A method combining the use of a mobile application and a dedicated pelvic positioner for acetabular cup insertion

Abstract

Background We developed a mobile device application and dedicated pelvic positioner with the aim of improving the acetabular cup placement accuracy in patients undergoing total hip arthroplasty (THA). The function of the application was to display the intra-operative cup angle. The accuracy and clinical usefulness of this combined method were verified through comparison with the conventional alignment guide method. Methods In total, 60 patients who underwent cementless THA were included in this study. We compared the cup alignment when using this combined method with that when using the conventional alignment guide method. The absolute value error between the intra- and post-operative angles of inclination and anteversion of the cup was calculated. Results The absolute value error of inclination was 2.4° ± 2.1° in the study group and 4.0° ± 3.3° in the control group (P = 0.107). The absolute value error of anteversion was 2.8° ± 2.6° in the study group and 7.4° ± 5.3° in the control group (P < 0.001). Conclusion Using the application and pelvic positioner is simple and can be introduced at a low cost. The more accurate measurement of the intra-operative cup angle using this combined method has improved the cup insertion accuracy compared with that of the conventional alignment guide method.

Minimally Invasive Derotational Osteotomy of Long Bones: Smartphone Application Used to Improve the Accuracy of Correction

“…However, no reliable methods of assessing the intraoperative rotational alignment of the lower limbs have been reported to date. SP technology has been used previously in various orthopedic surgeries [ 18 , 19 ], with experimental studies examining its accuracy in the measurement of rotational deformities [ 14 , 15 ]. The findings were largely similar to those obtained using CT scanning with markers placed over artificial bones without any soft tissue coverage.…”