Patent ID: 7172600

Claim:
A method for revision of an implanted cannulated bone screw, comprising the steps of: inserting a cannulated screwdriver into a screw head of said cannulated bone screw; introducing a removal device into said cannulated screwdriver; screwing a threaded distal end of said removal device into a corresponding threaded portion of said cannulated screw; and simultaneously unscrewing said screw using said cannulated screwdriver and pulling said screw using a handle located on a proximal end of said removal device; wherein: said bone screw secures a clamping element to a bone segment; a locking mechanism secures said bone screw to said clamping element, said locking mechanism comprising: at least two snap catches protruding from a bone-contacting surface of said clamping element and spaced around an edge of a screw hole; and a circumferential groove located on a top portion of said screw below a screw head for receipt of said snap catches; and said snap catches interlock with said groove to secure said bone screw to said clamping element when said bone screw is screwed into said bone segment through said screw hole of said clamping element.