title: Full circle: 3D femoral mapping demonstrates age-related changes that influence femoral implant positioning.
abstract: The geometry of the femur is important in the final position of an intramedullary implant; we hypothesised that the femoral geometry changes with age and this may predispose the elderly to anterior mal-positioning of these implants. We used CT DICOM data of 919 intact left femora and specialist software that allowed us to defined landmarks for measurement reference - such as the linea aspera - on a template bone that could be mapped automatically to the entire database. We found that older (>80 years) cortical bone is up to 1.5 mm thinner anteriorly and 2 mm thinner posteriorly than younger (<40 years) bone but the rate of change of posterior to anterior cortex thickness is greater in the older bone. We also found the isthmus in the elderly to be more distal and less substantial than in the younger bone. This study has demonstrated femoral geometry changes with age that may explain our perception that the elderly are at increased risk for anterior mal-positioning of intramedullary implants.
authors.affiliation: North Bristol NHS Trust, Bristol, United Kingdom. Electronic address: damientuckeruk@gmail.com.
authors.forename: Damien
authors.initials: D
authors.lastname: Tucker
authors.affiliation: Stryker R&D Virtual Engineering, Kiel, Germany.
authors.forename: Timm
authors.initials: T
authors.lastname: Surup
authors.affiliation: Stryker R&D Virtual Engineering, Kiel, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Petersik
authors.affiliation: North Bristol NHS Trust, Bristol, United Kingdom.
authors.forename: Michael
authors.initials: M
authors.lastname: Kelly
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001696:Biomechanical Phenomena; D001858:Bone Nails; D001860:Bone Plates; D001863:Bone Screws; D002358:Cartilage, Articular / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D005260:Female; D005264:Femoral Fractures / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D005269:Femur / Q000000981:diagnostic imaging / Q000473:pathology*; D005594:Fracture Fixation, Intramedullary / Q000009:adverse effects; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D056888:Patient Positioning; D011859:Radiography
keywords: Aged; Biomedical engineering; Femoral fractures; Femur; Fracture fixation; Intramedullary