Quantitative Lesser Trochanter Profile Versus Cortical Step Sign in Assessing Femoral Malrotation After Femoral Nailing.

We describe the novel quantitative lesser trochanter profile (QLTP) technique to determine the magnitude and direction of femoral malrotation and to compare its performance with the cortical step sign technique. For this assessment, 9 orthopaedic surgeons estimated the magnitude and direction of femoral malrotation with each technique in 198 anteroposterior view images of the proximal cadaveric femur and osteotomy sites. Based on the results, the main benefit of the QLTP technique over the cortical step sign technique is the ability to determine the direction of femoral malrotation. The QLTP technique was also more accurate in measuring malrotation and had less error. However, the QLTP technique requires additional imaging, and the mean difference in error between the 2 techniques might not be clinically meaningful.