Device with an open lock for a medical device - Patent application

Abstract

Provided herein are medical devices, assemblies, and methods for circulating materials within a medical device. The adapter includes a shaft, a cannula, a female orifice lock, a male conical surface, and threads, all designed for reversible engagement and material circulation. The assembly incorporates the adapter and is designed for use with a variety of medical devices, including bone screws. The method includes engaging a medical device having a pressurizing device and a scaffold with the adapter and circulating material in the medical device via negative or positive pressure. These innovations provide a versatile approach to circulating materials within a medical device, which can be beneficial in a variety of medical procedures and therapies and can increase the efficiency and effectiveness of material circulation.

Description

[Technical Field]

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

[0002] SUMMARY The present disclosure relates to adapters for medical devices, assemblies including these adapters and medical devices, and methods for infusing and circulating materials in medical devices.

[0003] Spinal fusion is a commonly indicated procedure for managing common degenerative conditions, including fractures, instability, and low back pain. Fusion techniques use bone grafts and hardware, such as pedicle screws, to encourage two vertebral bodies to grow together. The traditional lumbar implant design is a smooth-threaded pedicle screw that is fixed to the vertebrae with a rod to hold the correct height and angle until fusion is achieved.

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

[0005] A review of spinal fusion procedures in the PubMed database identified 11,692 patients. There were 3,646 complications. The mean age at surgery was 53.3 years (range: 25-77 years), and the mean follow-up was 3.49 years (range: 6 weeks-9.7 years). Major 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 remained substantially unchanged over the years. For example, lumbar interbody fusion (LIF) techniques have advanced due to computer navigation, augmented reality, minimally invasive surgical (MIS) approaches, disc arthroplasty, bone-stimulating pedicle screws, and bone void filler options. Nevertheless, due to an increasing patient population and high failure rates, the number of patients developing failed back surgery syndrome (FBSS) continues to increase. (FBSS is when the results of lumbar spine surgery do not meet the patient's and surgeon's preoperative expectations.)

[0007] The gold standard for lumbar interbody fusion involves inserting smooth-threaded screws into each pedicle (two per vertebral level) and placing rods in the tulip heads of the pedicle screws to stabilize the structure until fusion is achieved. However, since 1975, few technological advances have been made in spinal stabilization systems, and these configurations do not address important long-term stability issues related to bone mineral density quality and patient health. Hardware used in lumbar fusions is subject to significant forces that can cause hardware failure and loosening (the so-called "windshield wiper effect"). Estimates of the frequency of screw loosening during spinal fusion vary significantly, but recent reports estimate a loosening rate of over 40%, with approximately 10% being partial pullout. This loosening due to lack of fusion can put nerves or blood vessels at risk, often necessitating hardware removal and repeat surgery.

[0008] Unfortunately, spinal revision surgery also has a low success rate. Secondary revision cases have a 30% success rate, tertiary procedures 15%, and quaternary surgical interventions 5%. Furthermore, adult spinal deformity patients who have endured two or more previous revisions exhibit more coronal and sagittal imbalances and worse functional status. Other potential complications of LIF are dural tears, nerve injury, pseudarthrosis, infection, and wound healing problems.

[0009] Another complication of spinal fusion surgery is infection. Surgical site infections (SSIs) represent a major healthcare challenge, causing approximately 8,000 deaths annually. 21 The estimated total direct and indirect costs attributable to SSIs range from $1 billion to $10 billion per year. Instrumented spinal procedures pose a greater risk of SSI and result in higher infection rates compared to other orthopedic procedures. SSIs resulting from spinal surgery are estimated to occur at a rate of 0.2% to 16.7%. A recent meta-analysis suggested that instrumented spine procedures result in an SSI rate of 4.4%. Deep incision and organ space SSIs account for 80% of these infections and are associated with increased morbidity, longer hospital stays, and greater healthcare costs.

[0010] Furthermore, bone mineral density decreases after medical devices are implanted, regardless of the material used. This loss contributes to common medical device failures, including screw loosening, screw backout, and rod breakage. While many devices promote fusion within interbody cages, none have been developed for scaffolds that increase bone mineral density within vertebral bodies. Additionally, the structure of cortical bone within vertebrae differs from bone in other parts of the human body.

[0011] These challenges regarding long-term stability, including bone quality and functional ability to heal, remain unmet. None of the prior art addresses the top two reasons for implant failure revision surgery: pedicle screw backout and rod breakage before the patient achieves fusion. Smooth-threaded pedicle screws and rods do not address bone mineral density quality and patient health. Summary of the Invention

[0012] The present disclosure provides an adapter for injecting material into a medical device, the adapter comprising: a shaft having proximal and distal ends, a cannula disposed through the center of the shaft between the proximal and distal ends, a female aperture lock formed on the proximal end for reversibly engaging a male taper of a pressurizing device, a male conical surface formed on the distal end configured to reversibly engage a female conical surface on the medical device, and threads disposed around the shaft between the female aperture lock and the male conical surface, the threads configured to reversibly engage a groove.

[0013] The present disclosure also provides an assembly for injecting a material into a medical device, the assembly including an adapter comprising: a shaft having a proximal end and a distal end, a cannula disposed through the center of the shaft between the proximal and distal ends, a female aperture lock formed on the proximal end for reversibly engaging a male taper of a pressurizing device, a male conical surface formed on the distal end configured to reversibly engage a female conical surface on the medical device, and threads disposed around the shaft between the female aperture lock and the male conical surface, the threads configured to reversibly engage a groove on an interior surface.

[0014] The present disclosure further provides a method of infusing a material into a medical device, the method comprising engaging a pressure device and a medical device having a scaffold with an adapter as disclosed herein, and infusing 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 description that follows, and will become apparent to those skilled in the art upon examination of the specification or may be learned by practice of the embodiments discussed herein. A further understanding of the nature and advantages of particular embodiments may be realized by reference to the remaining portions of the specification and the drawings, which form a part of this disclosure. [Brief explanation of the drawings]

[0016] [Figure 1]FIG. 1 is a top view of a diagram showing a pedicle screw implanted through a pedicle into the vertebral body of a vertebra. [Figure 2] FIG. 1 shows a side view of one embodiment of a pedicle screw 3D printed in titanium. [Figure 3] 3 shows a top view of the pedicle screw of FIG. 2. [Figure 4] 3 shows a bottom view of the pedicle screw of FIG. 2. [Figure 5] FIG. 1 shows a side view of one embodiment of a pedicle screw 3D printed with a scaffold disclosed herein. [Figure 6] 6 shows a top view of the pedicle screw of FIG. 5. [Figure 7] 6 shows a bottom view of the pedicle screw of FIG. 5. [Figure 8] FIG. 14 shows a side view of another embodiment of a pedicle screw 3D printed with a scaffold disclosed herein. [Figure 9] 9 shows a top view of the pedicle screw of FIG. 8. [Figure 10] 9 shows a bottom view of the pedicle screw of FIG. 8. [Figure 11] FIG. 1 shows a side view of one embodiment of a porous pedicle screw. [Figure 12] 12 shows an exploded view of the porous pedicle screw of FIG. 11 with a tulip and pin. [Figure 13] 12 shows a top view of the cap of the porous pedicle screw of FIG. 11. [Figure 14] 12 shows a side view of the cap of the porous pedicle screw of FIG. 11. [Figure 15] 12 shows a perspective view of the saddle of the porous pedicle screw of FIG. 11. [Figure 16] 13 shows a perspective view of the tulip of FIG. 12. [Figure 17] 1 shows a cross-sectional view of a screw with an open locking feature at its proximal end, the screw having a lumen extending through a porous scaffold in the body of the screw. [Figure 18] FIG. 18 shows a top view of the screw of FIG. 17, showing the central opening at the proximal end of the screw. [Figure 19] 1 shows a perspective view of an adapter disclosed herein. [Figure 20] 20 shows a cross-sectional view of an assembly comprising a pedicle screw, a tulip, the adapter of FIG. 19, and a syringe. [Figure 21] 21 shows an inset of the assembly of FIG. 20 highlighting the junction of the female conical surface of the screw and the male conical surface of the adapter. [Figure 22] A front view of the adapter is shown. [Figure 23] 23 shows a rear view of the adapter of FIG. 22. [Figure 24] 23 shows a top view of the adapter of FIG. 22. [Figure 25] 23 shows a bottom view of the adapter of FIG. 22. [Figure 26] FIG. 10 shows a front view of the placement of the bone screw and syringe in the assembly. [Figure 27] 27 shows a front plan view arrangement of the adapter of FIG. 22 with a bone screw and syringe in the assembly of FIG. 26. [Figure 28] 26. FIG. 27 shows a front plan view arrangement of the tulip with the adapter of FIG. 22, the bone screw, and the syringe in the assembly of FIG. [Figure 29] 10 shows a side view of the placement of the bone screw and syringe within the assembly. [Figure 30] 27 shows a side view of the arrangement of the adapter of FIG. 22 with a bone screw and syringe in the assembly of FIG. 26. [Figure 31] 27 shows a side view of the placement of the tulip with the adapter, bone screw, and syringe of FIG. 22 in the assembly of FIG. 26.

[0017] The present disclosure will be readily understood from the following detailed description taken in conjunction with the accompanying drawings, in which like reference numerals indicate like structural elements, and in which: The drawings provide exemplary embodiments or aspects of the present disclosure and are not intended to limit the scope of the disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0018] The present disclosure provides an adapter for injecting material into 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; a female opening lock on the proximal end for reversibly engaging a male taper on a pressurizing device; a male conical surface on the distal end configured to reversibly engage a female conical surface on the medical device; and threads disposed around the shaft between the female opening lock and the male conical surface, the threads configured to reversibly engage a groove.

[0019] In certain embodiments, the medical device associated with the adapter is a bone screw. In certain embodiments, the pressurizing device associated with the adapter is a syringe. In certain embodiments, the groove that the adapter's threads engage is on a tulip. In certain embodiments, the adapter's female open lock is a female luer lock and the male taper is a male luer taper.

[0020] In certain embodiments, an assembly for injecting a material into a medical device includes an adapter with a shaft, a cannula, a female opening lock, a male conical surface, and a screw thread, all configured as described above.

[0021] In certain embodiments, the medical device associated with the assembly is a bone screw.In certain embodiments, the pressurizing device associated with the assembly is a syringe.

[0022] In certain embodiments, the groove that engages the threads of the adapter in the assembly is on the tulip.

[0023] In certain embodiments, the female open lock of the adapter in the assembly is a female luer lock and the male taper is a male luer taper.

[0024] In certain embodiments, the assembly further comprises a medical device having a body, a female conical surface, a cannula, and a scaffold for promoting osseointegration.

[0025] In certain embodiments, the body of the medical device in the assembly is a shaft.

[0026] 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.

[0027] In certain embodiments, the scaffolds in the assembly comprise an internal lattice structure with a porous architecture formed from a combination of mean curvature, Gaussian curvature, and net curvature that characterize the local geometry of healthy trabecular bone. In certain embodiments, the scaffolds in the assembly exhibit a predominantly hyperbolic shape, including saddle-shaped regions, spherical depressions, and cylindrical rod-like elements. In certain embodiments, the scaffolds in the assembly include one or more structural cues selected from porosity, pore size, particle size, and surface topography that enhance at least one of pluripotent mesenchymal stem cell (MSC) differentiation, osteoblast growth, extracellular matrix (ECM) deposition, and new bone formation. In certain embodiments, new bone formation in the assembly is subsequent to MSC differentiation, osteoblast growth, ECM deposition, or a combination thereof. In certain embodiments, the scaffolds in the assembly are configured to house one or more biological agents.

[0028] In certain embodiments, the assembly further comprises a tulip having a body, a top opening, a bottom opening, an inner surface, and an outer surface, the bottom opening configured to engage the proximal end of the medical device, and the inner surface of the top opening comprising a groove for reversibly engaging the threads of the adapter.

[0029] In certain embodiments, the tulip in the assembly further comprises a pair of side openings disposed on opposite sides of the body, the side openings configured to reversibly engage a pin that locks the tulip to the medical device.

[0030] In certain embodiments, the assembly further comprises a pressure device having a barrel, a plunger, and a male taper, the male taper configured to reversibly engage the female opening locking portion of the adapter.

[0031] In certain embodiments, the medical device in the assembly focuses bone growth throughout the body to minimize shear stress on the distal tip and minimize micromotion throughout the medical device due to bone ingrowth.

[0032] In certain embodiments, the medical device within the assembly is configured with an arcuate cross-sectional pattern that varies from the proximal end to the distal tip of the medical device for placement within the internal cavity of an anatomical feature, and thus the autograft is harvested within the medical device in response to coaxial rotation of the medical device.

[0033] In certain embodiments, the medical device in the assembly further comprises at least one autologous product that is sprayed onto or injected through the medical device.

[0034] The present disclosure further provides a method of injecting a material into a medical device, the method including engaging a pressure device and a medical device having a scaffold with an adapter, and injecting the material into the medical device using negative or positive pressure from the pressure device.

[0035] In certain embodiments, the pressurizing device in the method is a syringe with a plunger, and the material is circulated using negative pressure by withdrawing the plunger of the syringe or using positive pressure by pushing the plunger of the syringe.

[0036] In certain embodiments, the pressurizing device in this method is loaded with a material prior to engagement with the adapter, and the material is forced into the medical device.

[0037] In certain embodiments, the method further comprises drawing the biomaterial into a pressurized device and then injecting the mixture of the loaded material and the biomaterial into the medical device.

[0038] In certain embodiments, the material in the method is circulated by alternating negative and positive pressure on the medical device.

[0039] In certain embodiments, the circulation in this method creates a biological ripple effect that induces and promotes healing.

[0040] In certain embodiments, the healing in the method includes stem cells binding to the scaffold of the medical device.

[0041] In certain embodiments, the method results in the development of osteoclasts and osteoblasts.

[0042] Scaffold Surface curvature and Minkowski bone morphological curvature maps (functions that restore the concept of distance in linear space) show significantly different porous matrices in the trabecular bone within the vertebrae relative to other regions of the skeletal anatomy. The loads of conventional smooth-threaded pedicle screws may be too high for the vertebrae due to the loss of bone mineral density after implantation.

[0043] The porous 3D printed scaffold promotes osseointegration, healing, and fixation within the bone. The open framework of the scaffold resembles that of natural bone. This similarity allows the physician to make patient-specific choices using other agents to promote bone formation and / or stabilize the device.

[0044] Triangular shaped porous arrays have been previously described. Rounded, square / rectangular shapes and various patterns align more closely with natural vertebral bone structure. Furthermore, the scaffold structure reduces the likelihood of revision of the medical device from which the scaffold is fabricated, such as screw loosening, screw backout, rod breakage, and bone mineral density loss.

[0045] In certain embodiments, the disclosed scaffolds and devices integrate orthopedic products with tissue engineering and prevent the risk of delayed bone union to implanted devices.

[0046] In certain embodiments, the scaffold comprises one or more structural cues selected from porosity, pore size, particle size, and surface topography. Porosity and pore size cues mechanical strength, cell settlement, and cell migration. Particle size cues signal protein absorption, cell adhesion, cell proliferation, and cell adhesion. Surface topography cues signal specific surface area, cell adhesion, and material-tissue interface. Other scaffold characteristics include pH and wall thickness. In certain embodiments, the one or more structural cues enhance at least one of pluripotent 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.

[0047] In certain embodiments, the internal lattice structure of the scaffold mimics the geometric properties of healthy trabecular bone. In certain embodiments, the lattice structure comprises a combination of mean curvature, Gaussian curvature, and net curvature that characterize the local shape of the trabecular bone. Mean curvature (H) describes the local convexity or concavity of a surface, and Gaussian curvature (K) quantifies the type of surface (hyperbolic, essentially flat, or spherical). Net curvature (D) describes the local deviation of a surface from a planar region.

[0048] In certain embodiments, the lattice structure of the scaffold exhibits a predominantly hyperbolic shape (K<0), consistent with the high topological complexity of trabecular bone. In such embodiments, the structure comprises a combination of saddle-shaped regions, spherical depressions, and cylindrical rod-like elements. The distribution of curvature throughout the scaffold is designed to reflect the spatial correlation observed in healthy trabecular bone specimens, ensuring a more biomimetic design that aids in osseointegration, fusion, and fixation within the bone.

[0049] In certain embodiments, the internal lattice structure of the scaffold is based on the Minkowski functional, which provides a comprehensive and robust description of the overall shape of complex structures such as trabecular bone. The Minkowski functional includes scalar measures such as the total area of ​​interfaces (W1), the area-integrated mean curvature (W2), and the area-integrated Gaussian curvature (W3). These scalar measures capture the essential geometric properties of trabecular bone and enable more biomimetic designs that promote osseointegration, healing, and fixation within bone. Without being bound by theory, by incorporating the Minkowski functional into the scaffold design, the lattice structure may better reflect differences between specimens from various anatomical sites and potentially be more sensitive to subtle changes in connectivity, such as those caused by disease. This approach therefore ensures that the lattice structure of the scaffold closely mimics the natural shape of trabecular bone, enhancing its effectiveness in bone implant applications.

[0050] In certain embodiments, the Minkowski tensor (MT) captures orientation-dependent aspects of trabecular bone morphology. Six relevant rank-2 MTs are defined for 3D objects, including W02,0(B), W12,0(B), W10,2, and W20,2. Tensor W10,2 describes the distribution of surface normal vectors, W20,2 describes the distribution of mean curvature (curvature-weighted surface normals), and W12,0 measures the mass distribution when the total mass of B is uniformly distributed over the surface (i.e., for a "hollow" body).

[0051] 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 smallest and largest eigenvalues ​​of the tensor Wvr,s. In certain embodiments, different types of anisotropy of trabecular bone samples are quantified, including anisotropy of interface orientation (DA10,2) and mean curvature (DA20,2).

[0052] In certain embodiments, the ratio of the median to the maximum eigenvalue is plotted against the ratio of the minimum to the maximum eigenvalue, providing insight into the "ellipticity" of the bone specimen 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).

[0053] In certain embodiments, the Minkowski functional is applied to smaller substructures within the trabecular bone specimen to generate Minkowski maps that quantify the intra-specimen variation in the integral shape index. This spatially resolved analysis allows for local characterization of the ellipticity of the Minkowski tensors W10,2 and W20,2. The local degree of anisotropy (DA) can vary substantially across all samples, resulting in different distributions for both tensors. Clear angular differences in the local and global principal directions can also be observed for both tensors, with wider variations detected in the L2 and L4 specimens.

[0054] In certain embodiments, higher-order Minkowski tensors, such as the second-order (qs) and third-order (ws) rotation invariants of the irreducible Minkowski tensor, are calculated for spatially resolved specimens. These scalar invariants can be used as efficient structural metrics to detect local crystalline states in convex random packings. In certain embodiments, significant differences between the structural metric distributions of different bone types can be detected, demonstrating that these higher-order structural metrics are sensitive to structural differences between plate-like and rod-like specimens.

[0055] In certain embodiments, the surface curvature of trabecular bone is quantified using integrated shape descriptors (ISDs), which serve as effective shape fingerprints of trabecular bone from different anatomical sites. The ISDs capture the morphological differences between plate-like and rod-like specimens and intermediate morphologies along the plate-rod spectrum.

[0056] In certain embodiments, scalar and tensor Minkowski functionals are employed for global shape analysis of trabecular bone interfaces. These functionals are fundamental, highly versatile, and robust indices for integral shape quantification. In certain embodiments, Minkowski scalars are correlated with traditional bone morphometry indices. In certain embodiments, Minkowski tensors reveal different degrees of anisotropy and ellipticity depending on the morphological aspect considered.

[0057] In certain embodiments, higher-order Minkowski metrics are applied to shape quantification of spatially resolved bone specimens, demonstrating sensitivity to morphological differences in bone from different anatomical locations. The geometric properties of these metrics provide a unifying view and geometric foundation for traditional bone morphometric indices, which can advance our understanding of morphological changes in aging and disease, such as the plate-to-rod transition in osteoporosis.

[0058] In certain embodiments, the scaffold does not include planar truss units interconnected using multiple struts connected to multiple nodes, and one or more angles defined by two struts and a node of one or more planar truss units are different from one or more corresponding angles defined by two struts and a node of one or more other planar truss units. In certain embodiments, the scaffold does not need to connect exterior struts connecting nodes of non-conformal planar truss units to one another so that the implant has various heights.

[0059] In certain embodiments, a scaffold does not include an interior spatial truss structure at least partially enclosed by an exterior frame comprising two or more planar truss units with a plurality of struts joined at nodes, wherein at least two nodes in the interior spatial truss structure are connected by a strut that is curved or arced between the at least two nodes, and at least one of the two or more planar truss units lies in a plane that is not substantially parallel to the plane of at least one or more of the other two or more planar truss units.

[0060] In certain embodiments, the internal lattice structure of the scaffold does not comprise a web structure with multiple struts joined at nodes to form a space truss, the web structure is configured to interface with bone tissue, and the multiple planar truss units are interconnected such that one or more planar truss units lie in a plane that is not substantially parallel to the plane of a planar truss unit that shares at least one strut with the one or more planar truss units. Further, the scaffold does not have a predetermined strut diameter and / or length and / or web structure density such that at least a portion of the struts generate microstrains in attached osteoblasts, bone matrix, or lamella tissue when the web structure is in contact with bone.

[0061] bone Bones can generally be classified as cancellous bone and cortical bone. "Cancellous bone," also called "trabecular bone" or "spongy bone," is a light, porous bone that encloses numerous large spaces, giving it a honeycomb or spongy appearance. The bone matrix or skeleton is organized into a three-dimensional lattice of bony protrusions called trabeculae that are arranged along stress lines. The spaces between are often filled with bone marrow and blood vessels. In cross section, the trabeculae of cancellous bone may appear like septa. However, they are topologically distinct in three dimensions; trabeculae are roughly rod-like or column-like, while septa are sheet-like.

[0062] Cancellous bone constitutes about 20% of the human skeleton and provides structural support and flexibility without compact bone. It is found in most regions of bone that are not subjected to significant mechanical stress. It makes up many of the bulky ends (epiphyses) of long bones and is the major component of the ribs, scapulae, flat bones of the skull, and various short, flat bones elsewhere in the skeleton.

[0063] Due to the increasing frequency of total joint replacement surgery and its impact on bone remodeling, understanding the stress-related and adaptive processes of trabecular bone has become a central interest for bone physiologists. To understand the role of trabecular bone in age-related bone structure and design for bone-implant systems, the mechanical properties of trabecular bone are studied as a function of anatomical location, density, and age. Mechanical factors, including elastic modulus, uniaxial strength, and fatigue properties, are also investigated.

[0064] High porosity makes trabecular bone flexible. Large variations in architecture result in high heterogeneity. Elastic modulus and strength vary inversely with porosity and are highly dependent on the porous structure. Typically, cancellous bone has a porosity of 75% to 95%. Density is 0.2 to 0.8 g / cm. 3 Porosity reduces the strength of bone, but it can also reduce its weight.

[0065] Porosity and structure affect the strength of a material. Therefore, the microstructure of trabecular bone is typically oriented. The mechanical stiffness and strength are greatest when the porous "grains" are aligned. Due to the directionality of the microstructure, the mechanical properties of trabecular bone are highly anisotropic. The Young's modulus of trabecular bone, including vertebrae, is 800-14,000 MPa. Its fracture strength is 1-100 MPa.

[0066] "Cortical bone" or "compact bone" is much denser than cancellous bone. It forms the hard exterior (cortex) of bone. Cortical bone gives bone its smooth, white, and hard appearance. It accounts for approximately 80% of the total bone mass in the adult skeleton.

[0067] Trabecular bone is usually surrounded by a shell of compact bone, which provides greater strength and rigidity. The open structure of trabecular bone allows it to attenuate sudden stresses, such as load transmission through joints. Varying ratios of bone to air space are found in different bones, depending on the need for strength or flexibility. Trabecular bone also has a relatively high level of metabolic activity.

[0068] "Wolff's Law" states that a healthy human or animal's bone adapts to the loads it is placed on. For example, if the load on a particular bone increases, the bone will remodel itself over time to become stronger to resist the load.

[0069] vertebrae Each vertebra is an irregular bone in the vertebral column of a vertebrate, with a complex structure consisting of bone and some hyaline cartilage, the proportions of which vary according to the segment of the skeleton and the vertebrate species.

[0070] The basic structure of vertebrae varies. The majority is the body, and the central portion is the vertebral body. The superior and inferior surfaces of the vertebral body provide attachment to the intervertebral discs. The posterior portion forms the vertebral arch with 11 sections consisting of two pedicles, two laminae, and seven processes. The laminae provide attachment to the ligamentum flavum (ligaments of the spine). There are vertebral notches formed from the shape of the pedicles, which form the intervertebral foramina when the vertebrae articulate. These foramina are the entrance and exit canals for the spinal nerves. The vertebral body and vertebral arch form the vertebral foramen, a larger central opening that houses the spinal canal and surrounds and protects the spinal cord.

[0071] The pedicles and laminae form the vertebral arch. Two pedicles extend from the sides of the vertebral body, joining it to the vertebral arch. The pedicles are short, thick processes that extend posteriorly, one on each side, from the posterior junction of the superior surface of the vertebral body. From each pedicle, broad plates called "lamina" project posteriorly and medially to join and complete the vertebral arch and form the posterior boundary of the vertebral foramen, thereby completing the triangular shape of the vertebral foramen. The superior surfaces of the lamina are roughened to provide attachment to the ligamentum flavum. These ligaments connect the lamina 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 vertebrae articulate, the notches align with the adjacent vertebral notches, forming the intervertebral foraminal openings. The foramina allow spinal nerves and associated blood vessels to enter and exit each vertebra. Articulating vertebrae provide strong support for the body.

[0072] device The present disclosure provides a device formed from the scaffold disclosed herein. In certain embodiments, the device is cannulated and fenestrated with the scaffold. In certain embodiments, the device comprises a threaded distal region, an optional threaded central region, and an optional threaded proximal region, in response to a compressive force.

[0073] In certain embodiments, the device is selected from pedicle screws, cannulated pedicle screws, fenestrated pedicle screws, capitellar screws, capitellar screws, headless screws, traumatic hip fracture devices, glenoid cages, screws for glenoid cages, traumatic plates, tibial stems, femoral stems, hammertoe implants, nail fusion systems, Charcot foot deformity correction, radial head fracture devices, high tibial osteotomies, deformity corrections, corpectomy cages, oncological corrections, anchors, dental implants, maxillofacial implants, and sports medicine anchors.

[0074] In certain embodiments, the device is selected from a hip fracture system, a reverse total shoulder, a dental implant, upper extremity hardware, lower extremity hardware, a total joint replacement implant, a total joint revision implant, a spinal fusion, a spinal arthroplasty, a regenerative therapy, a cartilage implant, a maxillofacial hardware, and a cardiac implant.

[0075] In some embodiments, the screw is configured with features that encourage bone to grow through the structure of the screw from opposite sides, allowing bone to connect through the screw. In some embodiments, the features are narrow, such as through the screw threads, thereby allowing rapid through-growth. In some embodiments, the features are deeper, such as through a small diameter, thus providing a stronger connection. In some embodiments, the features are voids within the screw or are porous or structured to encourage bone growth. In some embodiments, the features collect autograft material within channels inside the device. In some embodiments, the features are impregnated with one or more polymers.

[0076] In some embodiments, the device is configured to enhance stabilization and fixation of the bone screw within the bone and improve bone mineral density. In some embodiments, the device includes a spinal implant configured to engage cortical and cancellous bone within the vertebra. In some embodiments, the device is configured to resist and / or prevent toggling of the bone screw when the bone screw is engaged with dense cortical and less dense cancellous bone resulting from loads 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 penetration growth to improve bone attachment to the bone screw. In some embodiments, the bone screw is anchored to the bone, thereby reducing pull-out. In some embodiments, the bone screw is designed to diffuse micromotion and reduce shear to enhance bone mineral density.

[0077] In some embodiments, the device includes a bone screw with bone-penetrating growth through the shaft of the screw to reduce screw toggling and potential failure. In some embodiments, the bone screw includes features that allow bone to grow through the structure of the bone screw from opposite sides, allowing bone to connect through their bone-penetrating structure. In some embodiments, the bone screw includes features that may be narrow, such as through the threads of the bone screw, which allows for rapid bone-penetrating growth. In some embodiments, the bone screw includes features that may be deeper, such as through a small diameter, which provides a larger volume of bone-penetrating growth. In some embodiments, the bone screw includes features that may be voids or cavities through both sides of the bone screw and / or voids or cavities that lead into or out of the same or adjacent surfaces. In some embodiments, the voids or cavities may contain scaffolds for bone attachment or porous structures on the surface of the voids.

[0078] In some embodiments, the bone screw includes features or structures that may be disposed along a shaft portion of the bone screw. In some embodiments, the bone screw includes features or structures that may be disposed continuously along a surface of the bone screw, such as along a distal end. In some embodiments, the bone screw includes features or structures that may be disposed discontinuously along a portion of the bone screw. In some embodiments, the bone screw includes features or structures that may include a scaffold or a polymer.

[0079] In some embodiments, the device comprises a spinal implant having a hybrid configuration that combines a manufacturing method, e.g., one or more traditional manufacturing features and materials, with a manufacturing method, e.g., one or more additive manufacturing features and materials. In some embodiments, the additive manufacturing comprises 3D printing. In some embodiments, the additive manufacturing comprises fused deposition modeling, selective laser sintering, direct metal laser sintering, selective laser melting, electron beam melting, layered object manufacturing, and stereolithography. In some embodiments, the additive manufacturing comprises one or more selected from rapid prototyping, desktop, direct, digital, instant, and on-demand manufacturing. In some embodiments, the device comprises a spinal implant that is manufactured, grown, or otherwise printed by a fully additive process.

[0080] In certain embodiments, the device comprises one or more selected from demineralized bone matrix (DBM), pre-packed DBM, pre-packed synthetic DBM, unpacked DBM, and magnesium-infused titanium.

[0081] In some embodiments, the device includes a spinal implant, such as a bone screw, manufactured by combining traditional and additive manufacturing methods. In some embodiments, the bone screw is manufactured by applying additively manufactured materials, allowing the bone screw to benefit from additively manufactured materials and properties. In some embodiments, traditional materials are used when advantages, such as physical properties and cost, are superior to those obtained from additively manufactured features and materials.

[0082] In some embodiments, the device treats a spinal disorder selected from degenerative disc disease, herniated disc, osteoporosis, spondylolisthesis, stenosis, scoliosis, other curvature abnormalities, kyphosis, tumors, and fractures.

[0083] "Treating" a disease or condition or "treatment" of a disease or condition refers to performing a procedure that may include administering one or more drugs to a patient, using an implantable device, and / or using a disease-treating instrument, e.g., a microdiscectomy instrument, to remove bulging or herniated disc portions and / or bone spurs to alleviate the signs or symptoms of the disease or condition. Treating or treatment does not require complete alleviation of signs or symptoms, does not require a cure, and specifically includes procedures that have a marginal effect on the patient. For example, treatment can include inhibiting the disease, e.g., halting its development, or relieving the disease, e.g., causing regression.

[0084] "Prevention" refers to the alleviation of signs or symptoms of a disease or condition before they appear. Thus, prevention includes preventing a disease from occurring in a patient who may be susceptible to the disease but has not yet been diagnosed as having it.

[0085] "Tissue" includes soft tissue, ligament, tendon, cartilage, and / or bone. In certain embodiments, the tissue is cancellous bone, cortical bone, or corticocancellous bone.

[0086] In some embodiments, the device is used in conjunction with other bone and bone-related applications, including diagnostics and therapeutics. In some embodiments, the device is alternatively used in surgical treatment of patients in prone or supine positions, and / or with various surgical approaches to the spine, including anterior, posterior, posterior midline, lateral, posterolateral, and / or anterolateral approaches, to other body regions, such as the maxillofacial and extremities. The device may alternatively be used in conjunction with procedures to treat the lumbar, cervical, thoracic, sacral, and pelvic regions of the spine. The device may also be used on animals, bone models, and other non-biological substrates, for example, in training, testing, and demonstrations.

[0087] In certain embodiments, the device is a custom medical device, hi certain embodiments, the device is adapted for sports medicine.

[0088] In certain embodiments, the device is temperature sensitive. In certain embodiments, the device is pH equilibrated.

[0089] In certain embodiments, devices are fabricated with porosity having porogens that are spheroidal, cubic, rectangular, elongated, tubular, fibrous, disc-shaped, platelet-shaped, polygonal, or mixtures thereof. In some embodiments, the porosity is based on a plurality of macropores, micropores, nanopore structures, and / or combinations thereof.

[0090] In certain embodiments, the device is fabricated from a biologically acceptable material suitable for medical use, including metals, synthetic polymers, ceramics, bone materials, and composites thereof, hi certain embodiments, the device comprises one or more selected from metals, ceramics, rubber, hydrogels, rigid polymers, fabrics, bone materials, and composites thereof.

[0091] 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, and superelastic plastic metals such as Gum Metal®. In certain embodiments, the device comprises a ceramic such as calcium phosphate (e.g., Skelite™) and composites thereof. In certain embodiments, the device comprises a rubber selected from polyaryletherketone (PAEK), polyetheretherketone (PEEK), polyetherketoneketone (PEKK), polyetherketone (PEK), carbon-PEEK composites, PEEK-BaSO4 rubber, polyethylene terephthalate (PET), silicone, polyurethane, silicone-polyurethane copolymer, and polyolefin rubber. In certain embodiments, the device comprises a hydrogel. In certain embodiments, the device comprises a fabric. In certain embodiments, the device comprises a rigid polymer selected from polyphenylene, polyimide, polyetherimide, polyethylene, and epoxy. In certain embodiments, the device comprises a bone material selected from autograft, allograft, xenograft, or transgenic cortical and / or cortical-cancellous bone. In certain embodiments, the device comprises tissue growth factors or differentiation factors. In certain embodiments, the device comprises absorbable materials such as composites of metal and calcium-based ceramics, composites of PEEK and calcium-based ceramics, composites of PEEK and absorbable polymers, fully absorbable materials such as calcium-based ceramics, e.g., calcium phosphate, tricalcium phosphate (TCP), hydroxyapatite (HA)-TCP, calcium sulfate, or other combinations such as other absorbable polymers such as polyketides, polyglycolides, polytyrosine carbonates, polycaprolactones, and hydrogels, laponite, and / or other shear-thinning materials.

[0092] In certain embodiments, the device comprises a rubber selected from polyaryletherketone (PAEK), polyetheretherketone (PEEK), polyetherketoneketone (PEKK), polyetherketone (PEK), carbon-PEEK composite, PEEK-BaSO rubber, polyethylene terephthalate (PET), silicone, polyurethane, silicone-polyurethane copolymer, polyolefin rubber, synthetic collagen, and a collagen matrix. In certain embodiments, the device comprises synthetic collagen. In certain embodiments, the device comprises a collagen matrix.

[0093] In certain embodiments, the device includes magnesium, vitamins, and minerals.

[0094] "Vitamin" refers to an organic molecule (or a set of chemically closely related molecules, i.e., vitamers) that is an essential micronutrient required in small amounts by an organism for the proper functioning of its metabolism. While some sources list 14 vitamins, including choline, major health organizations typically list the following: vitamin A (as all-trans-retinol, all-trans-retinyl esters, and all-trans-β-carotene and other provitamin A carotenoids), vitamin B1 (thiamine), vitamin B2 (riboflavin), vitamin B3 (niacin), vitamin B5 (pantothenic acid), vitamin B6 (pyridoxine), vitamin B7 (biotin), vitamin B9 (folic acid or folate), vitamin B 12 (cobalamin), vitamin C (ascorbic acid), vitamin D (calciferol), vitamin E (tocopherols and tocotrienols), and vitamin K (phylloquinone and menaquinone). In the context of nutrition, "mineral" refers to chemical elements required as essential nutrients by living organisms to perform functions necessary for life, and includes potassium, chlorine, sodium, calcium, phosphorus, magnesium, iron, zinc, manganese, copper, iodine, chromium, molybdenum, selenium, and cobalt.

[0095] In certain embodiments, the device comprises a metal selected from iron, 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, and superelastic plastic metals such as Gum Metal®. In certain embodiments, the device comprises titanium. In certain embodiments, the device comprises iron.

[0096] In certain embodiments, the device is fabricated or 3D printed from materials such as titanium, titanium alloys, cobalt chrome, carbon fiber, magnesium-infused titanium, iron, or stainless steel. In certain embodiments, the device is fabricated from a shape memory alloy or shape memory polymer, allowing the device to conform to the anatomical shape of the patient's body.

[0097] 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 cartilage collagen coating. In certain embodiments, the device is infused with antibiotics.

[0098] In certain embodiments, the device is employed to treat a diseased segment of a vertebra. A physician gains access to a surgical site containing the vertebra by any suitable method, such as by dissection and retraction of tissue. In certain embodiments, the device comprises a bone screw for augmenting the surgical treatment. In certain embodiments, the device may be pre-assembled for delivery to the surgical site or may be assembled in situ. In certain embodiments, the device is modified, removed, or replaced, in whole or in part.

[0099] In certain embodiments, the device is used in conjunction with surgical methods or techniques, including, but not limited to, open surgery, minimally invasive surgery (MIS), and percutaneous surgical implantation, whereby the vertebrae are accessed through a small incision, or the sleeve provides a protected passageway to the area. Once access to the surgical site is gained, a surgical procedure, such as a corpectomy or discectomy, can be performed to treat the disease or disorder.

[0100] In certain embodiments, the surface of the device comprises a non-solid structure, such as a lattice, hi some embodiments, the non-solid structure comprises a porous structure or a trabecular structure.

[0101] In various embodiments, the non-solid configuration is configured to provide one or more pathways for supporting bone growth within one surface of the device and from one surface of the device to the opposite surface. In some embodiments, the lattice comprises one or more portions, layers, or matrices. In some embodiments, one or more portions, layers, or matrices of the lattice are arranged side-by-side, offset, staggered, stepped, tapered, end-to-end, spaced apart, in series, or parallel. In some embodiments, the lattice defines a thickness that can be uniform, wavy, tapered, increasing, decreasing, variable, offset, stepped, arcuate, angled, and / or staggered. In some embodiments, one or more lattice layers are arranged in a side-by-side and parallel orientation within the wall. In certain embodiments, the lattice comprises one or more layers of a material matrix.

[0102] In some embodiments, the grid comprises 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, and in some embodiments, the plurality of nodes and openings are arranged in parallel.

[0103] In some embodiments, the lattice forms a rasp-like configuration. In some embodiments, the lattice is configured to engage tissue. In certain embodiments, the engagement of the lattice cuts, shaves, shears, dissects, or breaks the tissue. In some embodiments, the lattice comprises a configuration selected from cylindrical, circular, elliptical, oval, triangular, polygonal with flat or arcuate side portions, irregular, uniform, non-uniform, consistent, variable, horseshoe-shaped, U-shaped, or kidney-shaped. In some embodiments, the lattice is rough, textured, porous, semi-porous, dimpled, knurled, toothed, grooved, or polished, for example, to engage and cut tissue. In some embodiments, the lattice forms tunnels configured to guide, drive, or direct cut tissue into the opening, such as to weld the device to the tissue.

[0104] In certain embodiments, an adapter for injecting material into a bone screw is provided, the adapter comprising: a shaft having a proximal end and a distal end; a cannula disposed through the center of the shaft; a female aperture lock at the proximal end for reversibly engaging a male taper on the syringe; a male conical surface at the distal end for engaging a female conical surface on the bone screw; and threads on the shaft between the female aperture lock and the male conical surface configured to reversibly engage a groove on the tulip head.

[0105] In some embodiments, the female open lock of the adapter can be a female luer lock and the male taper can be a male luer taper.

[0106] In certain embodiments, an assembly for injecting material into, e.g., injecting or withdrawing material from, a bone screw is provided that includes an adapter having various features including a shaft, a cannula, a female open lock, a male conical surface, and a screw thread.

[0107] In a further embodiment, an assembly is provided that includes a bone screw comprising: a shaft having proximal and distal ends, a female conical surface on the proximal end for reversibly engaging a male conical surface of an adapter, a cannula disposed through a central axis of the shaft, and a scaffold within the shaft that promotes osseointegration, the scaffold comprising an internal lattice structure having a porous, structurally advanced structure formed from a combination of mean, Gaussian, and net curvatures that characterize the topography of healthy trabecular bone.

[0108] In another embodiment, a method is provided for injecting material into a bone screw, wherein a syringe is engaged with an adapter and material within the bone screw is circulated via either negative pressure by withdrawing the syringe plunger or positive pressure by pushing the syringe plunger. Without wishing to be bound by theory, the method creates a biological ripple effect that promotes healing, including stem cell attachment to the screw scaffold and osteoclast and osteoblast growth.

[0109] screw In certain embodiments, the device is a screw, hi some embodiments, the screw is selected from a posted screw, a pedicle screw, a bolt, a bone screw for a lateral plate, an interbody screw, a monoaxial screw, a fixed angle screw, a polyaxial screw, a lateral loading screw, a sagittal adjustment screw, a parasagittal adjustment screw, an awl tip, a dual rod polyaxial screw, a midline lumbar fusion screw, and / or a sacral screw.

[0110] In certain embodiments, the device is a bone screw. In certain embodiments, the device is a pedicle screw. Referring to FIG. 1 , a pedicle screw is shown implanted through a pedicle into the vertebral body of a vertebra. In certain embodiments, the pedicle screw has a cage with a polymer retained within a cannulated and / or fenestrated portion of the screw.

[0111] In certain embodiments, the inner core of the screw is a perforator for harvesting and harvesting autograft material at and / or during screw insertion.

[0112] In certain embodiments, the post-implantation option prevents revision surgery by injecting polymer through the screw.

[0113] In certain embodiments, the pedicle screws do not exhibit screw loosening, screw backout, rod breakage, or bone mineral density loss.

[0114] In certain embodiments, the pedicle screws have reduced one or more of screw loosening, screw backout, rod breakage, and bone mineral density loss.

[0115] The disclosed screw focuses bone ingrowth throughout the shaft to minimize shear stress at the distal tip and distribute micromotion evenly throughout the screw to promote bone ingrowth.

[0116] In certain embodiments, pedicle screw scaffolds offer options for simple to complex bone mineral densities and immunocompromised patients. In certain embodiments, the scaffolds are impregnated with one or more biologics, antibiotics, demineralized bone matrix, nanotechnology, or tissue engineering therapies.

[0117] 5-16, the structure of the pedicle screws 300, 400, 500 is specifically designed to encourage bone ingrowth through the pedicle screws 300, 400, 500 by using a scaffold 280 similar to the natural trabecular bone within the vertebral body. In combination with the threads 230 and scaffold 280, the core 260 aids in the harvesting of autograft during the insertion process, forcing the autograft into the built-in channel within the core 260 of the pedicle screws 300, 400, 500. The walls surrounding the holes harvest the autograft and act as perforators. This structure also aids in the structural integrity of the pedicle screws 300, 400, 500, resisting bone mineral density loss and reducing micromotion.

[0118] With reference to FIGS. 2-16 , the pedicle screws 200, 300, 400, and 500 disclosed herein overcome many of the shortcomings of prior art pedicle screws. In certain embodiments, the pedicle screws lack a windshield wiper effect. In certain embodiments, the pedicle screws resist backout. In certain embodiments, the pedicle screws do not exhibit excessive micromotion. In certain embodiments, the pedicle screws have a low frequency of low-virulence microorganisms detected by sonication, for example, due to the sterilization and packaging of the individual screws. In certain embodiments, the head and shaft of the pedicle screw resist breakage. In certain embodiments, the pedicle screws are adapted to each type of bone quality. In certain embodiments, the pedicle screws have an appropriate thread depth. In certain embodiments, the pedicle screws withstand insertion torque, especially at the head-to-screw interface. In certain embodiments, the fatigue life of the pedicle screws is not reduced when the screws are fully inserted. In certain embodiments, the pedicle screws have good instrumentation. In certain embodiments, the pedicle screws achieve angulation for rod acceptance. In certain embodiments, the pedicle screws do not have cyclic loading based on physiological conditions during ambulation. In certain embodiments, the pedicle screws do not require simultaneous C6 or T1 buttress pedicles and do not fail long-segment posterior cervical fusion. 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 or locking cap stresses.

[0119] In some embodiments, the distal tip 220 of the pedicle screw 200, 300, 400, 500 has a surface configuration selected from angled, irregular, uniform, non-uniform, offset, staggered, tapered, arcuate, wavy, mesh, porous, semi-porous, dimpled, pointed, textured, or a combination thereof. In some embodiments, the distal tip 220 includes nail configurations, barbs, extension elements, raised elements, ribs, and / or spikes to provide a fabrication platform for forming a portion thereon via additive manufacturing. In some embodiments, the distal tip 220 has a cross-sectional configuration selected from elliptical, oval, triangular, square, polygonal, irregular, uniform, non-uniform, offset, staggered, tapered, or a combination thereof.

[0120] In certain embodiments, the pedicle screw 200, 300, 400, 500 includes a thread 230 extending between the proximal end 210 and the distal tip 220. In certain embodiments, the thread 230 includes an external thread form. In certain embodiments, the thread form includes a leading edge 231 having a leading surface 235 and a trailing edge 232 having a trailing surface 236. The leading surface 235 defines a first opening 251. The trailing surface 236 defines a second opening 252. In some embodiments, the first and second openings 251, 252 are axially aligned. In some embodiments, the first and second openings 251, 252 are circumferentially disposed about the thread form.

[0121] In some embodiments, the leading surface 235 and / or the trailing surface 236 comprise at least one tissue collection member. In some embodiments, the tissue collection member comprises a cutting edge. In some embodiments, the cutting edge is configured to be rasp-like. In some embodiments, the cutting edge is configured to engage tissue and, for example, cut, shave, shear, incise, or disrupt the tissue. In some embodiments, the cutting edge is configured to be cylindrical, circular, oval, oval, triangular, polygonal, have flat or arcuate sides, irregular, uniform, non-uniform, consistent, variable, horseshoe-shaped, U-shaped, or kidney-shaped. In some embodiments, the cutting edge is rough, textured, porous, semi-porous, dimpled, knurled, toothed, grooved, or polished to engage and cut tissue. In some embodiments, the cutting edge forms a tunnel configured to guide, drive, or direct the cut tissue into a gap, such as to weld a screw to the tissue.

[0122] By manipulating the pedicle screw 200, 300, 400, 500, for example by rotation or translation, the cutting edges 271 of the screw cut tissue or bone and guide it into the core 260, thereby promoting bone ingrowth and fusion to the pedicle screw 200, 300, 400, 500. In some embodiments, tissue is embedded in the core 260 to promote bone ingrowth and fusion to the pedicle screw 200, 300, 400, 500. In some embodiments, a lattice is placed within the core 260 to form a scaffold 280 for bone ingrowth.

[0123] In some embodiments, threads 230 are configured to be fine, closely spaced, or shallow to engage tissue. In some embodiments, threads 230 include an increased pitch and equal lead between thread turns. In some embodiments, threads 230 include a smaller pitch or more thread turns per axial distance to secure stronger fixation with or resist loosening from tissue. In some embodiments, threads 230 are configured to be continuous along a portion. In some embodiments, threads 230 are configured to be interrupted, staggered, or discontinuous. In certain embodiments, threads 230 include a single thread turn.

[0124] In certain embodiments, the thread comprises a plurality of separate threads. In certain embodiments, the thread has a concave profile.

[0125] In some embodiments, the threads 230 comprise piercing elements selected from, for example, nail configurations, barbs, expanding elements, raised elements, ribs, or spikes. In some embodiments, the threads 230 are self-tapping or intermittent configured at the distal tip 220. In some embodiments, the distal tip 220 is rounded. In some embodiments, the distal tip 220 is self-drilling. In some embodiments, the distal tip 220 comprises a solid outer surface.

[0126] In certain embodiments, the screw is a 3D-printed porous pedicle screw. Its porosity mimics natural vertebral bone, allowing stem cells, growth factors, and other proteins to attach and retain within the pedicle screw's structure, promoting bone growth through the screw and stabilizing the entire construct. During insertion into the vertebra, built-in perforators collect autograft and regenerative cells within the porous matrix. The disclosed topography attracts osteogenic stem cells within and around the device, reducing macromotion of the overall construct. In certain embodiments, the device allows surgeons to meet patient-specific needs, including, but not limited to, the option to spray / inject regenerative products to stimulate the osteogenic cascade, aggressively inject antibiotics into the screw scaffold for diabetic-prone infections, and inject bone cement to further stabilize the construct in severely osteoporotic bone.

[0127] In certain embodiments, the screws reduce revision rates during spinal fusion, improve bone mineral density, and / or address patient-specific needs. In certain embodiments, bone mineral density is improved, constructs are stabilized, and revision likelihood is reduced.

[0128] In certain embodiments, the screw is a 3D printed titanium porous pedicle screw with a porous pattern throughout the screw similar to that of natural bone. Without wishing to be bound by theory, the function of the porous pattern is to attach to the surrounding bone, maintain bone-forming stem 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.

[0129] In certain embodiments, the surgeon can inject or spray concentrated autologous stem cells onto the screw. Without being bound by theory, as the screw rotates during insertion into the vertebra, the pores of the screw use their built-in perforators to collect the autologous graft / stem cell mixture inside. The osteogenic stem cells then combine with the concentrated blood stem cells and signal the process of mutation and replication, forming more osteogenic cells within the screw, subsequently forming a bone healing cascade directed within and around the screw. In these embodiments, the combination of stem cell (a) osteoconductive (bone growth on the surface), (b) osteoinductive (cell recruitment for bone healing), and (c) osteogenic (bone development and formation) healing cascades improves bone mineral density and supports superior bone integration and pull-out strength.

[0130] In certain embodiments, the patient is 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 before or after insertion into the pedicle, or on the screw within the pedicle, to provide antibiotic delivery to the area. In certain embodiments, the antibiotic is delivered for 2 to 6 weeks, thus reducing the likelihood of revision due to infection.

[0131] manufacturing The devices disclosed herein can be manufactured using a variety of methods. In some embodiments, the manufacturing includes machining, such as subtractive, deformation, or transformational manufacturing. In some embodiments, the manufacturing includes cutting, grinding, rolling, forming, molding, casting, forging, extruding, whirling, grinding, cold working, or a combination thereof. In some embodiments, the manufacturing includes a portion of the device formed by a medical machining process. In some embodiments, the machining uses a computer numerically controlled (CNC) high-speed milling machine, a Swiss machining device, CNC turning with living tooling, wire EDM 4th axis, and combinations thereof. In some embodiments, the manufacturing to fabricate a portion of the device includes a finishing process, such as laser marking, tumble blasting, bead blasting, microblasting, powder blasting, or a combination thereof.

[0132] In certain embodiments, the device is manufactured per instructions from a computer and processor based on data in a selected configuration via digital rendering and / or additive manufacturing.

[0133] In some embodiments, the additive manufacturing comprises 3D printing. In some embodiments, the additive manufacturing is selected from fused deposition modeling, selective laser sintering, direct metal laser sintering, selective laser melting, electron beam melting, layered object manufacturing, stereolithography, and combinations thereof. In some embodiments, the additive manufacturing comprises rapid prototyping, desktop manufacturing, direct manufacturing, direct digital manufacturing, digital fabrication, instant manufacturing, on-demand manufacturing, or combinations thereof.

[0134] In some embodiments, a portion of the device is manufactured by additive manufacturing and then mechanically attached to a surface of the device, for example, by welding, threading, adhesives, or crimping.

[0135] In one embodiment, the device is configured based on imaging from the patient's anatomy. Suitable imaging techniques include, but are not limited to, X-ray, fluoroscopy, computed tomography (CT), magnetic resonance imaging (MRI), surgical navigation, bone mineral density (DEXA), or any obtainable 2D or 3D image of the patient's anatomy. Selected configuration parameters of the device are collected, calculated, or determined. Examples of configuration parameters include, but are not limited to, imaging of the patient's anatomy, surgical treatment, patient history data, demographic data, treatment algorithms, implant material, implant dimensions, porosity, and manufacturing method. In some embodiments, the configuration parameters include implant material and device porosity based on the patient's anatomy and surgical treatment. In some embodiments, the porosity is selected. In some embodiments, the device configuration parameters are patient-specific. In some embodiments, the device configuration parameters are based on a general configuration and are not patient-specific.

[0136] For example, digital renderings or data of a device are generated for display from a graphical user interface or for storage on a database attached to the computer and processor. In some embodiments, the computer displays, via a monitor, saves, digitally manipulates, or prints a hard copy of the digital rendering or data. In some embodiments, the device is virtually designed using a CAD / CAM program on the computer display. In some embodiments, the processor executes code stored on a computer-readable storage medium to execute one or more computer instructions, for example, to send instructions to an additive manufacturing device. In some embodiments, the database or computer-readable medium comprises RAM, ROM, EPROM, magnetic, optical, digital, electromagnetic, flash drive, semiconductor technology, or a combination thereof. In some embodiments, the processor commands motors to control the movement and rotation of device components.

[0137] regenerative medicine "Regenerative medicine" refers to a branch of translational research in tissue engineering and molecular biology that deals with replacing, manipulating, or regenerating human cells, tissues, or organs to restore or establish normal function. This field promises to engineer damaged tissues and organs by stimulating the patient's internal repair mechanisms to functionally heal previously irreparable tissues or organs. For example, during bone regeneration, new bone formation is primarily influenced by physicochemical cues in the surrounding microenvironment. Tissue cells reside in the physiological microenvironment of a complex scaffold.

[0138] In certain embodiments, tissue engineering is incorporated with the scaffolds or devices disclosed herein. Autograft incorporation occurs in five stages: inflammation, angiogenesis, osteoinduction, osteoconduction, and remodeling.

[0139] Inflammation lasts approximately 7 to 14 days. Initial injury to the local blood supply and denudation results in a hematoma around the bone graft, into which inflammatory cells invade. Fibroblast-like cells in the inflamed tissue transform into a fibrovascular stroma. Intraoperative anti-inflammatory drugs decrease the rate of healing due to the inflammatory process.

[0140] Vascular sprouts appear in the fibrovascular stroma, resembling scar tissue formation during angiogenesis. Primary membranous bone forms adjacent to the denuded bone. Minimal cartilage and endochondral ossification then occur.

[0141] During osteoinduction (weeks 4-5), repair involves increased angiogenesis, necrotic tissue resorption, and osteoblastic and chondroblastic differentiation. In particular, stem cells differentiate into osteoblasts. New bone extends toward the central zone of the fusion mass. The cortical portion of the implant continues to resorb.

[0142] Osteoconduction is characterized by ingrowth and creep replacement into host bone. Osteoblasts form new bone, while osteoclasts simultaneously resorb the implant bone. A central zone of the endochondral interface is observed in the center of the fusion mass, connecting the inferior and superior halves of the fusion. Multipotent cells in this central zone differentiate into cartilage tissue with little vascularization.

[0143] During remodeling at 6-10 weeks, a peripheral cortical rim forms around the fusion. Bone marrow activity increases, forming secondary cancellous bone. The cortical rim thickens. Trabecular processes extend to the center of the fusion. Remodeling is typically complete 1 year after device implantation.

[0144] Nonunion (pseudarthrosis) is a major cause of postoperative pain and accounts for 45% to 56% of revision surgeries. Bone union directly correlates with successful clinical outcome. Patients with pseudarthrosis were asymptomatic in approximately 30% of cases. Younger patients had a significantly increased rate of symptomatic nonunion (43.8 years vs. 52.1 years, p<0.01).

[0145] In certain embodiments, bone marrow aspirate (BMA) with allograft substitutes for autologous bone graft in single-level revision posterolateral lumbar fusion (PLF). In certain embodiments, bone marrow aspirate with allograft is more cost-effective than recombinant human bone morphogenetic protein-2 (rhBMP). In certain embodiments, allografts enriched with bone marrow-derived cells are compared to autografts in bone grafting and spinal fusion. In certain embodiments, BMA increases the regenerative capacity of corticocancellous allografts. When treating unicameral bone cysts, the cure rate was high (98.7%) for bone marrow with demineralized bone matrix injection.

[0146] When introducing elements of the disclosure or embodiment(s) thereof, the articles "a," "an," "the," and "said" are intended to mean that there are 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 other than the listed elements.

[0147] 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.

[0148] While the disclosure described herein is susceptible to various modifications and alternative iterations, specific embodiments thereof are described in more detail above. However, it should be understood that the detailed description of the compositions is not intended to limit the disclosure to the specific embodiments disclosed. Rather, it should be understood that the disclosure is intended to encompass all modifications, equivalents, and alternatives falling within the spirit and scope of the disclosure as defined by the language of the claims.

[0149] Example The following examples are included to demonstrate specific embodiments of the present disclosure. It should be understood by those skilled in the art that the techniques disclosed in the examples represent techniques discovered by the inventors to function well in the practice of the present disclosure. However, those skilled in the art should, in light of the present disclosure, understand that many changes can be made in the specific embodiments disclosed and still obtain the same or similar results without departing from the spirit and scope of the present disclosure. Accordingly, all matters are to be interpreted as illustrative and not limiting.

[0150] [Table 1]

[0151] Example 1 - Pedicle Screw 2-4, pedicle screw 200 was 3D printed from titanium. Pedicle screw 200 included a thread 230 disposed around a shaft 240 extending between a proximal end 210 and a distal tip 220. Thread 230 included an external thread profile having a leading edge 231 with a leading surface 235 and a trailing edge 232 with a trailing surface 236. Leading surface 235 defined a first opening 251. Trailing surface 236 defined a second opening 252. The first and second openings 251, 252 were axially aligned. The pedicle screw 200 had a core 260 that extended through the center of the pedicle screw 200 from the proximal end 210 to the distal tip 220. The distal tip 220 was provided with two cutting members 270, each having a cutting edge 271.

[0152] 5-7, one embodiment of a pedicle screw 300 was 3D printed in titanium using the scaffold 280 disclosed herein. The pedicle screw 300 included threads 230 disposed about a shaft 240 extending between a proximal end 210 and a distal tip 220. The shaft 240 included two regions of scaffolding 280 exposed on the outer surface of the pedicle screw 300. The threads 230 included an external thread form having a leading edge 231 with a leading surface 235 and a trailing edge 232 with a trailing surface 236. The leading surface 235 defined a first opening 251. The trailing surface 236 defined a second opening 252. The first and second openings 251, 252 were axially aligned. The pedicle screw 300 included a core 260 filled with scaffolding 280 that extended through the center of the pedicle screw 300 from the proximal end 210 to the distal tip 220. The distal tip 220 included three cutting members 270, each with a cutting edge 271.

[0153] 8-10 , another embodiment of a pedicle screw 400 was 3D printed in titanium using a scaffold 280 disclosed herein. The pedicle screw 400 included threads 230 disposed about a shaft 240 extending between a proximal end 210 and a distal tip 220. The shaft 240 included a region of the scaffold 280 exposed on the outer surface of the pedicle screw 400 between the central seven turns of the threads 230. The threads 230 included an external thread form having a leading edge 231 with a leading surface 235 and a trailing edge 232 with a trailing surface 236. The leading surface 235 defined a first opening 251. The trailing surface 236 defined a second opening 252. The first and second openings 251, 252 were axially aligned. The pedicle screw 400 had a core 260 filled with a scaffold 280 that extended through the center of the pedicle screw 400 from the proximal end 210 to the distal tip 220. The distal tip 220 was provided with three cutting members 270, each with a cutting edge 271.

[0154] 11-16 , another embodiment of a pedicle screw 500 was 3D printed in metal using the scaffold 280 disclosed herein. The pedicle screw assembly 500 includes a cap 510, a saddle 520, and a shaft 540, and, if present, a tulip 590 and a pair of pins 595. The cap 510 is configured to couple to the saddle 520 via cap threads 513 operably disposed within the saddle groove 523. The saddle 520 is configured to couple to the shaft 540. In an embodiment of the pedicle screw having a tulip, the distal tip 220 of the shaft 540 may be placed through a bottom opening 592 of the tulip 590 and held in place with a pin 595 placed through a side opening 596 of the tulip 590.

[0155] The pedicle screw 500 includes threads 230 disposed about a shaft 240 extending between a proximal end 210 and a distal tip 220. The shaft 240 includes a region of scaffolding 280 exposed on the outer surface of the pedicle screw 500 between the central 13 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 had a core filled with scaffolding 280 extending through the center of the pedicle screw 500 from the proximal end 210 to the distal tip 220. The distal tip 220 included a cutting member 270.

[0156] 13 and 14, the cap 510 comprises a cap body 514 having a cap thread 513 helically disposed around the outer surface of the cap body 514 between a cap top 511 and a cap bottom 512.

[0157] 15 , saddle 520 includes a saddle top 521, a saddle bottom 522, and a saddle body 524 having at least one saddle groove 523 disposed on an inner surface of saddle body 524. At least one saddle groove 523 is configured to receive and operably couple with cap threads 513. Similarly, saddle bottom 522 is configured to receive and operably couple with proximal end 210 of shaft 540.

[0158] 16 , when present, tulip 590 comprises tulip body 594 having a top opening 591, a bottom opening 592, at least one pair of tulip grooves 593 disposed on an interior surface of tulip body 594, and a pair of side openings 596 between at least one pair of tulip grooves 593 and bottom opening 592. At least one pair of tulip grooves 593 are configured to receive and operably couple with threads 230 of shaft 540 when distal tip 220 of shaft 540 passes through bottom opening 592 of tulip 590. After the threads 230 engage at least one pair of tulip grooves 593 , a pair of pins 595 can be operably coupled to the tulip 590 via a pair of side openings 596 .

[0159] When present, pores in the scaffold 280 promoted bone ingrowth through the screw. Other materials from which pedicle screws were fabricated included pre-packed demineralized bone matrix (DBM), pre-packed synthetic DBM, unpacked DBM, and magnesium-infused titanium. Built-in channels captured the autograft during insertion. The screws had dual ball angulation and a low profile. The screws were equipped with locking caps with reverse-angle threads. The screws could be cannulated or non-cannulated.

[0160] In certain embodiments, scaffold 280 includes an internal lattice structure with a porous architecture formed from a combination of mean curvature, Gaussian curvature, and net curvature that characterize the local geometry of healthy trabecular bone. In certain embodiments, scaffold 280 exhibits a predominantly hyperbolic shape, including saddle-shaped regions, spherical depressions, and cylindrical rod-like elements. In certain embodiments, scaffold 280 includes one or more structural cues selected from porosity, pore size, grain size, and surface topography that enhance at least one of pluripotent mesenchymal stem cell (MSC) differentiation, osteoblast growth, extracellular matrix (ECM) deposition, and new bone formation. In certain embodiments, new bone formation is subsequent to MSC differentiation, osteoblast growth, ECM deposition, or a combination thereof. In certain embodiments, scaffold 280 is configured to accommodate one or more biological agents.

[0161] The screws were 35 to 65 mm in length and 4.5 to 8.5 mm in diameter. The rod acceptance was 5.5 mm.

[0162] The built-in channels for autograft collection enhanced the structural integrity of the implant. They provided excellent resistance to bone mineral density loss and reduced micromotion. The randomized porosity pattern of the scaffold 280 was typical of natural trabecular bone. Furthermore, the built-in struts provided structural integrity. The pedicle screws 200, 300, 400, and 500 were fabricated from cobalt chromium, titanium, and magnesium-infused titanium.

[0163] The device was tested in cobalt chrome and met American Society for Testing and Materials (ASTM) standards 543, 1798, and 1717.

[0164] ASTM Standard 543 evaluates the chemical resistance of plastic materials, including cast, thermoformed, cold-formed, laminated resin products, and sheet materials. Three procedures are presented: two immersion tests and one test, called Test B, which is mechanical stress and reagent exposure under standardized conditions of applied strain. These tests report changes in weight, dimensions, appearance, color, strength, and other mechanical properties. Standard reagents are specified to establish comparable results without excluding other chemical reagents related to specific chemical resistance requirements. Provisions are made for exposure to the reagents at various exposure times, stress conditions, and elevated temperatures. The type of conditioning (immersion or wet patch / wipe method) depends on the end use of the material.

[0165] ASTM Standard 1798 covers the measurement of uniaxial static fatigue strength and resistance to loosening of component interconnection systems in spinal fusion implants. This test method provides a means to mechanically characterize different interconnection designs for spinal implants. 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 substructures, nor does it define performance levels for spinal implants.

[0166] ASTM Standard 1717 covers materials and methods for static and fatigue testing of spinal implant assemblies in vertebral resection models. Test materials for combinations of spinal implant components can be specific, depending on the spinal location and intended method of application to the spine. These test methods provide a basis for mechanical comparison between past, current, and future spinal implant assemblies. They allow for 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 levels of performance. Instead, they set guidelines for load types and methods for applying loads, measuring displacement, determining yield loads, and evaluating the stiffness and strength of spinal implant assemblies. Three static load types and one fatigue test method are defined for the comparative evaluation of spinal implant assemblies.

[0167] In certain embodiments, the pedicle screws 200, 300, 400, 500 are individually packaged in double Tyvek™ stripping trays.

[0168] In certain embodiments, the pedicle screws 200, 300, 400, 500 are injected or sprayed with a material such as BMA concentrate, calcium phosphate, biologics, and / or antibiotics, and the filled or coated screws are allowed to rest for 10-15 minutes to absorb the material before insertion.

[0169] Example 2 - Opening locking part The present disclosure provides assemblies comprising a screw, a tulip, an adapter, and a syringe, in which an opening in the proximal portion of the screw is configured for the syringe to draw or push cells into the screw structure before or after implantation.

[0170] 17 and 18 , a pedicle screw 400 includes a shaft 240 having a scaffold 280, a cannula 290 extending from a proximal end 210 into the scaffold 280 through the center of the shaft 240 toward the distal end 220, and threads 230 disposed around the shaft 240. The proximal end 210 of the screw 400 includes a driver 250 configured to reversibly engage a screwdriver and a female conical surface 250 configured to reversibly engage a male conical surface 650 of an adapter 600.

[0171] 20, an adapter 600 is provided for circulating material within a bone screw 400. The adapter 600 includes a shaft 640 having a proximal end and a distal end. A cannula 690 is disposed through the center of the shaft 640 between the proximal and distal ends.

[0172] In certain embodiments, a female aperture lock 610 is formed on the proximal end of the shaft 640 for reversibly engaging a male taper on a syringe. A male conical surface 650 is formed on the distal end of the shaft 640 that 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 with the female conical surface 250 of the bone screw 400. This allows for secure attachment of these components while also allowing for their disassembly when necessary.

[0173] To further illustrate these embodiments, FIG. 21 shows an inset of the assembly of FIG. 20, highlighting the junction of the female conical surface of the screw and the male conical surface of the adapter.

[0174] In another embodiment, FIG. 22 shows a front view of the adapter of FIG. 22, FIG. 23 shows a rear view thereof, FIG. 24 shows a top view thereof, and FIG. 25 shows a bottom view thereof. To understand the context of the adapter within the assembly, FIG. 26 shows a front plan view of the arrangement of a bone screw and syringe within the assembly. FIG. 27 shows a front plan view arrangement of the adapter of FIG. 22 with the bone screw and syringe within the assembly of FIG. 26. FIG. 28 shows a front plan view arrangement of a tulip with the adapter of FIG. 22, bone screw, and syringe within the assembly of FIG. 26. FIG. 29 shows a side view arrangement of the bone screw and syringe within the assembly. FIG. 30 shows a side view arrangement of the adapter of FIG. 22 with the bone screw and syringe within the assembly of FIG. 26. FIG. 31 shows a side view arrangement of the tulip with the adapter of FIG. 22, bone screw, and syringe within the assembly of FIG. 26.

[0175] In certain embodiments, the adapter 600 and bone screw 400 may be connected using a different type of connection mechanism. In these embodiments, rather than using the male conical surface 650 and the female conical surface 250 for reversible engagement, the connection mechanism may be a snap fit, bayonet, or 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.

[0176] In certain embodiments, the threads 630 of the adapter 600 are disposed around the shaft 640 between the female opening lock 610 and the male conical surface 650. The threads 630 are configured to reversibly engage a groove on the tulip 590. In certain 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 590. This connection provides stability to the assembly 800 while also allowing for disengagement of the adapter 600 from the tulip 590 when desired.

[0177] In certain embodiments, the female opening lock 610 is a female Luer lock and the male taper is a male Luer taper. As used herein, "Luer taper" or "Luer lock" refers to a standardized system of small-scale fluid couplings used to make leak-tight connections between male taper fittings and their mating female components on medical and laboratory instruments, including hypodermic syringe tips and needles or stopcocks and needles. ISO 80369 defines Luer standards and test methods and is incorporated herein by reference.

[0178] In certain embodiments, an assembly 800 is provided for circulating material within a bone screw 400. The assembly 800 includes an adapter 600 with a shaft 640, a cannula 690, a female open stop 610, a male conical surface 650, and threads 630, as described herein.

[0179] In certain embodiments, the assembly 800 further comprises 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 osseointegration in the shaft 240. In certain embodiments, the apertures may be in fluid communication with the porous scaffold and / or one or more lumens of the screw. In certain embodiments, the screw includes one lumen in fluid communication with the apertures, extending the length of the screw toward the tip.

[0180] In certain embodiments, assembly 800 further comprises a tulip 590. Tulip 590 comprises a body 594 having a top opening 591, a bottom opening 592, an inner surface, and an outer surface. Bottom opening 592 is configured to engage the proximal end of bone screw 400. The inner surface of top opening 591 comprises a groove 593 that reversibly engages with threads 630 of adapter 600.

[0181] In certain embodiments, the tulip 590 further comprises a pair of side openings 596 located on opposite sides of the body 594. The side openings 596 are configured to reversibly engage pins 595 that lock the tulip 590 to the bone screw 400. This locking mechanism provides additional stability to the assembly 800 while allowing for disassembly of the tulip 590 from the bone screw 400 when necessary.

[0182] In certain embodiments, assembly 800 further comprises syringe 700. Syringe 700 comprises a barrel 740 having a distal end, a proximal end, and a lumen, a plunger 760 disposed within the lumen, and a male taper 710 formed on the distal end and configured to reversibly engage with female opening lock 610 of adapter 600. In certain embodiments, syringe 700 interacts with adapter 600 via engagement of male taper 710 of syringe 700 with female opening lock 610 of adapter 600. This connection allows negative pressure to be generated by withdrawing plunger 760 of syringe 700 or positive pressure to be generated by pushing plunger 760 of syringe 700, facilitating circulation of material within bone screw 400.

[0183] In certain embodiments, bone screw 400 is a pedicle screw. In certain embodiments, bone screw 400 focuses bone growth throughout shaft 240, minimizes shear stress at distal tip 220, and distributes micro-motion throughout bone screw 400 to promote bone ingrowth. In certain embodiments, bone screw 400 is configured with an arcuate cross-sectional pattern that varies from the proximal end to distal tip 220 for placement into the internal cavity of a bone body such that autograft is harvested into scaffold 280 upon coaxial rotation of bone screw 400. In certain embodiments, bone screw 400 further includes at least one autologous product sprayed onto or injected through bone screw 400.

[0184] In certain embodiments, a method is provided for circulating material within a bone screw 400. The method includes engaging a syringe 700 with an adapter 600 and circulating the material within the bone screw 400 with negative pressure by withdrawing a plunger 760 of the syringe 700 or with positive pressure by pushing a plunger 760 of the syringe 700.

[0185] In certain embodiments, the method for circulating material within the bone screw 400 may not rely on negative or positive pressure from the syringe 700. In these embodiments, the material may be circulated within the bone screw 400 using a different method, such as a pump or impeller, or another method known in the art for creating a pressure differential sufficient to circulate the material.

[0186] In certain embodiments, healing includes the growth of stem cells that attach to the scaffold 280 of the bone screw 400, as well as osteoclasts and osteoblasts.

[0187] In certain embodiments, the syringe 700 is loaded with material before engaging the adapter 600 and the material is forced into the bone screw 400 .

[0188] In certain embodiments, the material is circulated by applying alternating negative and positive pressure to the bone screw 400. In certain embodiments, the circulation creates a biological ripple effect that initiates and promotes healing.

[0189] In certain embodiments, the screw includes a thickened head-neck junction below the aperture, for example, to reduce the chance of the rod breaking during installation of the screw.

[0190] In certain embodiments, the material, such as an antibiotic or therapeutic agent, is inside the syringe before it is locked into the adapter, thus circulating with the bone marrow.

[0191] In certain embodiments, the syringe further comprises a mixer. In certain embodiments, the syringe and / or luer lock comprises an integrated mixing device for combining materials such as therapeutics, blood, drugs, bone marrow, peptides, regenerative therapies, and / or polymers.

[0192] In certain embodiments, the syringe is pre-filled with a therapeutic agent selected from a pharmaceutical, a biologic, a powder, a peptide, a polymer, and a regenerative therapy.

[0193] In certain embodiments, the assembly further comprises a filter. If present, the filter may or may not be internal to the adapter or on a peripheral device. Typically, filters are disposable membrane-based devices used to remove particulate impurities from small volumes (≦100 mL) of liquid samples. One skilled in the art will select a syringe filter based on the desired end use. Disposable syringe filters are commonly used in laboratories for fast and efficient filtration, material purification, or sterilization. Sterile filters sterilize non-sterile solutions or clarify sterile solutions. Non-sterile filters are used for general filtration and sample purification.

[0194] These filters typically comprise two components: a membrane and a housing. The housing is tailored based on composition and style, while the membrane is tailored to the end use by composition, filter diameter, and pore size. Typical housing styles include, but are not limited to, classic, overmolded, and dome-shaped. Examples of filter housing materials include, but are not limited to, high-density polyethylene (HDPE), modified acrylic, polycarbonate, polypropylene, and polyvinyl chloride (PVC).

[0195] The two most frequently used membrane pore sizes are 0.45 μm and 0.2 / 0.22 μm. 0.45 μm membranes are typically used for general filtration and particle removal applications. 0.2 / 0.22 μm membranes, or sterilizing-grade membranes, are most commonly used for solution sterilization (e.g., bacterial removal). Examples of filter membranes include, but are not limited to, alumina-based, 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 produced by converting and subsequently regenerating natural cellulose derivatives, typically to form either fibers (e.g., rayon) or films (e.g., cellophane).

[0196] Example 3 - Ovine studies of bone integration and pull-out strength In vivo evaluation, ex vivo evaluation, and data from this six sheep study will determine how this treatment modality affects bone mineral density, polymorphonuclear cells (PMNs), lymphocytes, plasma cells, macrophages (Mφ), giant cells, necrosis, osteoblasts, signs of bone remodeling by osteoclasts, angiogenesis, fibrosis, signs of implant degradation, and particulate debris.

[0197] The first specific objective was to determine whether porous pedicle screws promote bone integration and pullout strength compared to gold-standard pedicle screw / rod constructs in a posterior lumbar interbody fusion sheep model. The 3D-printed porous pattern topography has been shown to promote higher stem cell adhesion to titanium. Furthermore, mesenchymal stem cells and hematopoietic stem cells have therapeutic effects on bone. By combining these two modalities, the disclosed porous pedicle screws can achieve superior bone integration and pullout strength results compared to current pedicle screws.

[0198] To this end, bone mineral density (BMD) of 84 vertebral bodies (L1-L6) will be measured from six sheep 1 week before surgery and 24 and 36 weeks after surgery. Each subject will undergo two separate lumbar interbody fusions (LIFs) at the L2-L3 and L4-L5 joints. L1 and L6 will serve as naive controls to compare changes with and without hardware.

[0199] [Table 2]

[0200] In each subject, a titanium interbody cage and bone void filler packed into the cage were placed between the L2-L3 and L4-L5 segments. Screws with diameters of 4.5, 5.5, or 6.5 mm and lengths of 45±10 mm were then inserted into the right and left pedicles within the L2, L3, L4, and L5 vertebral bodies. This configuration represents a conventional fixation device and surgical technique. Prior to insertion, the porous pedicle screws (treatment) were sprayed with autologous stem cell concentrate along the length of the porous partial screws.

[0201] In-life radiographs of the lumbar spine are performed on all animals immediately post-operatively (PO) and at the time of sacrifice. Animals are visually evaluated at least once daily throughout the study. Abnormalities, such as signs of infection at the surgical site, are recorded. A total of six animals are sacrificed 36 weeks after surgery.

[0202] After euthanasia, lumbar segments (L1-L5) will be freshly dissected into single functional spinal units (FSUs) (L4-L5) for post-mortem evaluation. High-resolution biplanar digital radiographs and photographs will be taken at the time of sacrifice after fine dissection in the sagittal and coronal planes. Non-fracturing range of motion (ROM) biomechanics will be measured for all specimens, including ROM biomechanics under pure moment loads of up to 6.0 Nm in flexion-extension, lateral bending, and axial rotation, yield range of motion (degrees), construct stiffness (degrees / Nm), and neutral zone (degrees).

[0203] Destructive pedicle screw pull-out tests are performed. Quasi-static ramp to failure tests yield construct stiffness (N / mm), yield force (N), ultimate failure force (N), and visually observed failure mode (MOD). Destructive pedicle screw torque-out is tested for N=1 of four screws from each, and counterclockwise quasi-static torque to loosen the screw yields the ultimate torque (Nm).

[0204] Other tests included micro-computed tomography (MicroCT) of each FSU and associated pedicle screw, quantitative assessment of the posterior lumbar fusion (PLF) area (bone volume and bone density), qualitative assessment of bone ingrowth around the pedicle screws, pedicle screw histology, organ histology, and static histomorphometry of the screw region of interest (ROI), including the percentage of bone area within the ROI, the percentage of fibrous tissue within the ROI, the percentage of void space within the ROI, the percentage of the screw within the ROI, and the percentage of bone ingrowth into the device.

[0205] Slides are sent to a certified pathologist for histopathological analysis. The pathologist is initially blinded to the treatment parameters for each site. Sections are then analyzed and graded by cell type and response, if applicable, according to the grading scheme in Table 3. After scoring all slides for data post-processing, the pathologist is unblinded so that the data can be compared to control samples.

[0206] [Table 3] Reference: ISO 10993-6 Annex E (Biological evaluation of medical devices - Part 6: Testing for local effects after implantation)

[0207] The histopathology report will include, but is not limited to, a summary of methods and materials, tabulated qualitative data throughout the final time points and conclusions, low-magnification images, and representative photomicrographs to illustrate findings. Unpaired t-tests with an alpha (α) value of 0.05 will be performed to determine statistical significance for biomechanical and histomorphometric outcome parameters. Data will then be compared with similar retrospective studies.

[0208] The second specific objective of this study is to demonstrate the safety of injecting and spraying autologous concentrated stem cells into and around pedicle screws. Porous 3D-printed titanium interbody cages are commonly impregnated with autologous stem cells during surgery. They have been proven safe and are the gold standard for aiding fusion between vertebrae after disc removal. This study aims to demonstrate that the same can be done in sheep vertebrae to provide safety confidence for human clinical trials.

[0209] After sacrifice, histology will be compared with previous studies to determine differences and similarities in polymorphonuclear cells (PMNs), lymphocytes, plasma cells, macrophages (Mφ), giant cells, necrosis, osteoblasts, signs of osteoclast-mediated bone remodeling, angiogenesis, fibrosis, signs of implant degradation, and particulate debris. Histological reports will also be compared and contrasted between control, naive, and treated sites. Unpaired t-tests with an alpha (α) value of 0.05 will be performed to determine statistical significance for biomechanical and histomorphometric outcome parameters. Injecting autologous stem cells into and around porous pedicle screws is expected to be safe compared to control screws, naive screws, and previous studies.

[0210] The third specific objective of this study was to demonstrate that porous pedicle screws have a topography and porosity pattern suitable for promoting stem cell adhesion. Human mesenchymal stem cells have the strongest adhesion affinity, a more robust and dense internal cell migration pattern, and high cell viability for titanium surfaces with porosity between 50% and 70%. Therefore, the porosity pattern and topography of porous pedicle screws should have similar adhesion properties for stem cells.

[0211] After slaughtering the sheep, the screws are removed from the vertebrae and stem cell adhesion is studied. Cell viability on the implant surface is measured using a live / dead assay. Conditioned media assays are used to study bone morphogenetic protein 2 (BMP2) expression levels, vascular endothelial growth factor (VEGF), osteocalcin, osteoprotegerin expression, DNA, and alkaline phosphatase activity.

[0212] A correlation between cell adhesion to 3D-printed titanium patterns and porous pedicle screws is shown. Porous pedicle screws demonstrate better stem cell adhesion than control and naive subjects, and similar adhesion rates to previous studies.

[0213] Example 4 - Sheep studies on infection Another six animal studies will focus on testing the feasibility of injecting calcium sulfate with an antibiotic mixture as a means of reducing infection rates after spinal fusion. The primary objectives of this project are to determine (1) whether the tested pedicle screws support superior bone integration and pullout strength compared to the gold-standard pedicle screw / rod construct in a posterior lumbar interbody fusion sheep model, (2) whether injecting calcium sulfate with an antibiotic mixture can reduce infection rates after spinal fusion, and (3) whether the tested pedicle screws have the topography and porosity pattern to support the above-mentioned injection goals.

[0214] For the first objective, the rationale is that if a patient has infected bone, the surgeon can protect the hardware by injecting an antibiotic mixture through the device. Through the proposed animal studies, we will confirm that in infected and contained areas (e.g., vertebrae), pedicle screws (1) protect the surgical hardware (i.e., confirm that the infection has not spread to the hardware) and (2) reduce infection in the bone compared to controls.

[0215] The sheep model was chosen because it has a vertebral column that is most similar to the human spine. The sheep vertebrae are large enough to accommodate the pedicle screws disclosed herein. Smaller animals are not viable because the screws are too large for their bones.

[0216] This sample size was selected to realistically assess feasibility and achieve proof of concept within the scope and timeline of Phase I. In alignment with program objectives, Phase I results will be interpreted as preliminary, and tentative conclusions will be used to inform an anticipated Phase II, where we propose a large-scale, controlled, and adequately powered animal study that will evaluate efficacy endpoints in a scientifically rigorous manner.

[0217] The experimental design and methods were essentially the same as those described above in the sheep study in Example 3, including Tables 2 and 3.

[0218] All references, patents, or applications (U.S. or foreign) cited in this application are hereby incorporated by reference as if set forth in their entirety herein. In the event of a conflict, the material disclosed herein will control.

[0219] From the foregoing description, those skilled in the art can easily ascertain the essential features of the present invention, and can make various changes and modifications to the present invention to adapt it to various uses and conditions without departing from the spirit and scope of the present invention.

Claims

1. 1. An adapter for circulating a material within a medical device, 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 aperture lock formed at said proximal end for reversibly engaging a male taper of a pressure device; a male conical surface formed on the distal end configured to reversibly engage a female conical surface on a medical device; a thread disposed about the shaft between the female opening locking portion and the male conical surface, the thread configured to reversibly engage a groove.

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

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

4. An adapter according to any one of claims 1 to 3, wherein the groove is on a tulip.

5. 5. The adapter of claim 1, wherein the female opening locking portion is a female luer locking portion and the male taper is a male luer taper.

6. 1. An assembly for circulating a material within a medical device, comprising: an adapter; 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 aperture lock formed at said proximal end for reversibly engaging a male taper of a pressure device; a male conical surface formed on the distal end configured to reversibly engage a female conical surface on a medical device; a thread disposed around the shaft between the female opening locking portion and the male conical surface, the thread configured to reversibly engage a groove in an inner surface.

7. The assembly of claim 6 , wherein the medical device is a bone screw.

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

9. Assembly according to any one of claims 6 to 8, wherein the groove is on a tulip.

10. 10. An assembly according to any one of claims 6 to 9, wherein the female opening lock is a female luer lock and the male taper is a male luer taper.

11. 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 reversibly engaging the cannula of the adapter when assembled; The assembly of any one of claims 6 to 10, comprising: a scaffold for promoting osseointegration in the medical device.

12. The assembly of claim 11 , wherein the body is a shaft.

13. The assembly of claim 12 , wherein the medical device is a bone screw.

14. The assembly of claim 13 , wherein the bone screw is a pedicle screw.

15. 15. The assembly of any one of claims 11-14, wherein the scaffold comprises an internal lattice structure having a porosity architecture formed from a combination of mean curvature, Gaussian curvature, and net curvature that characterizes the local geometry of healthy trabecular bone.

16. 16. The assembly of any one of claims 11 to 15, wherein the scaffold exhibits a predominantly hyperbolic shape including saddle-shaped regions, spherical depressions, and cylindrically shaped rod-shaped elements.

17. 17. The assembly of any one of claims 11-16, wherein the scaffold comprises one or more structural cues selected from porosity, pore size, grain 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.

18. 18. The assembly of claim 17, wherein the new bone formation is following MSC differentiation, osteoblast outgrowth, ECM deposition, or a combination thereof.

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

20. Further comprising a tulip, the tulip comprising: a body having a top opening, a bottom opening, an inner surface, and an outer surface; the bottom opening is configured to engage the proximal end of the medical device; An assembly according to any one of claims 6 to 19, wherein the inner surface of the top opening is provided with a groove that reversibly engages with the threads of the adapter.

21. 21. The assembly of claim 20, wherein the tulip further comprises a pair of side openings disposed on opposite sides of the body, the side openings configured to reversibly engage a pin that locks the tulip to the medical device.

22. The pressure device further comprises: a barrel having a distal end, a proximal end, and a lumen; a plunger disposed within the lumen; The assembly of any one of claims 6 to 21, comprising a male taper formed on the distal end configured to reversibly engage the female opening locking portion of the adapter.

23. 23. The assembly of any one of claims 6 to 22, wherein the medical device is focused for bone growth throughout the body to minimize shear stress at the distal tip and minimize micro-motion throughout the medical device due to bone ingrowth.

24. 24. The assembly of any one of claims 6 to 23, wherein the medical device is configured with an arcuate cross-sectional pattern that varies from a proximal end to a distal tip of the medical device for placement in an internal cavity of an anatomical feature, and wherein an autograft is harvested within the medical device upon coaxial rotation of the medical device.

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

26. 1. A method of infusing a material into a medical device, comprising: Engaging a pressurizing device and a medical device having a scaffold with the adapter of any one of claims 1 to 25; injecting a material into the medical device with negative or positive pressure from the pressure device.

27. 27. The method of claim 26, wherein the pressure device is a syringe having a plunger, and the material is circulated by negative pressure by pulling the plunger of the syringe or positive pressure by pushing the plunger of the syringe.

28. 28. The method of claim 26 or 27, wherein the pressure device is loaded with a material before engaging the adapter, and the material is forced into the medical device.

29. 30. The method of claim 28, further comprising drawing a biomaterial into the pressurized device and then injecting a mixture of the loaded material and biomaterial into the medical device.

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

31. 30. The method of claim 29, wherein the circulation creates a biological ripple effect that induces and promotes healing.

32. 31. The method of claim 30, wherein the healing comprises stem cells binding to the scaffold of the medical device.

33. 32. The method of claim 31, wherein osteoclasts and osteoblasts are grown.

Images