Abstract: Embodiments of apparatus, systems, and methods relating to biomedical implants and other devices made up of unique and improved alumina-zirconia ceramic materials. In an example of a method according to an implementation of the invention, a slurry is prepared, compressed, and fired to obtain a fired ceramic piece comprising at least aluminum oxide, zirconium dioxide, yttrium oxide, cerium oxide, strontium oxide, magnesium oxide, titanium dioxide, and calcium oxide. Some embodiments and implementations may comprise selected concentrations of one or more such compounds to yield certain preferred results.

Abstract: Embodiments of apparatus, systems, and methods relating to spinal implants. In some embodiments, the spinal implant may comprise a first sidewall, a second sidewall opposite from the first sidewall, a pair of opposed frictional surfaces each comprising a plurality of raised structures, a first end wall joining the pair of opposed sidewall surfaces, and a second end wall joining the first sidewall and the second sidewall. The second end wall may comprise a recess formed by a first wall portion and a second wall portion arranged at an angle to one another to form a fish-tailed structure configured to be engaged with an inserter instrument. The interface between the recess and the inserter instrument may be configured to at least substantially eliminate any point or line contacts between the inserter instrument and the spinal implant during a flip maneuver of the spinal implant within an intervertebral space of a patient.

Abstract: Methods for threading ceramic materials, such as ceramic materials used for spinal implants or other biomedical implants. In some implementations, an expected rate of shrinkage of the block upon undergoing a firing process may be determined. A scaling factor may then be applied using the expected rate of shrinkage to select a tap having a size larger than a desired thread size. A green block may then be tapped with the selected tap to form a threaded opening in the green block. The block may be machined in order to remove cracks caused by the tapping process and/or to form the block into a desired shape/size. The green block may then be fired, which may result in a reduction of a size of the block and a size of the threaded opening.

Abstract: Methods for improving the antibacterial characteristics of biomedical implants and related implants manufactured according to such methods. In some implementations, a biomedical implant comprising a silicon nitride ceramic material may be subjected to a surface roughening treatment so as to increase a surface roughness of at least a portion of the biomedical implant to a roughness profile having an arithmetic average of at least about 500 nm Ra. In some implementations, a coating may be applied to a biomedical implant. Such a coating may comprise a silicon nitride ceramic material, and may be applied instead of, or in addition to, the surface roughening treatment process.

Abstract: Methods for improving the antibacterial characteristics of a biomedical implant. In some implementations, the method may comprise providing a biomedical implant material block. The biomedical implant material block may comprise a silicon nitride ceramic material. The surface chemistry of the biomedical implant material block may be altered to improve the antibacterial characteristics of the biomedical implant material block. In some implementations, the surface chemistry may be altered by firing the biomedical implant material block in a nitrogen-rich environment or otherwise increasing the nitrogen content in the transitional oxide layer of at least a portion of the biomedical implant material block. The surface of the biomedical implant material block may also, or alternatively, be roughened to improve antibacterial characteristics of the implant.

Abstract: Oral implants and related methods, systems, and apparatus. Some embodiments may comprise a silicon nitride bone anchor configured to be integrated with and affixed to alveolar bone of a patient's oral bone cavity. The bone anchor may comprise a core and an outer layer comprising a silicon nitride ceramic material. The outer layer may have a density less than a density of the core. An anchor abutment may be coupled with the bone anchor, and may be configured to protrude above epithelial tissue of the patient's oral cavity and provide a substrate for positioning and fixation of a dental component, such as a crown or bridge.

Abstract: Methods for performing a hemiarthroplasty procedure. In some implementations, the method may comprise providing a component of an endoprosthesis, such as a femoral component of a hip prosthesis. The component may comprise a silicon nitride ceramic material, and may further comprise a coated articulating surface. The coated articulating surface may comprise a coating configured to reduce a coefficient of friction of the articulating surface. The method may further comprise positioning the endoprosthesis such that the coated articulating surface is positioned adjacent to a patient's native articular cartilage. In this manner, the coated articulating surface may articulate with the native articular cartilage following the procedure.

Abstract: Systems and methods for forming an insert, such as a threaded or threadable insert, within a cavity in an implant, such as a spinal spacer. According to various embodiments, a spinal interbody spacer may include a proximal end and a distal end. The interbody spacer may be manufactured using a non-threadable material, or at least a material that is difficult to thread, such as a ceramic, a glass, or a porous material. Some embodiments may comprise a silicon nitride ceramic material. A cavity may be formed in the interbody spacer, such as in the proximal end. A material having desired properties lacking in the spacer, such as a threadable insert within a non-threadable spacer, may be inserted into the cavity. The threadable material may then be threaded in order to form a female-threaded insert within the otherwise non-threadable interbody spacer.

Abstract: Methods, apparatus, and systems for improving the performance of articulating prostheses. Some embodiments may comprise a first component comprising a first articulating surface and a second component comprising a second articulating surface configured for articulating with the first articulating surface. One or both of the first and second components may comprise a silicon nitride ceramic material. One or both of the first and second articulating surfaces may comprise a coating that is configured to accomplish at least one of increasing the hardness of the first articulating interface surface, reducing the coefficient of friction between the first and second articulating surfaces, decreasing the effects of wearing between the first and second articulating surfaces, and decreasing the intensity of audible noises produced by the endoprosthesis resulting from articulation between the first and second articulating surfaces during use.

Abstract: A spinal implant prosthesis includes a pair of end plates for affixation to adjacent vertebral bone structures and respectively defining inter-engaged convex and concave articulatory surfaces of elliptical profile. These elliptical articulatory surfaces are elongated in an anterior-posterior direction, and are comparatively shorter in a medial-lateral direction. With this configuration, in response to angular displacement and/or axial rotation, the elliptical surfaces displace in a manner increasing the distance between the adjacent vertebral bone structures, thereby tensioning the prosthesis and producing counteracting forces which urge the components back toward a substantially centered or neutral position. In addition, in the preferred form, the anterior-posterior length of the concave articulatory surface in incrementally greater than the anterior-posterior length of the convex articulatory surface to accommodate a limited range of anterior-posterior translation.

Abstract: A total disc implant (TDI) is provided for total replacement of a spinal disc or discs in a human patient or other mammal, wherein the TDI is designed to maintain a substantially full range of natural motion (ROM) following implantation. The TDI generally comprises, in one preferred form, upper and lower end plates for affixation to adjacent vertebral bodies, with an intervening insert disposed therebetween. The end plates each include elongated part-cylindrical surfaces oriented, generally perpendicular to each other, with one of the surfaces extending in an anterior-posterior direction and the other extending in a medial-lateral direction. The intervening insert defines concave upper and lower part-cylindrical seats oriented, for respectively engaging these part-cylindrical surfaces, wherein these part-cylindrical seats are defined by offset radii to include a somewhat flattened central base region merging smoothly with upwardly curving radiused sides.

Abstract: An improved bone graft is provided for human implantation, particularly such as a spinal fusion cage for implantation into the inter-vertebral space between two adjacent vertebrae. The improved spinal fusion cage includes a substrate block of high strength biocompatible material having a selected size and shape to fit the anatomical space, and a controlled porosity analogous to natural bone. The substrate block may be coated with a bio-active surface coating material such as hydroxyapatite or a calcium phosphate to promote bone ingrowth and enhanced bone fusion. Upon implantation, the fusion cage provides a spacer element having a desired combination of mechanical strength together with osteoconductivity and osteoinductivity to promote bone ingrowth and fusion, as well as radiolucency for facilitated post-operative monitoring. The fusion cage may additionally carry one or more natural or synthetic therapeutic agents for further promoting bone ingrowth and fusion.

Abstract: An improved implant is provided for human implantation, such as a spinal implant for implantation into the intervertebral space between two adjacent vertebrae. Some embodiments include a substrate of high strength biocompatible material, such as doped silicon nitride ceramic for example. In some embodiments, the substrate may also include one or more regions of a controlled porosity analogous to natural bone. In other embodiments, the substrate may comprise the entire implant.

Abstract: A spinal implant prosthesis includes a pair of end plates for affixation to adjacent vertebral bone structures and respectively defining inter-engaged convex and concave articulatory surfaces of elliptical profile. These elliptical articulatory surfaces are elongated in an anterior-posterior direction, and are comparatively shorter in a medial-lateral direction. With this configuration, in response to angular displacement and/or axial rotation, the elliptical surfaces displace in a manner increasing the distance between the adjacent vertebral bone structures, thereby tensioning the prosthesis and producing counteracting forces which urge the components back toward a substantially centered or neutral position. In addition, in the preferred form, the anterior-posterior length of the concave articulatory surface in incrementally greater than the anterior-posterior length of the convex articulatory surface to accommodate a limited range of anterior-posterior translation.

Abstract: An improved hlp prosthesis includes an acetabular cup bearing component constructed from a relatively hard and high strength ceramic material for articulation with a ball-shaped femoral head component which may be constructed from a compatible ceramic or metal material. In one form, the acetabular cup further includes a ceramic porous bone ingrowth surface adhered thereto for secure ingrowth attachment to natural patient bone.

Abstract: A total disc implant (TDI) is provided for total replacement of a spinal disc or discs in a human patient or other mammal, wherein the TDI is designed to maintain a substantially full range of natural motion (ROM) following implantation. The TDI generally comprises, in one preferred form, upper and lower end plates for affixation to adjacent vertebral bodies, with an intervening insert disposed therebetween. The end plates each include elongated part-cylindrical surfaces oriented generally perpendicular to each other, with one of said surfaces extending in an anterior-posterior direction and the other extending in a medial-lateral direction. The intervening insert defines concave upper and lower part-cylindrical seats oriented for respectively engaging these part-cylindrical surfaces, wherein these part-cylindrical seats are defined by offset radii to include a somewhat flattened central base region merging smoothly with upwardly curving radiused sides.

Abstract: A prosthesis for articulation (e.g., hip or joint prosthesis) is provided, which includes a pair of articulation components respectively defining a pair of articulation surfaces movably engageable with each other. In some embodiments, each of the articulation surfaces is formed from a biocompatible ceramic (e.g., doped silicon nitride ceramic) having a flexural strength greater than about 700 Mega-Pascal (MPa) and a toughness greater than about 7 Mega-Pascal root meter (MPam0.5).

Abstract: An improved hip prosthesis includes an acetabular cup bearing component constructed from a relatively hard and high strength ceramic material for articulation with a ball-shaped femoral head component which may be constructed from a compatible ceramic or metal material. In one form, the acetabular cup further includes a ceramic porous bone ingrowth surface adhered thereto for secure ingrowth attachment to natural patient bone.

Abstract: A prosthesis for articulation (e.g., hip or joint prosthesis) is provided, which includes a pair of articulation components respectively defining a pair of articulation surfaces movably engageable with each other. In some embodiments, each of the articulation surfaces is formed from a biocompatible ceramic (e.g., doped silicon nitride ceramic) having a flexural strength greater than about 700 Mega-Pascal (MPa) and a toughness greater than about 7 Mega-Pascal root meter (MPam0.5).

Abstract: A total disc implant (TDI) is provided for total replacement of a spinal disc or discs in a human patient or other mammal, wherein the TDI is designed to maintain a substantially full range of natural motion (ROM) following implantation. The TDI generally comprises, in one preferred form, upper and lower end plates for affixation to adjacent vertebral bodies, with an intervening insert disposed therebetween. The end plates each include elongated part-cylindrical surfaces oriented generally perpendicular to each other, with one of said surfaces extending in an anterior-posterior direction and the other extending in a medial-lateral direction. The intervening insert defines concave upper and lower part-cylindrical seats oriented for respectively engaging these part-cylindrical surfaces, wherein these part-cylindrical seats are defined by offset radii to include a somewhat flattened central base region merging smoothly with upwardly curving radiused sides.