JP3108707B2 - Plug for ligament fixation - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ligament fixing plug used to insert an artificial ligament into a hole formed in a bone and press the artificial ligament against the inner peripheral edge of the hole.

[0002]

2. Description of the Related Art Artificial ligament reconstruction is a technique in which a hole (tunnel) is drilled in a bone, the artificial ligament is inserted, and both ends of the artificial ligament are fixed to the bone. In this artificial ligament reconstruction, in order to prevent the artificial ligament from being broken due to abnormal movement in the tunnel and firmly fix the artificial ligament and the bone, insert a bone plug into the tunnel and press the ligament against the inner peripheral wall of the tunnel Is done.

[0003] As a bone plug, it is common to use autologous bone collected when drilling a bone tunnel, but it is difficult to collect a bone plug at a site where cortical bone is thin. In general, autogenous bone plugs have an unstable bone mass and cause bone atrophy, so that it is difficult to obtain a sufficient fixing strength. If the fixing strength is not sufficient, early rehabilitation cannot be performed. That is, the bone plug cannot be used except for the cortical bone from the point of strength, and requires a certain length, so that it must be collected from a thick portion of the cortical bone. However, such sites are limited, and the cortical bone is hard, so that it is difficult to collect it.

[0004]

SUMMARY OF THE INVENTION The present invention is based on the above problem awareness, and has excellent biocompatibility and can obtain stable fixation immediately after surgery regardless of the properties of the bone at the site where a bone tunnel has been pierced. It is an object of the present invention to obtain a ligament-fixing plug that enables the above. Another object of the present invention is to provide a ligament fixing plug that can be easily removed when it becomes necessary to remove it.

[0005]

SUMMARY OF THE INVENTION A plug for fixing a ligament according to the present invention is provided by inserting an artificial ligament into a hole drilled in a bone and pressing the artificial ligament against the inner peripheral edge of the hole. The body is made of a material having biocompatibility and has a maximum diameter of 5 to 5.
15mmφ, length 10mm or more, 2-4mm at the center
It is characterized by being composed of a cylindrical body having a bottomed hole or through hole of φ. It is preferable to provide a tapered portion at the tip of the tubular body to facilitate insertion. It is preferable to form an annular groove on the outer peripheral surface in order to enhance the fixability to the bone. The bottomed or through hole at the center is
If the bone plug needs to be removed after being inserted into the tunnel, the hole serves as a guide hole for a breaking drill for breaking only the bone plug without damaging the bone.

As the material having biocompatibility, at least a material selected from a sintered body of a calcium phosphate compound, titanium, stainless steel, alumina, zirconia, polylactic acid, and polydioxane can be used.

[0007] In the case of a sintered body of a calcium phosphate compound, the Ca / P molar ratio is preferably 1.5 to 2.0. Specifically, for example, hydroxyapatite,
Examples thereof include apatites such as fluorapatite, tricalcium phosphate, and tetracalcium phosphate, and one or more of these can be used. More specifically, these calcium phosphate compounds are sintered and used as sintered bodies having a relative density of 60% or more, preferably 80% or more, or hydraulic calcium phosphate is cured and used as a cured body. The relative density of the sintered body is 60
%, The strength is not sufficient, and the artificial ligament cannot be sufficiently pressed and fixed to the inner peripheral edge of the tunnel. In the case of a sintered body, it is more preferable to make it dense.

The ligament fixing plug of the present invention is obtained by processing a sintered body of a calcium phosphate compound, titanium, stainless steel, alumina, zirconia, polylactic acid, or polydioxane into a required shape. An example of a production method using hydroxyapatite as a raw material is as follows. First, a hydroxyapatite slurry is obtained by a wet synthesis method from a phosphate and a calcium salt by a known method. The obtained slurry is dried using a rotary drum type drier to obtain a hydroxyapatite powder, which is formed into a plug for fixing a ligament of the present invention by, for example, a dry isostatic press. The molded body is placed in an electric furnace at 1000 to 120
Baking is performed at a temperature of 0 ° C. to obtain the ligament fixing plug. As a molding method, a casting method, an injection molding method, a method of molding a green compact by lathing, and the like can also be adopted.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on embodiments. FIG. 1 is a front view of a ligament fixing plug 11 showing one embodiment of the present invention. The ligament fixing plug 11 has a fixed diameter portion 12 and a tapered tapered portion 13 at the tip.
, A plurality of annular grooves 14 are formed. In addition, a through hole 15 is provided at the center of the plug 11 for fixing a ligament.
Are formed.

The plug 11 for fixing a ligament is used, for example, in an artificial ligament reconstruction of a knee joint as schematically shown in FIG. Tunnel holes 23 and 24 are formed in the femur 21 and the tibia 22, respectively. The tunnel hole 24 on the tibia 22 side is also drilled in a direction perpendicular to the paper surface. Since the basic structure of the tunnel holes 23 and 24 is the same, the tunnel hole 23 will be described. The tunnel hole 23 has an outer large-diameter tunnel hole 23a and an inner small-diameter tunnel hole 23.
b. The artificial ligament 25 is inserted into the tunnel holes 23 and 24, and after the insertion, the ligament fixing plug 11 is inserted into the large-diameter tunnel hole 23a from the tapered tapered portion 13 side.
Is inserted. The ligament fixing plug 11 acts to fix the artificial ligament 25 by pressing it against the inner peripheral wall of the large-diameter tunnel hole 23a. Both ends of the artificial ligament 25 are fixed to the femur 21 and the tibia 22 by different fixing screws 26, respectively.

Diameter φ and length L of ligament fixing plug 11 (length L1 of constant diameter portion 12 and length L2 of tapered portion 13 at the tip)
Is set in consideration of the diameter of the large-diameter tunnel hole 23a and the thickness of the artificial ligament 25, so that the artificial ligament 25 can be fixed to the large-diameter tunnel hole 23a. In ordinary ligament reconstruction, it is preferable that φ is 5 to 15 mm, L is 10 mm or more, and the length ratio between L1 and L2 is about L1: L2 ≒ 3: 1.

The diameter φ ′ of the through hole 15 (or the bottomed hole) is
When it is necessary to remove the plug without impairing the overall strength of the ligament fixing plug 11, the thickness is set to 2 to 4 mm so that a fracture drill can be guided. It is preferable that the harder the material, the larger the diameter of the through hole 15. The annular groove 14 is preferably provided in order to enhance the adhesion with the bone.

[0013] The plug for fixing a ligament of the present invention comprises:
In the case of using titanium, stainless steel, alumina, zirconia, polylactic acid, or polydioxane, the mass can be obtained by machining into a required shape.

Next, a specific production example in the case of using hydroxyapatite as a raw material will be described. Production Example A hydroxyapatite slurry was wet-synthesized by a known method. This slurry was dried with a spray dryer to obtain a hydroxyapatite powder. The obtained powder was pressed by a mold to produce a green compact having a diameter of 15 mm and a length of 35 mm. The green compact is processed into the desired dimensions and shape with an NC lathe in consideration of the firing shrinkage, and fired at 1100 ° C for 2 hours in an electric furnace to produce a ligament fixing plug made of a sintered body as shown in FIG. did. Finished dimensions are L = 20mm, L1 = 15m
m, L2 = 5 mm, φ = 10 mm, φ ′ = 4 mm.

[0015]

The plug for fixing a ligament according to the present invention is made of a material having excellent biocompatibility with bone and has dimensions suitable for a bone tunnel into which an artificial ligament is inserted. Regardless of the properties of the bone, the artificial ligament can be stably fixed to the bone tunnel immediately after the operation. Therefore,
Early rehabilitation is possible. Further, when it is necessary to remove, it can be broken and removed using the through hole or the bottomed hole at the center. The plug for fixing a ligament of the present invention can be used in place of a bone plug made of autogenous bone.

[Brief description of the drawings]

FIG. 1 is a front view of a ligament fixing plug showing one embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view showing a state in which the ligament fixing plug of FIG. 1 is used for artificial ligament reconstruction of a knee joint.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Ligament fixing plug 12 Constant diameter part 13 Tip taper part 14 Annular groove 15 Through hole 21 22 Bone 23 24 Tunnel hole 23a Large diameter tunnel hole 23b Small diameter tunnel hole 25 Artificial ligament 26 Fixing screw

Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) A61F 2/08 A61L 27/00 WPI (DIALOG)

Claims (5)

(57) [Claims] 1. A ligament fixation plug inserted into a hole formed in a bone for inserting the artificial ligament through the hole and pressing the artificial ligament against the inner peripheral edge of the hole, which has biocompatibility. A plug for fixing a ligament, comprising a cylindrical body made of a material, having a maximum diameter of 5 to 15 mmφ, a length of 10 mm or more, and a bottomed hole or through hole of 2 to 4 mmφ in the center. 2. The ligament fixing plug according to claim 1, wherein an annular groove is formed on an outer peripheral surface. 3. The ligament fixing plug according to claim 1, wherein the distal end is provided with a tapered portion. 4. A material according to claim 1, wherein the material having biocompatibility is selected from a sintered body of a calcium phosphate compound, titanium, stainless steel, alumina, zirconia, polylactic acid, and polydioxane. Ligament fixation plug, which is made of a new material. 5. The plug for fixing a ligament according to claim 3, wherein the calcium phosphate-based compound sintered body has a Ca / P molar ratio of 1.5 to 2.0.