Orthopaedic implant fixation using an in-situ formed anchor

• US 20030083662A1
• Filed: 10/31/2002
• Published: 05/01/2003
• Est. Priority Date: 11/01/2001
• Status: Active Grant

• Current Assignee: Renova Orthopedics, LLC
• Original Assignee: Renova Orthopedics, LLC
• Inventors: Middleton, Lance M.
• Granted Patent: US 7,488,320 B2
• Time in Patent Office: Days
• US Class Current: 606/72
• 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 17/7098 wherein the implant is permeable or has openings, e.g. fenestrated screw hollow surgical screws A61B17/864
• CPC Class Codes: A61B 17/72 Intramedullary pins, nails or other devices A61B17/744 takes precedence
• CPC Class Codes: A61B 17/725 with locking pins or screws of special form
• CPC Class Codes: A61B 17/742 having one or more longitudinal elements oriented along or parallel to the axis of the neck
• CPC Class Codes: A61B 17/746 the longitudinal elements coupled to a plate opposite the femoral head
• CPC Class Codes: A61B 17/864 hollow, e.g. with socket or cannulated
• CPC Class Codes: A61B 17/866 Material or manufacture
• CPC Class Codes: A61B 17/8811 characterised by the introducer tip, i.e. the part inserted into or onto the bone
• CPC Class Codes: A61B 2017/0412 having anchoring barbs or pins extending outwardly from suture anchor body
• CPC Class Codes: A61B 2017/0414 having a suture-receiving opening, e.g. lateral opening lateral eyelet for attaching suture to needle A61B2017/06019
• CPC Class Codes: A61B 2017/0427 having anchoring barbs or pins extending outwardly from the anchor body
• CPC Class Codes: A61B 2017/0458 Longitudinal through hole, e.g. suture blocked by a distal suture knot

Abstract

An orthopaedic implant fixation using a surgically created bone cavity as a mold for forming an anchor from an in-situ hardenable material. An in-situ formed anchor of the present invention is especially useful for attaching an implant to osteoporotic cancellous bone. The injectable nature of the in-situ formed anchor allows implants to be adapted to minimally invasive surgical techniques. The present invention can be adapted to numerous implants or implant system components to include fasteners, pins, nails, intramedullary nails, and suture anchors. Applications include bone fracture fixation, bone fracture prevention, and soft-tissue repair.

Claims

1. A method for the fixation of an orthopaedic implant in bone, the method comprising the steps of:

(a) forming in the bone a pilot hole having a first diameter;

(b) forming in the bone a cavity connected to said pilot hole, said cavity having a second diameter that is substantially larger than the first diameter of said pilot hole;

(c) positioning a preformed element within said pilot hole and said cavity, said preformed element comprising;

a shank having a length, a proximal end and a distal end, the length of said shank being sized so that the distal end of said shank extends into said cavity when said shank is positioned within said pilot hole;

a proximal aperture disposed at the proximal end of said shank;

a distal aperture disposed at the distal end of said shank; and

a passage extending within said shank from said proximal aperture to said distal aperture;

(d) injecting a hardenable material into said proximal aperture so that said hardenable material flows through said passage and flows out of said distal aperture to fill said cavity;

(e) allowing said hardenable material to harden within said cavity while said preformed element remains positioned within said pilot hole and said cavity, thereby forming an in-situ anchor that interlocks said preformed element to the bone.

2. The method of claim 1 wherein the hardenable material is bone cement.

3. The method of claim 2 wherein the bone cement is a polymethylmethacrylate-based bone cement.

4. The method of claim 1 wherein the hardenable material is a load-bearing polymer.

5. The method of claim 1 wherein the hardenable material is a synthetic bone substitute.

6. The method of claim 5 wherein the synthetic bone substitute is an injectable calcium phosphate.