Wear Measurement of Retrieved Polyethylene Abg 1 Cups by Universal-Type Measuring Microscope and X-Ray Methods

Abstract

Background:Polyethylene wear is considered a most important part of periprosthetic osteolysis development. Thus, its measurement is central to contemporary orthopaedics.Aims: The aim of this paper was to compare the accuracy of three radiographic techniques for wear measurement. Secondly, the influence of the abduction angle of the cup on measurement accuracy was investigated.Methods: Wear was measured manually in 80 patients by a single observer according to the Livermore, Charnley, and Dorr description. A multi-component statistical analysis was used to test the hypothesis that the Livermore technique was superior. In vitro data obtained from a Universal-type measuring microscope served as a gold standard.Results: In vitro measurements showed an average linear wear of 0.363 mm per year (0.000-0.939, SD 0.241) with a corresponding volumetric wear rate of 161 mm 3 per year (0-467, SD 118.2). The Livermore technique showed the least deviation from the optical reference standard and a superior position from the viewpoint of error analysis but the correlation coefficient was slightly less (r = 0.761) than for the Dorr and Charnley techniques (r = 0.795 and r = 0.778, respectively). In addition, the mean error of the Dorr method differed significantly from zero (p = 0.036). Overall, the Livermore technique was the most accurate method for polyethylene wear measurement regardless of the abduction angle of the cup.Conclusions: The Livermore technique performed manually was more accurate than the Charnley and Dorr methods. Nevertheless, we consider the Dorr technique an adequate tool for day-to-day wear measurements, mainly due to its simplicity.

A prospective randomised controlled trial comparing three alternative bearing surfaces in primary total hip replacement

“…Second, in this study the assessment of wear involved the technique of Dorr and Wan, 38 using twodimensional digital clinical radiographs and templating software. 39 It is true that many studies [54][55][56] have shown the alternative Livermore technique 57 to be more accurate, even though there are studies that support the opposite. 56 We chose to use the Dorr and Wan 38 technique because it is simple to use 55 and we have used it successfully in previous studies.…”

“…39 It is true that many studies [54][55][56] have shown the alternative Livermore technique 57 to be more accurate, even though there are studies that support the opposite. 56 We chose to use the Dorr and Wan 38 technique because it is simple to use 55 and we have used it successfully in previous studies. 58 Additionally, both the techniques of Livermore and Dorr and Wan were described to measure wear on metal/UHMWPE articulations, and it is easy to modify the Dorr and Wan method for CoC articulations, but not easy to use the Livermore method on radiographs of CoC THRs.…”

Risk factors for accelerated polyethylene wear and osteolysis in ABG I total hip arthroplasty

“…Assuming that the diameter of the cup and the head are known, it is possible to calculate the linear and volumetric wear using a geometrical "two-sphere model" and a special computational algorithm that also takes into account the original position of the prosthetic head in the cup and the cross-sectional profile of the ABG I cup. The accuracy of the described method was previously assessed in a set of 30 retrieved cups, ranging between 1 and 4 μm and 1-9 mm 3 for linear and volumetric wear, respectively [14]. The reliability of the method has also been previously reported [15].…”

Male gender, Charnley class C, and severity of bone defects predict the risk for aseptic loosening in the cup of ABG I hip arthroplasty

“…In our previous studies, we found that a high risk for an increased wear rate was associated with ABG I prosthesis [11]. We also found a significant association between wear rate and severity of osteolysis in ABG I prosthesis, and an unacceptably high rate of aseptic loosening in ABG I cups [12,13].…”