MEASUREMENT OF POLYETHYLENE WEAR IN TOTAL HIP ARTHROPLASTY

초록

The purpose of this study was to compare the accuracy of four methods of measuring wear using an apparatus that simulated known amounts of three dimensional wear. Wear was measured using manual methods of Charnley, Livermore, Dorr and Wan and the computerized method of Devane. In addition, since the direction of wear was known, a correction factor was calculated for the method of Dorr and Wan and named the modified Dorr method. Only the method of Devane measured three-dimensional (superior and anterior) wear with reasonable accuracy, with a mean measurement error 0.21 mm. With superior wear alone, Charnley's method underestimated wear by 16.6%, with a mean error of 0.35mm; Livermore's method estimated wear to within 9.5%, with a mean error of 0.16mm; Devane's method estimated wear to within 9.5%, with a mean error of 0.15mm; and Dorr's method underestimated wear by 25.4%, with a mean error of 0.56mm. However, when the adjustment for direction was made, the modified Dorr method estimated superior wear to within 9.6%, with a mean error of 0.15mm.