It has been suggested that the wear of ultra-high molecular weight polyethylene (UHMWPE) in total hip replacement is substantially reduced when the femoral head is ceramic rather than metal. However, studies of alumina and zirconia ceramic femoral heads on the penetration of an UHMWPE liner in vivo have given conflicting results. The purpose of this study was to examine the surface characterist...

BACKGROUND AND PURPOSE Historically, a Schanz osteotomy of the femur has been used to reduce limp in patients with severely dysplastic hips. In such hips, total hip arthroplasty is a technically demanding operation. We report the long-term results of cementless total hip arthroplasty in a group of patients who had all undergone a Schanz osteotomy earlier. PATIENTS AND METHODS From 1988 throug...

As one of the important friction pairs a diesel engine, cylinder-liner piston ring (CL-PR) faces harsh high-temperature working environment. To explore mapping relationship between performance CL-PR and change in temperature, reciprocating-friction wear-testing machine was used to analyze lubrication four kinds lubricating oil at different temperatures (room 60 °C, 90 120 °C) from coefficient, ...

A long-stroke, low-speed marine engine is used as the prime mover of a ship. During operation such engines, excessive wear cylinder liners and piston rings frequently occurs. The breakdown or very dangerous for safety vessel, environment, people on board. reliability components an extremely important topic, it influences efficient vessel. Therefore, to prevent undesired events, essential that c...

Zinc dialkyldithiophosphate (ZDDP) is a widely used lubricant additive due to its high effectiveness in reducing wear by forming tribofilm on sliding surfaces. However, the formation and removal of are two competing processes depending working conditions, ZDDP loses anti-wear function when process prevails. In this paper, numerical model built up predict if can cover surfaces protect them from ...

BACKGROUND Concerns have been raised about the sequelae of metal-on-metal (MoM) bearings in total hip arthroplasty (THA). However, retrieval studies, which offer the best insight into the clinically relevant mechanisms of MoM wear, have followed predictable trends to date such as indicting cobalt-chromium (CoCr) metallurgy, cup design, high conformity between the head and cup, "steep cups," "mi...

A high incidence of acetabular osteolysis (43%), associated with osteolytic lesions in the proximal femur (22.6%) and leading to a high revision rate, was experienced with the Omnifit total hip prosthesis. We reviewed the clinical and radiological results with 429 Omnifit total hips in 356 patients after a mean follow-up of 60 months. Time to revision and wear of the polyethylene liner with dif...

This case illustrates the potential for systemic cobalt toxicity in non-metal-on-metal bearings and its potentially devastating consequences. We present a 71-year-old male with grinding sensations in his right hip following ceramic-on-ceramic total hip arthroplasty (THA). After diagnosing a fractured ceramic liner, the hip prosthesis was revised into a metal-on-polyethylene bearing. At one year...