Figure 1From: Fixation method does not affect restoration of rotation center in hip replacements: A single-site retrospective studyIllustration of how the center of rotation prior to (A) and after (B) implantation of a cementless cup was determined when the acetabular teardrop was not visible. Line a is drawn through the top of the foramina obtoratoria, and line b is drawn at a right angle to line a through the center of rotation. The vertical distance is measured from line a to the center of rotation, and the horizontal distance from the Köhler line (drawn along the medial aspect of the ilium and ischium) to the center of rotation.Back to article page