title: The biomechanics of screws.
abstract: Screws are simple machines, commonly used in orthopaedics. Understanding the mechanics by which a screw generates compression can facilitate screw selection and insertion techniques and help reduce failure rates. Screw strength depends on both the material and size of the screw. A screw's holding strength depends both on it's type and size and on the type of bone into which it is inserted. Other factors being equal, a larger screw will have greater holding strength than a smaller screw. Properly placed lag screws greatly increase fracture stability and lead to better fracture healing.
authors.affiliation: Hand Rehabilitation Center, Philadelphia, Pennsylvania.
authors.forename: R L
authors.initials: RL
authors.lastname: Uhl
mesh_terms: D001696:Biomechanical Phenomena; D001863:Bone Screws; D004867:Equipment Design; D006801:Humans; D013718:Tensile Strength