Accuracy of intraoperative estimation of femoral stem anteversion in cementless total hip arthroplasty by using a digital protractor and a spirit level

Abstract Background The femoral component anteversion during surgery is traditionally assessed by a visual assessment of the surgeon and has proven to be imprecise. We sought determine accuracy digital protractor spirit level measure stem cementless THA. Methods A prospective study was conducted among 107 patients (114 hips) who underwent primary THA via posterolateral approach. pipe with attached tibial tubercle intermalleolar midpoint. While leg held perpendicularly floor, estimated 3 methods: method assessment; B alone; C combined level. angles were compared true measured postoperative CT scan. Results average (22.8° ± 6.9°, range -2° 40°) significantly lower than (24.6° 5.2°, 0° 30°) (p=0.033), but not different from (22.1° 8.2°, -5.4° 43.1°) (p=0.445). There no significant differences between (23.2° -4° 45°) A, or anteversion. mean deviation intraoperative estimation 0.8° 3.7° (range -7.1° 8.0°) C; 1.2° 5.1° -8.8° 14.3°) B; 2.5° 7.4° -19.0° 16.0°) A. Estimation error within 5° found in hips (93.9%) 86 (75.4%) 59 (51.8%) Conclusion Accurate can determined intraoperatively use Trial registration Thai Clinical Trials Registry ( TCTR 20180326003 ). Registered on 20 March 2018. Retrospectively registered.