Comparisons of Preoperative Three-Dimensional Planning and Surgical Reconstruction in Primary Cementless Total Hip Arthroplasty

Reconstruction of important parameters such as femoral offset and torsion is inaccurate, when templating is based on plain x-rays. We evaluate intraoperative reproducibility of pre-operative CT-based 3D-templating in a consecutive series of 50 patients undergoing primary cementless THA through an anterior approach. Pre-operative planning was compared to a postoperative CT scan by image fusion. The implant size was correctly predicted in 100% of the stems, 94% of the cups and 88% of the heads (length). The difference between the planned and the postoperative leg length was 0.3 + 2.3 mm. Values for overall offset, femoral anteversion, cup inclination and anteversion were 1.4 mm +/- 3.1, 0.6 degrees +/- 3.3 degrees, -0.4 degrees +/- 5 degrees and 6.9 degrees +/- 11.4 degrees, respectively. This planning allows accurate implant size prediction. Stem position and cup inclination are accurately reproducible. (C) 2014 Elsevier Inc. All rights reserved.