GB2104386A

GB2104386A - Improvements in artificial limbs

Info

Publication number: GB2104386A
Application number: GB08126162A
Authority: GB
Inventors: Herbert Thompson
Original assignee: Blatchford & Sons Ltd; Chas A Blatchford and Sons Ltd
Current assignee: Blatchford & Sons Ltd; Chas A Blatchford and Sons Ltd
Priority date: 1981-08-27
Filing date: 1981-08-27
Publication date: 1983-03-09
Also published as: GB2104386B

Abstract

A thigh socket for an artificial limb has a polypropylene single walled container (1) with an integral downward extension (2). An end cap (4) to fit the end of a patient's stump is welded in the zone (4A) to the interior of the container (1). Above the zone (4A) the container has been thermo-formed to fit the patient's stump. A reinforcing plate (3) is fitted within the closed end (2A) of the container (1). Lower limb parts can be connected to the plate (3). Such a thigh socket can be of less weight and use less material than a conventional thermoplastics thigh socket which has separate container and socket parts, one within the other. <IMAGE>

Description

SPECIFICATION Improvements in artificial limbs This invention relates to an artificial limb socket, for example an artificial leg socket to receive a thigh stump.

A comparatively recent development in the manufacture of artificial limb sockets is to vacuum form them in a thermoplastics material, for example polypropylene, and in particular whereby the socket can be vacuum formed over a cast of the patient's stump.

Difficulties have arisen in attaching such a socket to the remainder of an artificial leg and a proposal for overcoming such difficulties is disclosed in our co-pending application No.

81 05624, in which such a socket is mounted in a particular way within a separate outer socket container, to the lower end of which, in the case of an artificial leg, the remainder of the leg is connected, for example by means of an alignment coupling and a knee mechanism.

It is an object of the present invention to provide a thermoplastics socket for an artificial limb, in such a manner as to save weight and to use less material.

According to this invention a thermoplastics socket for an artificial limb comprises a thermoplastics container at least part of which has been thermoformed to fit the patient's stump, and an end cap to fit over the end of the stump, the end cap being joined in sealing manner to the container, preferably by welding the material of the container and that of the end cap together.

The invention also includes a method of making the thermoplastics socket.

One embodiment of the invention will now be described by way of example with reference to the accompanying diagrammatic drawing, the single figure of which is a side elevation, partly in axial vertical section, of an artificial leg stump socket.

Referring to the drawing, a polypropylene socket 1 fits over the patient's stump, having been moulded as will be described below, to do so. The socket 1 has an integral downward extension 2 the lower end 2A of which is internally reinforced by a relatively thick plate 3 of thermoplastics material. The plate 3 has appropriate means for example threaded inserts (not shown) for attachment of the lower parts of the leg, for example an alignment device, a knee mechanism, a shin and a foot.

To fit over the distal end of the patient's stump, a moulded end cap 4 of polypropylene is fixed in position, for example by welding in the zone 4A, in the socket 1. A suction valve (not shown) of known kind may be arranged on the cap 4 and project into an opening (not shown) in the socket extension 2. (Such an arrangement would be similar to that shown in our co-pending application No. 81 05624).

Thus the invention provides a socket which acts also as a container and may be of single thickness and therefore lighter in weight and using less material than an arrangement in which a separate socket is mounted within a container. The moulded end cap 4 provides a closure for the socket, so that the normal suction fastening to the stump can be used.

The void 5 between the cap 4 and the plate 3 3 may be filled with an appropriate filler which may be retained or may be removed after forming of the socket and end cap, as will be referred to below.

One method of making the socket of the invention will now be briefly described by way of example.

A plaster cast of the patient's stump is made and then stood upside down. The end cap 4 is then thermoformed over the end of the cast. Then filler material is placed on the cap. Then heated polypropylene, for example in sheet form or as a preformed moulding is drawn down in a thermoforming procedure over the filler with the plate, and over the cap and cast. The socket conforms to the shape of the cast, and the filler occupies the void between the cap 4 and plate 3, keeping them spaced apart as required. The socket and end cap are welded together in the zone 4A. The filler can be removed (for example through the opening in the extension 2, as referred to above in connection with the suction valve).

Alternatively the filler can be retained.

Claims

1. A thermoplastics socket for an artificial limb, the socket comprising a thermoplastics container part of which has been thermoformed to fit a patient's stump, and an end cap to fit over the end of the stump, the end cap being joined to the container.

2. A socket according to claim 1 wherein the end cap is joined in sealing manner to the container.

3. A thermoplastics socket for an artificial limb, the socket comprising a thermoplastics container part of which has been thermoformed to fit a patient's stump, and an end cap to fit over the end of the stump, a peripheral zone of the end cap being joined in sealing manner to the interior of the con.

tainer, and the container extending beyond the said peripheral zone.

4. A socket according to any preceding claim, wherein the cap is of thermoplastics material heat welded to the container.

5. A socket according to any preceding claim, wherein the container has an integral extension which extends from the location of joining with the cap to a location beyond the end of the cap.

6. A socket according to any preceding claim, wherein the container has a closed end beyond the cap.

7. A socket according to claim 6, wherein the closed end has an internal reinforcing plate of thermoplastics material, the plate having means for attachment of another part of the artificial limb.

8. A socket according to claim 6 or claim 7, wherein the void between the cap and the closed end of the container is filled with a filler material.

9. A thermoplastics socket for an artificial leg, the socket having a container which i) is open at one end and closed at the other; ii) is single wall thickness; and iii) has a portion extending from the open end which portion is shaped to fit a patient's stump, the socket also having an end cap to fit over the end of the stump, and the cap being sealingly joined around a peripheral cap zone to the interior of the said portion of the container remote from the open end thereof.

10. An artificial leg having a thigh socket according to any preceding claim.

11. A method of making a thermoplastics socket for an artificial limb, comprising the steps of: making a plaster cast of a patient's stump and standing the cast upside down; thermoforming an end cap over the end of the cast, the cap being of thermoplastics material; placing filler material on the cap; providing heated thermoplastics material and drawing it in a thermoforming proce dure over the filler, cap and cast to form a container one part of which fits the cast; and heat welding the cap to the container in a peripheral zone of the cap.

12. A method according to claim 11, wherein the said heated thermoplastics material is heated polypropylene in sheet form or in the form of a preformed moulding.

13. A method according to claim 11 or claim 12, wherein a reinforcing plate for a closed end of the container is placed on the filler material before the heated thermoplastics material is drawn down.

14. A thermoplastics artificial limb thigh socket constructed and arranged substantially as herein described and shown in the drawing.