No abstract

Pelvic rotation during cup impaction causes excessive cup anteversion should be considered in direct anterior approach or anterior lateral approach total hip arthroplasty (THA) with supine position. There are two intraoperative support mechanical devices for THAs in supine position, one is based on functional pelvic plane (FPP) and the other is based on anatomical pelvic plane (APP). The purpose of this study was to compare the accuracy of two mechanical devices based on FPP or APP in THA with supine position.The subjects of this study were 90 hips of 80 patients who underwent DAA-THA in a supine position using HipPointer® based on FPP (Pointer group). The other subjects of this study were 29 hips of 27 patients using HipCOMPASS® (Lexi, Tokyo) based on APP (COMPASS group). There are no significant differences in age, gender and BMI between the two groups.Cup inclination and anteversion angle in Pointer group and COMPASS group were