GB2433033A

GB2433033A - Orthopaedic suction filter

Info

Publication number: GB2433033A
Application number: GB0525075A
Authority: GB
Inventors: Michael John Radley Young
Original assignee: Individual
Current assignee: Individual
Priority date: 2005-12-09
Filing date: 2005-12-09
Publication date: 2007-06-13
Also published as: GB0525075D0

Abstract

The filter device is for use in removing detritus from an intramedullary cavity during an operation thereon. A source of vacuum is connected to the device which comprises an elongate tube (2) which has, at a distal end thereof, a filter plate (1). The plate (1) has a plurality of apertures (3) spaced across its surface.

Description

1 2433033

ORTHOPAEDIC SUCTION FILTER

The present invention relates to a filter for use in joint replacement surgery. More particularlY but not exclusively, it relates to a filter for use when flushing the medullary canal prior to implanting a femoral component of a total hip joint, either during primary or revision arthroplasty.

In such operatiofls the space required for the prosthesis and the cement to hold it in place is obtained by removal of soft tissue or the remains of the previous cement. Using ultrasonic techniques, much of the cement can be removed with an extractor tool. However fragments of cement, soft tissue and possibly bone will be left in the canal.

The invention will be described with reference to its use in hip joint arthroplasty. However it is equally useful in respect of treatment of other joints.

Soft tissue and cement particles are usually removed from the femoral canal (or canal of other bones) by flushing with sterile water, some of which remains in the medullar, requiring the application of a suction device to clear it. Existing equipment causes water, tissue and solid particles to be drawn into the suction nozzle, either passing into a collecting chamber or being arrested by an in-line filter. However it is commonplace for the solid material to form a blockage at some point in the suction line and this will bring the procedure to a halt, until the blockage can be cleared. Hence, such devices do not provide an efficient means of completely clearing the canal without the need for protracted recovery of particulate material causing a blockage somewhere along the suction line.

It is therefore an object of the present invention to provide a suction means for orthopaedic use which enables both liquid and solid material to be removed without blockage. Thereby it enables the surgical procedure to be carried out more quickly, since tedious delays in which secondary implements are used to remove obdurate blockages are obviated.

According to a first aspect of the present invention, there is provided suction means comprising a source of vacuum, an elongate tube and, at a distal end thereof, filter plate means having a plurality of apertures spaced across its surface.

Preferably, the filter plate means comprises a plate of thickness less than a diameter of any one of said apertures.

AdvantageouslY, said thickness is less than a half of said diameter, optionally less than one third thereof In a preferred embodiment each aperture has a diameter of 1 to 2 mm.

In this case, the apertures are spaced one from the next by a distance of 1 to 2mm.

The thickness of the filter plate may be less then 1mm, ideally less than 0.3mm.

The filter plate is preferably of metal, such as stainless steel.

According to a second aspect of the present invention there is provided a method of clearing a femoral or other canal which comprises the steps of applying into said canal suction means as described in the first aspect above and applying vacuum to cause fluid to be passed along said tube, and periodically withdrawing the tube and wiping the distal end thereof to remove adhering material therefrom.

Preferably suction is continued until blocking of the filter plate is deemed to have had occurred, when the tube is withdrawn and wiped.

An embodiment of the invention will now be more particularly described by way of example and with reference to the accompanying drawings, in which: Figure 1 is a longitudinal cross sectional view of a distal end of the device; and Figure 2 is an end elevation of the distal end of the device.

Referring now to the drawings, in particular Figure 1, there is shown the distal end of a conventional plastic suction instrument 2 with a metal plate insert 1 moulded into the distal end. The tube is foreshortened at 5, whereas it would normally be equipped with a tapered end allowing the device to be attached to a length of standard plastic suction tube, and thence to a source of vacuum. The metal plate 1, as shown in Figure 2, has holes 3 spaced evenly over the area of the plate. Seven are shown but the number may be greater or less and their disposition may be changed as required to improve fluid throughput.

The diameter of the plate I should be in the region of 10mm. The holes are ideally between 1.0 and 2.0mm diameter, spaced between 1 and 2mm apart. The plate thickness must be less than 1.0mm and ideally less than 0.3mm in order to prevent solid particles adhering to it, particularly within the holes 3, making it difficult to clear with a single wiping action, which is the basic requirement of the process.

The intention of the process is to clear not only liquid but also all solid material from the medullar. The filter plate 1 ensures that only fluids and very fine solids pass down the suction tube 2. Every time the filter blocks the suction device is withdrawn from the canal and simply wiped away to remove adhering material from the distal filter face. By ensuring that the filter is constructed of a thin metal plate with correctly sized and spaced holes drilled through it, the solid material is very easily removed without the tendency to create an obdurate blockage. In this way, the suction process achieves its full objective without tedious delays in which secondary implements are used to remove blockages.

Claims

CLAIMS

I. A suction apparatus for removing detritus from an intramedullary cavity comprising a source of vacuum, an elongate tube and, at a distal end thereof, filter plate means having a plurality of apertures spaced across its surface.

2. A suction apparatus as claimed in claim 1, wherein the filter plate means comprises a plate of thickness less than a diameter of any one of said apertures.

3. A suction apparatus as claimed in claim 2, wherein said thickness is less than a half of said diameter.

: 4. A suction apparatus as claimed in claim 3, wherein said thickness is less than one third of said thickness. *.SS I. * *

* : . A suction apparatus as claimed in any one of the preceding claims, wherein each S..... * S

aperture has a diameter of Ito 2mm. S... S...

6. A suction apparatus as claimed in claim 5, wherein the apertures are spaced one from the next by a distance oil to 2mm.

7. A suction apparatus as claimed in any one of the preceding claims, wherein the thickness of the filter plate is less than 1mm.

8. A suction apparatus as claimed in claim 7, wherein the thickness of the filter plate is less than 0.3mm.

9. A suction apparatus for removing detritis from an intramedullary cavity substantially as described herein with reference to the figures of the accompanying drawings.

10. A method of clearing a femoral or other canal which comprises the steps of applying into said canal suction apparatus as claimed in any one of the preceding claims and applying vacuum to cause fluid to be passed along said tube, and periodically withdrawing the tube and wiping the distal end thereof to remove adhering material therefrom.

* Ii. A method as claimed in claim 10, wherein suction is continued until blocking of the ** filter plate is deemed to have had occurred, when the tube is withdrawn and wiped. * .*S S. * * S* * .*

I.....

S S

S S * I S * S. 5.5