Hybrid implant system and manufacturing method therefor

Abstract

The present disclosure discloses a hybrid implant system for fixing and repairing orthopedic fracture and a manufacturing method therefor. The hybrid implant system comprises an implant body having holes on both ends and a locking part configured for attaching the implant body to a broken bone through the holes. The hybrid implant system further comprises a healing assembly made from a material promoting healing of the bone. The implant body has at least one window on a side, the at least one window is aligned with a broken location of the bone, and the healing assembly is inserted into the window in a self-locking manner towards an interior of the implant body.

Claims

1. A hybrid implant system for fixing and repairing orthopedic fracture, comprising: an implant body, having holes on both ends; and a locking part, configured for attaching the implant body to a broken bone through the holes; a healing assembly made from a material promoting healing of the bone, the implant body having at least one window on a side, the at least one window aligned with a broken location of the bone, and the healing assembly inserted into the window in a self-locking manner towards an interior of the implant body, wherein the healing assembly has a resilient groove, the healing assembly is inserted into the window towards the interior of the implant body, and the healing assembly is snapped into the window by compressing the resilient groove.

2. The hybrid implant system according to claim 1, wherein the healing assembly is made from biodegradable magnesium or magnesium alloys.

3. The hybrid implant system according to claim 1, wherein the window comprises a first section and a second section on the side of the body in a direction from an outside to the inside, the first section having a diameter larger than a diameter of the second section; the healing assembly comprises: a first holding section having a shape corresponding to the first section; and a second holding section having a shape corresponding to the second section, the resilient groove being disposed in the second holding section.

4. The hybrid implant system according to claim 1, wherein the healing assembly gradually degrades during implantation.

5. The hybrid implant system according to claim 1, wherein the implant body is used for insertion into the broken bone.

6. The hybrid implant system according to claim 5, wherein the implant body is a hollow rod with a hollow cavity, and the healing assembly falls into the hollow cavity of the hollow rod only after falling off due to degradation.

7. The hybrid implant system according to claim 1, wherein the implant body is attached to an outer side of the broken bone.

8. The hybrid implant system according to claim 7, wherein the implant body has a plate shape.

9. A method for manufacturing a hybrid implant system, the method comprising: forming holes on both ends of an implant body to attach the implant body to a broken bone through the holes; forming at least one window on a side of the implant body; manufacturing a healing assembly body with a material promoting healing of the bone; and forming a self-locking part in the healing assembly body, wherein, at least one window is aligned with a broken location of the bone, and the healing assembly is inserted into the window in a self-locking manner through the self-locking part, wherein the healing assembly has a resilient groove, the healing assembly is inserted into the window towards the interior of the implant body, and the healing assembly is snapped into the window by compressing the resilient groove.

10. The method for manufacturing a hybrid implant system according to claim 9, wherein the healing assembly is made from biodegradable magnesium or magnesium alloys.

11. The method for manufacturing a hybrid implant system according to claim 9, wherein forming at least one window on a side of the implant body comprises: allowing the window to form a first section and a second section on the side of the body in a direction from an outside to the inside, the first section having a inner diameter larger than a diameter of the second section; the healing assembly body manufactured with the material promoting healing of the bone comprising: a first holding section having a shape corresponding to the first section; and a second holding section having a shape corresponding to the second section, the resilient groove being disposed in the second holding section.

12. The method for manufacturing a hybrid implant system according to claim 9, wherein the healing assembly gradually degrades during implantation.

13. The method for manufacturing a hybrid implant system according to claim 9, wherein the implant body is used for insertion into the broken bone.

14. The method for manufacturing a hybrid implant system according to claim 13, wherein the implant body is a hollow rod with a hollow cavity, and the healing assembly falls into the hollow rod only after falling off due to degradation.

15. The method for manufacturing a hybrid implant system according to claim 9, wherein the implant body is attached to an outer side of the broken bone.

16. The method for manufacturing a hybrid implant system according to claim 15, wherein the implant body has a plate shape.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Other features, objects and beneficial effects of the present disclosure will be apparent by reading the following detailed descriptions referring to the drawings. Same or similar elements in different drawings are indicated by same reference signs. In the attached drawings:

(2) FIG. 1 shows a schematic perspective view and a partially enlarged view of a hybrid implant system according to an implementation of the present disclosure;

(3) FIG. 2 shows a front view of an implant body of a hybrid implant system according to an implementation of the present disclosure;

(4) FIG. 3 shows various views of an implant body of a hybrid implant system according to an implementation of the present disclosure;

(5) FIG. 4 shows a partial section perspective view of a combined implant body and healing assembly of a hybrid implant system according to an implementation of the present disclosure;

(6) FIG. 5 shows a schematic diagram of a combination of a healing assembly of a hybrid implant system according to an implementation of the present disclosure;

(7) FIG. 6 shows a schematic diagram of a degradation process of a healing assembly of a hybrid implant system according to an implementation of the present disclosure;

(8) FIG. 7 shows a schematic space diagram and a partially enlarged view of a hybrid implant system according to another implementation of the present disclosure;

(9) FIG. 8 shows a schematic diagram of a combination of an implant body and a healing assembly of a hybrid implant system according to an implementation of the present disclosure;

(10) FIG. 9 shows a schematic perspective view of a hybrid implant system according to an implementation of the present disclosure; and

(11) FIG. 10 is a sequence diagram of a method for manufacturing a hybrid implant system according to an implementation of the present disclosure.

(12) FIG. 11 shows mechanisms of osteoinductive effect of a degradation product release via upregulation of a bone forming neuro protein calcitonin gene-related peptide (CGRP) and its release to the fracture site.

(13) FIG. 12 illustrates the healing process with large fracture callus by using a Magnesium (Mg)-containing Intramedullary Nail (IM).

DETAILED DESCRIPTION OF EMBODIMENTS

(14) The present disclosure will be further detailed by combining the drawings and embodiments. It will be appreciated that the specific embodiments described herein are only for explaining relevant inventions, not for defining such inventions. It will also be noted that the drawings, for the sake of description, only illustrate the parts associated with the relevant inventions.

(15) It will be appreciated that although terms such as first and second may be used herein to describe various elements, parts, assemblies or sections, these parts, elements, assemblies or sections should not be limited by these terms. These terms are only used to distinguish one element, part, assembly or section from a different element, part, assembly or section. Therefore, the first element, first part, first assembly or first section discussed below may be referred to as a second element, second part, second assembly or second section without departing from the teachings of the present disclosure.

(16) For ease of description, terms for relative space positions such as under . . . , below . . . , under, above . . . , upper, upper end or lower end may be used herein to describe the relationship between one part or feature and a different part (different multiple parts) or a different feature (different multiple features) as shown in the figures. It will be appreciated that, in addition to the orientation depicted in the figures, the terms for relative space positions are intended to encompass different orientations of a device in use or in operation. For example, if a device in a figure is turned over, an element described as below or beneath a different element or feature would then be oriented above the different element or feature. Therefore, the exemplary term below . . . may encompass two orientations above . . . and below . . . .

(17) The wording used herein is for the purpose of describing particular implementations only, and is not intended to limit the present disclosure. Unless otherwise clearly indicated in the context, the wording, if used herein, does not have a feature of defining singular forms and is intended to comprise the plural forms as well. It should also be understood that the terms comprise, comprising, have, contain and/or containing, when used in the description, specify the presence of stated features, integers, steps, operations, elements and/or parts, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and/or groups thereof. For example, the term and/or as used herein comprises any and all combinations of one or more of the associated listed items. Expressions such as at least one of . . . as appearing behind a list of elements modify the entire list of elements and do not modify the individual elements in the list. In addition, when the implementations of the present disclosure are described, may means one or more implementations of the present disclosure. In addition, the term exemplary is intended to refer to an example or to illustrate.

(18) As used herein, the terms substantial approximate and similar terms are used as terms indicating similarity, not as terms indicating degree, and are intended to describe the inherent deviations of a measurement value or a calculation value that will be understood by those skilled in the art.

(19) Unless otherwise defined, all terms (comprising technical and scientific terms) used herein have the same meanings as those commonly understood by those skilled in the art to which the present disclosure belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having meanings consistent with the meanings thereof in the context of the relevant art and will not be interpreted in an idealized or overly formal sense, unless expressly so defined herein.

(20) It should be noted that, the embodiments in the present disclosure and the features in such embodiments may be combined with each other in the case of no conflict. The present disclosure will be described in detail below with reference to the accompanying drawings and embodiments.

(21) The present disclosure will be further described in combination with specific implementations.

(22) FIG. 1 is a schematic perspective view and a partially enlarged drawing of a hybrid implant system according to an implementation of the present disclosure. For clearly displaying the details of the hybrid implant system 100, the bone in views other than the left view in FIG. 1 is shown as translucent. In the exemplary implementation as shown in FIG. 1, the hybrid implant system 100 may comprise an implant body 110, a locking part 120 and a healing assembly 130.

(23) In the present exemplary implementation, the implant body 110 may be a long tubular part and may have holes (not shown) on both ends thereof. The locking part 120 may be used to attach the implant body 110 to a broken bone 140 through the holes. In the present implementation, the locking part 120 may, for example, be a screw commonly used in orthopedic fixation. The healing assembly 130 may be made from a material capable of healing the broken bone 140, wherein the implant body 110 has at least one window 112 on a side thereof. The at least one windows 112 is aligned with the broken location 141 of the broken bone 140. The healing assembly 130 is inserted into the window 112 in a self-locking manner towards an interior of the implant body 110. In addition, there is no window 112 for inserting the healing assembly 130 on a concave-convex side of the implant body 110 since the concave-convex side is a region with high stress. The diameters of the holes on the implant body 110 and the window 112 as well as the spacing between the holes and the window 112 may be optimized to match the characteristics of the broken bone 140.

(24) In an alternative implementation of the present disclosure, the hybrid implant system 100 is actually an intramedullary nail system placed in a broken bone. However, it will be appreciated that the hybrid implant system 100 may be a different device suitable for osteopathic treatment.

(25) In an alternative implementation according to the present disclosure, the healing assembly 130 may be made from a material promoting and enhancing bone healing. In an exemplary implementation of the present disclosure, the healing assembly 130 may be made from magnesium (Mg) or magnesium alloys. The elastic modulus and compressive yield strength of the magnesium may match well with those of a natural bone, while magnesium has a greater toughness than ceramic biomaterials such as hydroxyapatite. In addition, about 60% of total physiological magnesium is stored in the bone matrix. Besides, magnesium deficiency may lead to osteoporosis in human body, while supplementing magnesium is beneficial for a patient with osteoporosis. In this case, it is attractive to develop magnesium as a scaffold material for orthopedic implants, not only for fracture fixation but also for healing enhancement.

(26) FIG. 2 is a front view of an implant body 110 of a hybrid implant system 100 according to an implementation of the present disclosure. The implant body 110 may be a long tubular part and may have at least one holes 111 on both ends thereof. In addition, the implant body 110 has at least one window 112 on the side thereof. In the present implementation, the implant body 110 may be a hollow rod that is made from a metal and has a hollow cavity 115, and the curvature of the hollow rod may be designed to fit a broken bone. A suitable implant body 110 may be conductive to reducing the movement between an implant and a broken bone and reducing the recurrence of fracture.

(27) In an alternative implementation according to the present disclosure, a surgeon may determine a broken location 141 with the help of a clinical image for the treatment of a long bone fracture. For a preoperative procedure, the implant body 110 will be aligned with the broken bone 140 and the healing assembly 130 will be positioned in the window 112 closest to the fracture location 141 of the broken bone 140, and then the mix system is inserted into the broken bone 140.

(28) FIG. 3 is various views of an implant body 110 of a hybrid implant system 100 according to an implementation of the present disclosure. In the present implementation, one groove, for example, may be provided on each side of the implant body 110. Four grooves on the four sides of the body 110 may make an angle of about 90 with each other. This design can avoid full contact of nail to the bone marrow cavity, avoiding resistance of nail insertion into the bone marrow cavity. It can seen from the views, there may be two holes 111 for the locking part 120 on the distal end of the implant body 110. In addition, there may also be a plurality of holes for the same purpose at the proximal end of the implant body 110, for example, three holes 111 as shown in the figure. Two of the three holes are oblique so that the locking part 120 may be inserted at an angle to the cross-section of the implant body 110. Therefore, the locking part 120 may be inserted to as much as the bone contents and the implant body 110 is fixed to the bone, which may improve the stability of the implant body 110 inside the bone cavity. After finite element analysis (FEA), creating holes at the lateral sites would minimize the loss of mechanical properties at Anterior-Posterior (AP) direction as AP direction sustains more physiological loading in vivo. However, the location, orientation and alignment of windows are not limited to the pattern we showed in FIG. 3.

(29) FIG. 4 is a partial section space diagram of combined implant body 100 and healing assembly 130 of a hybrid implant system 100 according to an implementation of the present disclosure. FIG. 5 is a schematic section view of a combination of a healing assembly 130 of a hybrid implant system 100 according to an implementation of the present disclosure. As shown in FIG. 5, the healing assembly 130 may have a resilient groove 131. The healing assembly 130 may be inserted into the window 112 towards an interior of the implant body 110 and then the healing assembly 130 may be snapped into the window 112 by compressing the resilient groove 131.

(30) The window 112 may comprise a first section 116 and a second section 113 in a direction from an outside to the inside along the side of the implant body 110. The first section 116 may have a inner diameter larger than a diameter of the second section 113 except for a combination of the two. In the present implementation, the first section 116 may be a partially tapered section that is opened outward, and the second section 113 may be a cylindrical cavity.

(31) The healing assembly 130 may comprise a first holding section 132 and a second holding section 133, wherein a shape of the first holding section 132 may correspond to the first section 116, and a shape of the second holding section 133 may correspond to the second section 113, wherein the resilient groove 131 may be disposed in the second holding section 133.

(32) In an alternative embodiment according to the present disclosure, the healing assembly 130 may be inserted directly into the window 112. During the insertion, the window 112 will squeeze the healing assembly 130 in a direction of an arrow F2, thus deforming the resilient groove 131, allowing the healing assembly 130 to be squeezed into the window 112. Once the healing assembly 130 is fully squeezed into the window 112, the healing assembly 130 will return to the original shape and will realize self-locking. The self-locking feature may prevent the healing assembly 130 from falling into the hollow cavity 115 of the implant body 110 when the healing assembly 130 is pushed into the window 112. As a result, the healing assembly 130 will be securely fixed in place. The healing assembly 130 will not fall off when the surgeon inserts the implant body 110 into the bone of a patient during surgery.

(33) FIG. 6 is a schematic diagram of a degradation process of a healing assembly 130 of a hybrid implant system 100 according to an implementation of the present disclosure, and the healing assembly 130 gradually degrades during implantation.

(34) The upper part of FIG. 6 schematically illustrates a healing assembly 130 that is to start degrading, and the lower part of FIG. 6 illustrates a healing assembly 130 that has gradually degraded to fall off.

(35) As shown in the upper part of FIG. 6, when the healing assembly 130 initially starts degrading, features of the first section 116 and the second section 113 of the window 112 as well as the first holding section 132 and the second holding section 133 of the healing assembly 130 may prevent the healing assembly 130 that starts degrading from falling into the hollow cavity 115 of the implant body 110. The healing assembly 130 is adjacent to a backbone wall 142 so that the healing assembly 130 is fully exposed to a fracture site.

(36) As shown in the lower part of FIG. 6, when the healing assembly 130 has degraded, the shape thereof is no longer intact. The healing assembly 130 will lose the self-locking function thereof over time. A degradation product 134 (such as a magnesium ion) released by the healing assembly 130 pass through the holes and distributed to the surrounding bone tissue to promote the growth of a surrounding tissue 143, which in turn fills the window 112, and prevents the degrading healing assembly 130 from falling off.

(37) If the healing assembly 130 still becomes loose and falls off from the window 112 in the fall off direction 160, the healing assembly 130 will fall into the hollow cavity 115 of the implant body 110 only.

(38) FIG. 7 to FIG. 9 illustrate a hybrid implant system according to another implementation of the present disclosure. In contrast to the previously described implementations, an implant body 110 in the present embodiment may be attached to the outside of the broken bone 140 instead of being inserted into the broken bone 140. In the present implementation, the implant body 110 has a tubular outline. For clearly showing the details of the hybrid implant system 100, the bones in the views other than the left view in FIG. 7 are shown as translucent.

(39) FIG. 10 is a sequence diagram of a method for manufacturing a hybrid implant system according to an implementation of the present disclosure.

(40) Referring to FIG. 10, the method 200 for manufacturing a hybrid implant system according to an implementation of the present disclosure starts from step 201. In step 201, forming holes on both ends of an implant body to attach the implant body to a broken bone through the holes.

(41) Then in step 202, forming at least one window on the side of the implant body.

(42) In step 203, manufacturing a healing assembly body with a material capable of promoting healing of the bone. In an alternative implementation according to the present disclosure, the healing assembly may be made from magnesium or magnesium alloys.

(43) In step 204, forming a self-locking part in the healing assembly body.

(44) In step 205, allowing at least one of the windows to align with the broken location of the bone, and inserting the healing assembly into the window in a self-locking manner through the self-locking part.

(45) In an alternative implementation according to the present disclosure, the self-locking part has a resilient groove, the healing assembly is inserted into the window towards the interior of the implant body, and the healing assembly is snapped into the window by compressing the resilient groove.

(46) According to an alternative implementation of the present disclosure, the step 202 may comprise: allowing the window to form a first section and a second section along the side of the body in sequence from the outside to the inside, the first section having a larger inner diameter than the second section. Step 203 may comprise: a first holding section with shape corresponding to the first section; and a second holding section with shape corresponding to the second section, the resilient groove being disposed in the second holding section.

(47) Alternatively, the healing assembly gradually degrades during implantation, and the implant body is used for being inserted into the broken bone.

(48) As mentioned above, the implant body is a hollow rod with a hollow cavity, and the healing assembly falls into the hollow rod only after fall off due to degradation.

(49) Alternatively, the implant body may also be attached to the outer side of the broken bone. As mentioned above, the implant body may also have a tabular outline.

(50) FIG. 11 shows mechanisms of osteoinductive effect of a degradation product release via upregulation of a bone-forming neuro protein CGRP and its release towards the periosteum (bone fibrous membrane) to enhance fracture callus formation and its remodeling.

(51) In this embodiment, the healing assembly 130 is made from magnesium, and thus the degradation product 134 is magnesium ion.

(52) As illustrated in FIG. 11, magnesium ion stimulates sensory neurons to release neuro protein CGRP; CGRP promotes osteogenic differentiation of periosteum-derived stem cells (PDSCs) and the underlying molecular mechanisms of new bone formation. This magnesium ions releasing hybrid system significantly promotes fracture healing at weight bearing site through linking sensory neurons and PDSCs.

(53) FIG. 11 illustrates how the magnesium ions releasing hybrid system promotes new bone formation through linking sensory neurons and PDSCs Four-point bending biomechanical test at week 12 that shows a significantly greater maximum compressive load (30% increase) of the femoral shafts in the hybrid system fixed group than in the conventional IMN group (refer to FIG. 12). The underlying biological mechanisms are related to Mg ions during Mg-implant degradation that diffuse across the bone toward the periosteum that is innervated by sensory neurons in dorsal root ganglion (DRG) and enriched with periosteum-derived stem cells (PDSCs) undergoing osteogenic differentiation into new bone. Then, the released Mg ions enter DRG neurons via Mg transporters or channels (i.e., MAGT1 and TRPM7) and promotes CGRP-vesicles accumulation and exocytosis. The DRG-released CGRP, in turn, activates the CGRP receptor (consisting of CALCRL and RAMP1) in PDSCs, which triggers phosphorylation of CREB1 via cAMP and promotes the expression of genes contributing to osteogenic differentiation.

(54) According to an example of the present disclosure, in the hybrid system, one more feature/function is added to the conventional IM nailing system for achieving fracture healing enhancement effect, including facilitating bone healing, promoting bone formation, and increasing bone mechanical strength, etc. Therefore, in order to achieve this healing enhancement effect, windows are created on the IM nail and designed self-locking Mg plug to incorporate Mg (potentially all biologically safe healing enhancement biodegradable metals) with the IM nail. The concept of the hybrid system design can be also applied to other fracture fixation devices, such as locking and compression plates.

(55) According to this example, Mg-based screws can be successfully applied for fixing bone fractures occurred at non-weight bearing sites in clinics. For example, a Mg-based MgYREZr screw is fabricated for hallux valgus surgery and CE mark approval can be obtained for clinical application, and Mg-5 wt % Ca-1 wt % Zn screw can be used to fix bone fractures at distal radius of the wrists in patients. A highly pure Mg screw (purity, 99.99%) can be applied to fix the vascularized bone graft to treat osteonecrosis of the femoral head. However, it is failed to fix femoral fracture (weight-bearing site) using Mg-based implants, owing to the rapid degradation at the initial phase which leads to impaired strength of the implant. Then, in order to make good use of the beneficial effect of Mg (i.e. enhancing bone formation), but avoid its weakness, a hybrid Mg-containing intramedullary nail is designed and assembled by inserting pure pin made of pure Mg pin into hollow nail with drilled holes (serving as vents for magnesium release). The efficacy of the hybrid intramedullary nail is firstly tested in the fixation of mid-shaft femoral fracture in osteoporotic rats. This hybrid system may significantly enlarge callus formation at early healing stage, whereas facilitating callus remodeling at late healing stage, and attributing to the magnesium-stimulated secretion of CGRP from dorsal root ganglion. The molecular and cellular mechanisms behind the biological effects of magnesium are identified at the first time by the inventors. The enhanced (30% increase vs conventional IMN) biomechanical strength of the healed bone is obtained, which is of defined great clinical importance.

(56) FIG. 12 illustrates the healing process with large fracture callus by using a Mg containing Intramedullary Nail (IM). As shown in FIG. 12, the Mg containing Intramedullary Nail (IM) accelerates healing process with large fracture callus at week 4 post-implantation that enhances bone healing with significantly improved mechanical strength at later stage of healing.

(57) Although the examples of the present disclosure have been described, those skilled in the art may make various modifications or changes to these examples on the basis of the known basic inventive concepts. It is intended that the appended claims are considered to comprise the examples and all modifications or changes that fall within the scope of the present disclosure.

(58) It will be apparent for those skilled in the art to make various modifications or changes to the present disclosure without departing from the spirit or scope of the present disclosure. Therefore, these modifications or changes should also fall within the scope of the present disclosure if they belong to the scope of claims and an equivalent technology.