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Table 1 Accuracy of the investigated acetabular cup component within a phantom-model and a performed relative motion protocol

From: Model-based roentgen stereophotogrammetric analysis using elementary geometrical shape models: 10 years results of an uncemented acetabular cup component

  RSA Translation [mm] EGS Translation [mm] set-point [mm]
x y z x y z  
mean 0.50 0.48 0.51 0.49 0.48 0.44 0.5
SD 0.03 0.05 0.08 0.03 0.05 0.18
bias 0.00 −0.02 0.01 −0.01 − 0.02 − 0.06
95% CI (↓) −0.05 − 0.08 − 0.12 −0.04 − 0.08 −0.27
95% CI (↑) 0.08 0.13 0.20 0.06 0.13 0.43
mean 1.49 1.47 1.52 1.49 1.47 1.49 1.5
SD 0.02 0.06 0.05 0.04 0.06 0.25
bias −0.01 −0.03 0.02 −0.01 −0.03 −0.01
95% CI (↓) −0.01 0.00 −0.02 −0.02 − 0.03 −0.12
95% CI (↑) 0.08 0.22 0.17 0.15 0.20 0.86
  1. After taking RSA image pairs of the reference setup, using a spring-loaded micrometer, stepwise increments of 0.5 up to 1.5 mm (set-point value for single translation along each axis) of the cup along the x-, y- and z-axis was performed. At each step a RSA image pair was taken. This protocol was repeated n = 8 times. RSA image pairs were analysed by marker-based RSA and model-based EGS-RSA
  2. SD standard deviation, bias difference between mean value and set point value, CI confidence interval with upper (↑) and lower (↓) limit