Threedimensional, CT-assisted preoperative planning for primary total hip arthroplasty

Abstract

Purpose: In hip arthroplasty, exact positioning of the implants is imperative. Preoperative planning is essential to achieve this and is generally conducted using conventional radiographs. The objective of our study was to examine the clinical feasibility of a 3D planning system. Methods: In 500 patients (average age 72.8 (31-87) years), a CT was performed preoperatively for 3D planning. The data were further processed in DICOM format on an external workstation for 3D planning, with the aid of special software (SYMBIOS® 3D-Hip Plan), whereby an exact presentation of the acetabulum and femur was possible in all three planes. The clinical outcome was documented by using the Harris Hip Score. Results: In 470/500 patients (94%), the acetabular cup was successfully implanted as planned. In the area of the stem, in 10/500 patients (2%) a custom made stem was implanted, as adequate treatment due to anatomical reasons could not have been achieved here. Overall, the stem planning could be implemented exactly in 475/500 patients (95%). The neck length of the head was implemented as planned in 465/500 patients (93%). The Harris Hip Score improved from a preoperative average of 47.6 to 70.6. Conclusion: 3D hip planning enables a preoperative simulation of implant positioning, which makes it possible to optimally determine and reconstruct the centre of hip rotation. Potential difficulties that might arise intraoperatively can already be identified preoperatively. Patients who require a custom made stem can be reliably identified.