Wound reduction screws and related methods

Abstract

The invention provides a wound reduction screw and an implantation method thereof. The screw includes a headless screw having a narrow thread at a proximal end and a reduction cap. The cap is adapted to be coupled to the headless screw via the narrow threads after the screw has been inserted into a substrate, such as a patient's bone. The method involves inserting a headless screw into a bone borehole using a headless screwdriver, and coupling a reduction cap to the inserted screw using a reduction screwdriver loaded with the reduction cap. This reverse torque approach enables efficient implantation of the reduction wound screw. These innovations provide potential improvements to patient care, particularly in terms of bone reposition traction and fixation.

Description

[0001] This application claims the benefit of priority to U.S. Provisional Patent Application Serial No. 63 / 385,682, filed on December 1, 2022, the disclosure of which is hereby incorporated by reference in its entirety for all purposes.

[0002] This disclosure relates to reduction trauma screws for bone implants and related methods, e.g., for reduction, traction, and fixation using a bone plate.

[0003] When a fracture occurs, the fracture fragments lose their alignment by displacement or angulation. Thus, the fracture fragments must be realigned to their normal anatomical position for the fracture to heal without any deformity. Orthopedic surgery attempts to re-form the normal anatomical structure of the fracture by reducing the displacement and restoring it to the natural position of the bone.

[0004] Reduction can counteract the forces that cause bone displacement. For example, if a fracture is caused by external foot rotation, reduction will apply a moment to produce internal rotation. This moment counteracts the displacement caused by the external rotation. Closed reduction is the manipulation of these fracture fragments without surgically exposing the fracture fragments. Open reduction is the method of surgically exposing the fracture fragments by dissecting the tissue. In either case, fixation using a bone plate and screws can be internal.

[0005] Risks and complications may include bacterial colonization of the bone, infection, stiffness, limited range of motion, nonunion, malunion, muscle injury, nerve injury and paralysis, arthritis, tendinitis, chronic pain associated with bone plates, screws, and pins, compartment syndrome, deformity, audible pops and clicks, and future surgery for removal of the hardware.

[0006] In addition, regardless of the material used, bone density decreases after implantation of a medical device. This loss can lead to common medical device failures, including screw loosening, screw pullout, and rod fracture. Although many devices facilitate the fusion of interbody cages, no device has been developed for supporting and increasing bone density within the vertebral body. Moreover, the structure of cortical bone within the vertebra is different from that of the bones in other parts of the human body.

[0007] Challenges related to long-term stability, such as bone quality and functional healing ability, remain unresolved. None of the prior arts have addressed the two main causes of implant revision surgery failure: screw pullout and rod fracture before the patient achieves fusion. Summary of the Invention

[0008] This disclosure provides a reduction trauma screw. The screw includes a headless screw having narrow threads at a proximal end and a reduction cap. The cap is adapted to be coupled to the headless screw via the narrow threads after the headless screw has been inserted into a substrate.

[0009] The present disclosure also provides a method of implanting a headless reduction screw. The method includes inserting a headless screw having a headless screwdriver into a drill hole in bone. Then, a reduction cap is coupled to the inserted headless screw via a reduction screwdriver loaded with the reduction cap. The coupling is achieved using the headless screwdriver to apply a reverse torque to the reduction screwdriver.

[0010] Additional embodiments and features are set forth in part in the description below. For those skilled in the art, upon viewing this specification, these embodiments and features will become apparent or may be learned by practicing the embodiments discussed herein. A further understanding of the nature and advantages of certain embodiments may be realized by reference to the remainder of the specification and the drawings that form a part of this disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 A front elevational plan view of the headless screw disclosed herein is shown.

[0012] Figure 2 Shows Figure 1 a side elevational plan view of the headless screw.

[0013] Figure 3 Shows Figure 1 a top plan view of the headless screw.

[0014] Figure 4 Shows Figure 1 a bottom plan view of the headless screw.

[0015] Figure 5 A top perspective view of a spherical reduction cap is shown.

[0016] Figure 6 Shows a cross-sectional view of a headless screw engaged with a spherical reduction cap implanted in bone Figure 5 of Figure 1 .

[0017] Figure 7 A top perspective view of a conical reduction cap with an arcuate taper is shown.

[0018] Figure 8 Shows a cross-sectional view of a headless screw engaged with a conical reduction cap implanted in bone Figure 7 of Figure 1 .

[0019] Figure 9 A top perspective view of a conical reduction cap with a linear taper is shown.

[0020] Figure 10 Shows a cross-sectional view of a headless screw engaged with a conical reduction cap implanted in bone Figure 9 of Figure 1Cross-sectional view of a headless screw.

[0021] Figure 11 Top perspective view showing a conical reset cap with a straight taper and external threads.

[0022] Figure 12 Top perspective view showing a flanged reset cap with external threads.

[0023] Figure 13 Shows the Figure 12 engaged with the Figure 1 flanged reset cap in the implanted bone

[0024] Figure 14 Perspective side view showing an adapter for a reset screwdriver for the castellated reset cap disclosed herein.

[0025] Figure 15 Shows attached to Figure 5 the Figure 14 adapter for the

[0026] Figure 16 Top perspective view showing a multi-axis reset cap.

[0027] Figure 17 Shows Figure 16 side plan view of the

[0028] Figure 18 Shows Figure 16 cross-sectional view of the

[0029] Figure 19 Shows the Figure 16 engaged with the Figure 1 multi-axis reset cap in the implanted bone

[0030] Figure 20 Shows a guide wire inserted into the bone.

[0031] Figure 21 Shows a drill bit sleeved on the Figure 20 guide wire.

[0032] Figure 22 Shows the drilled hole in the bone after removing the drill bit and guide wire from Figure 21 it.

[0033] Figure 23 Shows inserting the Figure 1 headless screw into the drilled hole using a headless screwdriver.

[0034] Figure 24A side plan view of the components of a reset cap screwdriver is shown. The reset cap screwdriver is sleeved on a headless screwdriver to Figure 5 connect the reset cap to Figure 1 a headless screw, which is implanted into a drill hole, as Figure 23 shown.

[0035] Figure 25 A perspective view of the components of Figure 24 is shown.

[0036] Figure 26 A perspective view of a bone with a visible implanted reset cap is shown.

[0037] Figure 27 A cross-sectional view of a headless screw engaging with a spherical reset cap of Figure 5 implanted in a bone is shown. Figure 1

[0038] Figure 28 A top view of a headless screw presenting a folded sheet-like bracket is shown.

[0039] Figure 29 A view of Figure 28 the headless screw from below is shown.

[0040] Figure 30 A view of Figure 28 the headless screw in perspective is shown.

[0041] Figure 31 A view of Figure 28 the headless screw from the back is shown.

[0042] Figure 32 A view of Figure 28 the headless screw from the front is shown.

[0043] Figure 33 A magnified inset of the front view of Figure 28 the headless screw, highlighting the bracket, is shown.

[0044] Figure 34 A top view of a headless screw presenting a folded sheet-like bracket and textured threads is shown.

[0045] Figure 35 A view of Figure 34 the headless screw from below is shown.

[0046] Figure 36 A view of Figure 34 the headless screw in perspective is shown.

[0047] Figure 37 A view of Figure 34 the headless screw from the back is shown. ​

[0048] Figure 38 shows Figure 34 a front view of a headless screw

[0049] Figure 39 shows Figure 34 an enlarged illustration of the front view of a headless screw, highlighting the bracket

[0050] Figure 40 shows a top view of a headless screw presenting a diamond - structured lattice, the lattice including a bone tissue collection feature at the distal tip and textured threads at the proximal end

[0051] Figure 41 shows Figure 40 a bottom view of a headless screw

[0052] Figure 42 shows Figure 40 a perspective view of a headless screw

[0053] Figure 43 shows Figure 40 a rear view of a headless screw

[0054] Figure 44 shows Figure 40 a front view of a headless screw

[0055] Figure 45 shows Figure 40 an enlarged illustration of the front view of a headless screw, highlighting the bracket

[0056] The present disclosure will be readily understood by the following detailed description and the accompanying drawings, in which like reference numerals represent like structural elements. These drawings provide exemplary embodiments or aspects of the present disclosure and do not limit the scope of the present disclosure Detailed Description

[0057] The present disclosure provides a reduction trauma screw. The screw includes a headless screw and a reduction cap, the headless screw having narrow threads at the proximal end. After the headless screw has been inserted into the substrate, the cap is adapted to be coupled to the headless screw via these narrow threads

[0058] In certain embodiments, the substrate is a bone of a patient in need of reduction, traction, fixation, or a combination thereof

[0059] In certain embodiments, the cap is spherical. In certain embodiments, the cap is conical. In certain embodiments, the cap is flanged

[0060] In certain embodiments, the cap includes four flanges radially distributed at 90° intervals

[0061] In some embodiments, the cap further includes a collar configured to engage the substrate multi-axially. In some embodiments, the collar includes ten flanges radially distributed at 36° intervals.

[0062] In some embodiments, the cap has an arcuate taper. In some embodiments, the cap has a linear taper. In some embodiments, the cap includes external threads.

[0063] In some embodiments, the cap is conical with an arcuate taper, conical with a linear taper, conical with a linear taper and external threads, or flanged with external threads.

[0064] In some embodiments, the cap includes at least one crenellation configured to be received by an adapter. In some embodiments, the cap includes four crenellations radially distributed at 90° intervals. In some embodiments, each crenellation includes a pit.

[0065] In some embodiments, the reduction trauma screw includes a scaffold. In some embodiments, the scaffold is characterized by a randomized porosity pattern typical of native trabecular bone, the randomized porosity pattern including one or more structural factors that enhance at least one of: multipotent mesenchymal stem cell (MSC) differentiation, osteoblast growth, extracellular matrix (ECM) deposition, and new bone formation.

[0066] In some embodiments, the scaffold includes a triply periodic minimal surface (TPMS) having a cubic repeat pattern that defines walls within the scaffold. In some embodiments, the TPMS is of the Schwartz Diamond type, which spirally wraps around the central axis of the screw to define a cubic repeat pattern in the X / Y / Z dimensions of the scaffold. In some embodiments, the TPMS spirally wraps into a single helix. In some embodiments, each turn of the helix of the screw has three radial spokes. In some embodiments, the cubic repeat pattern is about 1.8 mm in the X / Y / Z dimensions. In some embodiments, the period of the spiral wrap of the screw is defined as three times the size of the cubic repeat pattern. In some embodiments, the walls are about 0.5 mm thick.

[0067] In certain embodiments, the stent is a collapsible sheet stent. In certain embodiments, the collapsible sheet stent is a shell-like porous pseudo-randomly orientable structure that includes a continuous folded sheet with a topological genus of n, where the real three-dimensional space is partitioned into disjoint sub-volumes. In certain embodiments, these sub-volumes are non-uniform and disjoint. In certain embodiments, the pseudo-random structure is driven by a dimensionless three-dimensional noise field. In certain embodiments, the sheet structure has one or more properties selected from continuous, perforated, functionally graded, semi-regular, and is driven by a modulation algorithm that controls the spatially varying characteristics.

[0068] In certain embodiments, the threads of the screw near the proximal end are textured to have a morphology similar to that of the stent.

[0069] In certain embodiments, the screw reduces the occurrence of one or more of the following: screw loosening, screw withdrawal, rod fracture, and bone density reduction.

[0070] In certain embodiments, the screw concentrates bone growth along the entire shaft to minimize shear stress at the distal tip, and disperses micromotion throughout the screw to promote bone ingrowth.

[0071] In certain embodiments, the screw includes at least one trephine to harvest bone tissue inside the screw.

[0072] The present disclosure also provides a method of implanting a reduction trauma screw. The method includes inserting a headless screw with a headless screwdriver into a drilled hole in bone, and applying a reverse torque to a reduction screwdriver loaded with a reduction cap by using the headless screwdriver to couple the reduction cap to the inserted headless screw via the reduction screwdriver.

[0073] In certain embodiments, when the reduction cap is coupled to the headless screw, a compressive action is applied to the bone without moving the headless screw.

[0074] In certain embodiments, when a collar is present, the collar is adjusted multi-axially before applying the compressive action to the bone.

[0075] In certain embodiments, the method further includes aligning a drill guide, a tissue protector, or both.

[0076] In certain embodiments, the method further includes inserting a guide wire into the bone.

[0077] In certain embodiments, the method further includes drilling a hole with a hollow drill bit inserted around the guide wire.

[0078] In certain embodiments, the method further includes removing the drill bit and the guide wire.

[0079] In some embodiments, the drill bit has a diameter smaller than the screw to be inserted. In some embodiments, the diameter of the drill bit is 3.2 mm.

[0080] In some embodiments, the method is percutaneous.

[0081] Bone

[0082] Bone can generally be classified into cancellous bone and cortical bone. "Cancellous bone", also known as "trabecular bone" or "spongy bone", is a lightweight and porous bone that encloses many large spaces, resulting in a honeycomb or sponge-like appearance. The bone matrix or framework is composed of bony projections called trabeculae, which are arranged along stress lines to form a three-dimensional lattice structure. The spaces between them are usually filled with bone marrow and blood vessels. In cross-section, the trabeculae of cancellous bone may appear like septa. However, their topological structure in three-dimensional space is different, where the trabeculae are roughly rod-shaped or columnar, and the septa are sheet-like.

[0083] Cancellous bone constitutes approximately 20% of the human skeleton and provides structural support and flexibility in the absence of compact bone. It is present in most areas of the skeleton that are not subject to significant mechanical stress. It forms most of the enlarged ends (epiphyses) of long bones and is a major component of the flat bones of the ribs, scapulae, skull, and various short and flat bones in other skeletal regions.

[0084] Due to the increasing frequency of total joint replacement and its impact on bone remodeling, understanding the stress correlation and adaptation processes of trabecular bone has become a core concern for bone physiologists. To understand the role of trabecular bone in age-related bone structure and bone-implant system design, the mechanical properties of trabecular bone have been studied as a function of anatomical location, density, and age. Therefore, mechanical factors, including modulus, uniaxial strength, and fatigue properties, have also been studied.

[0085] High porosity gives cancellous bone flexibility. The large differences in structure result in a high degree of heterogeneity. Modulus and strength are inversely proportional to porosity and are highly dependent on the porous structure. Generally, the porosity percentage of cancellous bone ranges between 75% and 95%. The density is 0.2 g / cm 3 to 0.8 g / cm 3 . Porosity can reduce the strength of bone, but it also reduces its weight.

[0086] Porosity and its structure affect the strength of the material. Therefore, the microstructure of trabecular bone is usually oriented. Where mechanical stiffness and strength are greatest, the "grains" of porosity are aligned. Due to the directionality of the microstructure, the mechanical properties of trabecular bone are highly anisotropic. The Young's modulus of trabecular bone ranges between 800 Mpa and 14,000 Mpa. Its failure strength is 1 MPa to 100 MPa.

[0087] "Cortical bone" or "compact bone" is much denser than cancellous bone. It forms the hard outer layer (cortex) of bone. Cortical bone gives bone a smooth, white, and solid appearance. It accounts for approximately 80% of the total bone mass in adult bones. Cancellous bone is usually surrounded by a shell of cortical bone, which provides greater strength and rigidity. The open structure of cancellous bone enables it to buffer sudden stresses, such as loads transmitted through joints. Different ratios of space to bone are found in different bones, and this ratio varies according to the need for strength or flexibility. Cancellous bone also has a relatively high level of metabolic activity.

[0088] "Wolff's law" states that the bones of a healthy person or animal adapt to the loads they bear. For example, if the load on a particular bone increases, it will become stronger through remodeling to resist that load.

[0089] Bracket

[0090] Porous 3D-printed scaffolds promote bone integration, fusion, and fixation within bone. Open bone with a scaffold is similar to natural bone. This similarity allows physicians to choose to use other medications to promote bone formation and / or stabilize the device according to the specific situation of the patient.

[0091] Triangular porosity sequences have been used in the prior art. Circular, square / rectangular shapes, and irregular patterns are closer to the structure of natural bone. In addition, the structure of the scaffold reduces the likelihood of repair of medical devices made from it, such as screw loosening, screw pullout, rod fracture, and bone density reduction.

[0092] In certain embodiments, a 3D Voronoi surface lattice structure is applied at the small diameter of a screw, which has at least one different lattice size and a randomly shaped pattern and size. The 3D Voronoi surface lattice structure is defined by a Voronoi diagram, which is a plane divided into regions close to each of a given set of objects. In the simplest case, these objects are just a finite number of points in the plane (called seeds, sites, or generators). For each seed, the corresponding region is called a "Voronoi cell" or "Thiessen polygon", which consists of all the points in the plane that are closer to that seed than to any other seed. The Voronoi diagram of a set of points is dual to the Delaunay triangulation of that set.

[0093] In certain embodiments, the small diameter can be constant or variable. In certain embodiments, multiple surface lattice structures are superimposed, where each surface lattice structure provides random pore sizes and different size and / or cross-sectional values for the connecting elements. In certain embodiments, the structures of the multiple surface lattice structures are combined and joined, and then the interfaces between each structure are rounded and / or blended.

[0094] In certain embodiments, the internal lattice structure has a randomized pattern similar to healthy trabecular bone. Such natural lattice structures have been described, for example, in Callens et al., "The local and global geometry of trabecular bone", Acta Biomaterialia 130 (2021): 343 - 361, the entire content of which is incorporated herein by reference.

[0095] In certain embodiments, the average Gaussian curvature distribution of the pores in the scaffold is hyperbolic (K < 0). According to the Gauss - Bonnet theorem, this prevalence of negative Gaussian curvature is consistent with the high topological complexity (i.e., high genus) of trabecular bone. Net curvature captures regions of the trabecular bone surface that are strongly curved, without distinguishing between the saddle - like or spherical nature of these curvatures. In certain embodiments, the pores include arcuate transitions between plate - like elements. In certain embodiments, the high net curvature in the pores is concentrated in cylindrical rod - like elements.

[0096] In certain embodiments, the disclosed scaffolds and devices integrate orthopedic products with regenerative medicine to reduce the risk of delayed bone fusion in implanted devices.

[0097] In certain embodiments, the scaffold comprises one or more structural factors selected from the following: porosity, pore size, particle size, and surface topography. Porosity and pore size cue signals for mechanical strength, cell settlement, and cell migration. Particle size cues signals for protein absorption, cell adhesion, cell proliferation, and cell adhesion. Surface topography cues signals for specific surface area, cell adhesion, and the material - tissue interface. Other scaffold features include pH and wall thickness. In certain embodiments, the one or more structural factors enhance at least one of the following: differentiation of multipotent mesenchymal stem cells (MSCs), osteoblast growth, extracellular matrix (ECM) deposition, and new bone formation. In certain embodiments, new bone formation occurs after MSC differentiation, osteoblast growth, ECM deposition, or a combination thereof.

[0098] In certain embodiments, the scaffold comprises a folded-sheet scaffold. As used herein, a "folded-sheet scaffold" refers to a shell-like porous structure having a pseudo-randomly orientable configuration that is derived from a continuous folded sheet of genus n. This configuration divides three-dimensional space into two distinct, non-overlapping sub-volumes or mazes, which in certain embodiments are non-conforming. The pseudo-random orientation of the structure is influenced by a dimensionless three-dimensional noise field, the characteristics of which (including type, frequency, jitter, and amplitude) are all adjustable. In certain embodiments, the folded-sheet scaffold exhibits a continuous, perforated, or functionally graded sheet-like configuration. In various embodiments, the configuration is semi-regular or determined by a specific modulation algorithm that controls spatially varying features.

[0099] "Dimensionless" refers to a property, quantity, or performance that does not have associated physical or spatial dimensions. It is a purely numerical measure and is independent of any unit of measurement. In the case of a "dimensionless 3D noise field", the term "dimensionless" means that the noise field is defined or characterized by numerical values that do not correspond to specific physical dimensions but are used to affect the performance or properties of the folded-sheet scaffold.

[0100] "Functionally graded" refers to a property of the sheet-like configuration such that the performance of the sheet-like configuration varies gradually with volume due to a continuous change in structure or composition. This gradient can be designed to meet specific requirements of different parts of the scaffold.

[0101] The term "genus n" refers to a topological concept, i.e., the number of "holes" or "handles" in a given surface. In the context of a "continuous folded sheet of genus n", it represents the complexity of the folded-sheet structure, where n represents the number of such features.

[0102] A "maze" refers to a complex network structure formed within a sub-volume divided in three-dimensional space. These mazes are created by the pseudo-random orientation of the folded-sheet scaffold, resulting in intricate paths or channels.

[0103] "Perforated" refers to the presence of a series of holes or openings in the sheet-like configuration of the scaffold. The sizes and arrangements of these perforations vary. They contribute to the porous nature of the scaffold and thus affect its functional performance.

[0104] "Semi-regular" refers to a property of the sheet-like configuration such that there is a degree of regularity or consistency in the structure, but it is not absolutely uniform. In certain embodiments, "semi-regular" refers to a pattern or feature that repeats with some variation.

[0105] "Shell-like" refers to a specific type of porous structure that resembles a shell or a series of shells. This structure is a characteristic of the folded-sheet scaffold and contributes to its overall structure and functional performance.

[0106] "Spatial variation features" refer to the characteristics or properties of a folded sheet-like scaffold that vary or change at different points or regions in space. These features include, but are not limited to, changes in the structure, composition, or functional performance of the scaffold.

[0107] In the context of a "dimensionless 3D noise field", "statistical variation" refers to fluctuations or variations in a noise field that follow a specific statistical distribution. Such variations affect the pseudo-random orientation of the folded sheet-like scaffold.

[0108] "Sub-volumes" refer to separate or distinct parts of three-dimensional space that do not share common points or do not intersect. These sub-volumes are formed by dividing three-dimensional space with a continuous folded sheet of genus n.

[0109] In certain embodiments, the bone screw is 3D printed and tested with a diamond lattice structure. In certain embodiments, the spoon-shaped feature is positioned along a helical pattern, for example, a helical pattern corresponding to an opening into an internal lattice structure.

[0110] The design is based on triply periodic minimal surfaces (TPMS), i.e., minimal surfaces in R3 that are invariant under a translation lattice of rank 3. These surfaces have the symmetries of a crystallographic group. Many examples with cubic, tetragonal, rhombic, and orthorhombic symmetries are known.

[0111] Specifically, the Schwartz diamond type TPMS is used for such a lattice: the lattice is formed according to symmetry parameters, remapped from Cartesian coordinates to spherical polar coordinates about the central axis of the screw axis, sheared to form a helical winding, thickened, subtracted, and intersected with the 3D geometric space of the scaffold.

[0112] Surfaces are generated using symmetry parameters: given a solution to the Plateau problem for a polygon, reflections of the surface across boundary lines also produce valid minimal surfaces that can be continuously connected to the original solution. If a minimal surface intersects a plane at a right angle, the mirror image in the plane can also be connected to the surface. Thus, periodic surfaces can be constructed by given a suitable initial polygon inscribed in a unit cell.

[0113] Equation 1 approximately calculates the TPMS of these bone screws:

[0114] cos(x)cos(y)cos(z) - sin(x)sin(y)sin(z) = 0 (1)

[0115] This is the specific basic equation for this embodiment of the bone screw. The x, y, and z variables define the periodicity (i.e., the pattern) in X / Y / Z, similar to the way a cubic lattice is defined. This surface is called a "diamond-type" because it has two intertwined congruent labyrinths, each having the shape of a tubular inflated deformant with a diamond bond structure. For ease of discussion, it has been assumed herein that the unit cells are arranged in a regular repeating pattern, although the geometry of the TPMS is pseudo-random due to topological influences. Based on the Weierstrass-Ennepar parameterization, there are exact expressions for elliptic integrals.

[0116] As an equation, it defines the Schwartz diamond-type surface passing through infinite real space. Such a surface divides real space into two identical sub-spaces - the positive space enters the negative space, defining the isosurface or the intermediate surface. By taking 2D slices of the Schwartz diamond mathematical field, the "positive" and "negative" spaces are shown. In some embodiments, the cubic repeating pattern is 1.8 mm in X / Y / Z.

[0117] After creating the Schwartz equation, it is remapped (i.e., twisted) helically to form the base of the final shape. For this, the equation is mapped from Cartesian space to polar space using conventional methods. The periodicity is mapped as cylindrical. That is, the number of "spokes" remains radially a multiple of the selected unit size. This remapping is about the central axis of the screw shaft.

[0118] After remapping, the space is sheared to form a helical wrap, in a principle similar to wrapping an inclined plane around a cylinder to form a screw. To form the shear, the Schwartz diamond equation is remapped according to the X / Y / Z coordinate space - by applying a shear transformation to one (or more) coordinates: let x → x, let y → y, and let z → z + x, where the Schwartz diamond is sheared in the XZ plane. This shear operation maintains the continuity of the field.

[0119] After shearing the field and remapping it as a cylinder, the field is thickened using an absolute value operation - this operation converts the negative space of the equation to positive space in three dimensions. The period of the helical wrap of the medical device is defined as three times the size of the cubic repeating pattern (5.4 mm), thus forming a single helix with a circumferential count of three having three radial spokes. Subsequently, the central geometry is offset by a mathematical subtraction operation, thus forming a sheet-like structure. In some embodiments, the wall is approximately 0.50 mm thick. Once the thin-walled lattice field intersects the 3D geometric structure space defining the location of the lattice, a scaffold model is generated. See, for example Figure 45 .

[0120] Screw

[0121] The present disclosure provides a reduction trauma screw, which includes a headless screw and a reduction cap.

[0122] Screws are the basic elements for achieving compression between fracture fragments. They can be used as lag screws either individually or through a bone plate to bring two fracture fragments together under compression. Screws are also used to fix the bone plate to the bone. Screw sizes are named according to the outer diameter of their threaded part. Cortical screws are sized for hard cortical bone, such as in the diaphysis of long bones. Generally, cortical screws are not self-cutting and must have their threads cut before insertion. Cancellous bone screws are suitable for the metaphyseal and epiphyseal regions where the bone is softer, spongy, and has a thinner cortex.

[0123] Figure 1 A front elevation plan view of the headless screw 200 disclosed herein is shown. The screw 200 includes a thread 230 and a narrow thread 290, which are arranged to extend around a core 240 between a proximal end 210 and a distal tip 220. The narrow thread is arranged on a shaft 295 to be adapted to receive the reduction cap 500 at the proximal end 210. The core 240 includes a bracket 280 exposed on the outer surface of the screw 200. The thread 230 includes an external thread form having a leading edge 231 and a trailing edge 232. The leading edge has a front surface 235, and the trailing edge has a rear surface 236. The front surface 235 defines a first opening 251. The rear surface 236 defines a second opening 252. The first opening 251 and the second opening 252 are axially aligned. The screw 200 has a core 240 filled with the bracket 280, which extends from the proximal end 210 through the center of the screw 200 to the distal tip 220. The core 240 is the shank of the screw 200, from which the thread 230 projects. The distal tip 220 includes at least one cutting member 270, each cutting member having a cutting edge. The reduction cap 500 should not be confused with a nut used in emergency situations, which is only used when the threads of the screw hole are stripped. Figure 2 Shown is Figure 1 a side elevation plan view of the headless screw 200. Figure 3 Shown is Figure 1 a top plan view of the headless screw 200, which includes a transmission 215 and a cannula 260. Figure 4 Shown is Figure 1 a bottom plan view of the headless screw 200, which includes a cutting member 270.

[0124] Figure 5A top perspective view of a spherical reduction cap 500 is shown, which can be used as a trauma screw for compressing bone or as a compression screw in a bone plate. The cap 500 includes a cap body 540 having cap threads 530 that are helically disposed between a cap top 510 and a cap bottom 520 around an outer surface of the cap body 540. The body 540 of the cap 500 includes at least one crenelated portion 550, such as four crenelated portions 550 radially distributed at 90° intervals. The crenelated portions 550 allow the cap 500 to be driven onto a screw 200 that has already been implanted. Each crenelated portion 550 may include a pit 555.

[0125] Figure 6 shows the Figure 5 spherical reduction cap 500 engaged with the Figure 1 headless screw 200 in the implanted bone 300. The screw 200 traverses the cortical bone 320 between the periosteum 310 and the endosteum 330 and enters the cancellous bone 350. The cap 500 compresses the screw 200 by pressing on the cortical bone 320.

[0126] Figure 7 A top perspective view of a conical reduction cap 500 with an arcuate taper is shown, which can be used as a trauma screw to compress bone.

[0127] Figure 8 shows the Figure 7 conical reduction cap 500 engaged with the Figure 1 headless screw 200 in the implanted bone 300.

[0128] Figure 9 A top perspective view of a conical reduction cap 500 with a linear taper is shown, which can be used as a trauma screw to compress bone.

[0129] Figure 10 shows the Figure 9 conical reduction cap 500 engaged with the Figure 1 headless screw 200 in the implanted bone 300.

[0130] Figure 11 A top perspective view of a conical reduction cap 500 with a linear taper and external threads 535 is shown, which can be used as a locking screw in a bone plate.

[0131] Figure 12 A top perspective view of a flanged 560 reduction cap 500 having external threads 535 is shown, which is used as a trauma screw for compressing bone or as a compression screw in a bone plate. In this way, bone stripping can be minimized because the reduction cap produces a compression effect rather than advancing the screw.

[0132] Figure 13 shows theFigure 12 engaged with the flanged reset cap 500 Figure 1 Cross-sectional view of the headless screw 200

[0133] Figure 14 Perspective side view of the adapter 400 of the reset cap driver 900 for the castellated 550 reset cap 500 disclosed herein Figure 15 Shown coupled to Figure 5 the spherical reset cap 500 Figure 14 the adapter 400. The adapter includes an opening 440 and a plurality of protrusions 450, the opening being configured to receive the body 540 of the cap 500, and the plurality of protrusions engaging each of the plurality of castellations 550 on the cap 500. The protrusions 450 engage the castellations 550 until the cap 500 is installed onto the screw 200

[0134] Figure 16 Top perspective view of the multi-axis reset cap 500, which includes a cap body 540 and a collar 570 having a collar top 571 and a collar bottom 572. The cap body 540 includes internal threads 530 and a flange 560 radially distributed around the cap top 510. The collar 570 includes a collar flange 576 radially distributed around the collar bottom 572. The collar 570 is configured to engage the substrate multi-axially

[0135] As used herein, "multi-axis" refers to the characteristic or performance of an object or system that allows rotation or movement along multiple axes. In certain embodiments, a multi-axis system or component can be oriented or adjusted in various directions and is not limited to a single plane of rotation. For example, a multi-axis screw in a surgical application can be adjusted to align with different anatomical structures, or a multi-axis joint in a mechanical system can allow multi-directional movement

[0136] Figure 17 Shown is Figure 16 side plan view of the multi-axis reset cap 500. In this perspective view, one can see the external threads 535 on the cap body 540 near the cap bottom 520

[0137] Figure 18 Shown is Figure 16 cross-sectional view of the multi-axis reset cap 500, highlighting the internal threads 530 on the cap body 540 around the collar 570

[0138] Figure 19 Shown is Figure 1 cross-sectional view of the headless screw 200, which is engaged with and implanted into the bone 300 with the multi-axis reset cap 500 Figure 16 including a cap body 540 and a collar 570

[0139] Figure 20 A guide wire 600 inserted into the bone 300 is shown. For clarity, the tissue protector is not shown.

[0140] Figure 21 A drill bit 700 sleeved on the Figure 20 guide wire 600 is shown. For clarity, the tissue protector is not shown.

[0141] Figure 22 A drilled hole 360 in the bone 300 after removing the drill bit 700 and the guide wire 600 from the Figure 21 is shown.

[0142] Figure 23 Inserting the Figure 1 headless screw 200 into the drilled hole 360 using a screwdriver 800 is shown.

[0143] Figure 24 A side plan view of the assembly of the reset cap screwdriver 900 is shown. The reset cap screwdriver is sleeved on the headless screwdriver 800 to couple the Figure 5 reset cap 500 to the Figure 1 headless screw 200, which is implanted in the drilled hole 360, as Figure 23 shown. The adapter 400 holds the cap 500 for insertion.

[0144] Figure 25 A perspective view of the Figure 24 assembly is shown. The headless screwdriver 800 applies a reverse torque to the reset cap screwdriver 900, such that a compressive effect is achieved between the reset cap 500 and the bone 300 without further rotating or driving the headless screw 200 into the bone 300 when the reset cap screwdriver 900 tightens the cap 500.

[0145] Figure 26 A perspective view of the bone 300 with the implanted reset cap 500 visible is shown.

[0146] Figure 27 A cross-sectional view of the Figure 5 headless screw 200 engaged with the Figure 1 spherical reset cap 500 implanted in the bone 300 is shown.

[0147] Figure 28 A top plan view of the headless screw 200 presenting the folded sheet-like stent 280 is shown. The transmission 215 and the cannula 260 can be seen from this view. Figure 29 A bottom plan view of the Figure 28 headless screw 200 including two cutting members 270 is shown. Figure 30 A perspective view of the Figure 28 headless screw 200 is shown. Figure 31shows a rear plan view of the headless screw, and Figure 32 shows a front plan view of the headless screw. Figure 33 shows Figure 28 an enlarged illustration of a front view of the headless screw 200 of

[0148] In this embodiment, the screw 200 includes threads 230 and narrow threads 290. The threads are arranged to extend around a core 240 between a proximal end 210 and a distal tip 220. The narrow threads are arranged on a shaft 295 to be adapted to receive a reset cap 500 at the proximal end 210. The core 240 includes a bracket 280 exposed on the outer surface of the screw 200. The threads 230 include an external thread form having a leading edge 231 and a trailing edge 232. The leading edge has a front surface 235, and the trailing edge has a rear surface 236. The front surface 235 defines a first opening 251. The rear surface 236 defines a second opening 252. The first opening 251 and the second opening 252 are axially aligned.

[0149] The screw 200 has a core 240 filled with a bracket 280. The bracket extends from the proximal end 210 through the center of the screw 200 to the distal tip 220. The core 240 is the shank of the screw 200, and the threads 230 project from the shank. The distal tip 220 includes two cutting members 270 disposed on opposite sides of the distal tip 220, and each cutting member 270 has a cutting edge 271.

[0150] Figure 34 shows a top plan view of the headless screw 200 presenting the folded sheet-like bracket 280. The transmission 215 and the cannula 260 can be seen from this view. Figure 35 shows Figure 34 a bottom plan view of the headless screw 200 of Figure 36 shows Figure 34 the headless screw 200 of Figure 37 shows a rear plan view of the headless screw, and Figure 38 shows a front plan view of the headless screw. Figure 39 shows Figure 34 an enlarged illustration of a front view of the headless screw 200 of

[0151] In this embodiment, the screw 200 includes threads 230 and narrow threads 290. The threads are arranged to extend around the core 240 between the proximal end 210 and the distal tip 220. The narrow threads are provided on the shaft 295 to be adapted to receive the reset cap 500 at the proximal end 210. The core 240 includes a stent 280 exposed on the outer surface of the screw 200. The threads 230 are in the form of external threads, which have a leading edge 231 and a trailing edge 232. The leading edge has a front surface 235, and the trailing edge has a rear surface 236. The front surface 235 defines a first opening 251. The rear surface 236 defines a second opening 252. The first opening 251 and the second opening 252 are axially aligned. The threads 230 near the proximal end 210 are textured 237 to have a surface topography substantially the same as that of the surface of the stent 280.

[0152] The screw 200 has a core 240 filled with a stent 280, and the stent extends from the proximal end 210 through the center of the screw 200 to the distal tip 220. The core 240 is the shaft of the screw 200, and the threads 230 project from the shaft. The distal tip 220 includes two cutting members 270 disposed on opposite sides of the distal tip 220, and each cutting member 270 has a cutting edge 271.

[0153] Figure 40 A top plan view of the headless screw 200 presenting the diamond stent 280 is shown. The transmission 215 and the cannula 260 can be seen from this view. Figure 41 Shown is Figure 40 a bottom plan view of the headless screw 200, which includes two cutting members 270. Figure 42 Shown is Figure 40 a perspective view of the headless screw 200 Figure 43 a rear plan view of the headless screw is shown, and Figure 44 a front plan view of the headless screw is shown. Figure 45 Shown is Figure 40 an enlarged inset of the front view of the headless screw 200, highlighting the diamond stent 280 as described herein.

[0154] In this embodiment, the screw 200 includes threads 230 and narrow threads 290. The threads are arranged to extend around the core 240 between the proximal end 210 and the distal tip 220. The narrow threads are arranged on the shaft 295 to be adapted to receive the reset cap 500 at the proximal end 210. The core 240 includes a bracket 280 exposed on the outer surface of the screw 200. The threads 230 include an external thread form having a leading edge 231 and a trailing edge 232. The leading edge has a front surface 235, and the trailing edge has a rear surface 236. The front surface 235 defines a first opening 251. The rear surface 236 defines a second opening 252. The first opening 251 and the second opening 252 are axially aligned. The threads 230 near the proximal end 210 are textured 237 to have a surface topography substantially the same as that of the surface of the bracket 280.

[0155] The screw 200 has a core 240 filled with a bracket 280, and the bracket extends from the proximal end 210 through the center of the screw 200 to the distal tip 220. The core 240 is the shaft of the screw 200, and the threads 230 project from the shaft. The distal tip 220 includes two cutting members 270 arranged on opposite sides of the distal tip 220, and each cutting member 270 has a cutting edge 271.

[0156] When present, the holes in the bracket 280 facilitate the in-growth of bone along the screw.

[0157] In certain embodiments, the built-in channel in the screw captures autograft during insertion.

[0158] In certain embodiments, the screw is hollow. In certain embodiments, the screw is non-hollow. When a fracture in the metaphysis or epiphysis has been reduced and temporarily fixed with a Kirschner wire, the Kirschner wire can be used as a guide wire to implant the hollow screw into the site.

[0159] The length and diameter of the screw are selected according to the required application. In certain embodiments, the length ranges between 8 mm and 200 mm, such as between 34 mm and 60 mm, for example 34 mm, 36 mm, 38 mm, 40 mm, 42 mm, 44 mm, 46 mm, 48 mm, 50 mm, 52 mm, 54 mm, 56 mm, 58 mm or 60 mm. In certain embodiments, the length is greater than 8 mm. In certain embodiments, the length is less than 200 mm.

[0160] The diameter of the screw can be defined according to the following parameters: the thread diameter, the drill bit diameter of the sliding hole or threaded hole, or the tap diameter. In certain embodiments, the diameter ranges between 4 mm and 6.5 mm, such as 4.0 mm, 4.5 mm, 5.0 mm, 5.5 mm, 6.0 mm, and 6.5 mm. In certain embodiments, the thread diameter ranges between 1.0 mm and 7.3 mm, such as 1.0 mm, 1.3 mm, 1.5 mm, 2.0 mm, 2.4 mm, 2.7 mm, 3.0 mm, 3.5 mm, 4.0 mm, 4.5 mm, 6.5 mm, 7.0 mm, 7.1 mm, and 7.3 mm. In certain embodiments, the diameter is greater than 1 mm. In certain embodiments, the diameter is less than 7.3 mm.

[0161] In certain embodiments, the screw is self-tapping. In certain embodiments, the screw is non-self-tapping. In certain embodiments, the screw is self-drilling.

[0162] The design of the threads affects the holding power of the screw. Since the strength of bone is about 1 / 10 of the strength of a metal screw, in certain embodiments, the threads have an asymmetric support profile. To fix the screw, the threads should engage the entire distal cortex of the bone. The tip of the screw and one or two threads should protrude on the opposite side of the bone.

[0163] In certain embodiments, the thread length of the screw is short. In certain embodiments, the thread length is long. In certain embodiments, the thread length is partial. In certain embodiments, the thread length is complete. In certain embodiments, the thread length is a specified length, such as 16 mm or 32 mm.

[0164] The types of drives for the screw and the cap can be of different shapes and sizes, depending on the size of the screw and its application. In certain embodiments, the drive type is cross-shaped, hexagonal, star-shaped, or Torx (lobular). A common example of the cross-shaped drive type is the Phillips screw. "Torx" is a trademark for a type of screw drive characterized by a 6-point star pattern. According to the ISO 10664 standard of the International Organization for Standardization, the official common name for Torx is internal hexagon lobular.

[0165] When using a star-shaped or Torx (lobular) drive type, different numbers of points can be used, such as 5-point, 6-point, 7-point, 8-point, 10-point, or 12-point star-shaped or Torx screw drives. The Torx head sizes are described using a capital letter "T" followed by a number in the range from T1 to T100. The smaller the number, the smaller the point-to-point size of the screw head (the diameter of the circle circumscribing the cross-section of the tip of the screwdriver). The "external" variant of the Torx head size is described using a capital letter "E" followed by a number in the range from E4 to E44. See the details in Table 1.

[0166] Table 1 - Performance of Various Torx Drives

[0167]

[0168] In certain embodiments, the drive type is selected from a 1.0 mm cross, a 1.3 mm cross, a 1.5 mm cross, a 2.0 mm cross, a 2.4 mm cross, a 3.0 mm cross, a 2.5 mm hexagon, a 3.5 mm hexagon, a 4.0 mm hexagon, T8, T15, and T25.

[0169] The built-in channels for autograft collection enhance the structural integrity of the implant. These drives resist bone density loss excellently and reduce micromotion. The randomized porosity pattern of the stent 280 is characteristic of natural trabecular bone. In addition, the built-in struts provide structural integrity.

[0170] In certain embodiments, the screws and caps are made of cobalt-chromium alloy, titanium, and magnesium-added titanium. In certain embodiments, the screws and caps comprise Ti-6A1-7Nb, Ti6A14V-ELI (Grade 5 titanium alloy) according to ASTM F136, 316L stainless steel according to ASTM F138, 316LVM stainless steel according to ASTM F138, Mg-PSZ according to ASTM F2393-12, or Mg-Ti containing 5 wt% to 35 wt% Mg. The 316L stainless steel protrusions typically contain 62.5% iron, 17.6% chromium, 14.5% nickel, 2.8% molybdenum, and minor alloy additions. A low carbon content is specified to ensure that the material is not affected by intergranular corrosion. Titanium alloys have improved biocompatibility, functional properties, excellent corrosion resistance, and do not trigger allergic reactions. Other materials for manufacturing the screws include pre-filled demineralized bone matrix (DBM), pre-filled synthetic DBM, and unfilled DBM.

[0171] In certain embodiments, the inner core of the screw is a trephine to collect and harvest autograft during and / or upon insertion of the screw.

[0172] In certain embodiments, the post-implant option avoids revision surgery by injecting a polymer along the screw.

[0173] In certain embodiments, the screws do not exhibit screw loosening, screw withdrawal, rod fracture, or bone density reduction.

[0174] In certain embodiments, the screw includes a shaft that is thicker than the core, thereby strengthening the point where rod fracture most commonly occurs during screw installation.

[0175] In certain embodiments, the screw reduces the occurrence of one or more of the following: screw loosening, screw pullout, rod fracture, and bone density reduction.

[0176] The disclosed screw focuses bone growth throughout the core to minimize shear stress at the distal tip and evenly distributes micromotion throughout the screw to promote ingrowth of bone.

[0177] In certain embodiments, the screw's scaffold provides options for patients with simple to complex bone density and immunocompromised conditions. In certain embodiments, the scaffold is impregnated with one or more biologic agents, antibiotics, demineralized bone matrix, nanotechnology materials, or materials for regenerative medicine therapies.

[0178] In certain embodiments, the screw 200 is configured to assist bone ingrowth along the screw 200 by using a scaffold 280 that mimics natural trabecular bone. In combination with the threads 230 and the scaffold 280, the core 240 aids in autograft harvesting during insertion to push the autograft into a built-in channel within the core 240 of the screw 200. The wall around the hole harvests the autograft and acts as a trephine. This structure also contributes to the structural integrity of the screw 200, resists bone density loss, and reduces micromotion.

[0179] The screw 200 disclosed herein overcomes many of the failures of prior art screws. In certain embodiments, the screw does not have a windshield wiper effect. In certain embodiments, the screw resists pullout. In certain embodiments, the screw does not exhibit excessive micromotion. In certain embodiments, the screw has a lower frequency of low-virulence microorganisms detected after ultrasonic treatment, for example due to single-screw sterilization and packaging. In certain embodiments, the head and shaft of the screw resist failure. In certain embodiments, the screw is suitable for each type of bone quality. In certain embodiments, the screw has sufficient thread depth. In certain embodiments, the screw withstands insertion torque, particularly at the junction of the head and the screw. In certain embodiments, the fatigue life of the screw is not reduced when the screw is fully inserted. In certain embodiments, the screw has good maneuverability. In certain embodiments, the screw has an angle adjustment function to achieve rod adaptation. In certain embodiments, the screw does not generate cyclic loading based on physiological conditions during walking. In certain embodiments, the screw demonstrates stability in long-segment posterior cervical fusion and does not require an accompanying C6 or T1 supportive pedicle. In certain embodiments, the screw distributes stress. In certain embodiments, the screw does not immunocompromise the patient. In certain embodiments, the screw does not include PEEK. In certain embodiments, the screw does not have a tulip-shaped structure or locking cap stress.

[0180] In some embodiments, the distal tip 220 of the screw 200 has a surface configuration selected from the following: angled, irregular, uniform, non-uniform, offset, staggered, tapered, arcuate, wavy, reticulated, porous, semi-porous, indented, pointed, textured, or a combination thereof. In some embodiments, the distal tip 220 includes a nail configuration, barbs, expansion elements, elevation elements, ribs, and / or spikes to provide a manufacturing platform on which a portion can be formed via additive manufacturing. In some embodiments, the distal tip 220 has a cross-sectional configuration selected from the following: oval, elliptical, rectangular, triangular, square, polygonal, irregular, uniform, non-uniform, offset, staggered, tapered, or a combination thereof.

[0181] In some embodiments, the front surface 235 and / or the rear surface 236 include at least one tissue collection member. In some embodiments, the tissue collection member includes a cutting edge. In some embodiments, the cutting edge is configured to be file-like. In some embodiments, the cutting edge is configured to engage tissue, e.g., for cutting, shaving, shearing, incising, or disrupting tissue. In some embodiments, the cutting edge is configured to be cylindrical, oval, elliptical, rectangular, triangular, polygonal, having planar or arcuate side portions, irregular, uniform, non-uniform, consistent, variable, horseshoe-shaped, U-shaped, or kidney bean-shaped. In some embodiments, the cutting edge is rough, textured, porous, semi-porous, indented, knurled, serrated, grooved, or polished for engaging and cutting tissue. In some embodiments, the cutting edge forms a channel that is configured to direct, drive, or guide the cut tissue into a void, such as fusing the screw with the tissue.

[0182] For example, the screw 200 is manipulated, such as by rotation or translation, such that the cutting edge 271 of the screw cuts tissue or bone and directs the tissue or bone into the core 240, thereby promoting bone growth and fusing with the screw 200. In some embodiments, the tissue is embedded in the core 240 to promote bone growth and fuse with the screw 200. In some embodiments, a lattice is disposed within the core 240 to form a scaffold 280 for bone growth.

[0183] In some embodiments, the threads 230 are configured to be fine, closely spaced, or superficial to engage tissue. In some embodiments, the threads 230 include an increased pitch and an equal lead between thread turns. In some embodiments, the threads 230 include a smaller pitch or more thread turns per axial distance to fix more firmly to tissue or resist tissue loosening. In some embodiments, the threads 230 are configured to be continuous along a portion. In some embodiments, the threads 230 are configured to be discontinuous, staggered, or interrupted. In certain embodiments, the threads 230 include a single thread turn. In certain embodiments, the threads include multiple discrete threads.

[0184] In some embodiments, the threads 230 include penetrating elements such as selected from a nail configuration, barbs, expansion elements, elevation elements, ribs, or spikes. In some embodiments, the threads 230 are configured to be self-tapping or discontinuous at the distal tip 220. In some embodiments, the distal tip 220 is rounded. In some embodiments, the distal tip 220 is self-drilling. In some embodiments, the distal tip 220 includes a solid outer surface.

[0185] In certain embodiments, the screw is a 3D printed porous screw. Its porosity mimics natural bone to attach stem cells, growth factors, and other proteins and hold them within the screw structure, and promotes bone growth along the screw, thus stabilizing the entire construct. During insertion into bone, the built-in trephine collects autograft and regenerative cells within the porous matrix. The disclosed topography attracts osteogenic stem cells inside and around the device, thus reducing the macroscopic movement of the entire construct. In certain embodiments, the device enables the surgeon to meet the specific needs of the patient, such as but not limited to, spraying / injecting regenerative products to stimulate the osteogenic cascade, actively injecting antibiotics into the screw scaffold to prevent infections susceptible to diabetic patients, and optionally injecting bone cement to further stabilize the construct in severely osteoporotic bone.

[0186] In certain embodiments, the screw reduces the repair rate, improves bone density, and / or addresses the specific needs of the patient during spinal fusion. In certain embodiments, the bone density is improved, the construct becomes stable, and the likelihood of performing a repair is reduced.

[0187] In certain embodiments, the screw is a 3D printed titanium porous screw that has a porous pattern similar to natural bone throughout the screw. Without wishing to be bound by theory, the function of the porous pattern is to attach to the surrounding bone, hold osteoprogenitor cells in place, and collect autograft bone within its porous structure. The advantage of the porous structure is the ability to inject polymers and regenerative therapy products along the screw. In certain embodiments, a stem cell therapy product is injected along the screw implant. In such embodiments, the likelihood of failure is reduced.

[0188] In certain embodiments, the surgeon may inject or spray the screw with autologous concentrated stem cells. Without wishing to be bound by theory, as the screw rotates during insertion into the bone, the holes in the screw use their built-in trephine to collect an autograft / stem cell mixture internally. The osteoprogenitor cells then combine with the concentrated blood stem cells and signal the mutation and replication process to form more osteoblasts within the screw, which then direct the bone healing cascade inside and around the screw. In these embodiments, the combination of the following properties of the stem cells improves bone density and supports excellent bone integration and pullout strength: (a) osteoconductivity (bone growth on its surface), (b) osteoinductivity (recruiting cells to promote bone healing), and (c) osteogenic (bone development and formation) healing cascade.

[0189] In certain embodiments, the patient is a diabetic and is susceptible to infection. In these embodiments, the surgeon may inject a mixture containing a calcium sulfate product and an antibiotic along the screw before or after insertion or on the screw within the pedicle to provide antibiotic delivery in the area. In certain embodiments, the antibiotic is delivered for two to six weeks. Accordingly, the likelihood of a revision due to infection is reduced.

[0190] The present disclosure provides a device formed from the scaffolds disclosed herein. In certain embodiments, the device with the scaffold is hollow and open-pored. In certain embodiments, the device includes a threaded distal region, an optionally threaded central region, and an optionally threaded proximal region, depending on the compression force.

[0191] In some embodiments, the screw is configured to have features that promote bone growth along the screw structure from opposite sides, thereby allowing bone to connect along the screw. In some embodiments, the structure is narrow, such as along the threads, thereby allowing rapid through-growth. In some embodiments, the structure is deeper, such as along a small diameter, thereby achieving a stronger bond. In some embodiments, the feature is a void in the screw, or is porous, or is configured to promote bone growth. In some embodiments, the structure collects autograft within a channel inside the device. In some embodiments, the feature is impregnated with one or more polymers.

[0192] In some embodiments, the device is configured to enhance the stability and fixation of bone screws within bone and to improve bone density. In some embodiments, the device includes a spinal implant configured to engage cortical and cancellous bone. In some embodiments, the device is configured to resist and / or prevent wobbling of the bone screw when the bone screw engages dense cortical bone and less dense cancellous bone generated by the load on the bone screw. In some embodiments, the device is configured to resist and / or prevent loosening of the bone screw from the cortical bone and, in some cases, to prevent its pullout from the bone. In some embodiments, the device is configured to promote bone ingrowth to improve the attachment of bone to the bone screw. In some embodiments, the bone screw is anchored in the bone, thereby reducing the risk of pullout. In some embodiments, the bone screw is designed to distribute micromotion and reduce shear, thereby enhancing bone density.

[0193] In some embodiments, the device includes a bone screw having bone growing therethrough along the screw core, thereby reducing screw wobbling and potential failure. In some embodiments, the bone screw includes features that allow bone to grow along the bone screw structure from opposite sides, thereby allowing bone to connect along these bone screw structures. In some embodiments, the bone screw includes features that may be narrow, such as along the threads of the bone screw, which will allow rapid ingrowth. In some embodiments, the bone screw includes features that may be deeper, such as along a small diameter, which will provide a greater volume of bone ingrowth. In some embodiments, the bone screw includes features that may be voids or cavities along opposite sides of the bone screw and / or voids or cavities entering and leaving the same or adjacent surfaces. In some embodiments, the void or cavity may include a scaffold for bone attachment or a porous structure on the void surface.

[0194] In some embodiments, the bone screw includes features or structures that may be disposed along the core of the bone screw. In some embodiments, the bone screw includes features or structures that may be disposed continuously along the surface of the bone screw (e.g., along the distal end). In some embodiments, the bone screw includes features or structures that may be disposed discontinuously along a portion of the bone screw. In some embodiments, the bone screw includes features or structures that may include a scaffold or polymer.

[0195] In some embodiments, the device includes a spinal implant having a hybrid configuration that combines one manufacturing method (such as one or more prior manufacturing features and materials) and another manufacturing method, such as one or more additive manufacturing features and materials. In some embodiments, additive manufacturing includes 3D printing. In some embodiments, additive manufacturing includes fused deposition modeling, selective laser sintering, direct metal laser sintering, selective laser melting, electron beam melting, laminated object manufacturing, and stereolithography. In some embodiments, additive manufacturing includes one or more selected from the following: rapid prototyping manufacturing, desktop manufacturing, direct manufacturing, digital manufacturing, instant manufacturing, and on-demand manufacturing. In some embodiments, the device includes a spinal implant manufactured, grown, or otherwise printed by a fully additive process.

[0196] In certain embodiments, the device includes one or more selected from the following: demineralized bone matrix (DBM), pre-filled DBM, pre-filled synthetic DBM, unfilled DBM, and magnesium-added titanium.

[0197] In some embodiments, the device includes a spinal implant, such as a bone screw manufactured by combining traditional manufacturing methods and additive manufacturing methods. In some embodiments, the bone screw is manufactured by applying additive manufacturing materials where the bone screw can benefit from the materials and properties of additive manufacturing. In some embodiments, traditional materials are used where the benefits of traditional materials (such as physical properties and cost) are superior to the benefits provided by additive manufacturing features and materials.

[0198] In some embodiments, the device treats spinal conditions selected from the following: intervertebral disc degenerative disease, disc herniation, osteoporosis, spondylolisthesis, stenosis, scoliosis, other spinal curvature abnormalities, kyphosis, tumors, and fractures.

[0199] ″Treating″ a disease or condition means performing a protocol that may include administering one or more drugs to a patient, using an implantable device, and / or using an instrument for treating the disease (such as removing a bulging or herniated disc portion and / or bone spur using minimally invasive discectomy instruments) to relieve the signs or symptoms of the disease or condition. Treatment does not require complete relief of signs or symptoms, nor does it require a cure, and specifically includes protocols that have a marginal effect on the patient. For example, treatment may include suppressing the disease, such as preventing its progression, or alleviating the disease, such as causing regression.

[0200] ″Preventing″ means obtaining relief before the signs or symptoms of a disease or condition appear. Thus, prevention includes preventing a disease from occurring in a patient who may be susceptible to the disease but has not been diagnosed as having the disease.

[0201] "Tissue" includes soft tissue, ligaments, tendons, cartilage, and / or bone. In certain embodiments, the tissue is cancellous bone, cortical bone, or cortico-cancellous bone.

[0202] In some embodiments, the device is used in conjunction with other bone and bone-related applications, including diagnostics and therapeutics. In some embodiments, the device is alternatively used for surgical treatment of patients in the prone or supine position and / or for various surgical approaches to the spine, including anterior, posterior, posterior midline, lateral, posterolateral, and / or anterolateral approaches, and for treatment of other body regions such as the maxillofacial and extremities. The device may also alternatively be used for surgeries in the lumbar, cervical, thoracic, sacral, and pelvic regions of the spine. The device may also be used on animals, bone models, and other non-living substrates, e.g., for training, testing, and demonstration.

[0203] In certain embodiments, the device is a custom medical device. In certain embodiments, the device is suitable for sports medicine.

[0204] In certain embodiments, the device has a temperature sensing function. In certain embodiments, the device has a pH balancing function.

[0205] In certain embodiments, a porogen is used to make the device porous, and the porogen is spherical, cubic, rectangular, elongated, tubular, fibrous, disk-shaped, sheet-shaped, polygonal, or a mixture of their shapes. In some embodiments, the porosity is based on a plurality of macropores, micropores, nanopore structures, and / or combinations thereof.

[0206] In certain embodiments, the device is made of biocompatible materials suitable for medical applications, including metals, synthetic polymers, ceramics, bone materials, and composites thereof. In certain embodiments, the device comprises one or more selected from the following: metals, ceramics, rubber, hydrogels, rigid polymers, fabrics, bone materials, and composites thereof.

[0207] In certain embodiments, the device comprises metals selected from the following: stainless steel alloys, aluminum, commercially pure titanium, titanium alloys, grade 5 titanium, superelastic titanium alloys, magnesium-added titanium, cobalt-chromium alloys, superelastic metal alloys such as nitinol, superelastoplastic metals such as Gum In certain embodiments, the device comprises ceramics and their composites, such as calcium phosphate (e.g., Skelite TM)。In certain embodiments, the device comprises a rubber selected from the group consisting of polyaryletherketone (PAEK), polyetheretherketone (PEEK), polyetherketoneketone (PEKK), polyetherketone (PEK), carbon-PEEK composite, PEEK-BaSO4 rubber, polyethylene terephthalate (PET), silicone, polyurethane, silicone-polyurethane copolymer, and polyolefin rubber. In certain embodiments, the device comprises a hydrogel. In certain embodiments, the device comprises a fabric. In certain embodiments, the device comprises a rigid polymer selected from the group consisting of polyphenylene, polyimide, polyetherimide, polyethylene, and epoxy resin. In certain embodiments, the device comprises a bone material selected from the group consisting of autografts, allografts, xenografts, or transgenic cortical bone and / or cortico-cancellous bone. In certain embodiments, the device comprises a tissue growth factor or a differentiation factor. In certain embodiments, the device comprises an absorbable material, a fully absorbable material, or other absorbable polymers, and other combinations, such as composites of metals and calcium-based ceramics, composites of PEEK and calcium-based ceramics, composites of PEEK and absorbable polymers; the fully absorbable materials such as calcium-based ceramics, such as calcium phosphate, tricalcium phosphate (TCP), hydroxyapatite (HA)-TCP, calcium sulfate; the other absorbable polymers such as polyketone compounds, polyglycolic acid, polytyrosine carbonate, and polycaprolactone.

[0208] In certain embodiments, the device comprises a rubber selected from the group consisting of polyaryletherketone (PAEK), polyetheretherketone (PEEK), polyetherketoneketone (PEKK), polyetherketone (PEK), carbon-PEEK composite, PEEK-BaSO4 rubber, polyethylene terephthalate (PET), silicone, polyurethane, silicone-polyurethane copolymer, polyolefin rubber, synthetic collagen, and collagen matrix. In certain embodiments, the device comprises synthetic collagen. In certain embodiments, the device comprises a collagen matrix.

[0209] In certain embodiments, the device comprises magnesium, vitamins, and minerals. "Vitamins" refer to organic molecules (or a group of chemically closely related molecules, i.e., vitamers) that are essential micronutrients required in small amounts by an organism to maintain the normal functions of its metabolism. Some sources list fourteen vitamins, including choline, but major health organizations typically list thirteen: vitamin A (all-trans retinol, all-trans retinyl esters, and all-trans β-carotene and other provitamin A carotenoids), vitamin B1 (thiamine), vitamin B2 (riboflavin), vitamin B3 (niacin), vitamin B5 (pantothenic acid), vitamin B6 (pyridoxine), vitamin B7 (biotin), vitamin B9 (folic acid or folate), vitamin B 12Cobalamin, vitamin C (ascorbic acid), vitamin D (calciferol), vitamin E (tocopherols and tocotrienols), and vitamin K (phylloquinone and menaquinones). In the context of nutrition, "minerals" refers to chemical elements that are required by an organism as essential nutrients to perform functions necessary for life, including potassium, chlorine, sodium, calcium, phosphorus, magnesium, iron, zinc, manganese, copper, iodine, chromium, molybdenum, selenium, and cobalt.

[0210] In certain embodiments, the device comprises a metal selected from the group consisting of iron, stainless steel alloys, aluminum, commercially pure titanium, titanium alloys, grade 5 titanium, superelastic titanium alloys, magnesium-added titanium, cobalt-chromium alloys, superelastic metal alloys such as nitinol, and superelastoplastic metals such as Gum In certain embodiments, the device comprises titanium. In certain embodiments, the device comprises iron.

[0211] In certain embodiments, the device is fabricated or 3D printed from materials such as titanium, titanium alloys, cobalt-chromium alloys, carbon fiber, magnesium-added titanium, iron, or stainless steel. In certain embodiments, the device is made of a shape memory alloy or a shape memory polymer, allowing the device to conform to the anatomical shape of the patient's body.

[0212] In certain embodiments, the device comprises magnesium-added titanium. In certain embodiments, the device comprises an angiotensin receptor blocker coating. In certain embodiments, the device comprises a type 1 cartilage collagen coating. In certain embodiments, the device is infused with an antibiotic.

[0213] In certain embodiments, the device is used in conjunction with surgical methods or techniques including, but not limited to, open surgery, mini-open surgery, minimally invasive surgery (MIS), and percutaneous surgical implantation, accessing the damaged bone through a mini-incision or cannula to provide a protected pathway to the area. Once access to the surgical site is obtained, the disease or condition can be treated through surgical treatment, such as reduction, traction, or the placement of plates and screws.

[0214] In certain embodiments, the surface of the device comprises a non-solid configuration, such as a lattice. In some embodiments, the non-solid configuration comprises a porous structure or a trabecular configuration.

[0215] In various embodiments, the non-solid configuration is configured to provide one or more paths to assist bone growth within the device and penetrate from one surface of the device to the opposite surface. In some embodiments, the lattice includes one or more portions, layers, or substrates. In some embodiments, one or more portions, layers, or substrates of the lattice are arranged side by side, offset, staggered, stepped, tapered, end to end, spaced apart, in series, or in parallel. In some embodiments, the lattice defines a thickness that can be uniform, wavy, tapered, increasing, decreasing, variable, offset, stepped, arcuate, angled, and / or staggered. In some embodiments, one or more lattice layers are disposed within the wall in a side-by-side, parallel orientation. In certain embodiments, the lattice includes one or more layers of a material matrix.

[0216] In some embodiments, the lattice includes a plurality of nodes and openings arranged in rows and columns or randomly. In some embodiments, the plurality of nodes and openings are arranged in series. In some embodiments, the plurality of nodes and openings are arranged in parallel.

[0217] In some embodiments, the lattice forms a file-like configuration. In some embodiments, the lattice is configured to engage tissue. In certain embodiments, the engagement of the lattice is for cutting, shaving, shearing, incising, or disrupting tissue. In some embodiments, the lattice includes a configuration selected from the group consisting of cylindrical, oval, elliptical, rectangular, triangular, polygonal with planar or arcuate side portions, irregular, uniform, non-uniform, consistent, variable, horseshoe, U-shaped, or kidney bean-shaped. In some embodiments, the lattice is rough, textured, porous, semi-porous, recessed, knurled, serrated, grooved, or polished, for example, for engaging and cutting tissue. In some embodiments, the lattice forms a channel that is configured to direct, drive, or guide the cut tissue into an opening, such as fusing the device with the tissue.

[0218] In certain embodiments, a material such as BMA concentrate, calcium phosphate, biologic agent, and / or antibiotic is injected or sprayed into the screw 200. Before insertion, the filled or coated screw is allowed to stand for 10 to 15 minutes to allow the material to be absorbed.

[0219] In certain embodiments, the holes in the proximal portion of the screw are configured to allow a syringe to pull or push cells into or out of the screw structure before or after implantation. In certain embodiments, an adapter connects the syringe to the screw. In certain embodiments, the holes can be in fluid communication with the porous scaffold of the screw and / or one or more lumens. In certain embodiments, the screw includes a lumen in fluid communication with the holes and extending along the length of the screw toward the screw tip.

[0220] Bone plate

[0221] In certain embodiments, the screws and caps disclosed herein are used with one or more bone plates that have a plurality of holes for receiving the screws and / or caps to secure the plate to bone. The bone plates can be applied in a variety of modes, including protection (neutralization), compression, bridging, and support (anti-slip). Depending on the various anatomical sites and loads, the bone plates can be made larger or smaller, thicker or thinner. The holes in the bone plates are designed, for example, to receive locking or non-locking screws or to facilitate dynamic compression.

[0222] Open reduction internal fixation (ORIF) involves the implementation of implants to guide the bone healing process and the open reduction or osteosynthesis of bone. Open reduction refers to the osteosynthesis through open surgery, which is necessary for certain fractures. Internal fixation refers to fixation by screws and / or bone plates, intramedullary rods, and other devices to achieve or promote healing. Rigid fixation prevents micromotion across the fracture line to achieve healing and prevent infection, which occurs when using implants such as bone plates (e.g., dynamic compression bone plates). ORIF techniques are typically used in cases involving severe fractures, such as comminuted fractures or displaced fractures, or cases where the bone cannot heal properly with only a cast or splint.

[0223] The bone plates are shaped to fit the bone. For example, the midshafts of many long bones are straight, so the bone plates applied to these areas do not need to be contoured. However, many bones flare towards their metaphyses, so the bone plates applied to these areas need to be contoured. Flexible templates assist in the contouring of bone plates. Some bone plates reduce the contact area with the bone. Reconstructive bone plates are easily contoured in complex anatomical locations.

[0224] Anatomical bone plates are pre-contoured to fit the area. These bone plates are used for the general population and may therefore need to be adjusted to fit the individual patient. Protection bone plates counteract bending and rotational forces, thus providing protection for lag screw fixation, whether locking or non-locking screws are used. For implantation, the fracture is reduced and fixed with one or more lag screws. The appropriately contoured bone plate is applied to the bone. The screws are inserted in a neutral mode. Depending on the design of the bone plate, bone quality, availability of implants, and surgeon preference, fixed-angle locking head screws, variable-angle locking head screws, or non-locking screws can be inserted. If the inserted screws provide sufficient holding force to maintain fracture reduction until healing, not every hole needs to have a screw inserted.

[0225] Compression plates provide stability at the fracture site. If possible, the fracture is reduced and temporarily fixed with a clamp. Generally, compression plates are used for the treatment of transverse fractures and short oblique fractures (<30°). The fracture stability generated by the compression between fracture fragments can lead to direct bone healing. In some embodiments, self-compressing plates (such as dynamic compression plates, limited contact dynamic compression plates or limited contact plates), or axial compression is generated by the insertion of eccentric screws (load screws).

[0226] In some embodiments, an articulated tension device provides mechanical compression or distraction before the screws are inserted and fixed in the neutral mode. When in other procedures, the fracture is roughly reduced and the plate is firmly attached to one fracture fragment. The device is anchored to the bone using screws inserted along the articulated footplate. The hooks on the device are inserted into the holes at the ends of the plate. As the tension screws are gradually tightened, the two limbs of the device gradually come closer, thus achieving a compression effect at the fracture site. In oblique fractures, the plate forms a mechanical structure similar to an armpit shape, with the same principle as a pre-bent dynamic compression plate.

[0227] Bridge plates are suitable for multi-segment long bone fractures, especially when intramedullary nailing or conventional plate fixation methods (such as compression plates or protective plate fixation) are not applicable. The plate provides relative stability by fixing two main fracture fragments, thus ensuring the correct length, alignment and rotation of the fracture site. The fracture site remains intact. Callus formation promotes fracture healing.

[0228] Like other plates, bridge plates are usually inserted through a minimally invasive approach to keep the fracture site as intact as possible. The screws are inserted through a limited approach, only fully exposing the plate for screw insertion, or through small puncture incisions. When the plate is inserted using minimally invasive percutaneous techniques, the surgical interference to the fracture site is minimized. Especially for multi-segment fractures, the use of an external fixator or distractor can provide alignment and temporary stability for the bridge plate without disturbing the soft tissues at the fracture area. The proximal pins and distal pins are carefully inserted to avoid interfering with subsequent plate procedures.

[0229] Long plates with a longer working length can distribute the bending stress over the segments of the long plate, and the stress per unit area is correspondingly lower. This can prevent the fracture site from being under excessive pressure and reduce the risk of plate failure. Long plates also allow for a longer lever arm, thus reducing the risk of screw pullout.

[0230] Supportive bone plates are commonly used to assist lag screws in fixing metaphyseal shear fractures or split fractures to the metaphyseal region. The lag screws can be inserted through the supportive bone plate or inserted outside the supportive bone plate. According to standard techniques, the fracture is reduced and fixed with one or more lag screws.

[0231] In some embodiments, washers are used, for example, with osteoporotic bone. When used, the washer has a flat side and a recessed side. The flat side rests on the bone, and the recessed side accommodates the screw head of the nut. The washer prevents screw breakthrough of the thin cortex in the metaphyseal and epiphyseal regions by dispersing the load over a larger area.

[0232] In the case of using locking screws (such as those described herein), the bone - plate construct can remain stable even if the plate does not directly contact the bone. Thus, shaping does not need to be so precise.

[0233] Conventional screws or locking - head screws can be used. When using non - locking bone plates and screws, the bone plate fits precisely to the bone; otherwise, tightening of the screws may result in loss of reduction. In non - locking bone plate systems, screw loosening may also result in loss of reduction.

[0234] The locking - head screws described herein provide greater stability in osteoporotic bone by reducing the risk of screw pull - out and over - tightening of the screws. Well - reduced fractures maintain their reduced state. In some embodiments, the screws are unicortical, engaging only one - side cortex of the bone. In some embodiments, the screws are bicortical, engaging both - side cortices of the bone. The bone plate does not need to fit perfectly to the bone. The bone plate is not pressed against the bone, so the periosteum is not damaged.

[0235] The screws are less likely to loosen from the bone plate. Similarly, if a bone graft is threaded to the plate, the locking - head screws do not loosen during graft union and healing. The locked bone plate / screw system reduces the risk of inflammatory complications due to hardware loosening. The locked bone plate / screw system provides more stable fixation than conventional non - locked bone plate / screw systems.

[0236] The locking - head screws engage within the bone plate, and the bone plate is not pressed against the bone. This reduces interference with the blood supply to the bone beneath the bone plate. The bone plate and screws provide sufficient rigidity and do not rely on the underlying bone support (weight - bearing bone suture). On each side of the fracture, the screws are locked into the bone plate and the bone. Eventually, a rigid - frame construct (internal - external fixator) with high mechanical stability is formed.

[0237] When using a locking bone plate / screw system, the bone plate does not have to be precisely adapted to the bone. When tightening a locking head screw, the screw does not cause a direct loss of reduction because it is tightened into a threaded bone plate hole and does not pull the fracture fragment onto the plate. In a locking system, screw loosening rarely occurs because the screw head is locked to the bone plate.

[0238] Manufacture

[0239] The devices disclosed herein can be manufactured using a variety of methods. In some embodiments, manufacturing includes machining, such as subtractive manufacturing, transformative manufacturing, or conversion manufacturing. In some embodiments, manufacturing includes cutting, grinding, rolling, forming, molding, casting, forging, extrusion, swaging, lapping, cold working, or combinations thereof. In some embodiments, manufacturing includes forming a portion of the device by medical machining processes. In some embodiments, machining uses a computer numerical control (CNC) high-speed milling machine, Swiss machining device, CNC turning with live tooling, wire electrical discharge machining (EDM) 4th axis, and combinations thereof. In some embodiments, manufacturing for forming a portion of the device includes finishing processes, such as laser marking, tumble blasting, bead blasting, micro-blasting, powder blasting, or combinations thereof.

[0240] In certain embodiments, the device is made via additive manufacturing based on digital renderings and / or data of a selected configuration, according to instructions from a computer and a processor.

[0241] In some embodiments, additive manufacturing includes 3D printing. In some embodiments, additive manufacturing is selected from fused deposition modeling, selective laser sintering, direct metal laser sintering, selective laser melting, electron beam melting, laminated object manufacturing, stereolithography, and combinations thereof. In some embodiments, additive manufacturing includes rapid prototyping manufacturing, desktop manufacturing, direct manufacturing, direct digital manufacturing, digital manufacturing, instant manufacturing, on-demand manufacturing, or combinations thereof.

[0242] In some embodiments, a portion of the device is manufactured by additive manufacturing and then mechanically attached to the surface of the device, for example, by welding, threading, adhesives, or riveting.

[0243] In one embodiment, the device is configured based on imaging of the patient's anatomy. Suitable imaging techniques include, but are not limited to, X-ray, fluoroscopy, computed tomography (CT), magnetic resonance imaging (MRI), surgical navigation, bone density (DEXA), or 2D or 3D images of the patient's anatomy that are available. Selected configuration parameters for the device are collected, calculated, or determined. Examples of configuration parameters include, but are not limited to, patient anatomy imaging, surgical treatment, historical patient data, statistics, treatment algorithms, implant material, implant size, porosity, and manufacturing methods. In some embodiments, the configuration parameters include implant material and device porosity based on patient anatomy and surgical treatment. In some embodiments, the porosity is selected. In some embodiments, the configuration parameters of the device are patient-specific. In some embodiments, the configuration parameters of the device are based on a general configuration and are not patient-specific.

[0244] For example, a digital rendering or data of the device is generated for display from a graphical user interface or storage device attached to a computer and processor in a database. In some embodiments, the computer display saves, digitally processes the digital rendering or data via a monitor, or prints the digital rendering or data as a paper copy. In some embodiments, the device is virtually designed via a CAD / CAM program on the computer display. In some embodiments, the processor executes code stored in a computer-readable storage medium to execute one or more computer instructions, e.g., sending instructions to an additive manufacturing device. In some embodiments, the database or computer-readable medium includes RAM, ROM, EPROM, magnetic storage devices, optical storage devices, digital storage devices, electromagnetic storage devices, flash drives, semiconductor technology, or a combination thereof. In some embodiments, the processor instructs the movement and rotation of the motor control device components.

[0245] The screw was tested in cobalt-chromium alloy and complied with American Society for Testing and Materials (ASTM) Standard 543. ASTM Standard 543 evaluates the resistance of plastic materials to chemical reagents, including castings, thermoformed moldings, cold-molded moldings, laminated resin products, and sheets. Three procedures are given, two of which belong to Practice A (immersion testing), and one belongs to Practice B (mechanical stress and reagent exposure under standardized conditions of applied strain). These practices report changes in weight, dimensions, appearance, color, strength, and other mechanical properties. Standard reagents are specified to ensure comparable results, but the use of other chemical reagents relevant to specific chemical resistance requirements is not excluded. Provisions are made for various exposure times, stress conditions, and reagent exposure at elevated temperatures. The type of conditioning (immersion or wet patch / wiping method) depends on the end use of the material.

[0246] In certain embodiments, the screw 200 is individually packaged in a double-layer Tyvek TM peel tray.

[0247] Implantation method

[0248] The present disclosure provides a method of implanting a reduction trauma screw, the method comprising inserting a headless screw having a headless screwdriver into a drill hole in bone, and coupling a reduction cap to the inserted headless screw via a reduction screwdriver loaded with the reduction cap.

[0249] In certain embodiments, the implanting method further comprises aligning a drill guide and / or a tissue protector.

[0250] In certain embodiments, the implanting method further comprises inserting a guide wire into the bone. In certain embodiments, the implanting method further comprises drilling a drill hole with a hollow drill bit inserted around the guide wire. In certain embodiments, the implanting method further comprises removing the drill bit and the guide wire.

[0251] In certain embodiments, the drill bit has a diameter smaller than that of the screw to be inserted. In certain embodiments, the diameter of the drill bit is 3.2 mm.

[0252] In certain embodiments, the implantation is percutaneous.

[0253] The disclosed implanting method has the advantage of preventing over-drilling because the drill hole only needs to be drilled once instead of twice as in conventional procedures. The bone tissue collection feature on the screw allows for a single drill hole for insertion. In addition, using the insertion, the locking screw head is engaged and locked into the threaded hole of the bone plate. If needed, the threaded hole of the bone plate also accommodates non-locking screws, which allows for angulation. Tightening the screw presses the bone against the lower surface of the bone plate by a "tensile action".

[0254] Regenerative medicine

[0255] "Regenerative medicine" refers to a branch of tissue engineering and molecular biology translational research that involves replacing, engineering, or regenerating human cells, tissues, or organs to restore or establish normal function. This field holds promise for functionally repairing previously irreparable tissues or organs by stimulating the repair mechanisms within the patient's body to repair damaged tissues and organs. For example, during bone regeneration, new bone formation is mainly influenced by physicochemical factors in the surrounding microenvironment. Tissue cells exist in a complex scaffold physiological microenvironment.

[0256] In certain embodiments, regenerative medicine is combined with the scaffolds or devices disclosed herein. Autograft integration is divided into five stages: inflammation, angiogenesis, osteoinduction, osteoconduction, and remodeling.

[0257] The inflammation lasts for about 7 to 14 days. The initial damage to the local blood supply and desquamation lead to the formation of a hematoma around the bone graft, and inflammatory cells will invade it. Fibroblast-like cells in the inflammatory tissue transform into a fibrovascular matrix. The use of anti-inflammatory drugs during the perioperative period will reduce the fusion rate by inhibiting the inflammatory process.

[0258] Vascular buds appear in the fibrovascular matrix, and this process is similar to scar tissue formation during angiogenesis. Primary membranous bone formation occurs near the desquamated bone. Next, minimal endochondral ossification and intramembranous ossification occur.

[0259] During the bone induction period from week 4 to week 5, the repair includes increased angiogenesis, absorption of necrotic tissue, and differentiation of osteoblasts and chondroblasts. Specifically, stem cells differentiate into osteoblasts. New bone extends towards the central region of the fusion mass. The cortical part of the graft continues to be absorbed.

[0260] Osteoconduction is characterized by ingrowth into the host bone and creeping substitution. Osteoblasts form new bone, while osteoclasts absorb the graft bone simultaneously. The central region of the endochondral interface is observed at the center of the fusion mass, which connects the lower and upper halves of the fusion body. Multipotent cells in this central region differentiate into cartilage tissue with less angiogenesis.

[0261] During the remodeling period from week 6 to week 10, a peripheral cortical rim is formed around the fusion body. Marrow activity is enhanced, and secondary cancellous bone is formed. The cortical rim thickens. Trabecular projections extend to the center of the fusion body. Remodeling is usually completed one year after device implantation.

[0262] Pseudoarthrosis (nonunion) is the main cause of postoperative pain, accounting for 45% to 56% of revision surgery cases. Bone fusion is directly related to successful clinical outcomes. In about 30% of cases, patients with pseudoarthrosis do not show symptoms. Younger patients have a significantly increased incidence of symptomatic pseudoarthrosis (43.8 years old vs. 52.1 years old, p < 0.01).

[0263] In certain embodiments, in a single-segment posterior lateral lumbar fusion (PLF), bone marrow aspirate (BMA) of an allograft is used to replace autologous bone graft. In certain embodiments, the bone marrow aspirate of an allograft is more cost-effective than recombinant human bone morphogenetic protein-2 (rhBMP). In certain embodiments, allografts rich in bone marrow-derived cells can be compared with autologous grafts in bone grafting and spinal fusion procedures. In certain embodiments, BMA increases the regenerative potential of cortical cancellous allograft bone. When treating unicameral bone cysts, the injection of bone marrow into demineralized bone matrix has a high healing rate (98.7%).

[0264] In introducing elements of the present disclosure or embodiments thereof, the articles "a", "an", "the", and "said" are intended to mean that there is one or more than one element. The terms "comprising", "including", and "having" are intended to be inclusive and mean that additional elements may exist in addition to the listed elements.

[0265] Having described the present disclosure in detail, it will be apparent that modifications and variations can be made without departing from the scope of the present disclosure as defined in the appended claims.

[0266] Although various modifications and alternative forms of the disclosure described herein may exist, specific embodiments thereof have been described in greater detail above. However, it should be understood that the detailed description of the compositions is not intended to limit the present disclosure to the specific forms disclosed. On the contrary, it should be understood that the present disclosure is intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the language of the claims.

[0267] Table 2 shows the reference numerals used in the figures.

[0268] Table 2 - Reference Numerals

[0269]

[0270]

[0271] All references, patents, or applications (whether U.S. or foreign) cited in this application are hereby incorporated by reference as if their entire contents were written in this application. In the event of any inconsistencies, the materials disclosed herein shall prevail.

[0272] Based on the foregoing description, those skilled in the art can readily determine the basic features of the present invention, and without departing from the spirit and scope of the present invention, various changes and modifications can be made to adapt it to various uses and conditions of use.

Claims

1. A reduction trauma screw, the reduction trauma screw comprising: A headless screw having narrow threads at its proximal end; and a reduction cap adapted to couple to the headless screw via the narrow threads after the headless screw has been inserted into a substrate.

2. The screw according to claim 1, wherein the substrate is a bone of a patient in need of reduction, distraction, fixation, or a combination thereof.

3. The screw according to claim 1 or 2, wherein the cap is spherical.

4. The screw according to claim 1 or 2, wherein the cap is conical.

5. The screw according to any one of claims 1 to 4, wherein the cap is flanged.

6. The screw according to claim 5, wherein the cap includes four flanges radially distributed at 90° intervals.

7. The screw according to any one of claims 1 to 6, wherein the cap further includes a collar configured to engage the substrate multi-axially.

8. The screw according to claim 7, wherein the collar includes ten flanges radially distributed at 36° intervals.

9. The screw according to any one of claims 1 to 4, wherein the cap has an arcuate taper.

10. The screw according to any one of claims 1 to 4, wherein the cap has a linear taper.

11. The screw according to any one of claims 1 to 10, wherein the cap includes external threads.

12. The screw according to claim 1 or 2, wherein the cap is conical with an arcuate taper, conical with a linear taper, conical with a linear taper and external threads, or flanged with external threads.

13. The screw according to any one of claims 1 to 12, wherein the cap includes at least one serration configured to be received by an adapter.

14. The screw according to claim 13, wherein the cap includes four serrations radially distributed at 90° intervals.

15. The screw according to claim 13 or 14, wherein each serration includes a pit.

16. The screw according to any one of claims 1 to 15, the screw including a scaffold.

17. The screw according to claim 16, wherein the scaffold is characterized by a randomized porosity pattern typical of native trabecular bone, the randomized porosity pattern including one or more structural factors that enhance at least one of: multipotent mesenchymal stem cell (MSC) differentiation, osteoblast growth, extracellular matrix (ECM) deposition, and new bone formation.

18. The screw according to claim 16 or 17, wherein the scaffold includes a triply periodic minimal surface (TPMS) having a cubic repeat pattern that defines walls within the scaffold.

19. The screw according to claim 18, wherein the TPMS is of the Schwartz diamond type, the Schwartz diamond type helically wound about the central axis of the screw to define a cubic repeat pattern in the X / Y / Z dimensions of the scaffold.

20. The screw according to claim 19, wherein the TPMS is helically wound into a single helix.

21. The screw according to claim 19 or 20, wherein each turn of the helix of the screw has three radial spokes.

22. The screw according to any one of claims 19 to 21, wherein the cubic repeating pattern is about 1.8 mm in the X / Y / Z dimension.

23. The screw according to any one of claims 19 to 22, wherein the period of the helical winding of the screw is defined as three times the size of the cubic repeating pattern.

24. The screw according to any one of claims 19 to 23, wherein the wall is about 0.5 mm thick.

25. The screw according to claim 16 or 17, wherein the bracket is a folded sheet bracket.

26. The screw according to claim 25, wherein the folded sheet bracket is a shell-like porous pseudo-randomly orientable structure, the shell-like porous pseudo-randomly orientable structure comprising continuous folded sheets with a topological genus of n, wherein the real three-dimensional space is partitioned into disjoint sub-volumes.

27. The screw according to claim 26, wherein the sub-volumes are non-uniform and disjoint.

28. The screw according to claim 26 or 27, wherein the pseudo-random structure is driven by a dimensionless three-dimensional noise field.

29. The screw according to any one of claims 26 to 28, wherein the sheet structure has one or more properties selected from continuous, perforated, functionally graded, semi-regular, and is driven by a modulation algorithm that controls spatially varying features.

30. The screw according to any one of claims 16 to 29, wherein the threads of the screw near the proximal end are textured to have a morphology similar to that of the bracket.

31. The screw according to any one of claims 1 to 30, wherein the screw reduces the occurrence of one or more of the following: screw loosening, screw withdrawal, rod fracture, and bone density reduction.

32. The screw according to any one of claims 1 to 31, wherein the screw concentrates bone growth throughout the shaft to minimize shear stress at the distal tip, and disperses micromotion throughout the screw to promote ingrowth of bone.

33. The screw according to any one of claims 1 to 32, wherein the screw includes at least one trephine to collect bone tissue inside the screw.

34. A method of implanting a reduction trauma screw, the method comprising inserting a headless screw with a headless screwdriver into a drill hole in bone, and applying a reverse torque to a reduction screwdriver loaded with a reduction cap by using the headless screwdriver, thereby coupling the reduction cap to the inserted headless screw via the reduction screwdriver.

35. The method according to claim 34, wherein the headless screw is the headless screw according to any one of claims 1 to 33.

36. The method according to claim 34 or 35, wherein the reduction cap is the reduction cap according to any one of claims 1 to 16.

37. The method according to any one of claims 34 to 36, wherein when the reset cap is coupled to the headless screw, a compressive action is applied to the bone without moving the headless screw.

38. The method according to any one of claims 34 to 37, wherein when a collar is present, the collar is adjusted multi-axially before applying a compressive action to the bone.

39. The method according to any one of claims 34 to 38, the method further comprising aligning the drill guide, the tissue protector, or both.

40. The method according to any one of claims 34 to 39, the method further comprising inserting a guide wire into the bone.

41. The method according to claim 40, the method further comprising drilling a borehole with a hollow drill bit inserted around the guide wire.

42. The method according to claim 41, the method further comprising removing the drill bit and the guide wire.

43. The method according to claim 41 or 42, wherein the drill bit has a diameter smaller than the screw to be inserted.

44. The method according to claim 43, wherein the diameter of the drill bit is 3.2 mm.

45. The method according to any one of claims 34 to 44, the screw being percutaneous.

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