A constrained shoulder prosthesis
By designing restrictive shoulder prosthesis, the humeral head prosthesis is fixed using semicircular mulch cup and limit ring structure, the problems of subscapula impact, dislocation and loosening after shoulder prosthesis replacement are solved, significantly reducing the occurrence of complications Rate, suitable for a variety of patient forms.
Patent Information
- Application Number
- CN201811231429.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2018-10-22
- Publication Date
- 2024-12-17
- Estimated Expiration
- 2038-10-22
AI Technical Summary
Existing shoulder prostheses are prone to problems such as subscapula impact, postoperative dislocation and prosthesis instability, loose prosthesis and acromion stress fracture after replacement, and there is a lack of effective rescue plans.
A restrictive shoulder prosthesis is designed, including a semicircular outer mortar cup, a semicircular inner mortar cup liner, a humeral head prosthesis, a limiting ring and anatomical neck prosthesis, fixed with the scapula by dispersing screws Connection, the limit ring is fixed with the humeral head prosthesis, the anatomical neck prosthesis is connected to the humeral shaft, and the humeral shaft prosthesis is made of ceramic or polymer polyethylene material. The humeral shaft prosthesis is titanium alloy or ceramic, and the limit ring is made of ceramic or titanium alloy. Select and structure design to avoid complications.
It effectively avoids 50% or even higher complications, has not increased manufacturing process and cost, and has a wider range of indications. It can make corresponding adjustments based on the morphology of the patient's scapula, which will benefit a large number of patients.
Smart Images
Figure CN109172054B_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a shoulder joint prosthesis, in particular to a restrictive shoulder joint prosthesis. Background Art
[0002] The shoulder joint is the most mobile joint in the human body, and because of its large head and small glenoid cavity, it is also the most unstable joint in the human body. The rotator cuff is a group of muscles that wrap around the humeral head and is composed of the supraspinatus, infraspinatus, teres minor and subscapularis. This structure is an important dynamic stability structure of the shoulder joint.
[0003] For patients with end-stage shoulder degeneration and certain complex shoulder trauma that affect their lives, shoulder replacement, that is, replacing the humeral head and glenoid cavity with artificial materials at the same time or separately, is considered the only viable treatment option. The shoulder replacement prostheses currently used on the market include conventional or anatomical designs that conform to human anatomy, hereinafter referred to as positive shoulders, and reverse or inverted designs that are opposite to the human anatomy, hereinafter referred to as reverse shoulders. Positive shoulder replacement is suitable for patients with relatively intact rotator cuff function, because the rotator cuff is still needed to fix the humeral head to the glenoid cavity after the replacement. However, since positive shoulder replacement surgery will damage the rotator cuff, and patients still face the risk of rotator cuff degeneration and failure after the replacement, its use is currently decreasing year by year.
[0004] The characteristic of reverse shoulder is that the concave surface is designed on the side of humeral head and the convex surface is designed on the glenoid. In addition, reverse shoulder replacement ensures that the deltoid muscle is always tense by adjusting the position of the rotation center, extending the length of the humerus, adjusting the angle of the humeral neck and the humeral shaft (Neck-Shaft Angle, NSA), etc., so that the humeral head can be fixed in the glenoid through the tension of the deltoid muscle without relying on the rotator cuff. The original intention of the reverse shoulder design was to face patients with rotator cuff failure, so it has gradually been respected and is considered to be the ultimate solution for restoring shoulder joint function. The typical reverse shoulder prosthesis consists of five parts: humeral prosthesis stem 1, prosthesis epiphysis 2, polyethylene liner 3, spherical glenoid 4 and glenoid base 5.
[0005] At present, there are many products on the market that realize the formation of positive shoulder prosthesis and reverse shoulder prosthesis respectively through different assembly methods. For example, the CN 106999287 A patent published in 2017 includes a humeral component equipped with a rod, a head component, and a connection or joint connection device that connects or joints the humeral component to the head component. Such a structure meets the anatomical structure or the patient's own operational needs; at the same time, the patent also proposes two methods for adjusting the neck-shaft angle NSA. One is that the axis V of the recess or recess 6 corresponds to the main symmetry axis of the protrusion, but does not correspond to the symmetry axis S of the head component. In this case, the protrusion has an angle S2 relative to the symmetry axis S of the head component. This configuration allows the angle of the head component relative to the humeral component 1 to be adjusted so as to more accurately support the patient's anatomical structure and the surgical requirements of the implant.
[0006] Another is that the protrusion of the head component is not centered but eccentrically placed. The axis V of the recess or notch corresponds to the main symmetry axis Z2 of the protrusion, but has a certain translation relative to the symmetry axis S of the head component. This configuration allows the position of the head component to be adjusted relative to the humeral component in order to more accurately support the patient's anatomical structure and the surgical requirements of the implant.
[0007] Through the above methods, both methods can adjust the actual neck-shaft angle NSA of the prosthesis, that is, the angle between the symmetry axis S of the head component and the symmetry axis L of the rod, and then adjust the length and tension of the deltoid muscle when the humerus is in the same position, ensuring that the prosthesis does not dislocate from the glenoid cavity and does not cause excessive pressure on the scapula, thereby achieving balance.
[0008] Although the results of most reverse shoulder follow-ups are very good, its complications are difficult to avoid. Moreover, due to the unique anatomical structure of the shoulder joint and the differences in patients' habits of using the shoulder joint, the complications of shoulder replacement are significantly higher than other joint replacements, even for the more popular reverse shoulder. Scapula cutting and acromion stress fracture are unique complications of reverse shoulder replacement. Common complications include groove formation between the prosthesis and the bone, dislocation of the prosthetic joint, hematoma, infection, neuropathy, loose connection between the prosthesis and the bone, and periprosthetic fractures. It is worth mentioning that the second-stage surgery is also a high-risk factor for complications. Compared with the first-stage surgery, the second-stage complications and associated problems are twice as likely.
[0009] At the same time, since reverse shoulder replacement is the final solution for many shoulder joint problems, prosthesis failure is often catastrophic and there is a lack of effective rescue solutions. Compared with other joint replacements, reverse shoulder replacement has prominent complications in terms of scapula cutting, postoperative dislocation, prosthesis instability, and prosthesis loosening. Although the prosthesis design has undergone a series of improvements, these complications have not been fundamentally resolved.
[0010] In summary, the existing shoulder prosthesis replacement has the following problems: 1. The problem of subscapular impingement may occur. The reason for this is that the prosthesis adopts an inward-moving rotation center. In order to ensure the tension of the deltoid muscle, it is necessary to extend the length of the humerus, which will cause the polyethylene pad and the lower edge of the scapula to collide during the adduction and abduction activities of the shoulder joint; 2. Postoperative dislocation and prosthesis instability may occur. The reason for this is that the reverse shoulder design makes the prosthesis not fully fit when the patient's humerus naturally droops, and the humeral length is not enough to ensure that the deltoid muscle maintains tension, which will cause the prosthesis to completely detach. After the fulcrum is lost, the prosthesis will dislocate, causing prosthesis instability and dislocation; 3. Prosthesis loosening and acromion stress fractures may occur.
[0011] Therefore, existing shoulder prosthesis replacement may cause subscapular impingement, postoperative dislocation, prosthesis instability, prosthesis loosening and acromion stress fracture, which has become a technical problem that needs to be solved urgently by technical personnel in this field. Summary of the invention
[0012] The present invention provides a restrictive shoulder joint prosthesis and a method for using the same to solve the problems of subscapular impingement, postoperative dislocation, prosthesis instability, prosthesis loosening, and acromion stress fracture in existing shoulder joint prosthesis replacement.
[0013] To achieve the above object, the present invention adopts the following technical solutions:
[0014] A restrictive shoulder joint prosthesis is provided, comprising a semicircular outer acetabular cup 1, a plurality of screw through holes 2 are provided on the surface of the semicircular outer acetabular cup 1, a plurality of dispersed screws 3 pass through the screw through holes 2 and are fixedly connected to the human scapula, the semicircular outer acetabular cup 1 is ball-jointed with a semicircular inner acetabular cup pad 4, and the semicircular inner acetabular cup pad 4 is ball-jointed with a humeral head prosthesis 5; a limiting ring 6 is provided on one side of the semicircular inner acetabular cup pad 4, and the limiting ring 6 is fixedly connected to the left end face of the semicircular inner acetabular cup pad 4 by bolts to limit the humeral head prosthesis 5 within the semicircular inner acetabular cup pad 4; an anatomical neck prosthesis 7 is embedded in the humeral head prosthesis 5, and one end of the anatomical neck prosthesis 7 passes through the limiting ring 6 and is connected to a humeral shaft prosthesis 8.
[0015] Furthermore, the semicircular inner acetabular cup liner 4 is made of ceramic or high molecular polyethylene.
[0016] Furthermore, the humeral stem prosthesis 8 is made of titanium alloy or ceramic.
[0017] Furthermore, the material of the limiting ring 6 is ceramic, titanium alloy or highly cross-linked polyethylene.
[0018] Furthermore, the limiting ring 6 is in the shape of a symmetrical ring or an asymmetrical ring.
[0019] Furthermore, the number of the plurality of dispersion screws 3 is 4-6.
[0020] Furthermore, the humeral shaft prosthesis 8 is inserted into the humeral shaft of a human body by press-fitting or assembly with bone cement.
[0021] Furthermore, the humeral shaft prosthesis 8 is covered with a porous bioceramic hydroxyapatite coating.
[0022] Furthermore, the semicircular inner acetabular cup liner 4 is a non-restrictive hemispherical structure with an outer diameter of 4-7 cm, and the humeral head prosthesis 5 is rotated 180° in all directions on the semicircular inner acetabular cup liner 4 .
[0023] Furthermore, the length of the anatomical neck prosthesis 7 is 5-20 cm.
[0024] The present invention adopts the above technical solution, and has the following technical effects compared with the prior art:
[0025] The restrictive shoulder joint prosthesis provided by the present invention includes a semicircular outer acetabular cup, a semicircular inner acetabular cup liner, a humeral head prosthesis, a limiting ring, an anatomical neck prosthesis and a humeral shaft prosthesis. The surface of the semicircular outer acetabular cup is provided with a plurality of bolt through holes, through which the semicircular outer acetabular cup is connected to the human scapula, the semicircular inner acetabular cup liner is embedded in the semicircular outer acetabular cup, and the humeral head prosthesis is embedded in the semicircular inner acetabular cup liner. After the embedding is completed, the humeral head prosthesis is restricted in the semicircular inner acetabular cup liner by the limiting ring, and the anatomical neck prosthesis is connected to the humeral head prosthesis, and the humeral shaft prosthesis is inserted into the human humeral shaft by press fitting or bone cement.
[0026] The present invention can avoid 50% or even higher complications of existing designs, and its manufacturing process and cost are not increased in comparison. At the same time, its indications are more extensive, and corresponding adjustments can be made according to the patient's shoulder blade morphology, and a large number of patients benefit from it. BRIEF DESCRIPTION OF THE DRAWINGS
[0027] Figure 1 It is a schematic diagram of assembling the restrictive shoulder joint prosthesis of the present invention;
[0028] Figure 2 It is a schematic diagram of the structure of the semicircular outer acetabular cup in the restrictive shoulder joint prosthesis of the present invention;
[0029] Figure 3 It is a schematic structural diagram of a limiting ring in a restrictive shoulder joint prosthesis of the present invention;
[0030] Figure 4 A perspective view showing the structure of a restrictive shoulder joint prosthesis according to the present invention;
[0031] Figure 5It is a structural view of the restrictive shoulder joint prosthesis of the present invention;
[0032] Figure 6 It is a perspective view of the restrictive shoulder joint prosthesis embodiment 1 of the present invention;
[0033] Figure 7 It is a schematic diagram of the structure of the restrictive shoulder joint prosthesis in Example 1 of the present invention;
[0034] Figure 8 It is a schematic diagram of the structure of the restrictive shoulder joint prosthesis in Example 2 of the present invention;
[0035] Wherein, each figure is marked as:
[0036] 1-semicircular outer acetabular cup, 2-screw through hole, 3-dispersed screw, 4-semicircular inner acetabular cup liner, 5-humeral head prosthesis, 6-limiting ring, 7-anatomical neck prosthesis, 8-humeral shaft prosthesis, 9-bone graft, 10-original glenoid. DETAILED DESCRIPTION
[0037] The present invention is described in detail and specifically by specific examples below to provide a better understanding of the present invention, but the following examples do not limit the scope of the present invention.
[0038] Example 1
[0039] like Figure 6-7 As shown, an embodiment of the present invention provides a restrictive shoulder joint prosthesis, including a semicircular outer acetabular cup 1, a plurality of screw through holes 2 are provided on the surface of the semicircular outer acetabular cup 1, a plurality of dispersed screws 3 pass through the screw through holes 2 and are fixedly connected to the human scapula, the semicircular outer acetabular cup 1 and the semicircular inner acetabular cup liner 4 are ball-jointed, and the semicircular inner acetabular cup liner 4 and the humeral head prosthesis 5 are ball-jointed; a limiting ring 6 is provided on one side of the semicircular inner acetabular cup liner 4, and the limiting ring 6 is fixedly connected to the left end face of the semicircular inner acetabular cup liner 4 by bolts to limit the humeral head prosthesis 5 in the semicircular inner acetabular cup liner 4; an anatomical neck prosthesis 7 is embedded in the humeral head prosthesis 5, and one end of the anatomical neck prosthesis 7 passes through the limiting ring 6 and is connected to the humeral shaft prosthesis 8.
[0040] In one aspect of this embodiment, Figure 6-7 As shown, the material of the semicircular inner acetabular cup liner 4 is ceramic, which has higher wear resistance than metal and highly cross-linked polyethylene materials, and there is no risk of metal ion escape after metal interface wear. Ceramic materials have a higher Mohs hardness, but are more brittle and may break after severe violence. However, since the present invention is a restrictive prosthesis, the position of the humeral head is relatively fixed, and daily shoulder joint activities will not form too much impact on the prosthetic joint surface, so the selection of the semicircular inner acetabular cup liner 4 and the ceramic humeral head prosthesis 5 made of ceramic material will be the best solution.
[0041] In one aspect of this embodiment, Figure 6-7 As shown, the humeral stem prosthesis 8 is made of titanium alloy or ceramic.
[0042] In one aspect of this embodiment, Figure 6-7 As shown, the material of the limiting ring 6 is ceramic, titanium alloy or highly cross-linked polyethylene.
[0043] In one aspect of this embodiment, Figure 6-7 As shown, the shape of the limiting ring 6 is a symmetrical ring or an asymmetrical ring.
[0044] In one aspect of this embodiment, Figure 6-7 As shown, the number of the plurality of dispersion screws 3 is 4-6. In the present embodiment, 4 dispersion screws 3 are selected and respectively placed at the upper and lower bone surfaces of the glenoid, the junction of the acromion and scapular spine thickened and strengthened by the bone graft material, and the coracoid process thickened and strengthened by the bone graft material. Among them, the glenoid is the main attachment part of the dispersion screw 3, and the dispersion screw 3 should not penetrate or pierce the bone of the coracoid process.
[0045] In one aspect of this embodiment, Figure 6-7 As shown, the humeral shaft prosthesis 8 is inserted into the humeral shaft of a human body by press-fitting or assembly with bone cement.
[0046] In one aspect of this embodiment, Figure 6-7 As shown, the surface of the humeral shaft prosthesis 8 is covered with a porous bioceramic hydroxyapatite coating, and is assembled by press-fitting and bone cement. The porous coating on the surface helps to increase friction and induce bone tissue attachment.
[0047] In one aspect of this embodiment, Figure 6-7 As shown, the semicircular inner acetabular cup liner 4 is a non-restrictive hemispherical structure with an outer diameter of 4-7 cm. The humeral head prosthesis 5 is rotated 180° in all directions on the semicircular inner acetabular cup liner 4. The size data of the humeral head in the anatomical neck plane of the Asian population are as follows: Superiority and inferior diameter ML: male: 46.9±2.0 (43.5-51.4) mm female: 41.6±1.7 (37.9-45.2) mm; Anterior-posterior diameter (AP): male: 43.7±2.2 (39.4-49.5) mm female: 38.4±1.7 (34.0-42.4) mm; In our design, the outer diameter of the outer layer of the acetabular cup must be greater than or equal to the maximum diameter of the anatomical neck plane of the humerus, so the outer diameter AF of the outer layer of the acetabular cup in this design ranges from 4 to 7 cm.
[0048] In one aspect of this embodiment, Figure 6-7As shown, the length of the anatomical neck prosthesis 7 is 5-20 cm. Since the humeral shaft of Asians is thin, a very long design is not suitable, and generally a length of less than 20 cm is selected. Especially in the first surgery, inserting a shorter prosthesis can reserve space for possible revision surgery later.
[0049] Example 2
[0050] like Figure 6-7 As shown, an embodiment of the present invention provides a restrictive shoulder joint prosthesis that does not require supraspinatus fossa bone grafting, including a semicircular outer acetabular cup 1, a plurality of screw through holes 2 are provided on the surface of the semicircular outer acetabular cup 1, a plurality of dispersed screws 3 pass through the screw through holes 2 and are fixedly connected to the human scapula, the semicircular outer acetabular cup 1 and the semicircular inner acetabular cup liner 4 are ball-connected, and the semicircular inner acetabular cup liner 4 and the humeral head prosthesis 5 are ball-connected; a limiting ring 6 is provided on one side of the semicircular inner acetabular cup liner 4, and the limiting ring 6 is fixedly connected to the left end face of the semicircular inner acetabular cup liner 4 by bolts to limit the humeral head prosthesis 5 in the semicircular inner acetabular cup liner 4; an anatomical neck prosthesis 7 is embedded in the humeral head prosthesis 5, and one end of the anatomical neck prosthesis 7 passes through the limiting ring 6 and is connected to the humeral shaft prosthesis 8.
[0051] In one aspect of this embodiment, Figure 8 As shown, the material of the semicircular inner acetabular cup liner 4 is ceramic, which has higher wear resistance than metal and highly cross-linked polyethylene materials, and there is no risk of metal ion escape after metal interface wear. Ceramic materials have a higher Mohs hardness, but are more brittle and may break after severe violence. However, since the present invention is a restrictive prosthesis, the position of the humeral head is relatively fixed, and daily shoulder joint activities will not form too much impact on the prosthetic joint surface, so the selection of the semicircular inner acetabular cup liner 4 and the ceramic humeral head prosthesis 5 made of ceramic material will be the best solution.
[0052] In one aspect of this embodiment, Figure 8 As shown, the humeral stem prosthesis 8 is made of titanium alloy or ceramic.
[0053] In one aspect of this embodiment, Figure 8 As shown, the material of the limiting ring 6 is ceramic, titanium alloy or highly cross-linked polyethylene.
[0054] In one aspect of this embodiment, Figure 8 As shown, the shape of the limiting ring 6 is a symmetrical ring or an asymmetrical ring.
[0055] In one aspect of this embodiment, Figure 8As shown, the number of the plurality of dispersed screws 3 is 4-6. In this embodiment, 4-5 dispersed screws 3 can also be inserted. The glenoid, coracoid process and acromion are all solid bone structures. The three can form a stable bone "base" to directly fix the acetabular cup. In this embodiment, 4-5 screws can still be inserted. If the bone is abundant, the number of screws can be appropriately increased, such as placing more screws in the glenoid. Before fixing the acetabular cup, the original glenoid 10 needs to be properly planed and shaped so that the acetabular cup fits the planed bone surface, which can increase the contact area as much as possible without bone grafting.
[0056] In one aspect of this embodiment, Figure 8 As shown, the humeral shaft prosthesis 8 is inserted into the humeral shaft of a human body by press-fitting or assembly with bone cement.
[0057] In one aspect of this embodiment, Figure 8 As shown, the humeral shaft prosthesis 8 is covered with a porous bioceramic hydroxyapatite coating and is assembled by press-fit and bone cement. The porous coating on the surface helps to increase friction and induce bone tissue attachment.
[0058] In one aspect of this embodiment, Figure 8 As shown, the semicircular inner acetabular cup liner 4 is a non-restrictive hemispherical structure with an outer diameter of 4-7 cm. The humeral head prosthesis 5 is rotated 180° in all directions on the semicircular inner acetabular cup liner 4. The size data of the humeral head in the anatomical neck plane of the Asian population are as follows: Superiority and inferior diameter ML: male: 46.9±2.0 (43.5-51.4) mm female: 41.6±1.7 (37.9-45.2) mm; Anterior-posterior diameter (AP): male: 43.7±2.2 (39.4-49.5) mm female: 38.4±1.7 (34.0-42.4) mm; In our design, the outer diameter of the outer layer of the acetabular cup must be greater than or equal to the maximum diameter of the anatomical neck plane of the humerus, so the outer diameter AF of the outer layer of the acetabular cup in this design ranges from 4 to 7 cm.
[0059] In one aspect of this embodiment, Figure 8 As shown, the length of the anatomical neck prosthesis 7 is 5-20 cm. Since the humeral shaft of Asians is thin, a very long design is not suitable, and generally a length of less than 20 cm is selected. Especially in the first surgery, inserting a shorter prosthesis can reserve space for possible revision surgery later.
[0060] The restrictive shoulder prosthesis of the present invention is designed to address the problems of subscapular impingement, postoperative dislocation, prosthesis instability, prosthesis loosening, acromion stress fracture, etc. that may occur in existing shoulder prosthesis replacements. The restrictive shoulder prosthesis of the present invention can avoid 50% or even higher complications of existing designs, and its manufacturing process and cost are not increased in comparison. At the same time, its indications are more extensive, and corresponding adjustments can be made according to the patient's scapula morphology, and a large number of patients benefit from it.
[0061] The specific embodiments of the practical restrictive shoulder joint prosthesis and the method of using the same are described in detail above, but they are only used as examples, and the present invention is not limited to the specific embodiments described above. For those skilled in the art, any equivalent modifications and substitutions made to the present invention are also within the scope of the present invention. Therefore, the equalization changes and modifications made without departing from the spirit and scope of the present invention should be included in the scope of the present invention.
Claims
1. A restrictive shoulder joint prosthesis, characterized in that: The invention comprises a semicircular outer acetabular cup (1), a surface of which is provided with a plurality of screw through holes (2), a plurality of dispersed screws (3) passing through the screw through holes (2) to be fixedly connected to a human scapula, the semicircular outer acetabular cup (1) and a semicircular inner acetabular cup liner (4) are ball-jointed, and the semicircular inner acetabular cup liner (4) and a humeral head prosthesis (5) are ball-jointed; a limiting ring (6) is provided on one side of the semicircular inner acetabular cup liner (4), and the limiting ring (6) is fixedly connected to the left end surface of the semicircular inner acetabular cup liner (4) by bolts so as to limit the humeral head prosthesis (5) within the semicircular inner acetabular cup liner (4); an anatomical neck prosthesis (7) is embedded in the humeral head prosthesis (5), and one end of the anatomical neck prosthesis (7) passes through the limiting ring (6) to be connected to a humeral shaft prosthesis (8); Wherein, the material of the limiting ring (6) is ceramic, titanium alloy or highly cross-linked polyethylene; Wherein, the shape of the limiting ring (6) is a symmetrical ring or an asymmetrical ring; The semicircular inner acetabular cup liner (4) is a non-restrictive hemispherical structure with an outer diameter of 4-7 cm. The humeral head prosthesis (5) is rotated 180° in all directions on the semicircular inner acetabular cup liner (4).
2. The restrictive shoulder joint prosthesis according to claim 1, characterized in that: The material of the semicircular inner acetabular cup liner (4) is ceramic or high molecular polyethylene.
3. The restrictive shoulder joint prosthesis according to claim 1, characterized in that: The material of the humeral shaft prosthesis (8) is titanium alloy or ceramic.
4. The restrictive shoulder joint prosthesis according to claim 1, characterized in that: The number of the plurality of dispersion screws (3) is 4-6.
5. The restrictive shoulder joint prosthesis according to claim 1, characterized in that: The humeral shaft prosthesis (8) is inserted into the humeral shaft of a human body by means of press-fitting or bone cement assembly.
6. The restrictive shoulder joint prosthesis according to claim 1, characterized in that: The surface of the humeral shaft prosthesis (8) is covered with a porous bioceramic hydroxyapatite coating.
7. The restrictive shoulder joint prosthesis according to claim 1, characterized in that: The length of the anatomical neck prosthesis (7) is 5-20 cm.