Recovery of the Hip Rotation Center with Tantalum in Revision Arthroplasty.

 The objective of the present study is to evaluate the restoration capacity of the hip anatomic rotation center with the use of acetabular tantalum cups, associated or not with addition wedges.  Retrospective analysis of patients undergoing hip arthroplasty revision using tantalum between June 2013 and April 2017. The abduction angle of the acetabular component and the horizontal and vertical distances of the component to the center of anatomical rotation of the hip were evaluated. The measurements were made through baseline radiographs performed in the preoperative period and at the last follow-up visit.  A sample of 21 patients was obtained, 11 (52%) men and 10 (48%) women, with a mean age of 62 ± 13 years old. The mean abduction angle of the acetabular cup decreased from 48.76° ± 13.88 ° in the preoperative period to 38.52° ± 10.08 ° in the postoperative period, and this difference was statistically significant (  = 0.001). The distances from the center of rotation of the prosthesis relative to the center of anatomical rotation of the hip were also lower after revision surgery with tantalum. The mean horizontal distance of 12.74 ± 10.59 mm was reduced to 7.11 ± 4.84 mm, and the mean vertical distance was reduced from 14.79 ± 10.05 mm to 4.89 ± 6.21 mm, and these reductions were statistically significant (  < 0.001).  Hip arthroplasty revision with tantalum cups, associated or not with addition wedges, significantly recovered the anatomical rotation center of the hip.