Device with hole locks for medical devices

Abstract

Medical devices, assemblies, and methods for circulating materials in medical devices are provided herein. The adapter includes a shaft, a cannula, a female hole lock, a male tapered surface, and threads, all of which are designed for reversible engagement and material circulation. The assembly incorporates the adapter and is designed for use with various medical devices, including bone screws. The method involves joining a pressure device and a medical device having a stent to the adapter, and circulating material in the medical device by negative or positive pressure. These innovations provide a versatile approach for circulating materials in medical devices, which may be beneficial in various medical procedures and treatments, thereby improving the efficiency and effectiveness of material circulation.

Description

[0001] This application claims the benefit of priority of U.S. Provisional Patent Application Serial No. 63 / 422,638, filed Nov. 4, 2022, the disclosure of which is incorporated herein by reference in its entirety for all purposes.

[0002] The present disclosure relates to adapters for medical devices, assemblies including those adapters and medical devices, and methods of injecting and circulating materials in medical devices.

[0003] Spinal fusion is a commonly indicated procedure for treating fractures, instability, and common degenerative conditions, including low back pain. Fusion techniques use bone grafts and hardware, such as pedicle screws, to promote the growth of two vertebral bodies together. Existing lumbar implant designs are smooth-threaded pedicle screws that are fixed in the vertebrae with rods to maintain the corrected height and angulation until fusion is achieved.

[0004] It is estimated that low back pain affects 60%-80% of people globally. Between 1998 and 2008, the number of lumbar fusion surgeries performed annually in the United States increased from 77,682 to 210,407. Unfortunately, the overall failure rate of lumbar surgery is high, approximately 10%-46%.

[0005] In a review of spinal fusion surgeries within the PubMed database, 11,692 patients were extracted. There were 3,646 complications, the mean age of surgery was 53.3 years (range: 25 years - 77 years), and the mean follow-up time was 3.49 years (range: 6 weeks - 9.7 years). Severe perioperative complications occurred at an average rate of 18.5%. Minor perioperative complications occurred at an average rate of 15.7%. Long-term complications occurred at an average rate of 20.5%.

[0006] Despite advances in technology and surgical techniques, these rates have not changed substantially over the years. For example, due to computer navigation, augmented reality, minimally invasive surgery (MIS) methods, disc arthroplasty, bone-stimulating pedicle screws, and bone void filler options, lumbar interbody fusion (LIF) techniques have advanced. However, due to the increasing number of patients and high failure rates, the number of patients developing failed back surgery syndrome (FBSS) is increasing. (FBSS is a situation where the outcome of lumbar surgery does not meet the preoperative expectations of the patient and the surgeon).

[0007] The gold standard for lumbar spinal fusion involves inserting smooth-threaded screws into each pedicle (two per vertebral level) and placing rods into the tulip-shaped heads of the pedicle screws to stabilize the construct until fusion is achieved. However, since 1975, there has been little technological advancement in spinal stabilization systems, and these constructs do not address key long-term stability issues related to the quality of bone mineral density and patient health. The hardware used in lumbar fusion is subjected to significant forces that result in hardware breakage and failure (the so-called "wiper effect"). The estimated variation in the frequency of screw loosening during spinal fusion is significant, but recent reports estimate the loosening rate to exceed 40%, with nearly 10% being partial pullout. This loosening due to lack of fusion can place nerves or blood vessels at risk and often requires removal of the hardware and repeat surgery.

[0008] Unfortunately, spinal revision surgery also has a poor success rate. The success rate for secondary revision cases is 30%, for the third surgery is 15%, and for the fourth surgical intervention is 5%. Additionally, adult spinal deformity patients who have previously undergone two or more revisions exhibit more coronal and sagittal plane imbalance and a worse functional status. Other potential complications of LIF are dural tear, nerve injury, pseudarthrosis, infection, and wound healing problems.

[0009] Another complication of lumbar spinal fusion is infection. Surgical site infection (SSI) is a major healthcare challenge, causing approximately 8,000 deaths per year. The direct and indirect costs associated with SSI are estimated to total between $1 billion and $10 billion per year. Spinal instrumentation surgeries have a greater risk of SSI, resulting in a higher infection rate compared to other orthopedic surgeries. The incidence of SSI resulting from spinal surgery is estimated to be between 0.2% and 16.7%. A recent meta-analysis showed that spinal instrumentation surgery results in an SSI incidence of 4.4%. Deep incisional and organ space SSIs account for 80% of these infections and are associated with increased morbidity, longer hospital stays, and higher healthcare costs.

[0010] In addition, regardless of the material used, bone mineral density decreases after implantation of a medical device. This loss results in common medical device failures, including screw loosening, screw pullout, and rod fracture. Although many devices promote fusion in interbody cages, no device has been developed to form a scaffold within the vertebral body and increase bone mineral density. Additionally, the structure of cortical bone within the vertebrae is different from bone in other parts of the body.

[0011] These challenges related to long-term stability, such as bone quality and healing functional ability, have not been met. None of the prior arts have addressed the first two reasons for revision surgeries of implant failures: pedicle screw pullout and rod breakage before the patient achieves fusion. Smooth-threaded pedicle screws and rods do not address the issues of bone mineral density and the quality of patient health. Summary of the Invention

[0012] The present disclosure provides an adapter for injecting a material into a medical device. The adapter includes a shaft having a proximal end and a distal end; a cannula disposed through the center of the shaft between the proximal end and the distal end; a concave hole lock formed on the proximal end for reversibly engaging a convex cone on a pressure device; a convex conical surface formed on the distal end and configured to reversibly engage a concave conical surface on a medical device; and threads circumferentially disposed on the shaft between the concave hole lock and the convex conical surface, the threads being configured to reversibly engage a groove.

[0013] The present disclosure also provides a component for injecting a material into a medical device. The component includes an adapter, which in turn includes a shaft having a proximal end and a distal end; a cannula disposed through the center of the shaft between the proximal end and the distal end; a concave hole lock formed on the proximal end for reversibly engaging a convex cone on a pressure device; a convex conical surface formed on the distal end and configured to reversibly engage a concave conical surface on a medical device; and threads circumferentially disposed on the shaft between the concave hole lock and the convex conical surface, the threads being configured to reversibly engage a groove on an inner surface.

[0014] The present disclosure also provides a method for injecting a material into a medical device. The method includes engaging a pressure device and a medical device having a stent to the adapter disclosed herein, and injecting the material into the medical device using negative or positive pressure from the pressure device.

[0015] Additional embodiments and features are set forth in part in the following description. They will become apparent to those skilled in the art upon review of the specification, or may be learned by practice of the embodiments discussed herein. A further understanding of the nature and advantages of certain embodiments can be realized by reference to the remaining portions of the specification and the drawings that form a part of the present disclosure. Brief Description of the Drawings

[0016] Figure 1 is a top view of a diagram showing a pedicle screw implanted into a vertebral body of a vertebra through the pedicle.

[0017] Figure 2Shows a side plan view of an embodiment of a pedicle screw printed in titanium 3D.

[0018] Figure 3 Shows Figure 2 a top plan view of the pedicle screw.

[0019] Figure 4 Shows Figure 2 a bottom plan view of the pedicle screw.

[0020] Figure 5 Shows a side plan view of an embodiment of a pedicle screw printed in 3D using the stent disclosed herein.

[0021] Figure 6 Shows Figure 5 a top plan view of the pedicle screw.

[0022] Figure 7 Shows Figure 5 a bottom plan view of the pedicle screw.

[0023] Figure 8 Shows a side plan view of another embodiment of a pedicle screw printed in 3D using the stent disclosed herein.

[0024] Figure 9 Shows Figure 8 a top plan view of the pedicle screw.

[0025] Figure 10 Shows Figure 8 a bottom plan view of the pedicle screw.

[0026] Figure 11 Shows a side plan view of an embodiment of a porous pedicle screw.

[0027] Figure 12 Shows an exploded view of a porous pedicle screw having a tulip-shaped member and pins Figure 11 thereof.

[0028] Figure 13 Shows Figure 11 a top plan view of the cap of the porous pedicle screw.

[0029] Figure 14 Shows Figure 11 a side plan view of the cap of the porous pedicle screw.

[0030] Figure 15 Shows Figure 11 a perspective view of the saddle of the porous pedicle screw.

[0031] Figure 16 Shows Figure 12Perspective view of the tulip-shaped member.

[0032] Figure 17 Cross-sectional view of a screw having a hole locking feature at its proximal end. The screw has a lumen extending through a porous scaffold in the screw body.

[0033] Figure 18 Shows Figure 17 Top plan view of the screw, which illustrates a hole in the center of the proximal end of the screw.

[0034] Figure 19 Perspective view of the adapter disclosed herein.

[0035] Figure 20 Shows a component including a pedicle screw, a tulip-shaped member, Figure 19 the adapter, and a syringe in cross-section.

[0036] Figure 21 Shows Figure 20 Illustration of the component, highlighting the junction of the concave conical surface of the screw and the convex conical surface of the adapter.

[0037] Figure 22 Front plan view of the adapter.

[0038] Figure 23 Shows Figure 22 Rear plan view of the adapter.

[0039] Figure 24 Shows Figure 22 Top plan view of the adapter.

[0040] Figure 25 Shows Figure 22 Bottom plan view of the adapter.

[0041] Figure 26 Front plan view showing the arrangement of the bone screw and the syringe in the component.

[0042] Figure 27 Shows Figure 22 Front plan view arrangement of the adapter, where the bone screw and the syringe are in Figure 26 the component.

[0043] Figure 28 Shows the front plan view arrangement of the tulip-shaped member, where Figure 22 the adapter, the bone screw, and the syringe are in Figure 26 the component.

[0044] Figure 29 Side plan view showing the arrangement of the bone screw and the syringe in the component.

[0045] Figure 30 shows a side plan view arrangement of an adapter, where a bone screw and a syringe are in the Figure 22 components of Figure 26 .

[0046] Figure 31 shows a side plan view arrangement of a tulip-shaped member, where the Figure 22 adapter, bone screw and syringe of Figure 26 are in the components of

[0047] The present disclosure will be readily understood by the following detailed description in conjunction with the accompanying drawings, in which like reference numerals represent like structural elements. The drawings provide exemplary embodiments or aspects of the present disclosure and do not limit the scope of the present disclosure. Detailed Description

[0048] The present disclosure provides an adapter for injecting a material into a medical device, the adapter including a shaft having a proximal end and a distal end; a cannula disposed through the center of the shaft; a female bore lock on the proximal end that reversibly engages a male cone on a pressure device; a male conical surface on the distal end that is configured to reversibly engage a female conical surface on a medical device; and threads circumferentially disposed on the shaft between the female bore lock and the male conical surface, wherein the threads are configured to reversibly engage a groove.

[0049] In certain embodiments, the medical device associated with the adapter is a bone screw. In certain embodiments, the pressure device associated with the adapter is a syringe. In certain embodiments, the groove that engages the threads of the adapter is on a tulip-shaped member. In certain embodiments, the female bore lock of the adapter is a female Luer lock and the male cone is a male Luer cone.

[0050] In certain embodiments, a component for injecting a material into a medical device includes an adapter having a shaft, a cannula, a female bore lock, a male conical surface, and threads, all of which are constructed as described above.

[0051] In certain embodiments, the medical device associated with the component is a bone screw. In certain embodiments, the pressure device associated with the component is a syringe.

[0052] In certain embodiments, the groove that engages the threads of the adapter in the component is on a tulip-shaped member.

[0053] In certain embodiments, the female bore lock of the adapter in the component is a female Luer lock and the male cone is a male Luer cone.

[0054] In certain embodiments, the assembly further includes a medical device having a body, a concave conical surface, a cannula, and a scaffold for promoting osseointegration.

[0055] In certain embodiments, the body of the medical device in the assembly is a shaft.

[0056] In certain embodiments, the medical device in the assembly is a bone screw. In certain embodiments, the bone screw in the assembly is a pedicle screw.

[0057] In certain embodiments, the scaffold in the assembly includes an internal lattice structure having a porous architecture formed by a combination of mean curvature, Gaussian curvature, and net curvature, characterizing the local shape of healthy trabecular bone. In certain embodiments, the scaffold in the assembly exhibits a predominantly hyperbolic geometry, including saddle-shaped regions, globular indentations, and cylindrical rod-like elements. In certain embodiments, the scaffold in the assembly includes one or more structural cues selected from porosity, pore size, grain size, and surface topography, which enhance at least one of multipotent mesenchymal stem cell (MSC) differentiation, osteoblast growth, extracellular matrix (ECM) deposition, and new bone formation. In certain embodiments, new bone formation in the assembly occurs after MSC differentiation, osteoblast growth, ECM deposition, or a combination thereof. In certain embodiments, the scaffold in the assembly is configured to accommodate one or more biological agents.

[0058] In certain embodiments, the assembly further includes a tulip-shaped member having a body, a top opening, a bottom opening, an inner surface, and an outer surface, wherein the bottom opening is configured to engage the proximal end of the medical device, and the inner surface at the top opening includes grooves to reversibly engage the threads of an adapter.

[0059] In certain embodiments, the tulip-shaped member in the assembly further includes a pair of side openings disposed on opposite sides of the body, the side openings being configured to reversibly engage pins that lock the tulip-shaped member to the medical device.

[0060] In certain embodiments, the assembly further includes a pressure device having a barrel, a plunger, and a convex cone, wherein the convex cone is configured to reversibly engage a concave hole lock of an adapter.

[0061] In certain embodiments, the medical device in the assembly focuses bone growth throughout the body to minimize shear stress at the distal end and to minimize micromotion of the entire medical device due to ingrowth of bone.

[0062] In certain embodiments, the medical device in the assembly is configured with an arcuate cross-sectional pattern that varies from the proximal end to the distal end of the medical device for placement into an internal cavity of an anatomical feature such that an autograft is harvested within the medical device when the medical device is rotated coaxially.

[0063] In certain embodiments, the medical device in the assembly further comprises at least one autologous product sprayed onto or injected through the medical device.

[0064] The present disclosure also provides a method of injecting a material into a medical device, the method comprising engaging a pressure device and a medical device having a scaffold to an adapter, and injecting the material into the medical device using negative or positive pressure from the pressure device.

[0065] In certain embodiments, the pressure device in the method is a syringe having a plunger, and the material is circulated using negative pressure by withdrawing the plunger of the syringe or using positive pressure by pressing the plunger of the syringe.

[0066] In certain embodiments, the pressure device in the method is loaded with the material prior to being engaged to the adapter, and the material is pushed into the medical device.

[0067] In certain embodiments, the method further comprises drawing a biomaterial into the pressure device and then injecting a mixture of the loaded material and the biomaterial into the medical device.

[0068] In certain embodiments, the material in the method is circulated by alternating negative and positive pressure on the medical device.

[0069] In certain embodiments, the circulation in the method produces a bio-ripple effect that induces and promotes healing.

[0070] In certain embodiments, the healing in the method includes the binding of stem cells to the scaffold of the medical device.

[0071] In certain embodiments, the method results in the growth of osteoclasts and osteoblasts.

[0072] Bracket

[0073] Surface curvature and Minkowski bone morphological curvature maps (functions that restore the concept of distance in a linear space) demonstrate a porous matrix in the trabecular bone within the vertebra that is significantly different from other regions of the skeletal anatomy. Due to the reduced bone mineral density after implantation, the load of traditional smooth-threaded pedicle screws may be too high for the vertebra.

[0074] The porous 3D printed scaffold promotes bone integration, fusion, and fixation within the bone. The open framework with the scaffold is similar to the open framework of natural bone. This similarity allows the physician to use other reagents for patient-specific selection to promote bone formation and / or stabilize the device.

[0075] The triangular porosity sequence has been previously described. Circular, square / rectangular shapes, and diverse patterns are more closely aligned with the natural vertebral bone structure. Additionally, the structure of the scaffold reduces the likelihood of revision of the medical device used to fabricate it, such as screw loosening, screw pullout, rod fracture, and reduced bone mineral density.

[0076] In certain embodiments, the disclosed scaffolds and devices integrate orthopedic products with regenerative medicine to prevent the risk of delayed bone fusion of the implanted device.

[0077] In certain embodiments, the scaffold comprises one or more structural cues selected from porosity, pore size, grain size, and surface topography. Porosity and pore size cues indicate mechanical strength, cell settlement, and cell migration. Grain size cues indicate protein absorption, cell adhesion, cell proliferation, and cell adhesion. Surface topography cues indicate specific surface area, cell adhesion, and material-tissue interface. Other scaffold characteristics include pH and wall thickness. In certain embodiments, one or more of the structural cues enhance at least one of multipotent mesenchymal stem cell (MSC) differentiation, 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.

[0078] In certain embodiments, the internal grid structure of the scaffold mimics the geometric properties of healthy trabecular bone geometry. In certain embodiments, the grid structure comprises a combination of mean curvature, Gaussian curvature, and net curvature that characterize the local shape of trabecular bone. Mean curvature (H) represents the local convexity or concavity of the surface, while Gaussian curvature (K) quantifies the type of surface (hyperbolic, essentially flat, or spherical). Net curvature (D) describes the local deviation of the surface from a planar region.

[0079] In certain embodiments, the grid structure of the scaffold exhibits a predominantly hyperbolic geometry (K < 0), consistent with the high topological complexity of trabecular bone. In such embodiments, the structure comprises a combination of saddle-shaped regions, globular indentations, and cylindrical rod-like elements. The curvature distribution of the entire scaffold is designed to reflect the spatial correlations observed in healthy trabecular bone samples, thus ensuring a more biomimetic design that aids in bone integration, fusion, and fixation within the bone.

[0080] In certain embodiments, the internal mesh structure of the scaffold is based on Minkowski functionals, which provide a comprehensive and robust description of the global shape of complex structures such as trabecular bone. The Minkowski functionals include scalar measures such as the total area of the bounding surface (W1), the area integral mean curvature (W2), and the area integral Gaussian curvature (W3). These scalar measures capture the fundamental geometric properties of trabecular bone, thus allowing for a more biomimetic design that promotes bone integration, fusion, and fixation within the bone. Without wishing to be bound by theory, by incorporating the Minkowski functionals into the design of the scaffold, the mesh structure can better reflect the differences between samples from various anatomical sites and may be more sensitive to small changes in connectivity such as those caused by disease. Thus, this approach ensures that the mesh structure of the scaffold closely mimics the natural geometry of trabecular bone and enhances its effectiveness in bone implant applications.

[0081] In certain embodiments, the Minkowski tensors (MT) capture the orientation-dependent aspects of trabecular bone morphology. Six relevant rank-two MTs are defined for a 3D body, including W02,0(B), W12,0(B), W10,2, and W20,2. The tensor W10,2 describes the distribution of the surface normal vectors, the tensor W20,2 describes the distribution of the mean curvature (the surface normal weighted by the curvature), and the tensor W12,0 measures the mass distribution when the entire mass of B is uniformly distributed on the surface (i.e., a "hollow" body).

[0082] The degree of anisotropy (DA) of the tensor Wvr,s is defined as DAvr,s = 1 - |λvr,s|min / |λvr,s|max, where |λvr,s|min and |λvr,s|max are the absolute values of the minimum and maximum eigenvalues of the tensor Wvr,s. In certain embodiments, different types of anisotropy of trabecular bone samples are quantified, including the anisotropy of the interface orientation (DA10,2) and the anisotropy of the mean curvature (DA20,2).

[0083] In certain embodiments, the ratio of the median eigenvalue to the maximum eigenvalue is plotted relative to the ratio of the minimum eigenvalue to the maximum eigenvalue to provide insight into the "ellipticity" of the bone sample for a particular tensor. This allows for the quantification of different sources of bone anisotropy and ellipticity by considering different Minkowski tensors (e.g., W12,0 or W20,2).

[0084] In certain embodiments, the Minkowski functionals are applied to smaller substructures within a trabecular bone sample to create a Minkowski map that quantifies the within-sample variation of the overall shape index. This spatial decomposition analysis allows for a local characterization of the ellipticity of the Minkowski tensors W10,2 and W20,2. The degree of local anisotropy (DA) can vary significantly for the entire sample value, resulting in different distributions of the two tensors. For both tensors, different angular differences in the local and global principal directions can also be observed, with wider variations detected in the L2 and L4 samples.

[0085] In certain embodiments, higher-rank Minkowski tensors, such as the quadratic (qs) and cubic (ws) rotational invariants of the irreducible Minkowski tensor, are calculated for the spatially decomposed samples. These scalar invariants can be used as effective structural metrics to detect the local crystallization state in the disordered packing of convex shapes. In certain embodiments, significant differences can be detected between the distributions of the structural metrics for different bone types, indicating that these higher-order structural metrics are sensitive to the structural differences between plate-like and rod-like samples.

[0086] In certain embodiments, an integrated shape descriptor (ISD) is used to quantify the surface curvature of trabecular bone, and the ISD serves as an effective shape fingerprint for trabecular bone from different anatomical sites. The ISD captures the morphological differences between plate-like and rod-like samples as well as the intermediate morphologies along the plate-rod spectrum.

[0087] In certain embodiments, scalar and tensor Minkowski functionals are used for the global shape analysis of trabecular bone interfaces. These functionals are fundamental, highly general, and robust indices for integral shape quantification. In certain embodiments, the Minkowski scalars are related to traditional bone morphometric indices. In certain embodiments, the Minkowski tensors reveal different degrees of anisotropy and ellipticity depending on the morphological aspects considered.

[0088] In certain embodiments, higher-rank Minkowski metrics are applied to the shape quantification of spatially decomposed bone samples, showing sensitivity to morphological differences in bones from different anatomical sites. The geometric properties of these metrics provide a unified view and geometric basis for traditional bone morphometric indices, which can facilitate the understanding of morphological changes in aging and disease, such as the plate-rod transition in osteoporosis.

[0089] In some embodiments, the scaffold does not include planar truss elements that are interconnected with each other by a plurality of struts coupled to a plurality of nodes, wherein one or more angles defined by two struts and a node of one or more planar truss elements are different from one or more corresponding angles defined by two struts and a node of one or more other planar truss elements. In some embodiments, the scaffold need not connect outer surface struts that interconnect the nodes of non-equivalent angle planar truss elements such that the implant has a varying height.

[0090] In some embodiments, the scaffold does not include an internal space truss structure that is at least partially surrounded by an outer frame, the outer frame including two or more planar truss elements, wherein a plurality of struts are joined at nodes, wherein at least two nodes within the internal space truss structure are connected by a strut that is bent or arcuate between the at least two nodes, and wherein at least one of the two or more planar truss elements lies in a plane that is substantially non-parallel to the plane of at least one or more of the other two or more planar truss elements.

[0091] In some embodiments, the internal mesh structure of the scaffold does not include a mesh structure having a plurality of struts joined at nodes to form a space truss, wherein the mesh structure is configured to engage bone tissue, and wherein a plurality of planar truss elements are interconnected such that one or more planar truss elements lie in a plane that is substantially non-parallel to the plane of a planar truss element that shares at least one strut with the one or more planar truss elements. Additionally, the scaffold does not have a pre-determined diameter and / or length of the struts and / or density of the mesh structure such that when the mesh structure contacts bone, at least a portion of the struts creates micro-strain in adhering osteoblasts, bone matrix, or lamellar tissue.

[0092] Bone

[0093] Bone can generally be classified into cancellous bone and cortical bone. "Cancellous bone" (also known as "trabecular bone" or "spongy bone") is lightweight, porous bone that encloses many large spaces, providing a honeycombed or spongy appearance. The bone matrix or framework is organized into a three-dimensional grid of bony projections arranged along stress lines, called trabeculae. The spaces between them are typically filled with bone marrow and blood vessels. In cross-section, the trabeculae of cancellous bone can appear like septa. However, they are topologically different in three-dimensional space, where the trabeculae are generally rod-like or columnar, and the septa are sheet-like.

[0094] Cancellous bone makes up 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 bone that do not experience large mechanical stresses. It forms most of the expanded ends (epiphyses) of long bones and is a major component of the ribs, scapulae, flat bones of the skull, and various short flat bones elsewhere in the skeleton.

[0095] Due to the increasing frequency of total joint replacements and their impact on bone remodeling, understanding the stress-related and adaptive processes of trabecular bone has become a central 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 were studied as a function of anatomical location, density, and age. Accordingly, mechanical factors, including modulus, uniaxial strength, and fatigue properties, were also investigated.

[0096] High porosity gives trabecular bone compliance. Large variations in architecture result in high heterogeneity. Modulus and strength are inversely proportional to porosity and highly dependent on pore structure. Typically, the percentage of porosity in cancellous bone ranges between 75% and 95%. The density ranges between 0.2 g / cm 3 -0.8 g / cm 3 . Porosity can reduce the strength of bone but also reduces its weight.

[0097] Porosity and its structure affect the strength of the material. Accordingly, the microstructure of trabecular bone is typically oriented. The "grains" of porosity are aligned where mechanical hardness and strength are greatest. Due to the microstructural directionality, the mechanical properties of trabecular bone are highly anisotropic. The Young's modulus of trabecular bone, including that of vertebrae, ranges between 800 Mpa and 14,000 Mpa. Its failure strength is between 1 MPa and 100 MPa.

[0098] "Cortical bone" or "compact bone" is much denser than cancellous bone. It forms the hard outer (cortex) of bone. Cortical bone gives bone its smooth, white, and solid appearance. It accounts for approximately 80% of the total bone mass of the adult skeleton. Cancellous bone is typically surrounded by a shell of cortical bone, which provides greater strength and stiffness. The open structure of cancellous bone enables it to dampen sudden stresses, such as load transfer through joints. Different proportions of space to bone are found in different bones, depending on the need for strength or flexibility. Cancellous bone also has a relatively high level of metabolic activity.

[0099] "Wolff's law" states that the bones of a healthy person or animal adapt to the loads to which they are subjected. For example, if the load on a particular bone increases, it will remodel itself over time to become stronger to resist that load.

[0100] Vertebra

[0101] Each vertebra is an irregular bone in the vertebral column of vertebrates that has a complex structure composed of bone and some hyaline cartilage. The proportions vary according to the segment of the spine and the vertebrate species.

[0102] The basic structure of the vertebra is variable. Most of it is the body, and the central part is the vertebral body. The upper and lower surfaces of the vertebral body are attached to the intervertebral disc. The posterior part forms the vertebral arch of eleven parts, consisting of two pedicles, two laminae, and seven processes. The laminae are attached to the ligamentum flavum (spinal ligament). There are vertebral notches formed by the shape of the pedicles, and when the vertebrae perform articular movements, the pedicles form the intervertebral foramina. These foramina are the passageways for the spinal nerves to enter and exit. The vertebral body and the vertebral arch form the vertebral foramen, which is a large central opening that houses the spinal canal, and the spinal canal surrounds and protects the spinal cord.

[0103] The pedicles and laminae form the vertebral arch. Two pedicles extend from the sides of the vertebral body to connect the vertebral body to the vertebral arch. The pedicles are short, thick processes, one on each side, extending posteriorly from the junction of the posterolateral surface of the vertebral body to its upper surface. From each pedicle, a broad plate called the "lamina" projects posteriorly and medially to join and complete the vertebral arch and form the posterior boundary of the vertebral foramen, which completes the triangle of the vertebral foramen. The upper surface of the lamina is rough for attachment to the ligamentum flavum. These ligaments connect the laminae of adjacent vertebrae along the length of the spine from the level of the second cervical vertebra. Above and below the pedicles are shallow depressions called vertebral notches (superior and inferior). When the vertebrae perform articular movements, the notches align with those on adjacent vertebrae, thus forming the intervertebral foramen openings. The foramina allow the spinal nerves and associated blood vessels to enter and exit each vertebra. The articular movement of the vertebrae provides a strong pillar for the body.

[0104] Device

[0105] The present disclosure provides a device formed by the scaffolds disclosed herein. In certain embodiments, the device is hollow and perforated with the scaffolds. In certain embodiments, according to the compressive force, the device includes a threaded distal region, an optionally threaded central region, and an optionally threaded proximal region.

[0106] In certain embodiments, the device is selected from pedicle screws, hollow pedicle screws, perforated pedicle screws, large head screws, small head screws, headless screws, traumatic hip fracture devices, glenoid cages, glenoid cage screws, traumatic protection plates, tibial stems, femoral stems, hammer toe implants, screw fusion systems, Charcot foot deformity correction, radial head fracture devices, high tibial osteotomy, deformity correction, vertebral resection cages, tumor correction, anchors, dental implants, maxillofacial implants, and sports medicine anchors.

[0107] In certain embodiments, the device is selected from hip fracture systems, reverse total shoulders, dental implants, upper extremity hardware, lower extremity hardware, total joint replacement implants, total joint revision implants, spinal fusion, spinal arthroplasty, regenerative therapies, cartilage implants, maxillofacial hardware, and cardiac implants.

[0108] In some embodiments, the screw is configured to have features of a structure facilitating bone growth through the screw from opposite sides, thereby allowing bone connection through the screw. In some embodiments, the structure is narrow, such as through threading, allowing for rapid ingrowth. In some embodiments, the structure is deeper, such as through a smaller diameter, thus providing a stronger bond. In some embodiments, the feature is a void in the screw or is porous or structured to promote bone growth. In some embodiments, the structure collects autograft in a channel inside the device. In some embodiments, the feature is impregnated with one or more polymers.

[0109] In some embodiments, the device is configured to enhance the stability and fixation of the bone screw within bone and improve bone mineral density. In some embodiments, the device includes a spinal implant configured to engage cortical and cancellous bone within a vertebra. In some embodiments, the device is configured to resist and / or prevent toggling 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, pull-out of the bone screw from the vertebra. 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 bone, thereby reducing pull-out. In some embodiments, the bone screw is designed to disperse micromotion and reduce shear to enhance bone mineral density.

[0110] In some embodiments, the device includes a bone screw having bone ingrowth through the shaft of the screw to reduce toggling and potential failure of the screw. In some embodiments, the bone screw includes features of a structure allowing bone to grow through the bone screw from opposite sides, thereby allowing bone connection through those bone screw structures. In some embodiments, the bone screw includes features that can be narrow, such as through the bone screw threading, which will allow for rapid ingrowth. In some embodiments, the bone screw includes features that can be deeper, such as through a smaller diameter, which will provide a greater volume of bone ingrowth. In some embodiments, the bone screw includes features that can be voids or cavities through opposite sides of the bone screw and / or voids or cavities entering and exiting the same or adjacent surfaces. In some embodiments, the void or cavity can contain a scaffold for bone attachment or a porous structure on the void surface.

[0111] In some embodiments, the bone screw includes features or structures that can be disposed along the shaft portion of the bone screw. In some embodiments, the bone screw includes features or structures that can be disposed continuously along the surface of the bone screw (such as, for example, along the distal end). In some embodiments, the bone screw includes features or structures that can be disposed discontinuously along a portion of the bone screw. In some embodiments, the bone screw includes features or structures that can include a scaffold or polymer.

[0112] In some embodiments, the device includes a spinal implant having a hybrid configuration that combines manufacturing methods, such as, for example, one or more previously manufactured features and materials, and manufacturing methods, such as, for example, 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 rapid prototyping, desktop manufacturing, direct manufacturing, digital manufacturing, instant manufacturing, and on-demand manufacturing. In some embodiments, the device includes a spinal implant manufactured and grown or otherwise printed by a fully additive process.

[0113] In certain embodiments, the device comprises one or more selected from demineralized bone matrix (DBM), pre-filled DBM, pre-filled synthetic DBM, unfilled DBM, and magnesium-injected titanium.

[0114] 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 an additive manufacturing material, wherein the bone screw can benefit from the materials and properties of additive manufacturing. In some embodiments, traditional materials are used, wherein benefits such as physical properties and cost are superior to those provided by additive manufacturing features and materials.

[0115] In some embodiments, the device treats spinal disorders selected from degenerative disc disease, disc herniation, osteoporosis, spondylolisthesis, stenosis, scoliosis, other curvature abnormalities, kyphosis, tumors, and fractures.

[0116] "Treating" or "treatment" of a disease or disorder refers to a procedure that may include: administering one or more drugs to a patient, using an implantable device and / or using an instrument for treating a disease (such as a microdiscectomy instrument for removing a portion of a bulge or disc herniation and / or bone spur) to relieve the signs or symptoms of the disease or disorder. Treatment does not require complete relief of signs or symptoms, does not require a cure, and specifically includes procedures that have a marginal effect on the patient. For example, treatment may include inhibiting the disease, such as preventing its progression, or alleviating the disease, such as causing regression.

[0117] "Preventing" refers to alleviating before the signs or symptoms of a disease or disorder appear. Thus, prevention includes preventing a patient who is susceptible to the disease but has not been diagnosed with the disease from developing the disease.

[0118] "Tissue" includes soft tissue, ligament, tendon, cartilage, and / or bone. In certain embodiments, the tissue is cancellous bone, cortical bone, or cortico-cancellous bone.

[0119] In some embodiments, the device is used with other bone and bone-related applications, including diagnosis and treatment. In some embodiments, the device is alternatively used in surgical treatment with the patient in the prone or supine position and / or with various surgical approaches to the spine, including anterior, posterior, posterior midline, lateral, posterolateral, and / or anterolateral approaches, and for other body regions such as the maxillofacial and extremities. The device may also alternatively be used with procedures for treating the lumbar, cervical, thoracic, sacral, and pelvic regions of the spine. The device can also be used on animals, bone models, and other non-living substrates, for example, for training, testing, and demonstration.

[0120] In certain embodiments, the device is a custom medical device. In certain embodiments, the device is suitable for sports medicine.

[0121] In certain embodiments, the device is temperature-sensing. In certain embodiments, the device is pH-balanced.

[0122] In certain embodiments, the device is fabricated with a porosity using a pore former that is spherical, cubic, rectangular, elongated, tubular, fibrous, disc-shaped, flake-shaped, polygonal, or a mixture thereof. In some embodiments, the porosity is based on a plurality of macropores, micropores, nanopore structures, and / or combinations thereof.

[0123] In certain embodiments, the device is made of a biologically acceptable material suitable for medical applications, including metals, synthetic polymers, ceramics, bone materials, and composites thereof. In certain embodiments, the device includes one or more selected from metals, ceramics, rubber, hydrogel, rigid polymers, fabrics, bone materials, and composites thereof.

[0124] In certain embodiments, the device comprises a metal selected from: stainless steel alloys, aluminum, commercially pure titanium, titanium alloys, grade 5 titanium, superelastic titanium alloys, magnesium-infused titanium, cobalt-chromium alloys, superelastic metal alloys such as nitinol, superelastic-plastic 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: polyaryletherketone (PAEK), polyetheretherketone (PEEK), polyetherketoneketone (PEKK), polyetherketone (PEK), carbon-PEEK composites, PEEK-BaSO 4 rubber, polyethylene terephthalate (PET), silicone, polyurethane, silicone-polyurethane copolymers, and polyolefin rubbers. 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 polyphenylene, polyimide, polyetherimide, polyethylene, and epoxy resins. In certain embodiments, the device comprises a bone material selected from autograft, allograft, xenograft, or transgenic cortical bone and / or cortical cancellous bone. In certain embodiments, the device comprises a tissue growth or differentiation factor. In certain embodiments, the device comprises a resorbable material, such as a composite of a metal and a calcium-based ceramic, a composite of PEEK and a calcium-based ceramic, a composite of PEEK and a resorbable polymer, a fully resorbable material, such as a calcium-based ceramic, e.g., calcium phosphate, tricalcium phosphate (TCP), hydroxyapatite (HA)-TCP, calcium sulfate, or other resorbable polymers, such as polyketone compounds, polyglycolide, polytyrosine carbonate, polycaprolactone, and other combinations, such as hydrogels, laponite, and / or other shear-thinning materials.

[0125] In certain embodiments, the device comprises a rubber selected from: polyaryletherketone (PAEK), polyetheretherketone (PEEK), polyetherketoneketone (PEKK), polyetherketone (PEK), carbon-PEEK composites, PEEK-BaSO 4 rubber, polyethylene terephthalate (PET), silicone, polyurethane, silicone-polyurethane copolymers, polyolefin rubbers, synthetic collagen, and collagen matrix. In certain embodiments, the device comprises synthetic collagen. In certain embodiments, the device comprises a collagen matrix.

[0126] In certain embodiments, the device comprises magnesium, vitamins, and minerals. A "vitamin" refers to an organic molecule (or a group of chemically closely related molecules, i.e., vitamers) that is an essential micronutrient required in small amounts by an organism for the normal functioning of its metabolism. Some sources list fourteen vitamins, including choline, but major health organizations typically list thirteen: vitamin A (as all-trans retinol, all-trans retinyl esters, and all-trans β-carotene and other provitamin A carotenoids), vitamin B 1 (thiamine), vitamin B 2 (riboflavin), vitamin B 3 (niacin), vitamin B 5 (pantothenic acid), vitamin B 6 (pyridoxine), vitamin B 7 (biotin), vitamin B 9 (folic acid or folate), vitamin B 12 (cobalamin), vitamin C (ascorbic acid), vitamin D (calciferol), vitamin E (tocopherols and tocotrienols), and vitamin K (phylloquinone and menaquinones). In nutrition, a "mineral" refers to a chemical element required by an organism as an essential nutrient to perform life-essential functions, including potassium, chlorine, sodium, calcium, phosphorus, magnesium, iron, zinc, manganese, copper, iodine, chromium, molybdenum, selenium, and cobalt.

[0127] In certain embodiments, the device comprises a metal selected from the group consisting of iron, stainless steel alloy, aluminum, commercially pure titanium, titanium alloy, grade 5 titanium, superelastic titanium alloy, magnesium-infused titanium, cobalt-chromium alloy, superelastic metal alloys such as nitinol, superelastic-plastic metals such as Gum In certain embodiments, the device comprises titanium. In certain embodiments, the device comprises iron.

[0128] In certain embodiments, the device is manufactured or 3D printed from materials such as titanium, titanium alloy, cobalt-chromium alloy, carbon fiber, magnesium-infused titanium, iron, or stainless steel. In certain embodiments, the device is made of a shape memory alloy or a shape memory polymer, thereby allowing the device to conform to the anatomical shape of the patient's body.

[0129] In certain embodiments, the device comprises magnesium-infused titanium. In certain embodiments, the device comprises an angiotensin receptor blocker coating. In certain embodiments, the device comprises a type 1 collagen coating for cartilage. In certain embodiments, the device is infused with an antibiotic.

[0130] In certain embodiments, the device is used to treat an affected portion of a vertebra. A practitioner gains access to the surgical site, including the vertebra, in any suitable manner, such as by incising and retracting tissue. In certain embodiments, the device includes bone screws to enhance the surgical treatment. In certain embodiments, the device may be pre-assembled for delivery to the surgical site or assembled in situ. In certain embodiments, the device is fully or partially modified, removed, or replaced.

[0131] 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, whereby access to the vertebra is gained through a mini-incision or a cannula provides a protected passage to the area. Once access to the surgical site is obtained, a surgical treatment, such as a vertebrectomy or a discectomy, can be performed to treat a disease or disorder.

[0132] In certain embodiments, the surface of the device includes a non-solid configuration, such as a mesh. In some embodiments, the non-solid configuration includes a porous structure or a trabecular configuration.

[0133] In various embodiments, the non-solid configuration is configured to provide one or more paths to assist bone growth within the device and through from one surface of the device to the opposite surface. In some embodiments, the mesh includes one or more sections, layers, or substrates. In some embodiments, one or more sections, layers, or substrates of the mesh are arranged side by side, offset, staggered, stepped, tapered, end-to-end, spaced apart, in series, or parallel. In some embodiments, the mesh defines a thickness that can be uniform, wavy, tapered, increasing, decreasing, variable, offset, stepped, arched, angled, and / or staggered. In some embodiments, one or more mesh layers are arranged within a wall in a side-by-side parallel orientation. In certain embodiments, the mesh includes one or more layers of a material matrix.

[0134] In some embodiments, the mesh 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.

[0135] In some embodiments, the mesh forms a file-like configuration. In some embodiments, the mesh is configured to engage tissue. In certain embodiments, the engagement of the mesh is to cut, shave, shear, incise, or disrupt tissue. In some embodiments, the mesh includes a configuration selected from: cylindrical, circular, oval, rectangular, triangular, polygonal with planar or arcuate side portions, irregular, uniform, non-uniform, consistent, variable, horseshoe-shaped, U-shaped, or kidney bean-shaped. In some embodiments, the mesh is rough, textured, porous, semi-porous, shallowly recessed, knurled, toothed, grooved, or polished, e.g., to engage and cut tissue. In some embodiments, the mesh forms a tunnel that is configured to direct, drive, or guide the cut tissue into an opening, such as fusing the device to the tissue.

[0136] In certain embodiments, an adapter for injecting material into a bone screw is provided, the adapter including a shaft having a proximal end and a distal end; a cannula disposed through the center of the shaft; a female bore lock at the proximal end for reversibly engaging a male cone on a syringe; a male conical surface on the distal end for engaging a female conical surface on the bone screw; and threads on the shaft between the female bore lock and the male conical surface configured to reversibly engage a groove on a tulip-shaped member head.

[0137] In some embodiments, the female bore lock of the adapter can be a female Luer lock and the male cone can be a male Luer cone.

[0138] In certain embodiments, a component for injecting material (such as injecting material or withdrawing material from a bone screw) into a bone screw is provided. The component includes an adapter having various features including a shaft, a cannula, a female bore lock, a male conical surface, and threads.

[0139] In additional embodiments, a component including a bone screw is provided. The bone screw includes a shaft having a proximal end and a distal end; a female conical surface on the proximal end for reversible engagement with a male conical surface of an adapter; a cannula disposed through the central axis of the shaft; and a scaffold within the shaft to promote bone integration, the scaffold including an internal mesh structure having a porous architecturally advanced structure formed by a combination of mean curvature, Gaussian curvature, and net curvature characterizing the local shape of healthy trabecular bone.

[0140] In other embodiments, a method for injecting material into a bone screw is provided. Herein, a syringe is engaged to an adapter, and the material in the bone screw is circulated via negative pressure from the plunger of the withdrawn syringe or by positive pressure from pressing the plunger of the syringe. The method causes a bio-ripple effect, without wishing to be bound by theory, which promotes healing, including the binding of stem cells to the screw scaffold and the growth of osteoclasts and osteoblasts.

[0141] Screw

[0142] In certain embodiments, the device is a screw. In some embodiments, the screw is selected from the group consisting of threaded screws, pedicle screws, bolts, bone screws for side plates, intervertebral screws, uniaxial screws, fixed-angle screws, multi-axial screws, side-loading screws, sagittal adjustment screws, lateral sagittal adjustment screws, cone tips, double-rod multi-axial screws, midline lumbar fusion screws, and / or sacral bone screws.

[0143] In certain embodiments, the device is a bone screw. In certain embodiments, the device is a pedicle screw. See Figure 1 , which shows a pedicle screw implanted into the vertebral body of a vertebra through the pedicle. In certain embodiments, the pedicle screw has a cage, wherein the polymer is retained within the hollow and / or perforated portion of the screw.

[0144] 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.

[0145] In certain embodiments, post-implant options prevent revision surgery by polymer injection through the screw.

[0146] In certain embodiments, the pedicle screw does not exhibit screw loosening, screw pullout, rod breakage, or reduced bone mineral density.

[0147] In certain embodiments, the pedicle screw reduces one or more of screw loosening, screw pullout, rod breakage, and reduced bone mineral density.

[0148] The disclosed screws focus bone growth along the entire shaft to minimize shear stress at the distal end and to evenly distribute micromotion over the entire screw to promote bone ingrowth.

[0149] In certain embodiments, the pedicle screw scaffold provides options for patients with simple to complex bone density and immunodeficiency. In certain embodiments, the scaffold is impregnated with one or more biologics, antibiotics, demineralized bone matrix, nanotechnology, or regenerative medicine therapies.

[0150] See Figures 5 to 16, the structures of the pedicle screws 300, 400, 500 are specifically designed to assist bone ingrowth through the pedicle screws 300, 400, 500 by using the scaffold 280, similar to the natural trabecular bone in the vertebral body. In combination with the threads 230 and the scaffold 280, the core 260 assists in autograft harvesting during insertion to push the autograft into the built-in channels within the cores 260 of the pedicle screws 300, 400, 500. The walls around the holes harvest the autograft and act as a trephine. This structure also contributes to the structural integrity of the pedicle screws 300, 400, 500, resists bone mineral density loss, and reduces micromotion.

[0151] See Figures 2 to 16 , the pedicle screws 200, 300, 400, 500 disclosed herein overcome many of the failures of prior art pedicle screws. In certain embodiments, the pedicle screws lack a wiper effect. In certain embodiments, the pedicle screws resist pullout. In certain embodiments, the pedicle screws do not exhibit excessive micromotion. In certain embodiments, for example, due to separate screw sterilization and packaging, the pedicle screws have a low frequency of low toxicity microorganisms detected by ultrasonic treatment. In certain embodiments, the heads and shafts of the pedicle screws resist failure. In certain embodiments, the pedicle screws are suitable for each type of bone quality. In certain embodiments, the pedicle screws have sufficient thread depth. In certain embodiments, the pedicle screws withstand insertion torque, particularly at the junction of the head and the screw. In certain embodiments, when the screw is fully inserted, the fatigue life of the pedicle screw is not reduced. In certain embodiments, the pedicle screws have good instrumentation. In certain embodiments, the pedicle screws achieve angulation for rod reception. In certain embodiments, the pedicle screws do not have cyclic loading based on physiological conditions during walking. In certain embodiments, the pedicle screws do not fail in long segment posterior cervical fusions, thus eliminating the need for an accompanying C6 or T1 support pedicle. In certain embodiments, the pedicle screws distribute stress. In certain embodiments, the pedicle screws do not immunocompromise the patient. In certain embodiments, the pedicle screws do not include PEEK. In certain embodiments, the pedicle screws do not have tulip-shaped pieces or locking cap stress.

[0152] In some embodiments, the distal ends 220 of the pedicle screws 200, 300, 400, 500 have a surface configuration selected from angled, irregular, uniform, non-uniform, offset, staggered, tapered, arcuate, wavy, reticulated, porous, semi-porous, shallowly concave, pointed, textured, or combinations thereof. In some embodiments, the distal end 220 includes a nail configuration, barbs, expansion elements, raised elements, ribs, and / or spikes to provide a manufacturing platform for forming a portion thereon via additive manufacturing. In some embodiments, the distal end 220 has a cross-sectional configuration selected from oval, rectangular, triangular, square, polygonal, irregular, uniform, non-uniform, offset, staggered, tapered, or combinations thereof.

[0153] In certain embodiments, the pedicle screws 200, 300, 400, 500 include threads 230 extending between the proximal end 210 and the distal end 220. In certain embodiments, the threads 230 include an external thread form. In certain embodiments, the thread form includes a leading edge 231 having a front surface 235 and a trailing edge 232 having a rear surface 236. The front surface 235 defines a first opening 251. The rear surface 236 defines a second opening 252. In some embodiments, the first opening 251 and the second opening 252 are axially aligned. In some embodiments, the first opening 251 and the second opening 252 are circumferentially disposed around the thread form.

[0154] In some embodiments, the front surface 235 and / or the rear surface 236 includes 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., to cut, shave, shear, incise, or disrupt tissue. In some embodiments, the cutting edge is configured to be cylindrical, circular, oval, rectangular, triangular, polygonal with 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, shallowly concave, knurled, toothed, grooved, or polished to engage and cut tissue. In some embodiments, the cutting edge forms a tunnel configured to direct, drive, or guide the cut tissue into a void, such as fusing the screw with the tissue.

[0155] For example, the pedicle screws 200, 300, 400, 500 are manipulated by rotation or translation such that the cutting edges 271 of the screws cut tissue or bone and direct it into the core 260, thereby promoting bone growth and fusion to the pedicle screws 200, 300, 400, 500. In some embodiments, tissue is embedded into the core 260 to promote bone growth and fusion to the pedicle screws 200, 300, 400, 500. In some embodiments, a mesh is disposed within the core 260 to form a scaffold 280 for bone growth.

[0156] In some embodiments, the threads 230 are configured to be thin, closely spaced, or shallow to engage tissue. In some embodiments, the threads 230 include an increased pitch and an equal lead between the thread turns. In some embodiments, the threads 230 include a smaller pitch, or more thread turns per axial distance, to secure a stronger fixation to tissue or resist loosening from tissue. In some embodiments, the threads 230 are configured to be continuous along a portion. In some embodiments, the threads 230 are configured to be intermittent, staggered, or discontinuous. In certain embodiments, the threads 230 include a single thread turn.

[0157] In certain embodiments, the threads include a plurality of discrete threads. In certain embodiments, the threads have a concave profile.

[0158] In some embodiments, the threads 230 include penetrating elements, e.g., selected from a staple configuration, barbs, expansion elements, raised elements, ribs, or spikes. In some embodiments, the threads 230 are configured to be self-tapping or discontinuous at the distal end 220. In some embodiments, the distal end 220 is rounded. In some embodiments, the distal end 220 is self-drilling. In some embodiments, the distal end 220 includes a solid outer surface.

[0159] In certain embodiments, the screw is a 3D printed porous pedicle screw. Its porosity mimics natural vertebrae to attach and retain stem cells, growth factors, and other proteins within the structure of the pedicle screw and promote bone growth through the screw, thereby stabilizing the entire construct. During insertion into the vertebra, an in-built trephine collects autograft and regenerative cells within the porous matrix. The disclosed topography attracts bone-forming stem cells within and around the device, thereby reducing overall construct macro-movement. In certain embodiments, the device enables the surgeon to meet patient-specific needs, such as but not limited to, spraying / injecting regenerative products to stimulate the osteogenic cascade of bone formation, actively injecting antibiotics into the screw scaffold for diabetes-susceptible infections, and selecting to inject bone cement to further stabilize the construct in severely osteoporotic bone.

[0160] In certain embodiments, the screw reduces the revision rate, increases bone mineral density, and / or addresses patient-specific needs during spinal fusion. In certain embodiments, bone mineral density is improved, the construct is stabilized, and the likelihood of revision is reduced.

[0161] In certain embodiments, the screw is a 3D printed titanium porous pedicle screw having 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. An advantage of the porous structure is the ability to inject polymers and regenerative therapies through the screw. In certain embodiments, stem cell therapy is injected through the screw implant. In such embodiments, the likelihood of failure is reduced.

[0162] In certain embodiments, the surgeon can inject or coat the screw with autologous concentrated stem cells. Without wishing to be bound by theory, as the screw rotates during insertion into the vertebra, the holes in the screw use its 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, subsequently guiding the bone healing cascade within and around the screw. In these embodiments, the combination of the (a) osteoconductivity (bone growth on the surface), (b) osteoinductivity (cell recruiter for bone healing), and (c) osteogenicity (bone development and formation) healing cascades of the stem cells increases bone mineral density and supports excellent bone integration and pullout strength.

[0163] In certain embodiments, the patient is a diabetic and prone to infection. In these embodiments, the surgeon can inject a mixture containing a calcium sulfate product and an antibiotic through the screw or onto the screw within the pedicle before or after insertion to provide antibiotic delivery in the area. In certain embodiments, the antibiotic is delivered for between two and six weeks. Accordingly, the likelihood of revision due to infection is reduced.

[0164] Manufacture

[0165] The devices disclosed herein can be manufactured using a variety of methods. In some embodiments, manufacturing includes machining, such as subtractive, transformative, or formative manufacturing. In some embodiments, manufacturing includes cutting, grinding, rolling, forming, molding, casting, forging, extrusion, turning, lapping, cold working, or combinations thereof. In some embodiments, manufacturing includes a portion of the device formed by a medical machining process. In some embodiments, machining uses a computer numerical control (CNC) high-speed milling machine, Swiss machining device, CNC turning with a live tool, a fourth-axis EDM wire, and combinations thereof. In some embodiments, the manufacturing for forming a portion of the device includes a finishing process, such as laser marking, roll spray, shot peening, micro sandblasting, powder sandblasting, or combinations thereof.

[0166] In certain embodiments, the device is manufactured according to instructions from a computer and a processor, based on digital rendering and / or data of a selected configuration via additive manufacturing.

[0167] 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, desktop manufacturing, direct manufacturing, direct digital manufacturing, digital manufacturing, instant manufacturing, on-demand manufacturing, or combinations thereof.

[0168] 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.

[0169] In one embodiment, the device is constructed based on an imaging of a 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. The 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 materials, implant sizes, porosity, and manufacturing methods. In some embodiments, the configuration parameters include implant materials 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.

[0170] For example, digital renderings or data of a generating device are used for display from a graphical user interface or storage in a database attached to a computer and a processor. In some embodiments, a computer monitor saves, digitally manipulates, or prints a hard copy of the digital rendering or data. In some embodiments, the device is virtually designed on a computer monitor with a CAD / CAM program. In some embodiments, a processor executes code stored in a computer-readable storage medium to execute one or more computer instructions, e.g., transmitting instructions to an additive manufacturing device. In some embodiments, the database or computer-readable medium includes RAM, ROM, EPROM, magnetic, optical, digital, electromagnetic, flash drives, semiconductor technology, or a combination thereof. In some embodiments, the processor instructs the movement and rotation of motor control device components.

[0171] Regenerative medicine

[0172] ″Regenerative medicine″ refers to a branch of translational research in tissue engineering and molecular biology that involves replacing, engineering, or regenerating human cells, tissues, or organs to restore or establish normal function. The field holds promise for functionally curing previously irreparable tissues or organs by stimulating repair mechanisms within the patient, thereby engineering damaged tissues and organs. For example, during bone regeneration, new bone formation is primarily influenced by physicochemical cues in the surrounding microenvironment. Tissue cells exist within a complex scaffold physiological microenvironment.

[0173] In certain embodiments, regenerative medicine is combined with the scaffolds or devices disclosed herein. Autograft incorporation occurs in five stages: inflammation, angiogenesis, osteogenesis, osteoconduction, and remodeling.

[0174] Inflammation lasts approximately 7 to 14 days. The initial injury to the local blood supply and decortication result in a hematoma around the bone graft, into which inflammatory cells invade. Fibroblast-like cells in the inflamed tissue transform into a fibrovascular matrix. Perioperative anti-inflammatory drugs reduce the fusion rate due to the inflammatory process.

[0175] Vascular buds appear in the fibrovascular matrix, similar to scar tissue formation during angiogenesis. Primary membranous bone forms near the decorticated bone. Next, minimal endochondral ossification and intramembranous ossification occur.

[0176] During osteogenesis at weeks 4 to 5, repair includes increased angiogenesis, absorption of necrotic tissue, and differentiation of osteoblasts and chondrocytes. In particular, stem cells differentiate into osteoblasts. New bone extends toward the central region of the fusion mass. The cortical portion of the graft continues to be resorbed.

[0177] Osteoconduction is characterized by ingrowth into the host bone and creeping substitution. Osteoblasts produce new bone while osteoclasts resorb the graft bone simultaneously. The central region of the endochondral interface is observed at the center of the fusion mass, thus merging the lower and upper halves of the fusion. The pluripotent cells in this central region differentiate into cartilage tissue with less angiogenesis.

[0178] During remodeling at weeks 6 - 10, a peripheral cortical rim forms around the fusion. Marrow activity increases, thus forming secondary cancellous bone. The cortical rim thickens. Trabecular projections extend into the center of the fusion. Remodeling is typically completed one year after device implantation.

[0179] Pseudarthrosis (nonunion) is the main cause of postoperative pain and accounts for 45% - 56% of revisions. Bone fusion is directly related to successful clinical outcomes. Pseudarthrosis patients are asymptomatic in approximately 30% of cases. The incidence of symptomatic pseudarthrosis increases significantly at a younger age (43.8 years vs. 52.1 years, p < 0.01).

[0180] In certain embodiments, in single - level revision posterolateral lumbar fusion (PLF), bone marrow aspirate (BMA) replaces autograft bone together with allograft. In certain embodiments, bone marrow aspirate together with allograft is more cost - effective than recombinant human bone morphogenetic protein - 2 (rhBMP). In certain embodiments, allografts enriched with marrow - derived cells are compared with autografts in bone grafting and spinal fusion procedures. In certain embodiments, BMA increases the regenerative potential of cortical cancellous allografts. When treating unicameral bone cysts, the cure rate of injecting bone marrow with demineralized bone matrix is high (98.7%).

[0181] When introducing elements of the present disclosure or its embodiments, the articles "a", "an", "the", and "said" are intended to indicate the presence of one or more of the elements. The terms "comprising", "including", and "having" are intended to be inclusive and mean that there may be additional elements in addition to the listed elements.

[0182] Having described the present disclosure in detail, it will be apparent that modifications and variations are possible without departing from the scope of the present disclosure as defined in the appended claims.

[0183] Although the disclosure described herein is susceptible to various modifications and alternative iterations, specific embodiments thereof have been described in more detail above. However, it should be understood that the detailed description of the components is not intended to limit the present disclosure to the specific embodiments 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.

[0184] Example

[0185] The following examples are included to illustrate certain embodiments of the present disclosure. Those skilled in the art should understand that the techniques disclosed in the examples represent techniques that the inventors have found work well in the practice of the present disclosure. However, according to the present disclosure, those skilled in the art should understand that many changes can be made in the specific embodiments disclosed without departing from the spirit and scope of the present disclosure, and still obtain the same or similar results. Therefore, all content is to be construed as illustrative and not restrictive.

[0186] Table 1 - Reference signs

[0187]

[0188]

[0189] Example 1 - Pedicle screw

[0190] See Figures 2 to 4 , the pedicle screw 200 is 3D printed with titanium. The pedicle screw 200 includes threads 230 that are disposed around the shaft 240 and extend between a proximal end 210 and a distal end 220. The threads 230 include an external thread form that has a leading edge 231 with a front surface 235 and a trailing edge 232 with 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 pedicle screw 200 has a core 260 that extends from the proximal end 210 through the center of the pedicle screw 200 to the distal end 220. The distal end 220 includes two cutting members 270, each cutting member having a cutting edge 271

[0191] See Figures 5 to 7 , an embodiment of the pedicle screw 300 is 3D printed with titanium and has the bracket 280 disclosed herein. The pedicle screw 300 includes threads 230 that are disposed around the shaft 240 and extend between a proximal end 210 and a distal end 220. The shaft 240 includes two regions of the bracket 280 that are exposed to the outer surface of the pedicle screw 300. The threads 230 include an external thread form that has a leading edge 231 with a front surface 235 and a trailing edge 232 with 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 pedicle screw 300 has a core 260 filled with the bracket 280 that extends from the proximal end 210 through the center of the pedicle screw 300 to the distal end 220. The distal end 220 includes three cutting members 270, each cutting member having a cutting edge 271

[0192] See Figures 8 to 10 , another embodiment of the pedicle screw 400 is 3D printed with titanium and has the bracket 280 disclosed herein. The pedicle screw 400 includes threads 230 extending between a proximal end 210 and a distal tip 220 disposed around a shaft 240. The shaft 240 includes a region of the bracket 280 exposed to the outer surface of the pedicle screw 400, which region is between the middle seven turns of the threads 230. The threads 230 include an external thread form having a leading edge 231 with a front surface 235 and a trailing edge 232 with 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 pedicle screw 400 has a core 260 filled with the bracket 280, which core extends from the proximal end 210 through the center of the pedicle screw 400 to the distal tip 220. The distal tip 220 includes three cutting members 270, each cutting member having a cutting edge 271

[0193] See Figures 11 to 16 , another embodiment of the pedicle screw 500 is 3D printed with metal and has the bracket 280 disclosed herein. The pedicle screw assembly 500 includes a cap 510, a saddle 520, and a shaft 540, and, when present, a tulip 590 and a pair of pins 595. The cap 510 is configured to be coupled to the saddle 520 via cap threads 513 operatively disposed in a saddle groove 523. The saddle 520 is configured to be coupled to the shaft 540. In an embodiment of the pedicle screw having a tulip, the distal tip 220 of the shaft 540 may be disposed through a bottom opening 592 of the tulip 590 and held in place with pins 595 disposed through side openings 596 of the tulip 590.

[0194] The pedicle screw 500 includes threads 230 extending between a proximal end 210 and a distal tip 220 disposed around a shaft 240. The shaft 240 includes a region of the bracket 280 exposed to the outer surface of the pedicle screw 500, which region is between the middle thirteen turns of the threads 230. The threads 230 include an external thread form having a leading edge with a front surface and a trailing edge with a rear surface. The pedicle screw 500 has a core filled with the bracket 280, which core extends from the proximal end 210 through the center of the pedicle screw 500 to the distal tip 220. The distal tip 220 includes a cutting member 270.

[0195] See Figure 13 and Figure 14 , the cap 510 includes a cap body 514 having cap threads 513 that are helically disposed around the outer surface of the cap body 514 between a cap top 511 and a cap bottom 512.

[0196] See Figure 15 , the saddle 520 includes a saddle body 524 having a saddle top 521, a saddle bottom 522, and at least one saddle groove 523 disposed on the inner surface of the saddle body 524. The at least one saddle groove 523 is configured to receive and operatively couple to the cap thread 513. Also, the saddle bottom 522 is configured to receive and operatively couple to the proximal end 210 of the shaft 540.

[0197] See Figure 16 , when present, the tulip-shaped member 590 includes a tulip-shaped member body 594 having a top opening 591, a bottom opening 592, at least a pair of tulip-shaped member grooves 593 disposed on the inner surface of the tulip-shaped member body 594, and a pair of side openings 596 between the at least a pair of tulip-shaped member grooves 593 and the bottom opening 592. The at least a pair of tulip-shaped member grooves 593 are configured to receive and operatively couple to the thread 230 of the shaft 540 when the distal end 220 of the shaft 540 passes through the bottom opening 592 of the tulip-shaped member 590. After the thread 230 has engaged the at least a pair of tulip-shaped member grooves 593, a pair of pins 595 can be operatively coupled to the tulip-shaped member 590 through the pair of side openings 596.

[0198] When present, the holes in the bracket 280 facilitate bone ingrowth by screws. Other materials for making pedicle screws include pre-filled demineralized bone matrix (DBM), pre-filled synthetic DBM, unfilled DBM, and magnesium-injected titanium. During insertion, the built-in channel captures autograft. The screw has a double-ball angle and a low profile. The screw includes a locking cap with reverse-angle threads. The screw can be hollow or non-hollow.

[0199] In certain embodiments, the bracket 280 includes an internal grid structure having a porous architecture formed by a combination of mean curvature, Gaussian curvature, and net curvature, characterizing the local shape of healthy trabecular bone. In certain embodiments, the bracket 280 exhibits a geometry that is primarily hyperbolic, including saddle-shaped regions, spherical indentations, and cylindrical rod-like elements. In certain embodiments, the bracket 280 includes one or more structural cues selected from porosity, pore size, particle size, and surface topography that enhance at least one of multipotent mesenchymal stem cell (MSC) differentiation, 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. In certain embodiments, the bracket 280 is configured to accommodate one or more biologic agents.

[0200] The length of the screw is between 35 mm and 65 mm, and the diameter is between 4.5 mm and 8.5 mm. The rod is received as 5.5 mm.

[0201] The built-in channels for autograft collection enhance the structural integrity of the implant. These resist bone mineral density loss excellently and reduce micromotion. The random porosity pattern of the scaffold 280 is typical of natural trabecular bone. In addition, the built-in struts provide structural integrity. The pedicle screws 200, 300, 400, 500 are made of cobalt-chromium alloy, titanium, and titanium infused with magnesium.

[0202] The device was tested in cobalt-chromium alloy and met American Society for Testing and Materials (ASTM) standards 543, 1798, and 1717.

[0203] ASTM standard 543 evaluates the chemical reagent tolerance of plastic materials, including castings, thermo-molded, cold-molded, laminated resin products, and sheet materials. Three procedures are given, two under Practice A (immersion test) and one under 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. Specified standard reagents are used to establish results on a comparable basis, without excluding other chemical reagents relevant to specific chemical resistance requirements. Various exposure times, stress conditions, and exposure to reagents at elevated temperatures are specified. The type of conditioning (immersion or wet sheet / wiping method) depends on the end use of the material.

[0204] ASTM standard 1798 covers the measurement of uniaxial static, fatigue strength, and anti-loosening component interconnect mechanisms for spinal arthrodesis implants. This test method provides a means to mechanically characterize different designs of spinal implant interconnections. Various components and interconnections can be combined for static and fatigue testing of spinal implant constructs. This test method does not address the analysis of spinal implant constructs or sub-constructs, nor does it define the performance levels of spinal implants.

[0205] ASTM standard 1717 covers materials and methods for static and fatigue testing of spinal implant assemblies in vertebrectomy models. The test materials for combinations of spinal implant components can be specific, depending on the spinal location and the intended method of application to the spine. These test methods provide a basis for mechanical comparison between past, present, and future spinal implant assemblies. They allow comparison of spinal implant constructs with different intended spinal locations and methods of application to the spine. These test methods are not intended to define performance levels. Instead, these test methods provide guidelines for methods of load type and applied load, measuring displacement, determining yield load, and evaluating the stiffness and strength of spinal implant assemblies. Methods are defined for three static load types and one fatigue test for comparative evaluation of spinal implant assemblies.

[0206] In certain embodiments, the pedicle screws 200, 300, 400, 500 are individually packaged in dual Tyvek TM peel trays.

[0207] In certain embodiments, the pedicle screws 200, 300, 400, 500 are injected or sprayed with materials such as BMA concentrate, calcium phosphate, biologics, and / or antibiotics. The filled or coated screws are allowed to sit for 10 - 15 minutes prior to insertion to allow the material to absorb.

[0208] Example 2 - Hole lock

[0209] The present disclosure provides an assembly including a screw, a tulip, an adapter, and a syringe. In these assemblies, the holes in the proximal portion of the screw have been configured for the syringe to pull or push cells into or out of the screw structure before or after implantation.

[0210] See Figure 17 and Figure 18 , the pedicle screw 400 includes a shaft 240 having a bracket 280 and an intubation 290 extending from the proximal end 210 through the center of the shaft 240 into the bracket 280 toward the distal end 220; and threads 230 disposed around the periphery of the shaft 240. The proximal end 210 of the screw 400 includes a drive means 250 configured to reversibly engage a screwdriver, and a concave conical surface 250 configured to reversibly engage a convex conical surface 650 of an adapter 600.

[0211] See Figure 20 , an adapter 600 is provided for circulating material in the bone screw 400. The adapter 600 includes a shaft 640 having a proximal end and a distal end. An intubation 690 is disposed through the center of the shaft 640 between the proximal end and the distal end.

[0212] In some embodiments, a concave bore lock 610 is formed on the proximal end of the shaft 640 for reversibly engaging a male cone on a syringe. A male conical surface 650 is formed on the distal end of the shaft 640 and is configured to reversibly engage a female conical surface 250 on the bone screw 400. The relationship between the adapter 600 and the bone screw 400 is such that the male conical surface 650 of the adapter 600 reversibly engages the female conical surface 250 on the bone screw 400. This allows for a secure attachment of these components while also allowing for their disassembly when necessary.

[0213] To further illustrate these embodiments, Figure 21 an illustration of the components is shown Figure 20 highlighting the junction of the female conical surface of the screw and the male conical surface of the adapter.

[0214] In another embodiment, Figure 22 a front plan view of the adapter is shown Figure 23 and a rear plan view of the adapter is shown Figure 22 illustrating its top plan view, and Figure 24 a bottom plan view of it is shown. To understand the context of the adapter within the assembly, Figure 25 a front plan view of the arrangement of the bone screw and the syringe in the assembly is shown. Figure 26 A front plan view of the arrangement of the adapter is shown Figure 27 wherein the bone screw and the syringe are Figure 22 in the assembly. Figure 26 A front plan view of the arrangement of the tulip piece is shown Figure 28 wherein the Figure 22 adapter, the bone screw, and the syringe are Figure 26 in the assembly. Figure 29 A side plan view of the arrangement of the bone screw and the syringe in the assembly is shown. Figure 30 A side plan view of the arrangement of the adapter is shown Figure 22 wherein the bone screw and the syringe are Figure 26 in the assembly. Figure 31 A side plan view of the arrangement of the tulip piece is shown Figure 22 wherein the Figure 26 adapter, the bone screw, and the syringe are

[0215] In some embodiments, the adapter 600 and the bone screw 400 can be connected using different types of connection mechanisms. In these embodiments, instead of using the male conical surface 650 and the female conical surface 250 for reversible engagement, the connection mechanism can be a snap fit, a bayonet, or a magnetic coupling, or another type of connection mechanism known in the art that allows for reversible engagement and sufficient pressure to circulate material through the bone screw 400.

[0216] In some embodiments, the threads 630 of the adapter 600 are circumferentially disposed on the shaft 640 between the female bore lock 610 and the male conical surface 650. The threads 630 are configured to reversibly engage a groove on the tulip-shaped member 590. In some embodiments, the threads 630 on the shaft 640 of the adapter 600 are configured to reversibly engage a groove 593 on the inner surface of the top opening 591 of the tulip-shaped member 590. This connection provides stability to the assembly 800 while also allowing the adapter 600 to disengage from the tulip-shaped member 590 when needed.

[0217] In some embodiments, the female bore lock 610 is a female Luer lock and the male cone is a male Luer cone. As used herein, a "Luer cone" or "Luer lock" refers to a standardized system of small-scale fluid fittings for making leak-free connections between a male conical fitting on medical and laboratory instruments and its mating female component, including the end of a hypodermic syringe and a needle or a stopcock and a needle. ISO 80369 governs the Luer standards and test methods and is incorporated herein by reference.

[0218] In some embodiments, an assembly 800 is provided for circulating a material in the bone screw 400. The assembly 800 includes an adapter 600 that includes a shaft 640, a cannula 690, a female bore lock 610, a male conical surface 650, and threads 630, as described herein.

[0219] In some embodiments, the assembly 800 further includes a bone screw 400. The bone screw 400 includes a shaft 240, a female conical surface 250, a cannula 290, and a scaffold 280 for promoting bone ingrowth in the shaft 240. In some embodiments, the pores may be in fluid communication with the porous scaffold of the screw and / or one or more lumens. In some embodiments, the screw includes one lumen in fluid communication with the pores and extending the length of the screw towards the screw tip.

[0220] In some embodiments, the assembly 800 further includes a tulip-shaped member 590. The tulip-shaped member 590 includes a body 594 having a top opening 591, a bottom opening 592, an inner surface, and an outer surface. The bottom opening 592 is configured to engage the proximal end of the bone screw 400. The inner surface at the top opening 591 includes a groove 593 to reversibly engage the threads 630 of the adapter 600.

[0221] In certain embodiments, the tulip-shaped member 590 further includes a pair of side openings 596 disposed on opposite sides of the body 594. The side openings 596 are configured to reversibly engage a pin 595 that locks the tulip-shaped member 590 to the bone screw 400. This locking mechanism provides additional stability to the assembly 800 while allowing the tulip-shaped member 590 to be detached from the bone screw 400 when necessary.

[0222] In certain embodiments, the assembly 800 further includes a syringe 700. The syringe 700 includes a barrel 740 having a distal end, a proximal end, and a lumen; a plunger 760 disposed within the lumen; and a male cone 710 formed on the distal end and configured to reversibly engage a female bore lock 610 of the adapter 600. In certain embodiments, the syringe 700 interacts with the adapter 600 through the engagement of the male cone 710 of the syringe 700 with the female bore lock 610 of the adapter 600. This connection facilitates the circulation of the material within the bone screw 400 by creating a negative pressure by withdrawing the plunger 760 of the syringe 700 or a positive pressure by pressing the plunger 760 of the syringe 700.

[0223] In certain embodiments, the bone screw 400 is a pedicle screw. In certain embodiments, the bone screw 400 concentrates bone growth throughout the shaft 240 to minimize shear stress on the distal end 220, and spreads micromotion throughout the bone screw 400 to promote ingrowth of bone. In certain embodiments, the bone screw 400 is configured with an arcuate cross-sectional pattern that varies from the proximal end to the distal end 220 for placement within an internal cavity of a bone body such that when the bone screw 400 is rotated coaxially, an autograft is harvested within the stent 280. In certain embodiments, the bone screw 400 further includes at least one autologous product sprayed on or injected through the bone screw 400.

[0224] In certain embodiments, a method for circulating the material within the bone screw 400 is provided. The method includes engaging the syringe 700 to the adapter 600 and circulating the material within the bone screw 400 using a negative pressure from withdrawing the plunger 760 of the syringe 700 or a positive pressure by pressing the plunger 760 of the syringe 700.

[0225] In certain embodiments, the method for circulating the material within the bone screw 400 may not rely on the negative or positive pressure from the syringe 700. In these embodiments, different methods (such as a pump or an impeller, or another method known in the art for generating a pressure difference sufficient to circulate the material) may be used to circulate the material within the bone screw 400.

[0226] In certain embodiments, healing includes the binding of stem cells to the scaffold 280 of the bone screw 400 and the growth of osteoclasts and osteoblasts.

[0227] In certain embodiments, the syringe 700 is loaded with material prior to being engaged to the adapter 600, and the material is pushed into the bone screw 400.

[0228] In certain embodiments, the material is circulated by alternating negative and positive pressure on the bone screw 400. In certain embodiments, this circulation produces a bio-ripple effect that induces and promotes healing.

[0229] In certain embodiments, the screw includes a thickened head-neck junction below the hole, for example, to reduce the likelihood of rod breakage during screw installation.

[0230] In certain embodiments, prior to locking the syringe to the adapter, materials such as antibiotics or therapeutic agents are inside the syringe. In this way, the materials are circulated with the bone marrow.

[0231] In certain embodiments, the syringe further includes a mixer. In certain embodiments, the syringe and / or the Luer lock includes an integrated mixing device to combine materials such as therapeutic agents, blood, drugs, bone marrow, peptides, regenerative therapeutic agents, and / or polymers.

[0232] In certain embodiments, the syringe is pre-loaded with a therapeutic agent. The therapeutic agent is selected from drugs, biologics, powders, peptides, polymers, and regenerative therapies.

[0233] In certain embodiments, the assembly further includes a filter. When present, the filter may or may not be on the inside or periphery of the adapter. Generally, the filter is a disposable membrane-based device for removing particulate impurities from small (≤100 mL) liquid samples. Those skilled in the art select the syringe filter based on the desired end application; disposable syringe filters are commonly used in laboratories for rapid and efficient filtration, material purification, or even sterilization. Sterile filters sterilize non-sterile solutions or clarify sterile solutions. Non-sterile filters are used for general filtration and sample purification.

[0234] These filters typically include two components: a membrane and a housing. The housing is matched based on composition and form, while the membrane is matched to the final application based on composition, filter diameter, and pore size. Typical housing forms include, but are not limited to, classic, overmolded, and domed. Examples of filter housing materials include, but are not limited to, high-density polyethylene (HDPE), modified acrylic, polycarbonate, polypropylene, polyvinyl chloride (PVC).

[0235] The two most commonly used membrane pore sizes are 0.45 μm and 0.2 / 0.22 μm. The 0.45-μm membrane is typically used for general filtration and particle removal applications. The 0.2 / 0.22-μm membrane or sterilizing grade membrane is most commonly used for solution sterilization (e.g., bacteria removal). Examples of filtration membranes include, but are not limited to, cellulose acetate, cellulose nitrate, glass fiber, mixed cellulose ester (MCE), polyamide, poly(ether sulfone) (PES), polypropylene, polysulfone, polytetrafluoroethylene (PTFE) (hydrophilic, hydrophobic, or mixed), polyvinylidene fluoride (PVDF), and regenerated cellulose. "Regenerated cellulose" refers to a class of materials made by converting natural cellulose derivatives and then regenerating, typically forming fibers (such as rayon) or membranes (such as cellophane).

[0236] Example 3 - Sheep study for osseointegration and pull-out strength

[0237] In vivo evaluations, in vitro evaluations, and data from these six ovine studies will determine how this treatment modality affects bone mineral density, polymorphonuclear cells (PMNs), lymphocytes, plasma cells, macrophages giant cells, necrosis, osteoblasts, signs of bone remodeling by osteoclasts, neovascularization, fibrosis, signs of implant degradation, and particulate debris.

[0238] The first specific objective is to determine whether, in an ovine model of posterior lumbar interbody fusion, porous pedicle screws promote bone integration and pullout strength compared to the gold standard pedicle screw / rod construct. The topography of the 3D-printed porous pattern has higher adhesion of stem cells to titanium. Additionally, mesenchymal and hematopoietic stem cells have a therapeutic effect on bone. By combining these two approaches, the disclosed porous pedicle screws can achieve superior results in terms of bone integration and pullout strength compared to current pedicle screws.

[0239] To this end, 84 vertebral bodies (L 1 -L 6 ) from six sheep were measured for bone mineral density (BMD) at one week preoperatively and at 24 and 36 weeks postoperatively. Each subject will undergo two separate lumbar interbody fusion (LIF) procedures at the L 2 -L 3 and L 4 -L 5 joints. L 1 and L 6 will be blank controls to compare changes with and without hardware.

[0240] Table 2 - Animal subjects

[0241]

[0242]

[0243] In each subject, the titanium intervertebral fusion cage and the bone void filler packed into the intervertebral fusion cage will be placed between L 2 -L 3 and L 4 -L 5 segments. Then, screws with a diameter of 4.5 mm, 5.5 mm or 6.5 mm and a length of 45 ± 10 mm will be inserted into the right and left pedicles of the vertebral bodies of L 2 , L 3 , L 4 and L 5 . This configuration represents a traditional fusion device and surgical technique. Before insertion, the porous pedicle screws (treatment) will be sprayed with autologous stem cell concentrate along the length of the screws in the porous part.

[0244] All animals will undergo in vivo lumbar spine radiography immediately postoperatively (PO) and at sacrifice. Throughout the study, the animals will be visually evaluated at least once a day. Abnormalities such as signs of infection at the surgical site will be recorded. Thirty-six weeks after surgery, a total of 6 animals will be sacrificed.

[0245] After euthanasia, the lumbar segments (L 1 -L 5 ) will be freshly dissected into single functional spinal units (FSUs) (i.e., L 4 -L 5 ) for post-sacrifice evaluation. After fine dissection in the sagittal and coronal planes, high-resolution biplane digital radiographs and photographs will be taken at sacrifice. Non-destructive range of motion (ROM) biomechanics will be measured on all samples, including ROM biomechanics of flexion-extension, lateral bending, and axial rotation under pure moment loading up to 6.0 N-m, generating range of motion (degrees), construct stiffness (degrees / N-m), and neutral zone (degrees).

[0246] Destructive pedicle screw pullout will be tested. Quasi-static ramp failure testing will generate visually observed construct stiffness (N / mm), yield force (N), ultimate failure force (N), and failure mode (MOD). Destructive pedicle screw torque output will be tested for N = 1 of 4 screws from each, and the quasi-static torque to loosen the screw counterclockwise will generate the ultimate torque (Nm).

[0247] Other tests will include micro-computed tomography (MicroCT) of each FSU and associated pedicle screw, quantitative assessment (bone volume and bone density) of the posterior lumbar fusion (PLF) region, qualitative assessment of bone ingrowth around the pedicle screw, pedicle screw histology, organ histology, and static histomorphometric measurements of the screw regions of interest (ROI), including percentage of bone area within the ROI, percentage of fibrous tissue within the ROI, percentage of void space within the ROI, percentage of screw within the ROI, and percentage of bone growth onto the device.

[0248] Slides will be delivered to a board-certified pathologist for histopathological analysis. The pathologist will initially be blinded to the treatment parameters for each site. Then, when applicable, the grading scheme in Table 3 will be followed to analyze and grade the segments by cell type and response. After all slides have been scored for data post-processing, the pathologist will be unblinded so that they can compare the data to control samples.

[0249] Table 3 - Scoring system for histological evaluation of bone fragments by cell type and response

[0250]

[0251] Reference: ISO 10993-6 Annex E (Biological evaluation of medical devices - Part 6: Tests for local effects after implantation)

[0252] The histopathology report will include, but not be limited to, a summary of methods and materials, a list and qualitative data by the last time point and conclusions, low-power images, and representative photomicrographs to illustrate the findings. An unpaired t-test with an alpha (α) value of 0.05 will be performed to determine the statistical significance of the biomechanical and histomorphometric outcome parameters. Then, the data will be compared to similar retrospective studies.

[0253] The second specific aim of the study is to demonstrate that injecting and spraying autologous concentrated stem cells into and around pedicle screws is safe. Porous 3D-printed titanium interbody fusion cages are typically impregnated with autologous stem cells during surgery. They have been shown to be safe and are the gold standard for helping fusion between vertebrae after removal of the intervertebral disc. The study aims to demonstrate that the same method can be performed within the vertebrae of sheep to provide confidence in the safety for human clinical trials.

[0254] After sacrifice, histology will be compared to previous studies to determine polymorphonuclear cells (PMN), lymphocytes, plasma cells, macrophages Differences and similarities in giant cells, necrosis, osteoblast +, signs of bone remodeling by osteoclasts, neovascularization, fibrosis, signs of implant degradation, and particulate debris. Histological reports will also be compared and contrasted between control, blank, and treatment sites. An unpaired t-test with an alpha (α) value of 0.05 will be performed to determine the statistical significance of biomechanical and histomorphological outcome parameters. Injection of autologous stem cells within and around porous pedicle screws is expected to be safe compared to control screws, blank screws, and previous studies.

[0255] The third specific aim of this study is to show that porous pedicle screws have topographies and porous patterns for promoting stem cell adhesion. Human mesenchymal stem cells have the strongest adhesion affinity for titanium surfaces with a porosity between 50% and 70%, more robust and dense internal cell migration patterns, and high cell viability. Therefore, the porous patterns and topographies of porous pedicle screws should have adhesion properties similar to stem cells.

[0256] After sacrificing the sheep, the screws will be removed from the vertebrae and stem cell adhesion will be studied. Cell viability on the implant surface will be performed using a live / dead assay. Conditioned media assays will be used to study bone morphogenetic protein 2 (BMP2) expression levels, vascular endothelial growth factor (VEGF), osteocalcin, osteoprotegerin expression, DNA, and alkaline phosphatase activity.

[0257] A correlation between cell adhesion and 3D printed titanium patterns and porous pedicle screws will be shown. Porous pedicle screws exhibit better stem cell adhesion than control and blank subjects, as well as adhesion rates similar to previous studies.

[0258] Example 4 - Sheep study for infection

[0259] Another six-animal study will focus on testing the feasibility of injecting a mixture of calcium sulfate and antibiotics as a means of reducing the infection rate after spinal fusion. The primary aims of this project are to confirm (1) whether the tested pedicle screws contribute to excellent bone integration and pullout strength compared to the gold standard pedicle screw / rod construct in a sheep model of posterior lumbar interbody fusion; (2) whether injecting a mixture of calcium sulfate and antibiotics can reduce the infection rate after spinal fusion; and (3) whether the tested pedicle screws have topographies and porous patterns for injection to support the above objectives.

[0260] For the first aim, the rationale is that if a patient's bone is infected, the surgeon can protect the hardware by injecting an antibiotic mixture via the device. Through the proposed animal study, it will be confirmed that in infected and controlled areas (e.g., vertebrae), the pedicle screws will (1) protect the surgical hardware compared to the control (i.e., confirm that the infection has not spread to the hardware), and (2) reduce the infection in the bone.

[0261] The sheep model was chosen because sheep have the spine most similar to the human spine. The ovine vertebrae are large enough to accommodate the pedicle screws disclosed herein. Smaller animals are not feasible because the screws are too large for their bone.

[0262] This sample size was chosen to realistically assess feasibility and achieve proof of concept within the Phase I scope and timeline. Consistent with the planned objectives, the Phase I results will be interpreted as preliminary and tentative conclusions and will be used to inform the expected Phase II, in which a large, controlled, well-powered animal study can be proposed that evaluates efficacy endpoints in a scientifically rigorous manner.

[0263] The experimental design and methods will be substantially the same as those of the sheep study in Example 3 above, including Tables 2 and 3.

[0264] All references, patents, or applications (U.S. or foreign) cited in this application are hereby incorporated by reference as if they were written in full herein. In the event of any inconsistencies, the materials disclosed herein shall govern.

[0265] From the foregoing description, those skilled in the art can readily ascertain the essential characteristics of this invention, and without departing from the spirit and scope thereof, can make various changes and modifications to adapt it to various usages and conditions.

Claims

1. An adapter for circulating materials in a medical device, the adapter comprising: a shaft having a proximal end and a distal end; a cannula disposed through the center of the shaft between the proximal end and the distal end; a female bore lock formed on the proximal end for reversibly engaging a male cone on a pressure device; a male conical surface formed on the distal end and configured to reversibly engage a female conical surface on a medical device; and threads circumferentially disposed on the shaft between the female bore lock and the male conical surface, the threads being configured to reversibly engage a groove.

2. The adapter according to claim 1, wherein the medical device is a bone screw.

3. The adapter according to claim 1 or 2, wherein the pressure device is a syringe.

4. The adapter according to any one of claims 1 to 3, wherein the groove is located on a tulip-shaped member.

5. The adapter according to any one of claims 1 to 4, wherein the female bore lock is a female Luer lock and the male cone is a male Luer cone.

6. A component for circulating materials in a medical device, the component comprising an adapter, the adapter comprising: a shaft having a proximal end and a distal end; a cannula disposed through the center of the shaft between the proximal end and the distal end; a female bore lock formed on the proximal end for reversibly engaging a male cone on a pressure device; a male conical surface formed on the distal end and configured to reversibly engage a female conical surface on a medical device; and threads circumferentially disposed on the shaft between the female bore lock and the male conical surface, the threads being configured to reversibly engage a groove on an inner surface.

7. The component according to claim 6, wherein the medical device is a bone screw.

8. The component according to claim 6 or 7, wherein the pressure device is a syringe.

9. The component according to any one of claims 6 to 8, wherein the groove is located on a tulip-shaped member.

10. The component according to any one of claims 6 to 9, wherein the female bore lock is a female Luer lock and the male cone is a male Luer cone.

11. The component according to any one of claims 6 to 10, the component further comprising a medical device, the medical device comprising: a body having a proximal end and a distal end; a female conical surface formed on the proximal end and configured to reversibly engage the male conical surface of the adapter; a cannula disposed through the center of the body between the proximal end and the distal end, the cannula of the medical device reversibly engaging the cannula of the adapter upon assembly; and a stent for facilitating bone integration in the medical device.

12. The component according to claim 11, wherein the body is a shaft.

13. The component according to claim 12, wherein the medical device is a bone screw.

14. The component according to claim 13, wherein the bone screw is a pedicle screw.

15. The component according to any one of claims 11 to 14, wherein the scaffold comprises an internal lattice structure having a porous architecture formed by a combination of mean curvature, Gaussian curvature, and net curvature, characterizing the local shape of healthy trabecular bone.

16. The component according to any one of claims 11 to 15, wherein the scaffold exhibits a predominantly hyperbolic geometry, including saddle-shaped regions, spherical indentations, and cylindrical rod-like elements.

17. The component according to any one of claims 11 to 16, wherein the scaffold comprises one or more structural cues selected from porosity, pore size, particle size, and surface topography, which enhance at least one of multipotent mesenchymal stem cell (MSC) differentiation, osteoblast growth, extracellular matrix (ECM) deposition, and new bone formation.

18. The component according to claim 17, wherein the new bone formation occurs after MSC differentiation, osteoblast growth, ECM deposition, or a combination thereof.

19. The component according to any one of claims 11 to 18, wherein the scaffold is configured to accommodate one or more biological agents.

20. The component according to any one of claims 6 to 19, the component further comprising a tulip-shaped member, the tulip-shaped member comprising: a body having a top opening, a bottom opening, an inner surface, and an outer surface, wherein the bottom opening is configured to engage the proximal end of the medical device, and wherein the inner surface at the top opening includes the groove to reversibly engage the threads of the adapter.

21. The component according to claim 20, wherein the tulip-shaped member further comprises a pair of side openings disposed on opposite sides of the body, the side openings being configured to reversibly engage pins that lock the tulip-shaped member to the medical device.

22. The component according to any one of claims 6 to 21, the component further comprising a pressure device, the pressure device comprising: a barrel having a distal end, a proximal end, and a lumen; a plunger disposed within the lumen; and a male cone formed on the distal end and configured to reversibly engage the female hole lock of the adapter.

23. The component according to any one of claims 6 to 22, wherein the medical device concentrates bone growth throughout the body to minimize shear stress at the distal end and to minimize micromotion of the entire medical device due to ingrowth of bone.

24. The component according to any one of claims 6 to 23, wherein the medical device is configured to vary in arcuate cross-sectional pattern from the proximal end to the distal end of the medical device for placement into an internal cavity of an anatomical feature such that an autograft is harvested within the medical device when the medical device is rotated coaxially.

25. The component according to any one of claims 6 to 24, wherein the medical device further comprises at least one autologous product sprayed on the medical device or injected through the medical device.

26. A method of injecting a material into a medical device, comprising: engaging a pressure device and a medical device having a stent to the adapter according to any one of claims 1 to 25; and injecting a material into the medical device using negative or positive pressure from the pressure device.

27. The method according to claim 26, wherein the pressure device is a syringe having a plunger, and the material is circulated using negative pressure by withdrawing the plunger of the syringe or circulated using positive pressure by pressing the plunger of the syringe.

28. The method according to claim 26 or 27, wherein the pressure device is loaded with the material before being engaged to the adapter, and the material is pushed into the medical device.

29. The method according to claim 28, the method further comprising sucking a biological material into the pressure device and then injecting a mixture of the loaded material and the biological material into the medical device.

30. The method according to any one of claims 26 to 28, wherein the material is circulated by alternating negative and positive pressure on the medical device.

31. The method according to claim 29, wherein the circulation produces a biological ripple effect that induces and promotes healing.

32. The method according to claim 30, wherein the healing includes stem cells binding to the stent of the medical device.

33. The method according to claim 31, wherein osteoclasts and osteoblasts are grown.

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