A Customized Rectangular 3D Printed Guide for the Greater Tube of the Humerus and Its Design Method

Abstract

This invention discloses a customized rectangular 3D-printed guide for the greater tuberosity of the humerus and its design method. The method includes: supplementing the original trapezoidal anatomical shape of the greater tuberosity of the humerus into a rectangle; calculating and finding the optimal needle insertion point; and using large-scale data analysis of dried humeral specimens to find a universal rectangular shape. Using thin-slice CT scans of the patient, reconstruction is performed using Mimics software, and further smoothing and guide design are achieved using Geomagic software. Finally, an anatomical standard parallel screw fixation guide that also facilitates reduction is designed. This invention uses the rectangular principle to more accurately locate the needle insertion point for cannulated screw fixation in split fractures; the precise design of the 3D-printed guide provides a foundation for the subsequent clinical development of related instruments and theoretical systems and their further clinical application; it improves the cure rate of this disease, reduces complications, further alleviates patient suffering, and improves patients' quality of life.

Description

Technical Field

[0001] This invention relates to the field of guide design technology, and in particular to a customized rectangular 3D printed guide for the greater tuberosity of the humerus and its design method. Background Technology

[0002] Split fractures of the greater tuberosity of the humerus are a common clinical condition, and the shoulder joint is located at a central anatomical position. Due to significant changes in the biomechanical environment, blood supply, and bone structure, greater tuberosity fractures often disappear after surgery, and in severe cases, can lead to shoulder joint dysfunction.

[0003] Hollow screw fixation is one of the three main surgical procedures, but in clinical practice, it is always inserted manually, relying on the surgeon's experience. The lack of standardized auxiliary instruments leads to potentially drastically different outcomes. Whether in ideal cadaver studies or more complex clinical research, no one has yet addressed the issues of insertion point and height for hollow compression screws in greater tuberosity split fractures, or the design of corresponding auxiliary instruments.

[0004] Therefore, in order to solve the above problems, a customized rectangular 3D printed guide for the greater tubercle of the humerus and its design method are proposed. Summary of the Invention

[0005] The technical problem to be solved by the embodiments of the present invention is that, in the case of split fracture surgery of the greater tuberosity of the humerus, the use of hollow screws for manual insertion without instrument assistance leads to vastly different results. The present invention proposes a customized rectangular 3D printed guide for the greater tuberosity of the humerus and a design method therefor.

[0006] To address the aforementioned technical problems, embodiments of the present invention provide a design method for a customized rectangular 3D-printed guide for the greater tuberosity of the humerus. This design method includes:

[0007] Step 1: Locate the anatomical bony landmarks on the two-dimensional structure of the greater tubercle of the humerus: A is the intersection of the intertubercular groove and the insertion point of the supraspinatus muscle; B is the intersection of the supraspinatus and infraspinatus muscles; C is the intersection of the infraspinatus clivus point and the upper border of the teres minor muscle; D is the lowest point of the two-dimensional bony landmark of the teres minor muscle; E is the intersection of point D perpendicular to the intertubercular groove; H is the point 8 mm below the lower border of point D; O is the intersection of the vertical extension of point H and the intertubercular groove.

[0008] Step 2: Using point B as a marker, draw a line parallel to OH to supplement the original rectangle ABCDE into rectangles FGED and FGHO. Then, points I and J bisect FO and GH respectively, and points K and L trisect IJ. Find points K and L, and mark solid circles with a diameter of 10mm with points K and L as centers. Similarly, find the bisectors of FE and GD, and trisect the two bisectors to obtain two equal division points. Mark dashed circles with a diameter of 10mm with these two equal division points as centers.

[0009] Step 3: Measure the distances of AB, BC, CD and DE respectively, and further measure the size of ∠EAB, ∠ABC and ∠BCD. By collecting the above data from 1000 dried specimens and averaging the values, find the average data of the rectangle ABCDE. Use this large data average to print a general template.

[0010] Step 4: Using the patient's CT thin-section scan data and thin-section CT scan, reconstruct the image using Mimics professional software, and further smooth the image and design the guide using Geomagic software.

[0011] Step 5: Through mechanical experiments, the optimal guide among the two guides is obtained.

[0012] In step four, the guide design includes a guide with the center of the solid circle as the needle entry point and a guide with the center of the dashed circle as the needle entry point, and a needle entry sleeve is set at the needle entry point.

[0013] The guide with the center of the solid circle as the needle entry point and the guide with the center of the dashed circle as the needle entry point are designed in the shape of a rectangle ABCDE, and an inwardly buckled fixing claw is designed on the inner side of positions A, C, D and E respectively for fixing and resetting.

[0014] Specifically, the first fixing point is selected 3mm below point B on the guide, and the second fixing point is selected at the midpoint of BC. Kirschner wire fixing point guide sleeves are then set at the two fixing points respectively.

[0015] Among them, mechanical experiments have proven that the guide with the center of the dashed circle as the needle entry point is the best guide, and the center of the two dashed circles is the best needle entry point.

[0016] Implementing the embodiments of the present invention has the following beneficial effects: using the principle of a rectangle, the insertion point for fixing the hollow screw in the split fracture is found more systematically; the 3D printed guide is designed with precision, providing a foundation for the later clinical research and development of related instruments and theoretical systems and their further application in clinical practice; the cure rate of the disease is improved, complications are reduced, the suffering of patients is further alleviated, and the quality of life of patients is improved. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the marking points on a thin-slice CT image of the design method of the customized rectangular 3D printed guide for the greater tubercle of the humerus provided by the present invention;

[0019] Figure 2 This is a schematic diagram of the structure of the guide provided by the present invention;

[0020] Figure 3 This is a working state model diagram of the guide provided by the present invention. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Please see Figure 1 , Figure 1 This is a schematic diagram of the marking points on a thin-slice CT image of the design method for a customized rectangular 3D-printed guide for the greater tuberosity of the humerus provided by this invention. This invention provides a design method for a customized rectangular 3D-printed guide for the greater tuberosity of the humerus, comprising:

[0023] Step 1: Locate the anatomical bony landmarks on the two-dimensional structure of the greater tubercle of the humerus: A is the intersection of the intertubercular groove and the insertion point of the supraspinatus muscle; B is the intersection of the supraspinatus and infraspinatus muscles; C is the intersection of the infraspinatus clivus point and the upper border of the teres minor muscle; D is the lowest point of the two-dimensional bony landmark of the teres minor muscle; E is the intersection of point D perpendicular to the intertubercular groove; H is the point 8 mm below the lower border of point D (8 mm is the average measurement taken in previous studies when establishing the greater tubercle splitting model); O is the intersection of the vertical extension of point H and the intertubercular groove.

[0024] Step 2: Using point B as a marker, draw a line parallel to OH to supplement the original rectangle ABCDE into rectangles FGED and FGHO. Then, points I and J bisect FO and GH respectively, and points K and L trisect IJ. Find points K and L, and mark solid circles with a diameter of 10mm (10mm is the size of a hollow screw washer) with points K and L as centers. Similarly, find the bisecting points of FE and GD, and trisect the two bisecting points to obtain two equal division points. Mark dashed circles with a diameter of 10mm with these two division points as centers.

[0025] Step 3: Measure the distances of AB, BC, CD, and DE respectively, and further measure the sizes of ∠EAB, ∠ABC, and ∠BCD. By collecting the above data from 1000 dried specimens and averaging them, find the average data of the rectangle ABCDE. Use this large data average to print a general template.

[0026] Step 4: Using the patient's CT thin-section scan data and thin-section CT scan, reconstruct the image using Mimics professional software, and further smooth it and design the guide using Geomagic software.

[0027] Specifically, the guide design includes a guide with the center of a solid circle as the needle entry point and a guide with the center of a dashed circle as the needle entry point, with a needle entry sleeve 2 set at the needle entry point 1. Both guides are designed in a rectangular shape similar to ABCDE, with an inwardly folded fixing gripper 3 designed on the inner side of positions A, C, D, and E for fixation and repositioning. The first fixing point 4 is selected 3mm below the lower edge of point B, and the second fixing point 4 is selected at the midpoint of BC. Kirschner wire fixing point guide sleeves 5 are then set at both fixing points. These two fixing points not only serve a fixing function but also provide guidance for subsequent surgery. Please refer to [link / reference]. Figure 2 , Figure 2 This is a schematic diagram of the guide provided by the present invention. 1. Needle entry point; 2. Needle entry sleeve; 3. Small fixing gripper; 4. Fixing point; 5. Kirschner wire fixing point guide sleeve.

[0028] Step 5: Through mechanical experiments, the optimal guide among the two guides is obtained.

[0029] The mechanical experiment involved randomly selecting two identical split fracture models of the greater tuberosity of the humerus. After designing the two types of guides mentioned above, the two guides were fixed to the corresponding positions on the fracture models using Kirschner wires. Then, a traction test was conducted using a mechanical machine to destruct the two fracture models. The guide corresponding to the fracture model requiring the greater force was identified as the optimal guide. The mechanical experiment proved that the guide with the center of the dashed circle as the needle insertion point was the optimal guide, and the centers of the two dashed circles were the optimal needle insertion points. Please refer to [link to relevant documentation]. Figure 3 , Figure 3 This is a working state model diagram of the guide provided by the present invention.

[0030] The present invention provides a customized rectangular 3D printed guide for the greater tubercle of the humerus and a design method thereof, which includes supplementing the original trapezoidal anatomical model of the greater tubercle of the humerus into a rectangle, calculating and finding the optimal needle entry point, and using large data to dry humeral specimens to find a universal rectangular shape; then using the patient's thin-section CT scan, reconstructing the structure using Mimics professional software, and further smoothing and designing the guide using Geomagic software, finally designing an anatomical standard parallel screw fixation guide that also takes into account reduction.

[0031] This invention provides a customized rectangular principle for more precise fixation of fractures using compression screws according to AO standards. A related 3D-printed guide is designed to assist in reduction and further standardize fracture treatment, improving clinical efficacy. Precise and standardized biomechanical research on greater tuberosity split fractures can be applied clinically to improve cure rates, reduce complications, alleviate patient suffering, and improve quality of life. Further clinical translation and promotion can generate significant social benefits.

[0032] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for designing a customized humeral greater tuberosity quasi-rectangular 3D printed guide, comprising: Step one, finding anatomical bone marker points on the two-dimensional structure of the humeral greater tuberosity: A is the intersection of the intertubercular groove and the supraspinatus muscle insertion point, B is the intersection of the supraspinatus muscle and the infraspinatus muscle, C is the intersection of the infraspinatus muscle slope point and the upper edge of the teres minor muscle, D is the lowest point of the two-dimensional structure of the teres minor muscle bone marker, E is the intersection of D point perpendicular to the intertubercular groove, H is the point 8mm below the lower edge of D point, O is the intersection of the vertical extension line of H point and the intertubercular groove; Step two, taking B point as a mark, making parallel lines of OH, supplementing the original quasi-rectangular ABCDE into rectangle FGED and rectangle FGHO; then I point and J point respectively bisect FO and GH, K point and L point trisect IJ, and then find K point and L point, respectively taking K point and L point as the center, marking a 10mm diameter solid circle; similarly, find the bisecting points of FE and GD, and trisect the two bisecting points to get two equal points, respectively taking the two equal points as the center, marking a 10mm diameter dotted circle; Step three, measuring the distances of AB, BC, CD and DE, and further measuring the sizes of ∠EAB, ∠ABC and ∠BCD, finding the average data of quasi-rectangular ABCDE by collecting the data of 1000 dry specimens, and printing a universal template with the average data; Step four, using CT thin layer scanning data and thin layer scanning CT, reconstructing by Mimics professional software, and further smoothing processing and guide design by Geomagic software; the guide design includes a guide with the center of the solid circle as the needle entry point and a guide with the center of the dotted circle as the needle entry point, and a needle entry sleeve is arranged on the needle entry point; Step five, obtaining the best guide among the two guides through a mechanical experiment.

2. The method of designing a customized glenoid component according to claim 1, wherein, The guide with the center of the solid circle as the needle entry point and the guide with the center of the dotted circle as the needle entry point are designed as quasi-rectangular ABCDE, and an inner buckle fixing grip is designed inside the positions of A, C, D and E for fixation and reduction.

3. The method of designing a custom glenoid 3D printed guide according to claim 2, wherein, Selecting a position 3mm below the lower edge of B point on the guide as the first fixed point, and selecting the midpoint of BC as the second fixed point, then setting K-wire fixed point sleeves at the positions of the two fixed points respectively.

4. The method of designing a customized glenoid component according to claim 1, wherein, The mechanical experiment proves that the guide with the center of the dotted circle as the needle entry point is the best guide, and the centers of the two dotted circles are the best needle entry points.

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