Screw and driver

• US 5,498,265 A
• Filed: 04/01/1994
• Issued: 03/12/1996
• Est. Priority Date: 03/05/1991
• Status: Expired due to Term

• Current Assignee: Howmedica Osteonics Corp. (Stryker Corporation)
• Original Assignee: Howmedica Inc. (Pfizer Inc.)
• Inventors: Asnis, Stanley E., Crombie, John S.
• Primary Examiner(s): RIMELL, SAMUEL G
• Application Number:
  US08/222,517
• Time in Patent Office: 711 Days
• Field of Search: 606/53, 606/60, 606/62, 606/65, 606/66, 606/72, 606/73, 606/105, 81/439, 81/440
• US Class Current: 606/916
• CPC Class Codes: A61B 17/74 Devices for the head or neck or trochanter of the femur trochanteric devices connected to the proximal part of an endoprosthetic femoral shaft A61F2/30739; endoprosthetic internal fixation devices for the head or neck of the femur A61F2/3601
• CPC Class Codes: A61B 17/861 specially shaped for gripping driver
• CPC Class Codes: A61B 17/8685 comprising multiple separate parts
• CPC Class Codes: A61B 17/8875 Screwdrivers, spanners or wrenches

Abstract

An implant comprising a specially adapted bone screw having a threaded shank portion and a sleeve which mates with and operates in cooperation with the threaded shank portion is provided. Also provided is a driver specially adapted for inserting and removing the implant of the invention. A method of compressing a fracture in a bone is also provided. The implant generates bone compression by itself and can be used either alone or with plates and washers. It is easily inserted into a fracture and also is easily removed from the fracture. The driver which is specially adapted to be used in combination with the implant of the invention aids in the ease of insertion and removal of the implant.

Claims

1. A variable length implant comprising in a connected relationship:

(a) a threaded shank having;

(1) a distal threaded shank portion having a bone thread and having a distal end and

(2) a proximal threaded shank portion having a machine thread and having a proximal end,

wherein said bone thread and said machine thread are of opposite hand

(b) a sleeve having a head and having an inner threading which threads with said proximal threaded shank portion, so as to result in an implant having a maximum implant length and a minimum implant length; and

(c) a connector means which connects said sleeve near said distal end of said sleeve with said proximal threaded shank portion near said proximal end of said proximal threaded shank portion but which permits said sleeve to move longitudinally with respect to said distal threaded shank portion after said maximum implant length is reached.

2. An implant according to claim 1, wherein said connector means comprises a deformation of the first full thread in said proximal threaded shank portion and wherein said sleeve is not weakened by the presence of any aperture along said cylindrical surface.