CN103767808A - Femoral condyle measuring device used for unicompartmental knee arthroplasty - Google Patents

Abstract

The invention relates to a femoral condyle measuring device for unicondylar replacement, the femoral condyle measuring device is used in conjunction with a guide for unicondylar replacement, the femoral measuring device includes a positioning part and a measuring part; the positioning part and The measuring portion is detachably connected. The femoral condyle measuring device used for unicondylar replacement of the present invention can be directly measured in the operation, and compared with the traditional preoperative radiography indirect measurement, it is not affected by factors such as radiography quality, and the measurement is more accurate; in addition, according to According to surgical needs, different measuring parts can be set corresponding to different prosthesis radii, and the measuring parts are directly inserted into the femoral condyle, which is easy and convenient to operate.

Description

Femoral condyle gauge for unicompartmental arthroplasty

technical field

The invention relates to a femoral condyle measuring device for unicompartmental replacement.

Background technique

Osteoarthritis is a common chronic joint disease that occurs mostly in the heavily loaded knee joint. The knee joint is divided into three compartments, the medial compartment, the lateral compartment, and the patella compartment. Arthritis of the knee can affect any of these compartments.

Unicondylar knee arthroplasty (UKA) is only the surface replacement of the diseased compartment, but currently it is mainly for the replacement of the medial condyle.

Unicompartmental Knee Arthroplasty (UKA) refers to the surface replacement of only the medial or lateral compartment of the knee joint, and its main purpose is to replace the damaged cartilage surface of the tibiofemoral knee joint. However, early reports of its surgical outcomes were unsatisfactory, and its use was gradually neglected by many surgeons due to the poor results described in the literature. In recent years, with the improvement of prosthesis design, appropriate patient selection, improvement and thickening of polyethylene material, and mature surgical techniques, the clinical effect of the unicompartmental system has been greatly improved, and the application of UKA tends to be revived.

The prosthesis used in unicondylar replacement is generally divided into "femoral prosthesis" and "tibial prosthesis". Currently, the Oxford third-generation unicondylar prosthesis commonly used in clinical practice consists of femoral prosthesis, tibial prosthesis and movable meniscus. . It consists of 5 different sizes of femoral prosthesis, 5 thicknesses and 5 specifications of meniscal liners matching different curvature radii of femoral prosthesis, and 5 different sizes of tibial prosthesis, replacing the previous single-size femoral prosthesis. Enhance the fit between the prosthesis and the bone, reduce bone movement; better cover the surface of the tibia, and reduce the prosthesis’s irritation to the inner soft tissue.

In unicompartmental (femoral) replacement surgery, the femoral prosthesis is required to fit the femoral condyle cut through the bone. Therefore, the unicompartmental femoral prosthesis has a variety of different radii to fit patients with different bone sizes.

Accurate selection of the size of the prosthesis will ultimately affect the surgical effect and long-term survival rate of the prosthesis. Due to minimally invasive surgery, it is difficult to accurately measure the size of the femoral prosthesis in total knee replacement.

Regarding the measurement of the size of the femoral condyle, the commonly used measurement method at present is to take a lateral X-ray film before the operation, and then indirectly measure the size of the required prosthesis on the lateral X-ray film. However, this method has very high requirements for filming, and is usually affected by the quality of filming, zoom ratio, and operator experience, and the results are very inaccurate.

At present, there is a need for a femoral measuring instrument for unicompartmental replacement that can be measured conveniently and accurately.

Contents of the invention

In order to solve the above problems, the present invention provides a femur measuring device that can be used for measurement during unicompartmental replacement, and the measurement is more convenient and accurate.

A femoral condyle measurer for unicondylar replacement, the femoral condyle measurer is used in conjunction with a guide for unicondylar replacement, the guide is provided with a first positioning hole for installing a prosthesis;

The femur measurer includes a positioning part and a measuring part; the positioning part is detachably connected with the measuring part;

The positioning part is provided with a first positioning protrusion matching the first positioning hole on the guide;

The measuring part is in the shape of an arc hook, and its arc radius is the same as that of the prosthesis to be installed;

When the positioning part is connected to the measuring part, the protruding direction of the first positioning protrusion is parallel to and facing the same direction as the radial direction from the midpoint of the arc hook of the measuring part to the round point;

When the first positioning protrusion is matched with the positioning hole of the guide, the arc hook of the measuring part can be inserted from the crest of the femoral condyle and contain at least part of the surface of the femoral condyle.

In the operation of unicompartmental replacement, after the guider is positioned on the femur and tibia, the first positioning protrusion on the positioning part of the measuring device of the present invention is inserted into the positioning hole of the prosthesis installed on the guider, Then select a measuring part with a specific size (prosthesis size) to install and connect with the positioning part according to experience, insert the arc hook of the measuring part directly from the front of the femur and contain the surface of the femoral condyle; Judging whether the arc hook fits perfectly with the surface of the femoral condyle;

If it fits perfectly, directly select the prosthesis with the same radius size as the arc hook;

If the fit is not good, change the measurement part of an adjacent size and measure again until it fits completely.

Preferably, the positioning part is provided with a second positioning protrusion to cooperate with the corresponding positioning hole on the guide.

Preferably, the measuring part and the positioning part are detachably connected through a connecting part.

The femoral condyle measuring device used for unicondylar replacement of the present invention can be directly measured in the operation, and compared with the traditional preoperative radiography indirect measurement, it is not affected by factors such as radiography quality, and the measurement is more accurate; in addition, according to According to surgical needs, different measuring parts can be set corresponding to different prosthesis radii, and the measuring parts are directly inserted into the femoral condyle, which is easy and convenient to operate.

Description of drawings

Fig. 1 is the perspective view of femoral condyle measurer of the present invention;

Fig. 2 is a schematic front view without installing the femoral condyle measuring device in unicompartmental replacement;

Fig. 3 is a schematic diagram of the side use state of the femoral condyle measuring device of the present invention in unicondylar replacement.

Detailed ways

Referring to Fig. 1, a femoral condyle measurer for unicompartmental replacement, the femoral measurer includes a positioning part 1 and a measuring part 2; the positioning part 1 and the measuring part 2 are detachably connected by a connecting part 3;

The positioning part 1 is provided with a first positioning protrusion 11 and a second positioning protrusion 12;

The measuring part 2 is in the shape of an arc hook; when the positioning part 1 is connected to the measuring part 2, the protruding direction of the first positioning protrusion 11 is parallel to and facing the same direction as the radial direction at the midpoint of the arc hook of the measuring part 2;

The femoral condyle measurer is used in conjunction with the guide 4 for unicondylar replacement. Referring to FIG. 2 , the guide 4 is provided with a first positioning hole 41 for installing a prosthesis, and a second positioning hole 42 is also provided thereon. The guide 4 is positioned on the femur A and the tibia B as shown in FIG. 2 .

During intraoperative measurement, after the guider 4 is positioned, reposition the measuring device, specifically: match the first positioning protrusion 11 of the positioning part 1 with the first positioning hole 41 of the guider 4, and the second positioning part 1 of the positioning part 1. The positioning protrusion 12 cooperates with the second positioning hole 42 of the guide 4;

Then select a measurement part 2 of a specific size (prosthesis size) to install and connect with the positioning part 1 based on experience, insert the arc hook of the measurement part 2 directly from the front of the femur and contain the surface of the femoral condyle; Judging by the perspective of the measuring part 2, whether the arc hook is completely matched with the surface of the femoral condyle;

If it fits perfectly, directly select the prosthesis with the same radius size as the arc hook;

If the fit is not good, change the measurement part of an adjacent size and measure again until it fits completely.

The femoral condyle measuring device used for unicondylar replacement of the present invention can be directly measured in the operation, and compared with the traditional preoperative radiography indirect measurement, it is not affected by factors such as radiography quality, and the measurement is more accurate; in addition, according to According to surgical needs, different measuring parts can be set corresponding to different prosthesis radii, and the measuring parts are directly inserted into the femoral condyle, which is easy and convenient to operate.

To sum up, the present invention has excellent innovative practicability among similar products. At the same time, the relevant technical materials or patent documents at home and abroad have been searched, and no similar structure has been disclosed before. However, the above descriptions are only some feasible embodiments of the present invention, and any equivalent structural changes made by applying the description of the present invention and the scope of the patent application should be included in the scope of the patent of the present invention.

Claims (3)

1. for a condyle of femur measuring device for single condyle replacement, the guider of this condyle of femur measuring device and single condyle replacement is used in conjunction with, and described guider is provided with the first locating hole that prosthese is installed;

It is characterized in that: this femur measuring device comprises location division and measurement section; Described location division is removably connected with measurement section;

Described location division is provided with the first positioning convex mating with the first locating hole on described guider;

It is hook-shaped that described measurement section is circular arc, and its arc radius is identical with prosthese radius to be installed;

In the time that described location division is connected with measurement section, the described protrusion direction of the first positioning convex and the midpoint of the arc hook of described measurement section are parallel and towards identical to the radial direction of round dot;

In the time that the first described positioning convex coordinates with the first locating hole of described guider, the arc hook of described measurement section can insert and contain from the front of condyle of femur at least part of surface of condyle of femur.

2. the condyle of femur measuring device for single condyle replacement as claimed in claim 1, is characterized in that: described location division is provided with second positioning convex and coordinates with the corresponding locating hole on described guider.

3. the condyle of femur measuring device for single condyle replacement as claimed in claim 1, is characterized in that: described measurement section is removably connected by a connecting portion with location division.

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