Abstract
The purposes of this study were to report the accuracy of stem anteversion for Exeter cemented stems with the Mako hip enhanced mode and to compare it to Accolade cementless stems.
We reviewed the data of 25 hips in 20 patients who underwent THA through the posterior approach with Exeter stems and 25 hips in 19 patients with Accolade stems were matched for age, gender, height, weight, disease, and approaches. There was no difference in the target stem anteversion (20°–30°) between the groups. Two weeks after surgery, CT images were taken to measure stem anteversion.
The difference in stem anteversion between the plan and the postoperative CT measurements was 1.2° ± 3.8° (SD) on average with cemented stems and 4.2° ± 4.2° with cementless stems, respectively (P <0.05). The difference in stem anteversion between the intraoperative measurements and the postoperative CT measurements was 0.75° ± 1.8° with Exeter stems and 2.2° ± 2.3° with Accolade stems, respectively (P <0.05).
This study demonstrated a high precision of anteversion for Exeter cemented stems with the Mako enhanced mode and its clinical accuracy was better with the cemented stems than that with the cementless stems. Although intraoperative stem anteversion measurements with the Mako system were more accurate with the cemented stems than that with the cementless stem, the difference was about 1° and the accuracy of intra-operative anteversion measurements was quite high even with the cementless stems. The smaller difference in stem anteversion between the plan and postoperative measurements with the cemented stems suggested that stem anteversion control was easier with cemented stems under the Mako enhanced mode than that with cementless stems.
Intraoperative stem anteversion measurement with Mako total hip enhanced mode was accurate and it was useful in controlling cemented stem anteversion to the target angle.
