CT based measurement of anatomical dimensions of femur and its relevance in nail designs for proximal femoral fractures

Abstract

IntroductionThe purpose of this study was to obtain computed tomography (CT) based measurements of femoral dimensions in adults, to identify its relevance with intramedullary nails used in the management of proximal femur fractures and to suggest a best fitting implant dimensions to our population. To best of our knowledge our study would be first to compile different CT based dimension in single study. MethodsIn our retrospective study of 50 femurs, CT based femoral dimensions measured in standardized cuts and compared with previous studies and commonly available proximal femur intramedullary devices. Results68.4 was the mean age in our study, neck shaft angle (NSA) was 127.2±5.20, anteversion 11.2±7.40, endosteal isthmus diameter was 11.9 ± 1.7 mm, anterior radius of curvature (ROC) was 116.8 ± 20 mm, horizontal femoral offset 37.5 ± 4.6 mm, medio-lateral angle 7.8±1.60, with good inter and intra observer correlation. Femoral length and neck width was positively correlated to head diameter, horizontal femoral offset with medio-lateral (ML) angle. One of the 50 femur studied had the parameters in the range of available implant and could match appropriately. ConclusionCT based dimensions in our population is different from other population. Based on this study, a design modification of nails used in present day management of proximal femur fractures has been recommended.