Comparison of Femoral Anteversion Angle and Determination of Reliability Measured at Three Different Anatomical References of the Tibial Crest During the Trochanteric Prominence Angle Test

Abstract

The trochanteric prominence angle test (TPAT) has been used to measure the femoral anteversion angle between the tibial crest and the vertical line. However, the exact anatomical reference of the tibial crest has not yet been identified in the literature. Thus, the purposes of this research were twofold: first, to compare the femoral anteversion angle measured at three different anatomical references of the tibial crest (the proximal tibial crest, the proximal third of tibial crest, and the proximal half of tibial crest) and, second, to determine inter-and intra-rater reliabilities of the femoral anteversion angle measured at these three different anatomical references of the tibial crest during the TPAT. We recruited 14 healthy subjects, and a total of 28 legs were examined. The TPAT was measured using a digital inclinometer. A 1-way repeated-measure analysis of variance was used to compare the femoral anteversion angle measured at three different anatomical references of the tibial crest, and intraclass correlation coefficients (ICCs) were calculated to determine reliability. The femoral anteversion angle measured at the proximal tibial crest was significantly higher than that at the proximal third of the tibial crest and the proximal half of the tibial crest. The inter-and intra-rater reliabilities of femoral anteversion angle were measured at three anatomic references of the tibial crest were all found to be high during the TPAT (ICC=.9 0~.98). In conclusion, clinicians should recognize that the different degrees of the femoral anteversion angle could be measured when different anatomical references of the tibial crest were used, and that reliabilities were high when an exact anatomical reference of the tibial crest was used during the TPAT.