MXPA97005822A - Tapon acetabu - Google Patents

Abstract

A stopper is provided for use with a specially drilled acetabular cup which prevents waste (eg polymer residues) from passing through any hole in the cup and which can be removed from the cup if desired. The plug is metallic and acts with the hole in a compression adjustment ratio. A procedure is also provided to prevent waste from passing through a hole in an acetabular cup and into the patient's body.

Description

TflPON OCETñBULñR BACKGROUND OF THE INVENTION This invention relates, in general, to implants for use in hip surgery and, more particularly, to an acetabular implant with plugs specially designed to plug the observation holes in those devices or orifices used for fixing screws or other uses. In acetabular cups for use in hip surgery, one or more holes are often present, so that the orthopedic surgeon can observe the placement of the acetabular cup in a patient's acetabulum, and see if the cup is properly located in the acetabular cup. the acetabulum If the surgeon has sufficient experience, he will be able to know if the cup is properly located or not without actually seeing the cup placement, in which case said hole or holes located in the acetabular cup may not be necessary. It will be necessary to close said observation holes used in the acetabular cup for the placement thereof once the cup has been finally placed in the acetabulum to prevent residues from passing through them. It is known to use threaded screws or plugs to close said observation orifices and prevent wear residues from the polymer portion of the acetabular cup passing through said viewing orifices and contacting the patient's bone. However, said threaded plugs have a disadvantage, since they show micromotion if they are not blocked or screwed properly. In this way, the waste can penetrate through the observation hole and come into contact with the patient's bone. In addition, threaded plugs require an actuator mechanism for insertion into the acetabular cup, easily and frequently being threaded (that is, the threads are misaligned). An object of this invention is a plug for use in closing an observation hole located in an acetabular cup, so that it does not show micromotion whatsoever and which prevents the residues from penetrating through the orifice and coming into contact with the bone of the patient and that can also be removed from the acetabular cup. Another object of this invention is a method for inserting an acetabular cup into a patient, such that the cup is properly positioned within the acetabulum of the patient and such that the wear residues of the polymer are prevented from coming into contact with the patient's bone.

BRIEF DESCRIPTION OF THE INVENTION According to the invention, it is provided with a cap that can be used in an acetabular implant, which prevents the polymeric residues from coming into contact with the patient's bone and which can also be removed from the acetabular cup, which comprises: an orifice , a piece without thread of metal, substantially cup-shaped having a side part, an edge and a bottom part, and having a tapered segment on at least a part of the side part, so that the stopper and A special drill with two parts (ie a reaming hole) located inside the acetabular cup is actuated with a tightening fit. Preferably, a ridge is present on the plug segment to facilitate removal of the plug, if necessary. In addition, according to the invention. It is provided with equipment for use in orthopedic hip surgery comprising said metal plug (described above) and an acetabular cup with a special drill with two parts (ie, a reaming hole) located therein for placing said acetabular cup within the A body of a patient, such that the metal cap and the drill are adjusted to each other by a tightening fit, the cap can not be pushed through the hole and the cap can be removed. In addition, according to the invention, there is provided a method for inserting an acetabular cup into a patient such that the cup is appropriately positioned within the acetabulum of the patient and such that the wear residues of the polymer are prevented from coming into contact with the patient. the patient's bone, comprising: (a) inserting the acetabular cup of the equipment of the invention (described above) into the acetabulum of a patient, using the observation hole to properly position the acetabular cup and (b) then inserting the metal plug of the equipment of the invention in the observation hole so as to close the observation hole and prevent the debris from passing through the observation hole to the patient's bone.

BRIEF DESCRIPTION OF THE FIGURES In Figure 1 a preferred embodiment of a tapered metal plug for use with a metal acetabular cup, having a two-part bore through it (not shown in Figure 1), is shown in cross-section, with the tapered plug being along the entire length of its lateral part. In Figure 1A there is shown, in cross section, an alternate preferred embodiment of a metal plug for use with a metallic acetabular cup, the conical plug being only along a portion of its side portion. In Figure 2 is shown, in cross section, a preferred embodiment of an acetabular cup having a two-part bore located in the lower part of the hemispherical part of the cup, the bore having a projection therein and used with the cap of Figure 1. cross section, of an acetabular cup of Figure 2, together with the plug shown in Figure 1, before the plug has been fully inserted into the acetabular cup bore. In Figure 4 the plug of Figure 1 is shown in cross-section after it has been inserted into the acetabular cup of Figure 2 and is located therein, such that the lower part of the plug is in contact with the cap. the protrusion of the hole.

DETAILED DESCRIPTION OF THE FIGURES With reference to the drawings, in Figure 1 a preferred embodiment of the acetabular plug 10 is shown in cross-section. The plug 10 is made of metal and has a cup-like shape, and a hollow part 12, a smooth bottom part. and a lateral part 15 having a conical section 16, in at least a part thereof. In the preferred embodiment shown in Figure 1, the side portion 15 has a conical section 18 along its entire side. In Figure 1A, which shows another preferred embodiment, the conical section 18 extends only along a portion of the side portion 15 (sometimes referred to as "head." The conical section 18 is inclined at an angle a (alpha). with respect to a line perpendicular (or normal) to the substantially flat bottom part 14 of the plug 10. In Figure 2 a cross-sectional view of a preferred embodiment of an acetabular cup for use with the plug of the invention is shown. The acetabular cup 5 is generally designated with the number 24 and substantially hemispherical in shape, it has a recessed outer part 26, in which the spherical part (not shown) located of a hip implant can freely rotate within a polyethylene sheath ( not shown) inside the cup acetabular 24, when the cup 24 is placed inside the acetabulum of a patient. The outer surface 28 of the acetabular cup 24 will be in contact with the acetabulum bone of the patient when the acetabular cup 24 is implanted within the acetabulum of the patient. The flanges 29 of the cup 24 are present to hold a polyethylene insert (not shown) inside the cup 24. To properly locate the acetabular cup 24 within the acetabulum of the patient, a bore 30 is made through the outer surface 28 of the acetabular cup. 24 Preferably, the bore 30 is positioned so that the center line 32 of the bore 30 passes through the center 34 of the hemisphere forming the acetabular cup 24. The bore 30 has a total height H, 36, which is the sum of two parts, height hi 38 plus height 2 40. The ?! = Drill 30 is composed of a first part of the drill 42 and a second part of the drill 44. The first part of the drill 42 has a diameter 46 and the second part of the drill 44 has a diameter 48, such that the diameter 48 of the second part of the bore 44 is larger than the diameter 46 of the first part of the bore 42. Therefore, a projection 50 is produced. This projection 50 (also shown in Figure 4) serves to prevent the plug 10 from passing through through the bore 30 and protrude from the projection 50. In the practice of the invention it is required that the acetabular plug 10 has a conical section 16 throughoutat least part of its lateral part 15, so that a tightening fit occurs between the lateral part 15 and the second part of the bore 44. Preferably, the second part of the bore 44 and the first part of the bore 42 they will be shaped like cylinders with straight faces that do not have a conical section to facilitate the realization of the drill (used to visualize the placement of the acetabular cup 24). If desired, the lateral portion 15 of the acetabular plug 10 may be conical along only a portion thereof, ie, near the upper edge 52 of the side portion 15 that is farthest from the substantially flat bottom portion 14. of the plug 10. The upper edge 52 can extend inwards to form a flange 53 (as shown in Figure 3) and facilitate the removal of the plug 10 that it is desired to remove. In Figure 3, an acetabular plug 10 is shown shortly before it is inserted into the second part 44 of the bore 30. The corresponding parts are numbered in the same corresponding manner as in Figures 1, 1A, 2, 3 and 4 In Figure 4, an acetabular plug 10 located inside the second part 44 of the bore 30 is shown, such that the advance of the plug 10 is stopped by the projection 50. The plug 10 of the invention is made of a biocompatible material, for example, cobalt-chromium-molybdenum, stainless steel or titanium.

Claims (6)

NOVELTY OF THE INVENTION CLAIMS

1. - An acetabular stopper comprising a metal part substantially in the form of a hollow cup with a lower part and a lateral part without thread, which is at least partly conical.

2. A plug according to claim 1, wherein said plug has an upper edge with a flange extending inwards.

3. A plug according to claim 1, wherein said lateral part of the cup is conical along its entire length.

4. A plug according to claim 1, wherein said lateral part of the cup is conical only along a part of its length.

5. A device comprising a metal cap and an acetabular cup prosthesis, wherein (a) said acetabular cup prosthesis has a first unthreaded and non-conical bore, substantially cylindrical and a second unthreaded and non-taper bore , substantially cylindrical therethrough wherein said first bore and said second bore have unequal diameters and are concentric, so that a projection is formed between said first bore and said second bore, and (b) a plug comprising a part of said bore. metal with substantially hollow cup shape, with a non-threaded bottom side portion and a conical portion on at least a portion of said side portion, wherein said plug and said second bore have a relative shape therebetween, such that they it produces a tightening fit between said metal plug and said second hole and wherein said projection prevents said metal plug from traversing said acetabular cup.

6. Apparatus according to claim 5, wherein said plug has a conical section along the entire length of said side portion.