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Updated: Jun 27, 2026

An Anesthesia, Surgery, and Harvest Method for the Evaluation of Transpedicular Screws Using an In Vivo Porcine Lumbar Spine Model
Published on: May 31, 2017
A biomechanical comparison of two patterns of screw insertion
Sheldon Lichtblau1, Jessica Gallina, Philip Nasser
1Peter and Leni May Department of Orthopaedic Surgery, Mount Sinai School of Medicine, Mount Sinai Medical Center, New York, New York, USA. Llichtblau@earthlink.net
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.
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