Medical screw and method of installation

• US 6,743,233 B1
• Filed: 08/02/2000
• Issued: 06/01/2004
• Est. Priority Date: 08/02/2000
• Status: Expired due to Fees

• Current Assignee: Orthopaedic Biosystems Ltd. Inc. (Smith & Nephew PLC)
• Original Assignee: Orthopaedic Biosystems Ltd. Inc. (Smith & Nephew PLC)
• Inventors: Hatch, Laird, Baldwin, Jeffrey P.
• Primary Examiner(s): Manahan, Todd E.
• Application Number:
  US09/630,401
• Time in Patent Office: 1,399 Days
• Field of Search: 606/65, 606/66, 606/73, 606/232
• US Class Current: 606/323
• CPC Class Codes: A61B 17/0401 Suture anchors, buttons or pledgets, i.e. means for attaching sutures to bone, cartilage or soft tissue; Instruments for applying or removing suture anchors A61B17/0642 takes precedence; fixation devices for tendons or ligaments A61F2/0811
• CPC Class Codes: A61B 17/8625 Shanks, i.e. parts contacting bone tissue
• CPC Class Codes: A61B 17/863 with thread interrupted or changing its form along shank, other than constant taper
• CPC Class Codes: A61B 17/8635 Tips of screws
• CPC Class Codes: A61B 2017/0409 Instruments for applying suture anchors
• CPC Class Codes: A61B 2017/0414 having a suture-receiving opening, e.g. lateral opening
• CPC Class Codes: A61B 2017/044 with a threaded shaft, e.g. screws

Abstract

A medical screw includes a shaft having a threaded portion and a distal guiding tip for introducing the screw into a pre-drilled implantation site. The threaded portion of the medical screw has a first series of helical threads having a first diameter and a second series of helical threads interleaved with the first series of helical thread and having a second diameter, where the first diameter is different than the second diameter. In addition, the medical screw may have a counter-rotation channel configured to receive bone growth.

Claims

1. A method of installing a medical screw comprising the steps of:

providing a medical screw having a head for receiving a screw driving device and a shaft extending from said head along a longitudinal axis, wherein said shaft includes (a) a threaded portion including helical threads and (b) a distal guiding tip extending longitudinally and distally from the threaded portion and including a cylindrical portion;

drilling an implantation site into bone at a desired location, the implantation site having a cylindrical core;

tapping the cylindrical core with tracks that correspond to the helical threads; and

inserting said distal guiding tip into said implantation site at a depth sufficient that a surface of the cylindrical portion contacts at least three points on the cylindrical core with each of the at least three points being separated by a track.

2. The method of claim 1 further comprising rotating said medical screw to a desired degree of installation.

3. The method of claim 2 wherein rotating said medical screw comprises inserting a screw driving device into a slot formed on said head and rotating said screw driving device.

4. The method of claim 1 wherein inserting said distal guiding tip comprises inserting a screw driving device into a slot formed on said head.