THỰC NGHIỆM ĐO GÓC NGHIÊNG Ổ CỐI VÀ PHƯƠNG PHÁP ĐIỀU CHỈNH ĐỂ ĐẠT GÓC NGHIÊNG MỤC TIÊU TRÊN MÔ HÌNH SAWBONE NỬA KHUNG CHẬU NGƯỜI TRƯỞNG THÀNH

Abstract

Experimental study on adult half-pelvis sawbones model, 1:1 ratio to measure the tilt of the cup and adjustment method to achieve the target angle. Results: average time to measure complementary Operative Inclination (cOI), Operative Anteversion (OA), and Anatomical Inclination (AI): 8,49; 8,39, and 7,87 seconds, respectively. The error of the angle OI and OA which are set by the external alignment system compared to the target is 2,23⁰ and 1,73⁰, a significant difference (p < 0,05, Confidence Index (CI) 95%); 24% of the RI and 16% of the RA are outside the Lewinnek’s safe zone. We performed 26 OI adjustments and 39 OA adjustments to reach the target RI and RA angles. Error RI and RA after adjustment 0,47⁰ and 0,24⁰, respectively, no significant difference (p > 0.05, CI 95%). Conclusion: The Cup’s external alignment system has low accuracy. The implementation of measuring the angle OI through its complementary to the vertical and the AI ​​angle has the highest reliability. The calculation based on the value of these angles makes it possible to adjust the angle of the cup to very close to the target value simply and effectively.