Laboratory wear tests and clinical observations of the penetration of femoral heads into acetabular cups in total replacement hip joints

The computer simulation of wear behavior appearing in total hip prosthesis

“…The acetabular cup is made of UHMWPE with an interior diameter of 22 mm and an outer diameter of 50 mm. The wear coefficient at the interface between hip joint and acetabular cup is 0.8× 10 − 6 mm 3 /Nm, which is the same as that used by Saikko [25] and within the range declared in most studies [9,26]. Other material properties are described in Section 3.2.1.…”

“…Studies concerning wear behavior of UHMWPE sliding against stainless steel have been performed, for example Atkinson et al [9], Wang et al [17,21] and Wang and Li [22]. According to their descriptions, there are three periods existing in a sliding wear process: the wearing-in period, the steady-state period and the severe wear period.…”

“…In clinical investigation, Atkinson et al [9] used the casting technique to measure wear of the retrieved polyethylene acetabular cup sliding against the stainless femoral head. Livermore [10], Kabo [11] and Hall [12] measured wear rates by radiographic and shadowgraph techniques, respectively.…”

Micro-wear features on unique 100-Mrad cupsTwo retrieved cups compared to hip simulator wear study

“…The superior region of UHMWPE cups generally has a smooth surface, due to the micropolishing wear processes (Dowling et al 1978) A border region usually called the ridge-line (Dowling et al 1978), separates these two regions of wear. In the main wear region, there are various micro-wear phenomena to be observed (Dowling et al 1978, Atkinson et al 1985, McKellop 1995, Oonishi et al 1995Yamamoto et al 1999. Specific details of wear considered in our study included the presence of the original machined tracks (evidence of minimal wear), the occurrence of ripples, indicative of a strain-hardening mechanism in the PE surface layer, and PE fibrils, suggesting incipient wear debris (Bragdon et al 1996, Wang et al 1996b).…”

A Comparative Study on Wear Behavior of Hip Prosthesis by Finite Element Simulation

“…Concluding the investigations on wear mecha nisms in [8][9], [15][16][17], three major wear mechanisms occurred in the artificial hip joints have been identified, namely, adhesive wear, abrasive wear and fatigue wear. These wear mechanisms may occur in interrelating ways with the physiological conditions during the long-term wearing process, but they usually cannot be clarified with each other since they are related to the bearing materials sliding against mutually, the result ing lubrication conditions, and the patient activity.…”