title: A biomechanical comparison of two patterns of screw insertion.
abstract: Inserting a screw into a long bone introduces a stress riser that can predispose the bone to fracture. Where multiple screws are inserted this vulnerability may be increased. It is thought that the pattern of screw insertion plays an important part in determining the susceptibility of the bone to stress fracture. In order to study the importance of pattern of screw insertion, third generation composite femora with cannulated screws inserted in two different patterns were tested to failure by a servohydraulic materials test system. The vertical pattern of screw insertion is less apt to predispose a long bone to subsequent fracture than a horizontal pattern.
authors.affiliation: Peter and Leni May Department of Orthopaedic Surgery, Mount Sinai School of Medicine, Mount Sinai Medical Center, New York, New York, USA. Llichtblau@earthlink.net
authors.forename: Sheldon
authors.initials: S
authors.lastname: Lichtblau
authors.forename: Jessica
authors.initials: J
authors.lastname: Gallina
authors.forename: Philip
authors.initials: P
authors.lastname: Nasser
authors.forename: Musyoka
authors.initials: M
authors.lastname: Munyoki
authors.forename: Karl
authors.initials: K
authors.lastname: Jepsen
mesh_terms: D001696:Biomechanical Phenomena; D001863:Bone Screws; D018786:Bone Substitutes; D019544:Equipment Failure Analysis; D005265:Femoral Neck Fractures / Q000209:etiology; D005269:Femur / Q000601:surgery*; D005593:Fracture Fixation, Internal / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods*; D015775:Fractures, Stress / Q000209:etiology; D006801:Humans; D008422:Materials Testing; D011474:Prosthesis Design; D011475:Prosthesis Failure; D013314:Stress, Mechanical
chemical_list: D018786:Bone Substitutes