BMCRI method for measuring cup anteversion after total hip replacement

Abstract Study design Prospective clinical study Back ground In total hip replacement the cup placement is critical. Orientation is determined by anteversionand abduction. We have devised a simple geometrical method to calculate anteversion using simple instruments which does not require complicated conversion tables, scientific calculators, trigonometric tables and special x ray equipment. Objectives The aim of study is to evaluate the new method in terms of reliability and validity in comparison with other commonly used radiological methods against CT evaluation. Methodology In 30 hips of 25 consecutive patients, 13 females and 12 males who underwent primary total hip replacement in our institution, the component version in our method was calculated and compared with CT evaluation of angles. The intra and inter observer reliability were assessed. Results Average CT measurement was 23.28 for ante version.We found our method had good correlation with CT calculation with average variability of +/_ 3.913800 in planar anteversionand CT methods had excellent intra and inter observer reliability (C.I. = 0.884 to 0.947&0.866 to 0.963). Conclusion Our method is accurate in comparison with CT (P value > 0.05), which does not need any reference tables, conversiontables, scientific calculators, multiple radiation exposures and not time consuming.