title: Two or three screws for fixation of femoral neck fractures?
abstract: This study compares the stability of 3 cannulated cancellous lag screws with that of 2 cannulated cancellous lag screws for fixation of subcapital femoral neck fractures. Using 10 matched pairs of human cadaveric femurs, subcapital femoral neck osteotomies were created, reduced, and then randomized to 1 of the 2 fixation methods. The constructs were tested with anterior loading to 500 N, incremental axial loading from 100 N to 1000 N, and cyclic loading at 1000 N. The specimens stabilized using 3 screws showed greater resistance to anterior loading, less inferior femoral head displacement, and less superior gapping at the osteotomy site. Although 2 screws may be an acceptable fixation method for this fracture type, the addition of a third screw provides supplemental stability and appears justified.
authors.affiliation: Department of Orthopaedic Surgery, New York University-Hospital for Joint Diseases, New York, New York, USA.
authors.forename: Stephen G
authors.initials: SG
authors.lastname: Maurer
authors.forename: Kevin E
authors.initials: KE
authors.lastname: Wright
authors.forename: Frederick J
authors.initials: FJ
authors.lastname: Kummer
authors.forename: Joseph D
authors.initials: JD
authors.lastname: Zuckerman
authors.forename: Kenneth J
authors.initials: KJ
authors.lastname: Koval
mesh_terms: D015502:Absorptiometry, Photon; D001696:Biomechanical Phenomena; D001863:Bone Screws; D005265:Femoral Neck Fractures / Q000503:physiopathology / Q000601:surgery*; D005593:Fracture Fixation, Internal / Q000295:instrumentation / Q000379:methods*; D006801:Humans