DE8318360U1 - Cement-free implantable prosthesis with grid profiling - Google Patents

Description

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LAW FIRM

B (ir; iiTl & RiiL'hmcrt. I '(i5llach / P. O Box 107127, D-2B0 (l Bremen 1

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To the

German Patent Office

Zweibrückenstrasse 12th

8000 Munich 2

PATENT ADVOCATE DR.-ING. KARL BOEHMERT (1933-1973) PATENT Attorney DlPL-ING. ALBERT BOEHMERT, BREMEN LAWYER WILHELM). H. STAHLBERG, BREMEN PATENT ADVOCATE DR.-ING. WALTER HOORMANN. BREMEN PATENT ADVERTISEMENT DIPL.-PHVS. DR. HEINZ GODDAR, BKtMEN PATENT Attorney DIPL-ING. EDMUND F. EITNER. MUNICH LAWYER WOLF-DIETER KUNTZE, BREMEN-LAWYER DIPL-ING.) TO G.TÖNNIES.BREMEN PATENT Attorney DIPL-CHEM. DR. C. NEIDL-STIPPLER. MUNCH

Your sign Your ref.

New application

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O 259

Bremen, Hollerallee 32

June 24, 1983

orthoplant Vertriebs-GmbH, Leerkämpe 12, 2800 Bremen 1

Cement-free implantable prosthesis with grid profiling

The invention relates in particular to an implantable prosthesis, usually also referred to as an endoprosthesis a hip prosthesis, the portions of which come into engagement with bone tissue after implantation Outside are provided with a grid profile protruding from the outside.

A grid profiling is described above and below one of preferably integral with the remainder in question Understood prosthesis part formed surface profiling, the total of which forming a grid individual Profile elements have dimensions that are

529
Bremen / Bremen Office:

P.O. Box / PO Box 10 7127
Hollerallee 32.D-2800 Bremen 1

Telephone: (04 21) * 34 90 71 ^,

Telecop./Telecop .: (0421) «349071 CClTT ?: » ^ * | _ar Telegr./Cables: Diagram Bremen. **. *
Telex: 244958bopatd * .. '*

Accounts: Bremer Bank. Bremen (BLZ 29080010) 100144900 Deutsche Bank. Bremen. Munich

(BLZ 20010020) 126083-202 Munich / M unich Office (only Patemanu> ii

P.O. Box / P. O. Box 22 0137 Schlotthauerstraße 5. D-8000 Munich Telephone: (089) '223311 Telescope. / Telecop .: (089] 221569 CCITT Telegr. / Cables: Forbopat Munich Telex 524282forbod

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ratio to the dimensions of the prosthetic part in question are relatively small.

To create endoprostheses that can be used without cement, it is known, for example, from DE-OS 28 39 093 for a hip joint prosthesis to provide the shaft that comes into engagement with the medullary canal of the femur bone on its upper side with a thread, which is preferably in the manner of a Trapezoidal thread is formed, the over the per se
Usually the smooth outer surface of the prosthesis shaft then cuts outwardly protruding threads into the bone tissue during and after the implantation «
Such a configuration clearly represents a considerable stress and a corresponding weakening of the bone tissue and, taken in and of itself, does not yet ensure that the prosthesis part in question is
does not dissolve in the course of the exposure time. For this purpose rather additional measures must be taken which not only lead to a whole is relatively complicated and expensive prosthesis, but take dis natural bone tissue also accordingly. In addition, such measures can only be carried out in the case of pin-shaped or bolt-shaped prostheses or prosthetic parts and not in the case of prostheses or prosthetic parts which, due to their shape, cannot be screwed in.

In order to improve the cement-free implantability of prostheses, a fine grid profiling has therefore been proposed using the example of a hip prosthesis (patent application P 32 47 726.0, FIGS. 6, 7), the individual,
Profiling elements that are directly adjacent to one another are pyramid-shaped. It has been shown, however, that such a grid profiling

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with regard to the abutments to be created with it to accommodate or transfer those that occur in use Forces can still be improved.

The present invention is based on the object of the known prostheses of the type described above, more precisely their (in relation to the prosthesis dimensions) relatively fine grid profiling, see above to improve that created by the grid profiling, in the implanted state with the bone tissue coming into engagement profile elements or their Abutment surfaces are designed and arranged so that they can withstand the stresses occurring during use Optimally absorb or reduce pressure, tension and torsion while protecting the natural bone tissue as much as possible. transferred and overall create a gentle but intimate connection with the bone tissue.

As a solution to this problem is provided according to the invention; that the grid profiling with mutual horizontal

■ and vertically spaced, knob-like approaches

ϊ is of essentially constant height.

L It is preferably provided that the knob-like

ί Approaches at right angles - again preferably at

f at least essentially square - are formed.

It has proven to be particularly useful when the

jf the knob-like approaches forming the grid profile

in the longitudinal or / and transverse direction in rows

ϊ align with each other, and if the knob-like approaches

are designed or arranged so that they each

% have a side surface that is substantially perpendicular

~ to the compressive forces occurring during loading.

BOEHMERT & BQ £ HMf, RT., _§

The same applies to the tensile forces and / or torsional moments that may occur during loading. In the event of of the shaft of a hip endoprosthesis, the knob-shaped extensions are on the one hand preferably ring-shaped arranged around the shaft and on the other hand in rows which are essentially parallel run to the longitudinal axis of the shaft.

A particularly preferred embodiment of the present invention is that two groups of knob-shaped Approaches are provided, preferably between one consisting of first knob-shaped approaches first grid profiling from (geometrically, possibly completely identical, but with regard to local orientation arranged differently) second knob-shaped approaches existing second grid profiling is, the second knob-shaped approaches with respect to their - with a right-angled configuration at the same time their Free edges to the corresponding edges or side surfaces of the first knob-shaped Approaches are arranged rotated by an angle, which is preferably about 45 °.

Preferred embodiments of the present invention are described in the subclaims.

The invention is further explained below using an exemplary embodiment with reference to a drawing. It shows:

Fig. 1 is a plan view of one with one according to the invention Grid profiling provided outer side section of an endoprosthesis to be anchored without cement in

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Seen in the direction of arrow I in Fig. 2;

FIG. 2 shows a partial section through the one in FIG. 1

section shown seen in the direction of section line II-II;

3 shows a representation corresponding to FIG. 1 of a variant in the direction of arrow III in Fig. 4 seen;

FIG. 4 shows a section corresponding to FIG. 2 through the variant according to FIG. 3 in the direction of FIG Section line IV-IV seen in Figure 3; and

Fig. 5 as an application example, a part of a hip endoprosthesis, the shaft of which on its entire, in the implanted state in engagement with the bone tissue of the femoral canal The upcoming surface is provided with a grid profile according to FIGS. 1 and 2 is, but for the sake of clarity, this is shown in Fig. 1 only in a small section to the To show the arrangement of the knob-like approaches.

1 and 2 of the drawing show an outer side section of an endoprosthesis to be implanted without cement, for example a hip joint endoprosthesis (See Fig. 5), the shaft of which on its entire surface coming into contact with the bone tissue with the Grid profiling is provided. The grid profiling consists of square, nub-like when viewed from above Approaches 1 and 1 'in terms of their sizing

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are designed identically, but offset by 45 to one another with regard to their spatial orientation or are arranged rotated, as can be seen from FIG. 1. The forming a first grid profile Approaches 1 are arranged with a mutual horizontal distance h and mutual vertical distance ν and each have a height s of 0.6 mm. The mutual horizontal distances h and vertical distances ν are exactly as large as the edge length k of the approaches 1 as well as the approaches 1 ', which is shown above Embodiment is 2 mm.

It can be seen that the first notch>: profiling forming, knob-shaped approaches 1 in the vertical and horizontal direction or in the longitudinal and transverse directions to each other are aligned and arranged in rows. The same applies to the knob-shaped approaches 1 'of the second grid profiling, which leads to the approaches 1 are each rotated by 45 ° and are symmetrical to the first grid profile, i.e. between vief Approaches 1 'are arranged, the terms first and the second grid profiling has only been introduced here for purposes of distinction, and both grid profilings together form the entire grid profiling.

The main pulling and printing direction coincides with the dash-dotted line 2-2 in Fig. 1, this being Line when using the grid profile on a hip prosthesis corresponds to the longitudinal axis of the shaft 2 'as directed.

In Fig. 5 the over the entire fichaftoberflache Proposed approaches 1, 1 'on a middle section of the shaft 3 of a hip joint endoprosthesis shown in FIG. 5 can be seen, at the same time being

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I can be seen that the approaches 1, T with respect to their

$ Dimensioning are quite considerably smaller than that

II dimensions of the shaft 3, so overall a fine ^ structure grid profiling, which on the one hand % the bone tissue during implantation and then completely

I is considerably gentle and yet not only safe

| · Cement-free anchoring guaranteed, but also

I ensures that the

% Forces are absorbed in an optimal way. From the

% Fig. 1, 2 and 5 it can be seen that the upper ones ilen

\ Lateral surfaces 4 of the lugs 1 run at right angles to the shaft longitudinal axis 2 ″ and thus essentially perpendicular to the compressive forces occurring under load and

: thus optimal abutment for recording or transmission

give this print collar. The same applies to the 'lower side surfaces 6 of the approaches 1 with regard to the

tensile forces occurring under load and with regard to the lateral side surfaces 7 and 8 of the approaches 1 to-I? visibly absorbed forces in the case of around the

; ■. Shaft longitudinal axis 2 'occurring torsional moments.

As has already been mentioned, the approaches are at 45 ° to the approaches 1 in terms of their local Orientation on the (not profiled) outside

, the prosthesis part offset by 45 ° and take accordingly

in a correspondingly optimal way components of the compressive and / or tensile and / or stresses occurring Torsional forces, but above all forces that occur under any bending loads, at an angle to the axis 2 'running torsions or the like., wherein in in such cases, Approaches 1 also correspond to

¹ absorb speaking components of such forces.

The grid profiling according to the invention solves the problem on them requirements in an almost optimal way and

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can also be justified with a for such purposes and the advantages offered Create effort.

3 and 4 show a variant in which the Approaches 1 as well as approaches 1 'each triangular are formed, with an edge length of 3 mm, the height s being the height of the lugs 1, 1 ' in the embodiment according to FIGS. 1, 2 corresponds. It can be seen that in this embodiment too the approaches in the longitudinal and transverse directions are each arranged in rows, and that, in addition, approaches 1 'are present, which are arranged rotated relative to the lugs 1.

HOr.MMERT & .BOEHMFKT,

File: O 259 June 24, 1983

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REFERENCE LISTS (LIST OF IiEFSRSNGE NUMERALS)

1 ■ approaches 1 P. Line 2 'longitudinal axis of the shaft (Fig. 5) P. shaft Ά 4th upper side surfaces (of 1) 4th 5 - 5 6th lower side surfaces (of 1) 6th 7th lateral side surfaces (of 1) 7th 8th lateral side surfaces (of 1) 8th 9 Surface (of 3) 9 10 10 11th 11th 12th 12th 13th 14th 14th 15th 16 16 17th 17th 18th 18th 19th 19th 20th 20th 21 21 22nd 22nd 23 23 24 24 25th 25th ? fS 26th 27 27 28 28 29 29 30th 30th

Claims (13)

BCl ί> 1 ίM EHT & BiIEH MERJ .., O 259 June 24, 1983 claims 1. Cement-free implantable prosthesis, in particular hip prosthesis, the outside of which sections coming into engagement with bone tissue after implantation are provided with a grid profile protruding from the outside, characterized in that the grid profile consists of mutual horizontal spacing (h) and vertical spacing (v ) arranged _r . knob-like projections (1, 1 ¹ ) of essentially constant height (s), 2. Prosthesis according to claim 1, characterized in that the knob-shaped forming the grid profile Approaches (1, 1 ') are essentially rectangular in plan view. 3. Prosthesis according to claim 2, characterized in that the knob-shaped lugs (1, 1 ¹ ) are essentially square. 4. Prosthesis according to claim 1, characterized in that the knob-shaped lugs (1, 1 ¹ ) in plan view as - are formed triangles - preferably isosceles. 5. Prosthesis according to claim 3 or 4, characterized in that the edge length (k) of the knob-shaped lugs (1, 1 ¹ ) is about 2 to 4 mm. "f. 6. Prosthesis according to one or more of the preceding ti claims, characterized in that the knob-shaped % Approaches (1 or 1 ") in the longitudinal direction of a profiled Align surface section to each other. f 7. Prosthesis according to one or more of the preceding χ Claims, characterized in that the knob.>. Shaped ; Approaches (1 or 1 ') are aligned with one another in the transverse direction. ?; 8. Prosthesis according to one or more of the preceding Claims, characterized in that between a '{ consisting of first knob-shaped projections (1) '; ■ first grid profiling one of the second knob-shaped Approaches (1 ¹ ) existing second grid profiling ■ * is ordered, the second knob-shaped approaches (V) with respect to their edges or side surfaces (4, 6 to ι 8) to the corresponding edges or side surfaces of the first knob-shaped lugs (1) are arranged rotated by an angle. 9. Prosthesis according to claim 8, characterized in that de: wearing. that the angle of relative rotation is about 45 10. Prosthesis according to one or more of the preceding claims, characterized in that at least one Group of knob-shaped approaches (T; is provided, the corresponding side surfaces (4 and 6) thereof essentially perpendicular to those when the prosthesis is stressed occurring compressive and / or tensile forces, while the other side surfaces (7, 8) essentially lower BC) EHMERT & - BOEHMEKT «Hi * ti ' ^c · · ¹ * »ι H right to the forces occurring under torsional loads. 11. Prosthesis according to one or more of the preceding Claims, characterized in that the height (s) of the knob-shaped extensions (1, 1 ') is 0.5 to 1 mm. 12. Prosthesis according to one or more of the preceding claims / characterized in that the mutual Distance between similarly oriented, knob-shaped attachments (1 or V) roughly equal to the edge length (k) of the attachments (1; T) is. 13. Prosthesis according to one or more of the preceding Claims, characterized by the production from forged titanium.