PREOPERATIVE TEMPLATING

The re-establishment of appropriate hip biomechanics is an objective of paramount importance in total hip arthroplasty (THA). 1-4 Numerous texts have discussed the value of preoperative x-ray review and measurement to help achieve this goal. Early techniques that utilized cement on both the femoral and acetabular side allowed the surgeon to adjust the position of either component within the cement mantle and more easily compensate to achieve proper hip biomechanics. The increased popularity of cementless implants beginning in the 1980s forced a change in this practice. 5 With cementless implants, the placement of the components was most significantly determined by the patient’s native anatomy. Thus, the surgeon’s ability to dictate and customize component position within the cement mantle became limited. This change made preoperative templating an even more crucial step in the planning of a cementless THA and refined the preoperative planning process. Engh et al published enhanced radiographic techniques and templating principles that addressed these developments. 6, 7 With the advent of digital x-rays, some templating is now being done with computer software. This chapter will focus on the use of the printed radiograph, and the principles of digital templating are the same. Overall, the common goals of hip reconstruction are to recreate the anatomic biomechanical axis as accurately as possible by focusing on restoring the anatomic center of rotation and femoral offset while attempting to equalize limb length.