GB2205045A

GB2205045A - An instrument for the surgical treatment of pieces of tissue

Info

Publication number: GB2205045A
Application number: GB08812533A
Authority: GB
Inventors: Martin Franz Fischmeister; Siegfried Hiltebradt
Original assignee: Richard Wolf GmbH
Current assignee: Richard Wolf GmbH
Priority date: 1987-05-27
Filing date: 1988-05-26
Publication date: 1988-11-30
Anticipated expiration: 2008-05-26
Also published as: GB8812533D0; GB2205045B; FR2615725A1; DE3717966A1

Description

k_ 22050 j 5 "AN INSTRUMENT FOR THE SURGICAL TREATMENT OF PIECES OF

TISSUE" This invention relates to an instrument for the surgical treatment of pieces of tissue, more particularly of the meniscus in knee joints, of the type comprising an outer shaft having an inner shaft mounted drivably for rotation therein with said shafts being provided at the distal end with cutouts of which the edges form cutting edges and counter cutting edges.

Instruments of the aforementioned type are so designed that in operation cartilage and/or pieces of tissue are gradually removed by the cutting edges and counter cutting edges. In this respect, for the surgical treatment the shafts have to have very thinwalls, and thereby also the width of the recesses in the cutting edge region have to be small, so that the cutting-edge region can slip off the tissue surfaces that are being treated. This results in a surgical treatment by removal of pieces of tissue or of cartilage being made more difficult or at least unnecessarily prolonged, which severely burdens the patient.

Accordingly the main object of the present invention is to avoid or substantially reduce slipping-off of the cutting-edge region from the surfaces of the cartilage or tissues in particular the meniscus undergoing surgical treatment with an instrument of the type referred to hereinabove.

To this end the present invention consists in an R k instrument for the surgical treatment of pieces of tissue, such as a meniscus in a knee joint, of a patient, said instrument comprising an outer shaft and an inner shaft which is mounted drivably for rotation therein, said shafts being both provided at the distal end with cutouts of which the edges form cutting edges and counter cutting edges, characterised in that provided in the region of the shaft cutouts is a ledge which is fixed transversely to the direction of rotation of the inner shaft and which has an outwardly directed supporting surface which supports, projects or grips under the piece of tissue that is to be surgically removed.

By means of the invention, the instrument can be so guided that the supporting ledge arrives with the supporting surface under the piece of tissue or piece of meniscus that is to be removed, wherewith the supporting ledge forms a support of the piece of tissue or piece of meniscus that is to be removed or respectively to be trimmed, in which respect the pieces that are to be removed also arrive between the co-operating cutting edges of the inner and outer shaft. Because of the supporting ledge, the surface of which may be arbitrarily profiled or roughened, the result is also achieved that, after the cutting-off the pieces arriving between the shaft cutting edges, the tissue or the meniscus remains in the necessary treatment position.

The supporting ledge makes possible a surgical operation which is safe, simple and can be 1 i f carried out rapidly, with minimum burdening of the patient.

In order that the invention may be more readily understood, some embodiments thereof will now be described by way of example with reference to the accompanying drawings in which:- Figure 1 is a side elevation of the distal end region of an instrument for the surgical treatment of pieces of tissue and showing shaft cutouts, Figure 2 is a side elevation of the distal end region of the instrument, looking in the direction of the arrow II of Figure 1, Figure 3 is a cross-section taken along the line III-III of Figure 1, Figure 4 is a cross-section through the same region as Figure 3, but of another embodiment having an additional outer shaft, Figure 5 is a top plan view of the distal end of another embodiment which is a modification of Figure 1, and Figure 6 is a side elevation of the embodiment of Figure 5.

An instrument for the removal of pieces of tissue such as meniscii comprises a handle (not shown) to which an outer shaft 1 having a distal cutout 2 is connected so as to be easily releasable and exchangeable. Mounted in the outer shaft 1 is an inner shaft 3 which is rotatable by a drive by way 1 of the:handle and which is likewise exchangeable and which is provided with a distal cutout 4. The edges of the cutout 4 form movable cutting edges 5 and 6 and those of the cutout 2 form fixed cutting edges 7 and 8, 1 The outer shaft 1 is provided with an outwardly extending supporting ledge or projection 9 which may be radial or is advantageously at an angle to the radius, from the cutting edge 8 towards the direction of rotation of the inner shaft 3. Advantageously the supporting ledge 9 extends axially over the length of the cutouts 2 and 4 and is rounded-off over the distal front end of the outer shaft 1, as will be apparent from Figure 2. If the direction of rotation of the inner shaft 3 is reversed, an outer shaft 1 is used in which the supporting ledge 9 projects from the cuttingedge 7.

The instrument is so manipulated that the supporting ledge 9 engages e.g. under the meniscus 10 of a knee joint, in which respect pieces of the meniscus pass into the region of the cutting edges 5, 6 and of the counter cutting edges 7, 8 and are cut off by the drive of the inner shaft 3. In this respect, the supporting ledge 9 may be flat or arbitrarily profiled in design and can also be roughened in design on the surface which supports the meniscus 10.

In the embodiment of Figure 4, the direction of rotation ofthe inner shaft 3 relative to the outer shaft 1 is reversed with respect to that of the embodiment of Figure 2. In addition, there is provided 1 on the outer shaft 1 a further exchangeable surrounding shaft 11 having a cutout lla and a radial or angular supporting ledge 9. The shaft 11 extends as far as the proximal end of the outer shaft 1 and is connectable to this in known manner, e.g. by a bayonet catch. Also in this case the tissue that is to be removed or a meniscus is undergripped and supported by the supporting ledge 9 and a supporting of the tissue or of the meniscus remains even after cutting off of pieces of tissue or meniscus.

In the embodiment of Figures 1 and 3 the procedure can also in accordance with Figures 5 and 6 be such that the supporting ledge 9 engages in the central longitudinal direction over the cutout 2 of the outer shaft 1, so that the ledge 9 both upon rotation of the inner shaft 3 clockwise and anticlockwise forms a support for the tissue or the like that is to be removed. In this respect the inner edge 8 of the ledge 9 is in both cases the counter cutting edge to the cutting edges 5 and 6 of the inner shaft.

In further development of the invention, the supporting ledge 9 may be fashioned in the form of a bearing surface which is secured only at the proximal side on an additional outer shaft and the essential length of which projects beyond the frontal end of the additional outer shaft, in order to remove the supporting ledge if need be by drawing back or by radial rotation from the region of the piece of tissue, 1 cartilage or bone that is to be removed.

0

Claims

1 1. An instrument for the surgical treatment of pieces of tissue, such as a meniscus in a knee joint, of a patient, said instrument comprising an outer shaft and an inner shaft which is mounted drivably for rotation therein, said shafts beingloth provided at the distal end with cutouts of which the edges form cutting edges and counter cutting edges, characterised in that provided in the region of the shaft cutouts is a ledge which is fixed transversely to the direction of rotation of the inner shaft and which has an outwardly directed supporting surface which supports, projects or grips under the piece of tissue that is to be surgically removed.

2. An instrument according to claim 1, in which the supporting ledge emanates with its supporting surface from the counter cutting edge, directed towards the direction of rotation of the inner shaft, of the outer shaft radially or at an angle to the radius outwards.

3. An instrument according to claim 1, in which the outer shaft is surrounded by a separate exchangeable shaft with a distal cutout, and in which from it the supporting ledge emanates from its edge, directed towards the direction of rotation of the inner shaft, with its supporting surface radially or at an angle to the radius outwards.

4. An instrument according to claim 1 or 2, in which along the or approximately along the central longitudinal direction of the distal cutout of the outer shaft there extends a supporting ledge with a radial supporting surface, the inner edge of which h b 1 1 forms the counter cutting edge to the cutting edges of an inner shaft rotating clockwise or anticlockwise.

5. An instrument according to any one of claims 1 to 4, in which the supporting ledge has a length which extends over the longitudinal directed length of the distal lateral cutout of the outer shaft and over the distal front end of the outer shaft.

6. An instrument according to any one of claims 1 to 5, in which the supporting ledge has a surface which is flat or profiled and the peripheral edge thereof is atraumatic in design.

7. An instrument according to any one of claims 1 to 6, in which the supporting ledge has a supporting surface which is rough in design.

8. An instrument for the surgical treatment of pieces of tissue substantially as hereinbefore described with reference to Figures 1 to 3 of the accompanying drawings.

9.' An instrument for the surgical treatment of pieces of tissue substantially as hereinbefore described with reference to Figure 4 of the accompanying drawings.

10. An instrument for the surgical treatment of pieces of tissue substantially as hereinbefore des cribed with reference to Figures 1 to 3 as modified by Figures 5 and 6 of the accompanying drawings.

Published 1988 at The Patent Office, State House. 66'71 High Holborn, London WClR 4TP. Further copies may be obtained from The Patent Office, Sales Br3zich, St Mary Cray, Orpington, Kent BR5 3RD Printed by Multiplex techniques ltd, St Mary Cray, Kent. Con. 1/87.