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? ? 3.3?, - 0.4? ? 5? and 6.9? ? 11.4?, respectively. This planning allows accurate implant size prediction. Stem position and cup inclination are accurately reproducible. ? 2014 Elsevier Inc.