title: An anatomical study of the entry point in the greater trochanter for intramedullary nailing.
abstract: Malpositioning of the trochanteric entry point during the introduction of an intramedullary nail may cause iatrogenic fracture or malreduction. Although the optimal point of insertion in the coronal plane has been well described, positioning in the sagittal plane is poorly defined. The paired femora from 374 cadavers were placed both in the anatomical position and in internal rotation to neutralise femoral anteversion. A marker was placed at the apparent apex of the greater trochanter, and the lateral and anterior offsets from the axis of the femoral shaft were measured on anteroposterior and lateral photographs. Greater trochanteric morphology and trochanteric overhang were graded. The mean anterior offset of the apex of the trochanter relative to the axis of the femoral shaft was 5.1 mm (sd 4.0) and 4.6 mm (sd 4.2) for the anatomical and neutralised positions, respectively. The mean lateral offset of the apex was 7.1 mm (sd 4.6) and 6.4 mm (sd 4.6), respectively. Placement of the entry position at the apex of the greater trochanter in the anteroposterior view does not reliably centre an intramedullary nail in the sagittal plane. Based on our findings, the site of insertion should be about 5 mm posterior to the apex of the trochanter to allow for its anterior offset.
authors.affiliation: Case Western Reserve University, Department of Orthopaedic Surgery, 2500 Metrohealth Drive, Cleveland, Ohio 44109, USA.
authors.forename: K
authors.initials: K
authors.lastname: Farhang
authors.affiliation: Case Western Reserve University, Department of Orthopaedic Surgery, 2500 Metrohealth Drive, Cleveland, Ohio 44109, USA.
authors.forename: R
authors.initials: R
authors.lastname: Desai
authors.affiliation: Case Western Reserve University, Department of Orthopaedic Surgery, 2500 Metrohealth Drive, Cleveland, Ohio 44109, USA.
authors.forename: J H
authors.initials: JH
authors.lastname: Wilber
authors.affiliation: Yale University School of Medicine, Department of Orthopaedics and Rehabilitation, PO Box 208071, New Haven, Connecticut 06520-8071, USA.
authors.forename: D R
authors.initials: DR
authors.lastname: Cooperman
authors.affiliation: Rainbow Babies and Children's Hospital, 11100 Euclid Ave, Cleveland, Ohio, 44106, USA.
authors.forename: R W
authors.initials: RW
authors.lastname: Liu
mesh_terms: D000328:Adult; D000368:Aged; D001858:Bone Nails; D005260:Female; D005269:Femur / Q000033:anatomy & histology* / Q000601:surgery; D005594:Fracture Fixation, Intramedullary / Q000295:instrumentation / Q000379:methods*; D006620:Hip Fractures / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged
keywords: Femur iatrogenic fracture; Femur malunion; Greater trochanter; Greater trochanter anatomy; Intramedullary nailing; Trochanteric nail stating point