted by Wiles in the 1930...

The UHMWPE has a plastic behaviour but it is specified only the surface wear, unless the evaluation of the great importance of this behaviour of plasticity for the calculation of the depth of penetration. This work tries to demonstrate the fact that there are components of the wear by plastic deformation. Also, by this type of wear an explanation of smooth surface of the UHMWPE in the contact z...

When subjected to a monotonically increasing deformation state, the mechanical behavior of UHMWPE is characterized by a linear elastic response followed by distributed yielding and strain hardening at large deformations. During the unloading phases of an applied cyclic deformation process, the response is characterized by nonlinear recovery driven by the release of stored internal energy. A num...

Ultra-high molecular weight polyethylene (UHMWPE) is frequently employed in joint replacements because of its high biocompatibility; however, this material does not exhibit particularly strong wear performance, thus potentially reducing the longevity of such devices. Numerous techniques have been investigated to increase the resistance to wear of UHMWPE, but they are all based on expensive mach...

Introduction: Wear of ultra-high molecular weight polyethylene (UHMWPE) is a major factor that affects longevity of the total joint replacement. In total hips (THR), cross-linking of polyethylene has been shown to be highly effective in reducing wear both clinically and experimentally [1-3]. Also, in TKR, Schmidig et al. [4] showed a 90% reduction of wear rate in 10 Mrad compared to 3 Mrad tibi...

Nitrogen Plasma Immersion Ion Implantation (PIII) has been used to modify the surface chemical structure of Ultra High Molecular Weight Polyethylene (UHMWPE). Grinding and polishing processes based on abrasive papers and alumina pastes have been evaluated with regard to their results on the improvement of polymer surface roughness, which has shown to be of crucial importance for hardness charac...

The purpose of this multicenter study was to evaluate the clinical performance of an ultrahigh molecular weight polyethylene (UHMWPE) fiber cable for re-attachment of the osteotomized greater trochanter in hip surgery. Included in the study were 85 hips that had undergone surgery with greater trochanter osteotomy, including 50 hip arthroplasty procedures and 35 hip osteotomies. The osteotomized...

The applications of synchrotron radiation (SR) in medical imaging have become of great use, particularly in angiography, bronchography, mammography, computed tomography, and X-ray microscopy. Thanks to recently developed phase contrast imaging techniques non-destructive preclinical testing of low absorbing materials such as polymers has become possible. The focus of the present work is characte...

Introduction The orthopaedic industry has expended significant research effort in recent years in reducing wear of UHMWPE articulating surface components. One such approach has been in the development of a heavily crosslinked polyethylene. Crosslinking for long has been known to improve the wear resistance of industrial polyethylene. Clinical experience for over 20 years and an increasing magni...

Study Design. In vivo analysis in an ovine model.Objective. To evaluate the feasibility of radiopaque UHMWPE sublaminar wires in a growth-guidance spinal system by assessing stability, biocompatibility and growth potential.Summary of Background Data. Several growth-guidance systems have been developed for the treatment of early onset scoliosis (EOS). The use of gliding pedicle screws and metal ...