New bearing materials for total joint replacement have been explored as the need to improve longevity and enhance performance is driven by changing demands of patient demographic. Carbon-reinforced PEEK has demonstrated good wear characteristics in experimental simulation both simple geometry pin-on-plate studies hip replacement. Carbon reinforced CFR-PEEK potential reduce tibial insert thickness preserve bone knee. This study investigated a low conformity knee configuration. Custom-made...

Ceramic-on-ceramic bearings have become of great interest due to the substantial improvements in manufacturing techniques and material properties polyethylene wear debris–induced osteolysis issues with metal debris ion release by metal-on-metal bearings. Edge loading conditions translational malpositioning (microseparation conditions) been shown replicate clinically relevant mechanisms increase ceramic-on-ceramic bearings; thus, it was necessary test new bearing materials designs under these...

Abstract Ceramic‐on‐ceramic (CoC) bearings in total hip replacements (THRs) have shown low wear volumes under standard gait simulator studies. However, clinical reports indicated variations rates and formation of stripe‐like area on the ceramic femoral heads. The aim this study was to investigate influence cup inclination angle microseparation CoC THRs. six station Leeds II Physiological Anatomical Joint Simulator used 28 mm diameter alumina matrix composite (BIOLOX ® delta ). It that...

Abstract Further development of ceramic materials for total hip replacement aim to increase fracture toughness and further reduce the incidence bearing fracture. Edge loading due translational mal positioning (microseparation) has replicated stripe wear, wear rates, bimodal debris observed on retrievals. This method early zirconia ceramic‐on‐ceramic bearings. shown necessity introducing microseparation conditions gait cycle when assessing tribological performance new Two novel matrix...

PEEK-OPTIMA ™ (Invibio Ltd, UK) has been considered as an alternative joint arthroplasty bearing material due to its favourable mechanical properties and the biocompatibility of wear debris. In this study, potential use injection moulded cobalt chrome in femoral component a total knee replacement was investigated terms performance. Experimental simulation three components articulating against all-polyethylene tibial carried out under two kinematic conditions: 3 million cycles intermediate...

Total joint replacement is a successful surgical intervention for the treatment of degeneration many joints, particularly hip and knee. As demand grows, life expectancy population increases, performance requirements these implants also changes. New materials, to improve longevity enhance have been explored including PEEK CFR-PEEK. This study investigated whether CFR-PEEK were appropriate materials total by examining wear in simple configuration studies articulating against cobalt chrome...

In vivo fluoroscopic studies of patients with total knee replacements (TKRs) have shown lift-off the femoral condyles from tibial insert. This study investigated influence condylar on ultra-high molecular weight polyethylene (UHMWPE) wear fixed bearing (FB) and rotating platform mobile (RP MB) replacements, using a physiological joint simulator. absence lift-off, RP MB knees exhibited lower rate 5.2;;2.2 mm 3 per million cycles (mm /MC) compared 8.8;;4.8 /MC for FB knees. The presence was...

Knee arthroplasties in young and active patients place a substantial increase the lifetime tribological demand potential for wear-induced osteolysis. Polyethylene materials have advanced recent years, reducing oxidative degradation delamination failure. It is timely to consider design variables their reduce surface wear long-term risk of The influence reduced cross shear rotating platform mobile-bearing knee designs area low conforming fixed-bearing knees has been investigated. A reduction...

Crosslinked ultra-high molecular weight polyethylene (UHMWPE) has been developed and introduced into clinical practice in order to reduce wear the hip. Zero of highly crosslinked UHMWPE vitro reported by some groups using lubricants with high concentrations serum proteins hip simulators. In contrast, studies have finite rates. The aim this study was compare rates, surfaces, debris produced different levels crosslinking a joint simulator, lower, more physiologically relevant protein...

Currently available replacement heart valves all have limitations. This study aimed to produce and characterize an acellular, biocompatible porcine pulmonary root conduit for reconstruction of the right ventricular outflow tract e.g., during Ross procedure. A process decellularization roots was developed incorporating trypsin treatment adventitial surface scraped artery sequential with hypotonic Tris buffer (HTB; 10 mM pH 8.0, 0.1% (w/v) EDTA, KIU aprotinin), sodium dodecyl sulfate in HTB,...

Abstract Metal‐on‐metal (MoM) bearings have shown low‐wear rates under standard hip simulator conditions; however, retrieval studies large variations in wear and mechanisms. High‐wear vivo has caused catastrophic complications been associated with steep cup‐inclination angle (rotational malpositioning). However, increasing the vitro not replicated increases to same extent as those observed retrievals. Clinically relevant rates, patterns, particles were for ceramic‐on‐ceramic when...

PEEK-OPTIMA™ is being considered as an alternative bearing material to cobalt chrome in the femoral component of total knee replacement provide a metal-free implant. The aim this study was investigate influence lubricant temperature (standard rig running and elevated (~36 °C)) on wear UHMWPE-on-PEEK OPTIMA™ couple using different protein concentrations (0%, 2%, 5%, 25% 90% bovine serum) simple geometry pin-on-plate configuration. Friction also investigated under single condition for...

A more robust pre-clinical wear simulation framework is required in order to simulate wider and higher ranges of activities, observed different patient populations such as younger active patients. Such a will help understand address the reported failure rates for patients (National_Joint_Registry, 2016). The current study has developed validated comprehensive combined experimental computational total knee replacements (TKR). input mechanical (elastic modulus Poisson's ratio) parameters...

The clinical use of decellularized cardiac valve allografts is increasing. Long-term data will be required to determine whether they outperform conventional cryopreserved allografts. Valves using different processes may show varied long-term outcomes. It therefore important understand the effects specific decellularization technologies on characteristics donor heart valves. Human aortic and pulmonary valved conduits were hypotonic buffer, 0.1% (w/v) sodium dodecyl sulfate nuclease digestion....

Experimental wear simulation of a PEEK-OPTIMA™ polymer-on-UHMWPE total knee replacement has shown equivalent UHMWPE to conventional materials (cobalt chrome-on-UHMWPE) when tested in clean environment. The aim this study was experimentally investigate the all-polymer under third body conditions. Three and three cobalt chrome femoral components articulating against all-polyethylene tibial were simulator. One million cycles carried out lubricant conditions replicating walking followed by one...

The wear and creep characteristics of highly crosslinked ultrahigh-molecular-weight polyethylene (UHMWPE) articulating against large-diameter (36 mm) ceramic cobalt chrome femoral heads have been investigated in a physiological anatomical hip joint simulator for 10 million cycles. UHMWPE/ceramic combination showed higher volume deformation due to plus during the first 2 cycles, steady-state rate 40 per cent lower than that UHMWPE/cobalt combination. Wear particles were isolated characterized...

Unicompartmental knee replacements (UKR) are an option for surgical intervention the treatment of single-compartment osteoarthritis. The aim this study was to compare wear a low-conformity fixed-bearing UKR with conforming mobile bearing under two kinematic conditions, investigate effect implant design and kinematics on performance in physiological simulator. Under both sets relatively low-conforming fixed showed lower wear, compared more anterior-posterior sliding bearing. However, it...

The mean average life is increasing; therefore, there a need to increase the lifetime of prostheses. To fulfil this requirement, new prosthetic designs and materials are being introduced. Two design parameters that may affect wear total knee replacements, hence expected lifetime, insert conformity material. Computational models have been used extensively for prediction optimisation artificial designs. objective present study was use previously validated non-dimensional coefficient-based...

Wear of total knee replacement continues to be a significant factor influencing the clinical longevity implants. Historically, failure due delamination and fatigue directed design towards more conforming inserts reduce contact stress. As new generations oxidatively stable polyethylene have been developed, flexibility in bearing has introduced. The aim this study was investigate effect insert conformity on wear performance fixed through experimental simulation. Two geometries were studied...

As life expectancy and activity levels of patients increase so does the demand on total knee replacements (TKRs). Abnormal mechanics wear TKRs can lead to implant loosening revision. Component alignment after surgery varies due presurgical alignment, accuracy surgical instrumentation patient factors, such as soft tissue balance. This study experimentally investigated effect variation in component conditions kinematics a fixed bearing TKR. DePuy Sigma with moderately cross-linked UHMWPE were...