JPH08126650A - Rotational osteoectomy for head of thigh bone and inner fixing member for therapy of fracture of neck of thigh bone - Google Patents

Abstract

PURPOSE: To provide an inner fixing member which prevents varus deformation after surgery from occuring to make early rehabilitation possible and can be easily inserted even when a large varus angle is added in rotational osteoectomy and does not give instability and shortening of the neck part after surgery. CONSTITUTION: An inner fixing member 1 has a plate 2, a main screw 3, a sub-screw 4 and a plurality of bone screws 5. A bone screw guiding hole 2c, a main screw guiding hole 2d and a sub-screw guiding hole 2e are made in the plate 2 and a tube 6 for fixing a screw with an angle of slope of 125-135 deg. is projected on the inner face side of the plate of the main screw guiding hole 2d. The sub-screw guiding hole 2e has a shape being adjustable in a range where the angle of insertion of the sub-screw 4 is 20 deg..

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal fixation member used for rotary osteotomy for femoral head necrosis and treatment of femoral neck fracture.

[0002]

2. Description of the Related Art For a femoral head necrosis, a rotary osteotomy is performed with the intention of changing the load line so that the necrotic part of the femoral head is released from the load area and a relatively healthy part is loaded. In this case, the bone head that undergoes rotational dislocation needs to be firmly internally fixed, but a plurality of large bone screws have been used as a conventional internal fixation member. The conventional internal fixation method using this large bone screw is shown in FIG. In the rotary osteotomy, as shown in FIG. 6 (a), the femoral bone 10 was cut across the trochanter 10a, the cut surface 10b was added, and the bone head 10c was rotated about the neck axis 10d. It will be fixed internally later. Conventionally, a configuration is used in which a plurality of large bone screws 11 are inserted from the trochanteric front portion 10e through the bone neck portion 10f and inserted into the bone head 10c (Fig. 6 (b)), and the load acting on the bone head 10c is mainly used. It was supported by a large bone screw head 11a fixed to the trochanteric front portion 10e.

In the case of a femoral neck fracture or the like, similarly, a plurality of screws are similarly used for internal fixation, or a plate as shown in FIG. 7 and a plurality of screws for inserting the plate are used. Treatment of osteosynthesis was performed using a fixing member. This conventional inner fixing member 21 is a plate 22 fixed along a diaphyseal portion 10g with a bone screw 25 which is a diaphyseal fixing screw, and a tube projecting on the upper portion of the plate 22 with an inclination angle of about 130 to 150 degrees. 26, and a bone head fixing screw 23 that is inserted through the tube 26 and inserted in the direction of the bone head 10c.
Further, in order to prevent the screw from rotating in the tube during treatment, various internal fixing members having a groove in the tube as a locking mechanism or a screw end having a planar structure have been proposed.

[0004]

However, when the large bone screw 11 is used as the internal fixing member, the structure is such that the load acting on the bone head 10c is mainly supported by the large bone screw head 11a. A concentrated load acts on the bone part. In particular, when the rotary osteotomy is performed, a bone thickened portion inside the neck portion is lost as shown in FIG. 6B, so that a larger concentrated load acts on the large bone screw head 11a. When such a concentrated load is applied, there is a possibility that varus may occur due to the deformation of the femoral portion that comes into contact after the surgery, and there is a drawback that the rehabilitation start time is delayed in order to avoid this. In addition, it was technically difficult to insert a large number of large bone screws into predetermined positions when a large inversion angle was applied when the head was rotated. Further, since the conventional head fixing screw has only a single size, there is a disadvantage that the screw to be inserted into the head is too large for a patient with a small body.

Further, there has been a treatment method using a plate and a screw shown in FIG. 7 as an internal fixing member of the rotary osteotomy in order to disperse the concentrated load described above. Inclination angle is about 130 degrees
It is 150 degrees, and has a drawback that it cannot be applied to rotary osteotomy that takes a varus angle up to about 30 degrees.

Further, in the case of a femoral neck fracture or the like, when a plurality of screws are inserted, if they are inserted only in parallel, the axial sliding movement of the screws is caused by the compression sliding force applied to the postoperative fracture. There was a risk of causing it or shortening the neck. Further, when the inner fixing member of the single bone head fixing screw plate is used for treatment of elderly patients and patients with degenerative bone disorders, there is a possibility that rotation may occur.
As mentioned above, there are also internal fixing members that are equipped with a lock mechanism for preventing rotation, but these have the drawback that it is difficult to insert the screw tip to the optimum position of the bone head because the lock position is specified. .

The present invention solves the above-mentioned problems, prevents varus deformity after surgery, and enables early rehabilitation.
Moreover, it is an object of the present invention to provide an internal fixation member that can be easily inserted even when a large varus angle is applied by rotary osteotomy and that can be applied to a wide range of patients. In addition, there is no risk of instability or neck shortening after surgery, rotation can be prevented even when used for treatment of elderly people and patients with degenerative bone disorders, and the screw tip should be inserted to the optimum position of the bone head. It is also an object to provide an inner fixing member capable of

[0008]

In order to solve the above-mentioned problems, an internal fixation member for rotational femoral head osteotomy and treatment of a femoral neck fracture of the present invention is provided with a diaphyseal fixation screw along a diaphysis. A plate to be fixed, a bone head fixing screw which is inserted through a guide hole formed in the upper part of the plate and is inserted in the direction of the bone head from the upper part of the diaphysis, and a screw which is circumscribed in the guide hole and projects on the inner surface of the plate In the internal fixing member having a fixing tube, the plate is prepared in a plurality of sizes of large, medium and small according to the size of the bone, the bone head fixing screw has two screws of a main screw and a sub-screw, The guide hole includes a main screw guide hole including the screw fixing tube and a sub-screw guide hole having a shape in which the sub-screw insertion angle can be adjusted. It is characterized in that to obtain.

Further, in the inner fixing member according to the second aspect, the screw fixing tube is 12
The sub-screw guide hole is provided with a protrusion angle of 5 to 135 degrees, and the sub-screw insertion angle can be freely adjusted within a range of 20 degrees centering on a line parallel to this inclination angle. It is characterized by.

[0010]

The internal fixation member of the present invention is used when the bone head is reduced and fixed by rotary osteotomy or cervical fracture treatment, and the plate is fixed along the diaphysis with the diaphysis fixing screw. Prepare multiple sizes of large, medium and small so that it can correspond to A sub-screw, which is a bone head fixing screw, is inserted into the sub-screw guide hole formed in the upper part of the plate, and the main screw is inserted through the screw fixing tube from the upper part of the diaphysis toward the bone head.
The main and sub-screws are selected and used with an appropriate length so that the tip of the screw is inserted to the optimum position of the bone head.

The load acting on the bone head after the operation is transmitted to the plate portion via the main and sub-screws, so that the diaphysis fixing screw also dispersively supports it. Therefore, even if a rotational osteotomy is performed and a bone defect inside the neck occurs, the load can be distributed and varus deformity does not easily occur.

The penetration angle of the main screw is fixed to the inclination angle of the screw fixing tube, but since the penetration angle of the sub-screw can be adjusted, it can be inserted parallel to or crossing the main screw. . Therefore, the sub-screw can be inserted at an appropriate position even when a large varus angle is added when the bone head rotates. Further, when the main and sub screws are cross-fixed and internally fixed, there is no risk of axial movement due to the compressive sliding force after surgery, and therefore neck shortening does not occur. Also, rotation does not occur in the elderly and patients with degenerative bone disorders.

In the inner fixing member according to the second aspect, the main screw can surely be inserted into the bone head even when the varus angle is up to about 30 degrees in the rotary osteotomy, and the sub-screw is 2
Since it can be freely adjusted in the range of 0 degree, it is possible to select and insert an appropriate direction of the dislocated bone head.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will now be described in detail with reference to the accompanying drawings. FIG. 1 is a cross-sectional view of an internal fixation member used for rotational femoral head osteotomy and treatment of a femoral neck fracture of the present invention. The inner fixing member 1 includes a plate 2, a main screw 3, a sub screw 4, and a plurality of bone screws 5.
Have. The plate 2 is formed with a straight portion 2a and a bending portion 2b in conformity with the shape of the femur to be internally fixed which corresponds to the unillustrated femoral anonymous tubercle. Further, a plurality of types of large, medium, and small plates are prepared for the plate 2 so that it can be applied to a wide range of bone sizes.

A front view and a rear view of this plate are shown in FIGS. 2 and 3, respectively. In order to fix the plate 2 along the diaphysis with the bone screw 5, a plurality of bone screw guide holes 2c are formed in the linear portion 2a. This guide hole 2
A plurality of types of c, such as 2 holes and 3 holes, are prepared according to the size of the plate 2. A main screw guide hole 2d is provided at the base of the bending portion 2b, and a sub-screw guide hole 2e is provided at the upper portion thereof at positions eccentric from the central axis of the plate 2. There are two types of eccentric positions, one for the left femur and the other for the right femur.

As shown in FIG. 1, a screw fixing tube 6 having an inclination angle α with respect to the straight line portion 2a is provided so as to project on the plate inner surface side of the main screw guide hole 2d. The inclination angle α is in the range of 125 degrees to 135 degrees. The main screw 3 is fixedly inserted along the inclination angle α of the screw fixing tube 6. The sub-screw guide hole 2e has a shape slightly larger than the screw diameter so that the insertion angle of the sub-screw 4 can be adjusted. It is desirable that this shape be such that the sub-screw 4 can be freely adjusted in the range of β ≦ 20 degrees in any of the up / down, left / right, and front / back directions centering on a line parallel to the inclination angle α.

Plural types of each screw are prepared and appropriately selected and used according to the shape of the femur. For example, the main screw 3 has a diameter of 10 mm, 9 mm, and 8 mm, the sub-screw 4 has a diameter of 7 mm, and various neck lengths and screw thread lengths are available.

Next, the operation of the inner fixing member of the present invention will be described with reference to FIGS. 4 and 5 are explanatory views of internal fixation of the femoral rotary osteotomy. Femur 1 for rotary osteotomy
In 0, the bone head 10c is rotated on the cut bone surface 10b and then fixed using the internal fixing member 1. Before and after the operation, prepare front and rear images to check the bone condition and the like, and set the length of the plate to be used in advance. Make a decision.

Main screw 3 and sub-screw 4
Is guided by an unillustrated guide pin inserted into the bone head 10c, determines the length of each with a depth gauge, punches and taps, and then attaches the plate 2 and the screw fixing tube 6 to the upper part of the diaphysis 10g. . After that, the main screw 3 and the sub-screw 4 are inserted, and the bone screw 5 is further inserted into the diaphyseal portion 10g to fix the whole.

The load acting on the head of the bone after the operation is transmitted to the plate 2 via the main screw 3 and the sub-screw 4, but the main screw 3 is supported by the screw fixing tube 6 and thus serves to prevent varus deformation. Fulfill.
Further, since the lower portion of the plate 2 is fixed by the bone screw 5, the load is dispersed and supported almost entirely on the plate 2. Therefore, even if a rotational osteotomy is performed as shown in FIG. 4 and a bone defect occurs inside the neck, varus deformity after surgery due to instability of the screw is unlikely to occur.

The piercing angle of the main screw 3 is fixed to the inclination angle of the screw fixing tube 6, but if this inclination angle is appropriately selected within the range of 125 to 135 degrees, it will be within 30 degrees by rotary osteotomy. Even when the anti-angle is set, the main screw 3 can be reliably inserted into the bone head 10c. or,
FIG. 4 shows the case where the sub-screw 4 is inserted in parallel with the main screw 3, but since the insertion angle of the sub-screw 4 can be adjusted in the range of 20 degrees, the sub-screw 104 is replaced with the main screw as shown in FIG. It can also be crossed with 103. Therefore, the two screws can be surely inserted into the head of the bone that is inverted, and the degree of freedom of setting the varus angle is increased.

When the main and sub-screws are cross-fixed internally as described above, there is no risk that the screws will move in the axial direction due to the compressive sliding force acting after the operation, and therefore the neck will not be shortened. Also, rotation does not occur in the elderly and patients with degenerative bone disorders. In addition, this internal fixing member can also be applied to surgery such as femoral neck fracture,
As described above, it is possible to prevent varus deformation and rotation after the operation.

[0023]

As described above, since the inner fixing member of the present invention uses the main screw supported by the screw fixing tube, it is possible to prevent the varus deformation after the operation and use the plate to apply the load. Since it can be distributed, early rehabilitation is possible. Also, since it has two screws, a main screw and a sub screw, as the bone head fixing screw, and the piercing angle of the sub screw can be adjusted,
Even if the head of the bone is displaced, the sub-screw can be easily inserted, and the angle selection eliminates the risk of postoperative instability and shortening of the neck, making it suitable for the elderly and patients with degenerative bone disorders. It is also possible to prevent rotation, and since no special locking mechanism is provided, the tip of the screw can be inserted to the optimum position of the bone head. Moreover, since the main and sub two screws are inserted while adjusting them appropriately, the screw can be appropriately inserted into the bone head even in the case of a patient with a small body. In addition, the plates are available in a variety of sizes including large, medium, and small according to the size of the bone, so that the plates can be closely attached to the curve of the anonymous femoral nodule.

Further, in the inner fixing member according to the second aspect of the present invention, the screw fixing tube is projected at an inclination angle of 125 to 135 degrees, and the sub-screw has a structure in which the angle can be adjusted within the range of 20 degrees. Each screw can be easily inserted even when a large inversion angle is added by an incision.

[Brief description of drawings]

FIG. 1 is a sectional view of an inner fixing member.

FIG. 2 is a front view of a plate.

FIG. 3 is a rear view of the plate.

FIG. 4 is an explanatory view of internal fixation in rotary femoral osteotomy.

FIG. 5 is an explanatory view of the internal fixation of another rotary femoral osteotomy.

FIG. 6 is an explanatory view of a conventional internal fixation method using a large bone screw.

FIG. 7 is an explanatory diagram of a conventional inner fixing member including a plate and a screw.

[Explanation of symbols]

 1 Internal fixing member 2 Plate 2c Bone screw guide hole 2d Main screw guide hole 2e Sub screw guide hole 3 Main screw 4 Sub screw 5 Bone screw 6 Screw fixing tube

Claims (2)

[Claims] 1. A plate which is used for rotational femoral head osteotomy and treatment of a femoral neck fracture and which is fixed along a diaphysis with a diaphyseal fixing screw, and a guide hole formed in the upper part of the plate. In the internal fixation member having a bone head fixing screw that is inserted from the upper part of the diaphyseal portion in the direction of the bone head, and a screw fixing tube that is circumscribed in this guide hole and projects on the inner surface of the plate, the plate is the size of the bone. Prepare a plurality of sizes of large, medium, and small according to this, the bone head fixing screw has two screws of a main screw and a sub-screw, the guide hole is a main screw guide hole provided with the screw fixing tube, An inner fixing member comprising: a sub-screw guide hole having a shape capable of adjusting the sub-screw insertion angle. 2. The screw fixing tube is projected at an inclination angle of 125 to 135 degrees with respect to the straight plate portion of the plate, and the sub-screw guide hole is centered on a line parallel to this inclination angle. The inner fixing member according to claim 1, wherein the inner fixing member has a shape in which an entering angle can be freely adjusted within a range of 20 degrees.