Instrument for the removal of a bone insert and corresponding method

Patent metadata

Field	Value
Publication number	US-10952872-B2
Application number	US-201916351335-A
Country	US
Kind code	B2
Filing date	Mar 12, 2019
Priority date	Jun 12, 2014
Publication date	Mar 23, 2021
Grant date	Mar 23, 2021

Abstract

A method for the removal of a bone insert for a shoulder prosthesis, which provides for: forming a hole inside a proximal bone portion; inserting in the hole an operating end of an instrument provided with a moveable cutting element deep-cutting a distal base of the bone insert, by rotating the instrument through 360 degrees around its longitudinal axis; removing the instrument from the hole; inserting and fixing a pin element inside the hole; milling the bone insert; removing the bone insert and the pin element attached thereto.

First claim

The invention claimed is:

1. Method for the removal of a bone insert, for example of a bone insert for a shoulder prosthesis, the method comprising:
forming a hole of predefined diameter inside a proximal bone portion from which said bone insert is to be removed;
inserting inside said hole an operating end of an instrument provided with a cutting element, wherein said cutting element is moveable to project through a side opening in said operating end, transversely with respect to a longitudinal axis of the instrument;
deep-cutting by the cutting element a distal base of said bone insert, wherein said instrument is pushed and is rotated through 360 degrees around the longitudinal axis of the instrument;
removing the instrument from said hole;
inserting and fixing a pin element inside said hole;
perimetrally milling the bone insert at a predefined second diameter, by centering a milling cutter on said pin element;
removing the bone insert and the pin element attached thereto.

2. Method according to claim 1 , wherein said deep-cutting has an essentially circular shape in a spongy part of the bone to be cut.

3. Method according to claim 1 , wherein said bone is a long bone, in particular a femur or a humerus.

4. Method according to claim 1 , wherein a flange is integral with said pin and removal of the bone insert and of the pin is performed by engaging with said flange.

5. Method according to claim 4 , wherein perimetrally milling the bone insert is performed by a circular milling cutter circumscribing said flange.

6. Method according to claim 1 , wherein said hole has a frustoconical form matching said operating end.

7. Method according to claim 6 , wherein said operating end is a frustoconical portion of a larger-diameter operating head housing an adjustment mechanism of the projecting cutting element.

8. Method according to claim 1 , wherein said proximal bone portion in which said hole is formed is flattened or made concave beforehand or afterwards, so as to receive a flat or convex flange from which said pin element projects.

9. Method according to claim 8 , wherein said pin element is inserted with interference fit inside the hole until the flange achieves a bearing contact.

10. Method according to claim 1 , wherein said pin element is perimetrally threaded or partially threaded.

11. Method according to claim 1 , wherein said pin element is hollow.

12. Method according to claim 11 , wherein perimetrally milling the bone insert is performed by centering the milling cutter on a guide rod inserted inside a cavity of said hollow pin element.

13. Method according to claim 1 , wherein said cutting element is made to project only when said operating end is completely inserted inside said hole.

14. Method according to claim 13 , wherein said cutting element is movably guided from a rest position, where it is concealingly housed inside said operating end, to an operative position, where it projects through a side opening in said operating end, transversely with respect to the longitudinal axis of the instrument.

15. Method according to claim 1 , wherein said pin element is configured for attachment to a shoulder prosthesis portion.

Assignees

• Limacorporate Spa

Inventors

• Pressacco Michele
• Ursella Simone
• Fiedler Christoph
• Paterson Paul D

Classifications

• A61B17/1684 Primary

  for the shoulder · CPC title

• A61F2002/4018

  Heads or epiphyseal parts of humerus · CPC title

• A61B17/1637

  Hollow drills or saws producing a curved cut, e.g. cylindrical (A61B10/025, A61B17/1695 take precedence) · CPC title

• A61B17/1617

  with mobile or detachable parts · CPC title

• A61B17/147

  with circularly moving saw blades, i.e. non-reciprocating saw blades · CPC title