DD219384A5 - PROSTHESIS FOR REMOVING SHAEDEL BUNNY AND METHOD FOR THE PRODUCTION THEREOF - Google Patents

Abstract

The prosthesis is used in reconstruction operations of an injured skull cap and serves as a replacement for the removed bone. The prosthesis is in the form of a hollow shell or ellipsoidal section and is formed by the at least two knit layers consisting of two types of synthetic yarns having different melting temperatures, preferably at least 85% polypropylene yarn and at most 15% polyester yarn. The production process is characterized in that two knitted layers in the form of rolls are joined to the surfaces by sewing together, washed with a non-toxic union detergent, rinsed in distilled water and dried. The bonded rolls are laid on the convex metal molds and subjected to a heat treatment at a low melt temperature yarn phase transition temperature for about 30 minutes. The molded pieces are hardened by cooling, removed from the metal molds, cut circumferentially and subjected to a pre-sterilization. DD # AP

Description

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Berlin, the 17V 9 » 84 63 873 16

Prosthesis for a removed cranial bone and method for manufac ng

Scope of the invention

The invention relates to a prosthesis for a detached skull bone in the form of a bowl or an ellipsoidal section, which is intended to replace the removed bone in the skullcap, and a method for its preparation.

Characteristics of the known technical solutions

In the cases of skullcap injuries in which the cranial bone can not be compensated with its own bone, so-called prostheses for the detached cranial bone are used in reconstruction operations in addition to transplants of various types.

The prostheses known for years for a detached skull bone in the form of metal plates adversely affect the mental state of the patient, since the metal and the human organism have different thermal conductivity and the prosthesis is a great weight «Moreover, these known prostheses have a definite and unchanging shape, with the result that you must adapt the prosthesis accordingly.

In addition, the metal prostheses interfere with the EEG diagrams and the recognizability of cranial radiographs, »

There are also prostheses for detached skull bone in the form of plates made of acrylic, which are described in the journal "Polymers in Medicine", 1972, T, II »Nr, 2, pages 197 to 202« In use, these prostheses are quite advantageous, but their implementation and implantation is very time consuming "The filling of the removed skull bone with a rapidly polymerizing acrylic mass, which is described in the above-mentioned journal, 1974, T. IV, Nr" 1, pp 13 to 54, although allows a shortening and simplification of the surgical procedure, but the exothermic reaction that takes place during the polymerization risks damaging the surrounding tissue. Moreover, the rapidly polymerizing masses have a lower resistance and can cause perforations in them »

Object of the invention

The aim of the invention is to ensure a faster and easier handling in a surgical procedure and to largely reduce the disadvantages for the patient *

Darlea and the essence of the invention,

The invention has for its object «to provide a prosthesis for a detached cranial bone knitted fabric, which is composed of synthetic yarns and in addition to good physico-mechanical properties, should have a rough surface structure, which has a better overgrowth

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allows the tissue and also allows easier adjustment according to the removed skull bone.

It has been found that a prosthesis consisting of at least two types of layers of synthetic yarns having different melting temperatures has such properties. The prosthesis for a detached cranial bone according to the invention is in the form of a hollow bowl or an ellipsoidal section and is preferably made of polypropylene. Polyester fabric, in the composition: polypropylene not less than 85 % and polyester - not more than 15 % * V

The method for producing the prosthesis for a detached skull according to the invention is that at least two rolls of knitted fabric, which is formed from the two types of synthetic yarns with different melting temperatures, especially of polypropylene yarn with a proportion of at least 85 % and polyester yarn of maximum 15 % . After placing a roll on the other, and after sewing together they are subjected to a washing process, and using a non-toxic Union detergent "They are then rinsed twice in distilled water and at a temperature-* temperature of about 90 ⁰ C ca x 1 hour dried. Thereafter, the bonded rollers are placed on the convex metal molds having the shape of a bowl or an ellipsoidal portion and subjected to a heat treatment, wherein heating air having a temperature of the yarn phase transition

After this time, the moldings are hardened on the molds by dipping in distilled water at a temperature of 18 - 21 ⁰ C within about 5 minutes and then cooled and dried. The fittings are removed from the mold and enfold as "Then they will © iner pre-sterilization subjected _e namely long by 30 minutes cooking in distilled water" by the prostheses dimensional cut

The prosthesis produced by the process according to the invention is preferably characterized by good thermal conductivity, low intrinsic mass, good ductility and elasticity. It has a good stiffness, which is expressed by a deflection force in the range from 10 to 25 daN. Moreover, this prosthesis allows a shadow-free image with X-ray images * As far as the physical properties are concerned, the prosthesis according to the invention for a detached skull bone achieves the properties of the natural cranial bones.

This prosthesis is further characterized by a specific surface structure. The special feature of this structure is that the elements of knitted mesh formed from yarn having the increased melting temperature protrude on the surfaces of the prosthesis and form additional protrusions which are very advantageous for better overgrowth of the tissue are ^

The prosthesis according to the invention also has the advantage

that it can easily be adapted to the size of the removed bone in the cranial flap during the surgical procedure by cutting with a sharp instrument.

embodiment

The invention will be explained in more detail below on some embodiments

Example I

The prosthesis for a detached skull bone in the form of a hollow bowl with a curvature height of 12 mm is formed from two fabric layers, which is executed with a left-hand binding of yarns:

Proles 110 dtex f 33 χ 18 Torlen 167 dtex f 32 χ 1

and cut out in the form of rolls with a diameter of 1Θ5 mm.

Example II

The prosthesis for a detached cranial bone in the form of a section of a hollow ellipsoid with a curvature height of 24 mm is formed from two knit layers made with a left-hand weave of yarns:

Proles 110 dtex f 33 χ 17 torlen 167 dtex f 32 x 2

and cut out in the form of rolls with a diameter of 225 mm »

Seismic III

Made of knitted fabric with the left-hand binding, consisting of Proles 110 dtex f 33 χ 18 and Torlen 167 dtex f 32 x 1, the rolls are cut out with a diameter of 225 mm. Two rolls are sewn together with the right sides inwards, placing them parallel to uprights »The rolls sewn together with their faces, longitudinally and transversely, with the seams at a distance of 1 cm, using plied yarn, undergo a washing process subjected to application of Rokaphenol N8, rinsed twice in distilled water and dried at a temperature of about 90 ⁰ C within 1 hour · Thereafter, the associated rollers at the convex side of the metal mold in the form of a bowl with a curvature height of 24 M (a length of 205 mm and a width of 205 mm and subjected to a heat treatment, wherein hot air with a temperature of 180 - 185 ⁰ C is acted on for 30 minutes · After this time, the moldings on the molds in distilled water at room temperature within 5 Minutes cooled «They are dried · They are removed from the metal mold and cut Extend the edge circumferentially to balance it and give the prosthesis a dimension according to item 1 of the table below, with the fittings now being subjected to pre-sterilization by boiling in distilled water in the sterilizer for 30 minutes.

Examples IV - VII

The successive examples consist in the realization of dimensions of the prosthesis according to positions 2-5 of the following table.

table

Diameter of the roll mm Length of the metal form mm Width of the metal mold mm Prothral length mm Prosthesis width mm Curvature height of the pots / mold mm Prothe senab measurement 225 205 205 130 125 24 1 225 230 205 134 110 19 2 185 145 120 105 60 10 3 185 125 125 75 75 · 12 4 185 125 125 75 57 12 5 Example VIII

The difference in the design of the prosthesis is that the rollers are placed with the right sides inwards in a vertical direction to stands and sewn together along the edge.

Claims (2)

Inventory claim A "prosthesis for the removal of the skull bone in the form of a hollow bowl or an ellipsoidal section", characterized in that it is formed by at least two layers of knitted fabric consisting of two types of synthetic yarns with different melting temperatures, preferably of polypropylene yarn in a proportion of at least 85 % and polyester yarn of maximum 15 % « 2 # A process for the preparation of the prosthesis for the removal of the skull bone according to item 1, characterized in that the at least two knitted layers consisting of two types of synthetic yarns with different melting temperatures, preferably of polypropylene yarn with a proportion of at least 85 % and polyester yarn of at most 15 % , in the form of rolls, and joined together by sewing, followed by washing using a non-toxic union detergent, unwinding in distilled water and drying, and then rolling the rolls joined to their faces onto the convex metal molds in the form of a roll Bowl or Ellipsoidabschnittes placed and subjected to a heat treatment at the temperature of the yarn phase transition with the low melting temperature of about 30 minutes, then the moldings are molded on the molds in distilled water at a temperature of 18 to 21 ⁰ C in Hardened within about 5 minutes, the fittings are removed from the metal molds, dried, cut in bulk and subjected to pre-sterilization *