Modular bone implant, arrangement and kit

Abstract

A modular bone implant for affixation to a bone having a bone end surface and a bone side surface oriented at an angle with respect to each other. The implant comprises an anchor seat with an inner seat surface configured for abutting the bone end surface, and an elongate stem extending from the anchor seat with a proximal end portion, a distal end portion and a stem long axis. The proximal end portion comprises a planar surface obliquely angled relative to the stem long axis and configured for positioned placement under the bone side surface. At least one fixating element extends from the anchor seat adjacent the stem, having a fixator long axis parallel to the stem long axis and a length shorter than that of the stem. The implant may include a connecting portion configured to breach the bone side surface for attachment to a bone plate, which may be covered by a fixation plate.

Description

[0001] MODULAR BONE IMPLANT, ARRANGEMENT AND KIT

[0002] TECHNOLOGICAL FIELD

[0003] The presently disclosed subject matter generally relates to surgical implants. More particularly, the presently disclosed subject matter relates to a modular bone implant arrangement and kit for supporting arthroplasty.

[0004] BACKGROUND

[0005] US20080051909A1 to WOLFE et al. discloses “An implant system and apparatus configured to permit motion of the wrist in at least one physiological direction, as well as in a dart thrower's motion, and constrain motion of the wrist in at least one non-physiological direction are provided. The implant according to one embodiment includes a distal component and proximal component. Each of the distal and proximal components includes a primary articulating portion and a secondary' articulating portion. Primary and secondary articulating portions include at least one component having either a substantially convex or a substantially concave shape. The secondary articulating portion is configured to be radially and volarly disposed in relation to the primary articulating portion;’

[0006] GENERAL DESCRIPTION

[0007] There is provided in accordance with a first aspect of the presently disclosed subject matter a modular bone implant for affixation to a bone having a bone end surface and a bone side surface oriented in an angle with respect to each other. The modular bone implant comprises an anchor seat, and elongate stem, and at least one fixating element. The anchor seat has an inner seat surface configured for abutting the bone end surface. The stem extends from the anchor seat and comprises a proximal end portion, a distal end portion and a stem long axis extending between the proximal and distal end portions. The proximal end portion comprises a planar surface obliquely angled relative to the stem long axis configured for positioned placement under the bone side surface and in proximity thereto.

[0008] The at least one fixating element extends from the anchor seat adjacent the stem. The at least one fixating element has a fixator long axis parallel to the stem long axis, and a length shorter than that of the stem. In some embodiments, the modular bone implant comprises a pair of fixating elements which together with the stem provide a triangular stance adjacent the anchor seat. In some embodiments, each fixating element comprises at least one cavity formation at an outer surface thereof. In some embodiments, each fixating element comprises a non-circular transverse cross-section.

[0009] In some embodiments, a connecting portion is integrally or selectively mounted onto the planar surface at the proximal end. The connecting portion is configured to breach the bone side surface, at least partially. In some embodiments, the connecting portion is matable with a bone plate. In some embodiments, the bone plate comprises a pallet portion formed with an inner pallet curvature which corresponds to a surface curvature of the bone side surface. In some embodiments, the bone plate comprises at least one elongate aperture defined within the pallet portion. The elongate aperture has a first end and a second end located along a pallet long axis of the pallet portion. The elongate aperture is configured to slidably receive at least a part of the connecting portion.

[0010] In some embodiments, the at least a part of the connecting portion abuts against the pallet portion at the first end of the elongate aperture while a remaining area of the elongate aperture is configured to receive at least one screw fastener therethrough, which fixates the pallet portion to the bone and prevents the at least a part of the connecting portion from slipping out of the elongate aperture. In some embodiments, the bone plate has a distal plate end and a proximal plate end. The distal plate end includes the at least one elongate aperture and is matable with the at least a part of the connecting portion, and the proximal plate end is fastenable to the bone side surface.

[0011] In some embodiments, the modular bone implant may further comprise a fixation plate configured to be mounted on top of the bone plate and to cover at least a majority of the bone plate and the at least a part of the connecting portion. In some embodiments, the fixation plate is configured to fasten to the bone plate. In some embodiments, the stem comprises serrations at least along a portion of an outer surface thereof. In some embodiments, the elongate stem comprises a non-circular transverse cross-section along the stem long axis. In some embodiments, the anchor seat is configured to provide a hemiarthroplasty basis. In some embodiments, the bone is a radius bone.

[0012] There is thus provided in accordance with another aspect of the presently disclosed subject matter a modular bone implant arrangement for selective affixation to a bone having a bone end surface and a bone side surface. The modular bone implant arrangement comprises an anchor seat, an elongate stem, and a connecting portion. The anchor seat defines an imaginary anchor seat plane and is configured for abutting the bone end surface.

[0013] The elongate stem extends from the anchor seat and comprises a proximal end portion, a distal end portion and a stem long axis extending between the proximal and distal end portions. The stem long axis extends obliquely relative to the imaginary anchor seat plane. The connecting portion extends from the proximal end portion of the stem and is configured to: be fixated at the bone side surface by way of a bone plate; or be fixated at the bone side surface by way of the bone plate and a fixation plate, said fixation plate at least partially covering the bone plate and the connecting portion.

[0014] In some embodiments, the modular bone implant arrangement comprises a pair of fixating elements which together with the stem provide a triangular stance. In some embodiments, each of the fixating elements comprises at least one cavity formation at an outer surface thereof. In some embodiments, each of the fixating elements comprises a non-circular transverse cross-section.

[0015] In some embodiments, the proximal end portion has a planar surface. The connecting portion may be integrally or selectively mounted onto the planar surface and is configured to breach the bone side surface, at least partially. In some embodiments, the planar surface is obliquely angled relative to the stem long axis and is positionable within a cortical layer under the bone side surface.

[0016] In some embodiments, the bone plate has a distal plate end and a proximal plate end. The connecting portion is matable with the distal plate end, and the proximal plate end is fastenable to the bone side surface. In some embodiments, the bone plate comprises a pallet portion formed with an inner pallet curvature which corresponds to a surface curvature of the bone side surface. In some embodiments, the bone plate comprises at least one elongate aperture defined within the pallet portion. The elongate aperture has a first end and a second end located along a pallet long axis of the pallet portion. The elongate aperture is configured to slidably receive the proximal end.

[0017] In some embodiments, the proximal end abuts against the pallet portion at the first end of the elongate aperture while a remaining area of the elongate aperture is configured to receive at least one screw fastener therethrough. The at least one screw fastener fixates the pallet portion to the bone and prevents the proximal end from slipping out of the elongate aperture. In some embodiments, the fixation plate is configured to cover at least a majority of the bone plate and the connecting portion and fasten to the bone plate. In some embodiments, the elongate stem comprises serrations at least along a portion of an outer surface thereof. In some embodiments, the elongate stem comprises a non-circular transverse cross-section along the stem long axis. In some embodiments, the anchor seat is configured to provide a hemiarthroplasty basis.

[0018] There is thus provided in accordance with another aspect of the presently disclosed subject matter a bone plate for fixation of a bone implant having an elongate stem which extends through the bone and ends with a connecting portion positionable at an outer bone surface of the bone. The bone plate comprises a pallet portion formed with an inner pallet curvature corresponding to a surface curvature of the outer bone surface and at least one elongate aperture defined within the pallet portion. The elongate aperture has a first end and a second end located along a pallet long axis of the pallet portion.

[0019] The elongate aperture is configured to slidably receive at least a portion of the connecting portion such that when the connecting portion abuts against the pallet portion at the first end of the elongate aperture, a remaining area of the elongate aperture is configured to receive at least one fastener therethrough which fixates the pallet portion to the bone and prevents the connecting portion from slipping out of the elongate aperture. In some embodiments, one or more additional apertures are formed along the length of the bone plate for receipt of screw fasteners therethrough.

[0020] In some embodiments, the one or more additional apertures are aligned along a pallet long axis of the pallet portion. In some embodiments, the bone plate comprises a distal plate end and a proximal plate end. The distal plate end is matable with a connecting portion and the proximal plate end is fastenable to the outer bone surface. In some embodiments, the pallet portion comprises an outer pallet surface configured to mate with an inner plate surface of a fixation plate configured to cover at least a majority thereof.

[0021] In some embodiments, the first end of the elongate aperture comprises laterally opposed plate formations and the connecting portion comprises laterally opposed connector formations matable with the laterally opposed plate formations. In some embodiments, the connecting portion comprises a head portion superficially defining the laterally opposed connector formations and having a head width and head length configured to correspondingly mate with the laterally opposed plate formations. In some embodiments, the second end of the elongate aperture is configured to receive the head width and head length such that the bone plate is linearly displaceable so as to migrate the head portion toward the first end of the elongate aperture for slidably mating with the bone plate.

[0022] There is thus provided in accordance with another aspect of the presently disclosed subject matter a bone implant kit. The bone implant kit comprising a bone implant comprising an anchor seat, an elongate stem, and a connecting portion. The anchor seat has an inner seat surface configured for abutting a bone end surface. The elongate stem extends from the anchor seat and comprises a proximal end portion, a distal end portion and a stem long axis extending between the proximal and distal end portions. The connecting portion is selectively mountable onto the proximal end portion of the stem for enabling the attachment of a bone plate to the bone implant via the connecting portion. The connecting portion comprises a directional geometrical locking mechanism configured for locking the connecting portion to the proximal end of the stem. In some embodiments, the connecting portion is configured to at least partially protrude from the bone side surface when mounted onto the proximal end portion of the stem. In some embodiments, the proximal end portion of the stem comprises a planar surface, the connecting portion being mountable to the planar surface. In some embodiments, the planar surface is obliquely angled relative to the stem long axis and positionable within a cortical layer under the bone side surface.

[0023] In some embodiments, the connecting portion is mountable to the proximal end portion of the stem after implantation of the bone implant. In some embodiments, the connecting portion comprises an axis of rotation orthogonal to the planar surface about which the connecting portion may be rotated to fix the connecting portion to the proximal end portion. In some embodiments, the connecting portion is mountable to the proximal end portion of the stem before implantation of the bone implant. In some embodiments, the connecting portion comprises an axis of rotation orthogonal to the stem long axis about which the connecting portion may be rotated to fix the connecting portion to the stem.

[0024] In some embodiments, the bone implant may comprise a pair of fixating elements which together with the stem provide a triangular stance at the anchor seat. In some embodiments, each of the fixating elements comprises at least one cavity formation at an outer surface thereof. In some embodiments, the bone plate is formed with an elongate aperture in which the connecting portion is receivable, the elongate aperture being configured to slidably receive the connecting portion. In some embodiments, the connecting portion abuts against a first end of the elongate aperture when slidably received while a remaining area of the elongate aperture is configured to receive at least one screw fastener therethrough operable to fix the bone plate to the bone and prevent the connecting portion from slipping out of a second end of the elongate aperture. As generally described herein, a “connecting portion” can include any suitable structure which, when located at the proximal end of the stem, provides for the stem inclusive of the connecting portion to have a length long enough so that when the anchor seat abuts against the bone end surface, at least a part of the connecting portion protrudes outwardly from the outer side surface of the bone, enabling the engagement with a bone plate or any other fixation element via the connecting portion. The connecting portion can be integrally formed as part of the stem, or, in other embodiments, selectively mounted and optionally geometrically locked to the stem.

[0025] BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Other features and objectives of the presently disclosed subject matter will become more evident from a consideration of the following brief descriptions of patent drawings.

[0027] FIG. 1 is a first sequential simplified diagrammatic depiction of a long bone before a modular bone implant according to the presently disclosed subject matter is affixed thereto.

[0028] FIG. 2A is a second sequential simplified diagrammatic depiction of a long bone with a basic modular bone implant according to the presently disclosed subject matter affixed to the long bone such that a proximal end portion of the modular bone implant is positioned within a cortical layer of a bone side surface of the long bone.

[0029] FIG. 3A is an enlarged fragmentary sectional depiction of a proximal end portion of the basic modular bone implant according to the presently disclosed subject matter positioned within a cortical layer of a bone side surface of a bone reflective of the arrangement otherwise shown in FIG. 2A.

[0030] FIG. 2B is a third sequential simplified diagrammatic depiction of a long bone with a first modular bone implant according to the presently disclosed subject matter affixed to the long bone such that a proximal end portion of the modular bone implant is positioned within a cortical layer of a bone side surface of the long bone and a connecting portion extending from the proximal end portion minimally breaching the outer cortical layer.

[0031] FIG. 3B is an enlarged fragmentary sectional depiction of a proximal end portion of the first modular bone implant according to the presently disclosed subject matter positioned within a cortical layer of a bone side surface of a bone and the connecting portion extending from the proximal end portion minimally breaching the outer cortical layer reflective of the arrangement otherwise shown in FIG. 2B.

[0032] FIG. 4 is a fourth sequential simplified diagrammatic depiction of a long bone with the first modular bone implant according to the presently disclosed subject matter affixed to the long bone such that a connecting portion mounted at a proximal end portion of the modular bone implant breaches an outer cortical layer at the bone side surface of the long bone.

[0033] FIG. 5 is an enlarged fragmentary sectional depiction of a proximal end of the first modular bone implant according to the presently disclosed subject matter positioned such that a connecting portion mounted at a proximal end portion breaches an outer cortical layer at a bone side surface of a bone reflective of the arrangement otherwise shown in FIG. 4.

[0034] FIG. 6 is a fifth sequential simplified diagrammatic depiction of a long bone with a first modular bone implant arrangement according to the presently disclosed subject matter affixed to the long bone such that a bone plate connects to the connecting portion mounted at the proximal end of the first modular bone implant, the connecting portion breaching the cortical layer at the bone side surface of the long bone.

[0035] FIG. 7 is a first lateral perspective view of the first modular bone implant arrangement otherwise depicted in FIG. 6 wherein the bone plate is connected to the connecting portion. FIG. 8 is a sixth sequential simplified diagrammatic depiction of a long bone with a second modular bone implant arrangement according to the presently disclosed subject matter affixed to the long bone such that a bone plate connects to the connecting portion mounted at a proximal end of the first modular bone implant, the connecting portion breaching the cortical layer at the bone side surface of the long bone and a fixation plate which covers the bone plate and is affixed to the bone plate and the long bone.

[0036] FIG. 9 is a lateral perspective view of the second modular bone implant arrangement otherwise depicted in FIG. 8 wherein the bone plate is connected to the connecting portion mounted at the proximal end of the elongate stem of the first modular bone implant, and the fixation plate covers the bone plate.

[0037] FIG. 9A is a lateral view of the first modular bone implant according to the presently disclosed subject matter depicting a stem long axis of an elongate stem extending in parallel relation to a fixator long axis of a fixating element, which axes are angled relative to an imaginary anchor seat plane of an anchor seat.

[0038] FIG. 10A is a dorsal perspective view of the basic modular bone implant according to the presently disclosed subject matter showing a planar surface at a proximal end of an elongate stem of the basic modular bone implant.

[0039] FIG. 1 OB is a dorsal perspective view of the first modular bone implant according to the presently disclosed subject matter shown with an integrally formed connecting portion extending from a proximal end of an elongate stem of the first modular bone implant.

[0040] FIG. 11 is a first lateral perspective view of the first basic modular bone implant according to the presently disclosed subject matter. FIG. 12 is a second lateral perspective view of the first basic modular bone implant according to the presently disclosed subject matter.

[0041] FIG. 13 is a dorsal plan view of the first basic modular bone implant according to the presently disclosed subject matter.

[0042] FIG. 14 is a ventral plan view of the first basic modular bone implant according to the presently disclosed subject matter.

[0043] FIG. 15 is a distal end perspective view of the first basic modular bone implant according to the presently disclosed subject matter.

[0044] FIG. 16 is a proximal end perspective view of the first basic modular bone implant according to the presently disclosed subject matter.

[0045] FIG. 17 is a dorsal perspective view of a second basic modular bone implant according to the presently disclosed subject matter shown with a separately mountable and optionally lockable connecting portion mounted to a proximal end of an elongate stem of the second basic modular bone implant.

[0046] FIG. 18 is an exploded dorsal perspective view of the second basic modular bone implant according to the presently disclosed subject matter shown with the separately mountable connecting portion rotated in a mounting orientation before being mounted to the proximal end of the elongate stem of the second basic modular bone implant.

[0047] FIG. 19 is an exploded dorsal perspective view of the second basic modular bone implant according to the presently disclosed subject matter shown with the separately mountable connecting portion rotated in a mounted orientation exploded from the proximal end of the elongate stem of the second basic modular bone implant. FIG. 20 is a dorsal perspective view of a third basic modular bone implant according to the presently disclosed subject matter shown with a separately mountable stem attachment portion with integrally formed connecting portion separately mounted to a proximal end of an abbreviated elongate stem of the third basic modular bone implant.

[0048] FIG. 21 is an exploded ventral view of the third basic modular bone implant according to the presently disclosed subject matter shown with the separately mountable stem attachment portion exploded from the proximal end of the abbreviated elongate stem and axially aligned therewith before being connected to the proximal end.

[0049] FIG. 22 is an exploded lateral view of the third basic modular bone implant according to the presently disclosed subject matter shown with the separately mountable stem attachment portion exploded from the proximal end of the abbreviated elongate stem and rotated in a mounting orientation before being connected to the proximal end.

[0050] FIG. 23 is a dorsal perspective view of the first modular bone implant arrangement according to the presently disclosed subject matter shown with the bone plate mounted to the connecting portion integrally formed with the proximal end of the elongate stem of the first basic modular bone implant.

[0051] FIG. 24 is a second lateral perspective view of the first modular bone implant arrangement according to the presently disclosed subject matter.

[0052] FIG. 25 is a dorsal plan view of the first modular bone implant arrangement according to the presently disclosed subject matter.

[0053] FIG. 26 is a ventral plan view of the first modular bone implant arrangement according to the presently disclosed subject matter. FIG. 27 is an exploded lateral perspective view of the first modular bone implant arrangement according to the presently disclosed subject matter shown with the bone plate exploded from the proximal end of the elongate stem in a mounting orientation before being mounted to the proximal end.

[0054] FIG. 28 is a dorsal perspective view of a bone plate according to the presently disclosed subject matter.

[0055] FIG. 29 is a distal end view of the bone plate according to the presently disclosed subject matter positioned adjacent a fragmentary section of a bone side surface to depict relative curvatures of the opposed structures.

[0056] FIG. 30 is a transverse cross-sectional view of a junction site between a bone plate and a connecting portion according to the presently disclosed subject matter depicting a tongue-and- groove mounting arrangement of the bone plate and the connecting portion.

[0057] FIG. 31 is a dorsal plan view of the bone plate according to the presently disclosed subject matter.

[0058] FIG. 32 is a ventral plan view of the bone plate according to the presently disclosed subject matter.

[0059] FIG. 33 is a first dorsal perspective view of the second modular bone implant arrangement according to the presently disclosed subject matter shown with the bone plate mounted to the connecting portion integrally formed with the proximal end of the elongate stem of the second basic modular bone implant and the fixation plate covering the bone plate devoid of cortical screw fasteners.

[0060] FIG. 34 is a dorsal plan view of the second modular bone implant arrangement according to the presently disclosed subject matter. FIG. 35 is a ventral plan view of the second modular bone implant arrangement according to the presently disclosed subject matter.

[0061] FIG. 36 is a distal end perspective view of the second modular bone implant arrangement according to the presently disclosed subject matter.

[0062] FIG. 37 is a transverse cross-sectional view as sectioned through an elongate stem and a pair of fixating elements of a modular bone implant according to the presently disclosed subject matter depicting a triangular stance of the elongate stem and pair of fixating elements.

[0063] FIG. 38 is an exploded lateral perspective view of the second modular bone implant arrangement according to the presently disclosed subject matter showing from top to bottom the fixation plate, the bone plate and the first basic modular bone implant.

[0064] FIG. 39 is a dorsal perspective view of the fixation plate according to the presently disclosed subject matter.

[0065] FIG. 40 is a dorsal plan view of the fixation plate according to the presently disclosed subject matter.

[0066] FIG. 41 is a ventral plan view of the fixation plate according to the presently disclosed subject matter.

[0067] FIG. 42 is a proximal end perspective view of the fixation plate according to the presently disclosed subject matter.

[0068] FIG. 43 is a second dorsal perspective view of the second modular bone implant arrangement according to the presently disclosed subject matter shown with screw fasteners received in fastener-receiving apertures for fastening the second modular bone implant to a bone.

[0069] DETAILED DESCRIPTION OF THE EMBODIMENTS Referring now to the drawings with more specificity, the presently disclosed subject matter provides a bi-cortical modular bone implant as variously exemplified and referenced at 10, 80 and 90. The modular bone implant 10 is generally depicted and referenced in FIGS. 10A - 16; the modular bone implant 80 is generally depicted and referenced in FIGS. 17 - 19; and the modular bone implant 90 is generally depicted and referenced in FIGS. 20 --- 22. The modular bone implants 10, 80 and 90 are particularly configured for affixation to a bone as diagranimatically depicted and referenced at 100 in FIGS. 1, 2A, 2B, 4, 6 and 8 for ease of understanding and introduction to the modular bone implants 10, 80 and 90.

[0070] The bi-cortical modular bone implants 10, 80 and 90 according to the presently disclosed subject matter may affix to any two surfaces of a bone 100, and particularly a long bone as has been diagranimatically depicted in FIGS. 1, 2A, 2B, 4, 6 and 8, whereby the two surfaces of the bone 100 are non-parallel to one another providing bases for anchored attachments for the modular bone implants 10, 80 and 90. A radius bone has been chosen as an exemplary’ bone for ease of description and understanding within these specifications, with the implant being a wrist joint replacement implant which is intended to enable the various natural motions of the wristin some cases, the implant is introduced in a minimally invasive surgery, via small incisions which may allow the patient to have a quicker recovery time and less pain than a traditional open surgery.

[0071] The human wrist is a complex joint interface that bridges proximal aspects of the metacarpal bones with distal aspects of radius and ulna. The carpal bones are bones of the wrist that connect these distal aspects of the radial and ulnar bones of the forearm to the bases of the five metacarpal bones of the hand providing multiple joints that intercommunicate in a common synovial cavity. These articulations work together to allow for a wide range of motion in the wrist joint.

[0072] Most of the wrist motion occurs in the radiocarpal joint (RCJ) and the distal radioulnar joint (DRUJ). The motion of the radiocarpal joint occurs between the radius and the first proximal row of carpal bones, which act together through the articular disc, and between the proximal and distal row of carpal bones. The DRUJ is a pivot joint located between the radius and ulna for supmation and pronation movements of the hand. Different waist pathologies may occur in the waist bones or joints resulting from conditions such as osteoarthritis, or from traumas, such as bone fractures, for example. A patient, or subject, with these wrist pathologies may experience severe pain during waist movements ranging to severe disabilities clue to limitations in wrist movements.

[0073] The waist joint allows multi-axial movement with wide range of motion in all axes. In a healthy joint, the range of motion (ROM) for flexion-extension (bending of the hand in the direction of the palm or back of the hand) is almost 90 degrees in each direction, and between 20° and 30° for ulnar and radial lateral bending of the hand (e.g., in the direction of the thumb or little finger). ’The center of rotation (COR) in the physiological joint is not fixed. This floating quality of the center of rotation of the joint allows the joint to adjust to and remain stable in the face of large loads.

[0074] The radius is one of two forearm bones and is located on the thumb side. The part of the radius connected to the wrist joint is called the distal radius. When the radius breaks near the wrist, it is called a distal radius fracture. Distal radius fractures typically occur when a person falls on an outstretched or flexed hand and compressive force is directed into the radiocarpal joint. Radiocarpal joint replacement is sometimes required to help the injured person regain use of his or her wrist.

[0075] The radius bone as periodically described or referenced within these specifications is an exemplary bone in which the modular bone implants 10, 80 and 90 may be implanted and should not be construed as limiting. In other words, while the modular bone implants 10, 80 and 90 according to the presently disclosed subject matter have been designed to support arthroplasty involving long bones, and particularly radiocarpal arthroplasty involving the radius bone, these specifications are not to be construed as necessarily being limited to long bone or radius bone applications. In other words, in some embodiments, the modular bone implants 10, 80 and 90 according to the presently disclosed subject matter may affix to long bones as exemplified by the radius; other bone implant applications are contemplated as being embraced by these specifications.

[0076] Very basically , the long bones are those that are longer than they are wide. The long bone category includes the femora, tibiae, and fibulae of the legs, and the humeri, radii, and ulnae of the arms. The outer shell or cortex of a long bone is compact or cortical bone and the deeper layer of a long bone is generally cancellous or spongy bone which contains bone marrow. Referencing FIG. 1, the reader will there consider a simplified diagrammatic depiction of a long bone 100 having an outer cortical bone layer as at 101; an inner medullary cavity as at 102 containing the cancellous or spongy bone; a bone side surface at 104 at or about a metaphysis region; and a bone end surface 119 at a bone end 105 at the epiphysis region.

[0077] The bone side surface 104 referenced in FIG. 1 has been depicted with a normal vector 120 extending therefrom and the bone end surface 119 has been depicted with a normal vector 121 extending therefrom. The normal vectors 120 and 121 are oriented at a non-parallel angle relative to one another, and in the simplified diagrammatic representation depicted in FIG. 1, the non-parallel angle is on the order of 90 degrees for ease of understanding. It will be understood the outer surfacing of an actual bone is complexly contoured whereby the bone end surface 119 and the bone side surface 104 are generally non-parallel to one another. The modular bone implants 10, 80 and 90 according to these specifications are configured to affix to two such bone surfaces.

[0078] The bone 100 as diagrammatically depicted in the drawing support submitted in support of these specifications has two ends, and in the illustrated example, comprises a distal bone end referenced at 105 and a proximal bone end referenced at 106. The distal bone end 105 and the proximal bone end 106 are opposite one another spaced along a bone long axis 103. The dorsal and ventral bone side surfaces are respectively referenced at 107 and 108 in FIGS. 1, 2, 4, 6 and 8. Medial and lateral bone side surfaces of the bone 100 have not been specifically referenced but may also define the bone side surface 104 in some applications.

[0079] In other words, the bone side surface 104 may be defined any one of the side surfaces here exemplified, including the dorsal bone side surface 107, the ventral bone side surface 108 or medial / lateral bone side surfaces. The bone side surface 104 may be surgically selected by a surgeon to maximize anchored attachment of a proximal portion of the modular bone implants 10, 80 and 90 thereto in axially spaced relation relative to the articulating bone end surface 119 of the distal bone end 105. As depicted in the drawing support submitted in support of these specifications, the bone side surface 104 is located at the dorsal bone side surface 107. As used in these specifications, the descriptor “anchor” or “affixation” may be construed to connote fixing at least most of the degrees of freedom between opposed elements, and not necessarily all degrees of freedom.

[0080] The modular bone implants 10, 80 and 90 according to the presently disclosed subject matter essentially function to preserve so far as practicable the structural integrity of the outer cortex 101 of an outfitted bone 100. The modular bone implants 10, 80 and 90 are configured to affix to a bone 100 having bone long axis 103, which axis 103 extends through the bone 100 passing through opposed bone ends as exemplified by the distal and proximal bone ends 105 and 106.

[0081] Referencing FIG. 2A, the reader will consider a simplified diagrammatic modular bone implant affixed to the bone 100 otherwise depicted in FIG. 1. FIG. 2A is presented to diagrammatically illustrate how the modular bone implants according to the presently disclosed subject matter generally affix to the bone 100. The modular bone implant 10 according to the presently disclosed subject matter is more particularly depicted and referenced in FIGS. 10 - 17 and may provide a basis for most of the descriptive content contained herein. The alternative modular bone implants 80 and 90 are substantially similar to the modular bone implant 10 but for certain structural features that provide optimal anchored attachments in certain applications as discussed in more detail below in connection therewith.

[0082] The modular bone implants 10, 80 and 90, for example, each comprise an anchor seat 11 attachable to a bone end exemplified by distal bone end 105 and an elongate stem extendable through the bone 100 from the anchor seat 11 toward the bone side surface 104. In the case of modular bone implant 10, the elongate stem is referenced at 16; in the case of modular bone implant 80, the elongate stem is referenced at 16’; and in the case of modular bone implant 90, the elongate stem is referenced at 16”. In some embodiments, the elongate stem, as variously referenced by root reference numeral 16, is integrally or monolithically formed with the anchor seat 11.

[0083] The anchor seat 11 comprises an inner seat surface 13 configured to abut the bone end surface 119 at the bone end 105 and an outer seat surface 53. In some embodiments, the anchor seat 11 may provide a hemiarthroplasty basis at outer seat surface 53. The outer seat surface 53, for example, may provide a synthetic articulating surface for articulating with a radiocarpal joint replacement assembly in some applications. In this regard, it will be recalled the modular bone implants 10, 80 and 90 according to the presently disclosed subject matter may support partial or full wrist arthroplasty or radiocarpal joint replacement as an exemplary bone implant application.

[0084] The elongate stem 16 comprises a proximal end 12 and a stem long axis 110. In some embodiments, the proximal end 12 comprises a planar surface 17 obliquely angled relative to the stem long axis 110. In some applications, the planar surface 17 is configured for positioned placement deep to or under the outer cortical layer 101 at the bone side surface 104. In other words, in some applications, the planar surface 17 at the proximal end 12 does not protrude through the outermost (dorsal) cortical layer 101.

[0085] In these applications, the planar surface 17 can affixed within the cortical bone, for example with the aid of bone cement 25. The bone cement 25 can be introduced (e.g. injected) through a bore formed in the bone for insertion of the elongate stem therethrough, such as introduced from the direction of the anchor seat 11 towards (but not breaching) the bone side surface 104. Alternatively, in cases in which the formed bore extends and breaches the bone side surface, bone cement 25 may be introduced into the bore from the direction of the bone side surface 104. Additionally, or alternatively, the bone cement 25 can be introduced via a dedicated cement-receiving cavity 89, which may be formed in the cortical layer 101 in superficial adjacency to the planar surface 17 to bolster the anchored attachment at the side surface anchor site.

[0086] In some embodiments, a connecting portion 14 at the proximal end 12 may breach the outer cortical layer 101 (e.g., the dorsal cortex) as generally and comparatively depicted in FIGS. 4 and 5 for further attachments to overlying plate structures. These plate structures may include a first fixation plate or bone plate 15 as comparatively depicted in FIGS. 6 and 7 and, in some embodiments, a second fixation plate or fixation plate 35 as comparatively depicted in FIGS. 8 and 9.

[0087] In some embodiments, an angle 111 between an anchor seat plane 125 of the anchor seat 11 and the stem long axis 110 may be configured such that the planar surface 17 would be positioned within the cortical layer 101 as generally depicted in FIGS. 2 A and 3 A. In those applications including a connecting portion 14, the connecting portion may minimally breach the cortical layer 101 as generally depicted in FIGS. 2B and 3B or maximally breach the cortical layer 101, for example for providing an anchor attachment site for the overlying plate structures as generally depicted in FIGS. 4 and 5. In other words, in some applications, the articulating anchor seat 11 can be implanted such that the elongate stem 16 extends through the bone 100 so that the planar surface 17 will not breach the (dorsal) cortex, but the connecting portion 14 may either minimally or maximally breach the cortex.

[0088] The angular difference of angle 111 between the anchor seat plane 125 and the stem long axis 110 in these two applications is generally within a range of 70-85, for example 80 degrees. Referencing FIG. 9A, the reader will there note the anchor seat plane 125 can be defined as an imaginary plane in which the lowermost points 66 of the anchor seat 11 are located, assuming that the anchor seat 11 is formed with a curvature, and the lowermost points 66 are those located farthest apart from the bone end surface 105. The reader will further note the stem long axis 110 of the elongate stem 16 may, in some embodiments, be parallel to fixator axes 122 of fixating elements 42 such that the angle 111 is equal to an angle 140 between the fixator axes 122 and the anchor seat plane 125.

[0089] Referring back now to the connecting portion, in some applications, the modular bone implants 10, 80 and 90 according to the presently disclosed subject matter may further comprise a connecting portion 14, which may be either integrally or monolithically formed with the proximal end 12 or selectively mounted to the proximal end 12. The modular bone implant 10 comprises an integrally formed connecting portion 14 at the proximal end 12. The modular bone implant 80 comprises a mountable connecting portion 14’ comprising a first directional geometrical locking mechanism 81 that mounts to the proximal end 12 of elongate stem 16’. Basically, the planar surface 17 of elongate stem 16’ comprises an aperture 82 configured to structurally connect to the first directional geometrical locking mechanism 81 of the mountable connecting portion 14’. In the example shown, aperture 82 is oblong, but can be otherwise shaped for receipt of at least a portion of the locking mechanism 81.

[0090] The modular bone implant 90 comprises a connecting portion 14 integrally formed with a stem attachment portion 91 having a planar surface 17 at the proximal end 12 thereof and a second directional geometrical locking mechanism 92 at a distal end 93 thereof. Basically, the second directional geometrical locking mechanism 92 structurally connects to the elongate stem 16” which is abbreviated in length as compared to the elongate stems 16 / 16’ such that a length of the stem attachment portion 91 and the length of the elongate stem 16” together provide a length for positioning the connecting portion 14 at the bone side surface 104. The modular bone implants 80 and 90 are described in more detail hereinafter, but are substantially similar to the modular bone implant 10 excepting for the form of the directional geometrical locking mechanisms associated therewith for selectively mounting the connecting portions 14 / 14’ to the primary stem portions of the implants 80 and 90.

[0091] In all modular bone implants 10, 80 and 90, the connecting portion 14 is configured to breach the outer cortical layer 101 at the bone side surface 104, at least partially as generally and comparatively depicted in FIGS. 2B - 5. In some applications, the connecting portions 14 / 14’ may be anchored to or fixated at the bone side surface 104 directly using bone cement as at 25 in FIGS. 2B and 3B. Whether to anchor the connecting portions 14 / 14’ directly to the bone side surface 104 is case specific or situation dependent and may be decided upon the attending surgical team.

[0092] In some embodiments, to minimize implant displacement or movement at the side surface anchor site at the bone side surface 104, the modular bone implant 10 may further comprise a basal anchor or bone plate 15 connectable to the connecting portion 14 as diagrammatically depicted in FIG. 6 and more particularly depicted in FIGS. 7 and 23 - 27. The bone plate 15 is depicted separated from the connecting portion 14 in FIGS. 28, 29, 31 and 32 and connected to the connecting portion 14 in FIG. 30. The bone plate 15 may be used in certain instances, for example, when the risk of implant displacement is greater; when tendon / musculature irritation which may be caused by the bone plate 15 is deemed acceptable; when the bone is at a risk of crumbling or deteriorating (for example, in osteoporosis conditions); or other situations in which an additional, overlying fixation can be advantageous.

[0093] In some embodiments, the bone plate 15 comprises a distal plate end 56 and a proximal plate end 58. The connecting portion 14 is matable with the distal plate end 56 and the proximal plate end 58 is fastenable to the bone side surface 104 in proximal adjacency to the proximal end 12 in these embodiments. In some embodiments, the bone plate 15 comprises a pallet portion 23 formed with an inner pallet curvature 19 which matches or approximates an outer surface curvature 120 of the bone side surface 104 as generally depicted in FIG. 29. In long bone applications, it is noted the outer cortex 101 is generally rounded in transverse cross-section.

[0094] Accordingly, in some embodiments, the inner pallet curvature 19 is generally concave in transverse cross-section particularly configured for abutting the bone side surface 104.

[0095] In some embodiments, a distally-located, elongate aperture 20 is formed or defined within the pallet portion 23 having a first or distal end 21 and a second or proximal end 22 located along a pallet long axis 109 of the pallet portion 23 as generally depicted and referenced in FIG. 31. In some embodiments, the elongate aperture 20 is configured to slidably receive the connecting portion 14 extending from the proximal end 12 of the elongate stem 16. In this regard, the bone plate 15 may be directed as at arrow 126 toward the connecting portion 14 such that the connecting portion 14 is received via the proximal end 22 of the aperture 20 as at arrow 127 in FIG. 27.

[0096] Once the connecting portion 14 (at least a portion thereof) is received through the proximal end 22 of the elongate aperture 20, the bone plate 15 may be proximally displaced as at arrow 128 to slide the connecting portion 14 toward the distal end 21 of the elongate aperture 20. In some embodiments, the connecting portion 14, extending from the proximal end 12, abuts against the pallet portion 23 at the first end 21 of the elongate aperture 20, while a remaining area of the elongate aperture 20 is configured to receive at least one screw fastener 24 therethrough. A diagrammatic screw fastener 24 has been depicted in FIGS. 25 and 26 to help illustrate this relationship. The screw fastener 24 fixates the pallet portion 23 to the bone 100 and prevents the connecting portion 14 at the proximal end 12 from slipping out of the elongate aperture 20 in some embodiments. In such arrangement, the bone plate 15 can be easily guided and placed over the implant, due to the larger size of the elongate aperture 20 as compared to the size of the connecting portion 14 (at least the top thereof); then, sliding of the bone plate in the direction of arrow 128 sets the plate at the desired position with the connecting portion acting as a stopper of the movement, as it abuts against the walls of the aperture.

[0097] In some embodiments, the bone plate 15 may comprise one or more additional apertures 26 along the length of the bone plate 15 for receipt of one or more screw fasteners 27 therethrough. The one or more additional apertures 26 and screw fasteners 27 provide for enhanced fixation of the bone plate 15 at the side surface anchor site by preventing rotation of the bone plate 15 about a fastener axis extending through the screw fastener 24 and added anchored attachment of the bone plate 15 to the bone 100. The screw fasteners 24 and 27, and all such similar screw fasteners discussed herein, are particularly depicted in FIG. 43 and may be exemplified or characterized by cortical screws, which are typically used to secure cortical bone. It is noted that other fastener types suitable for fixating the bone plate 15 to the bone and / or to the implant are also contemplated (bone nails, k- wires, lag screws, etc.).

[0098] In some embodiments, the first end 21 of the elongate aperture 20 comprises laterally opposed plate formations 28 and the connecting portion 14 comprises laterally opposed connector formations 29. In some embodiments, the laterally opposed plate formations 28 may be characterized by tongue-like protuberances and the laterally opposed connector formations 29 may be characterized by groove-like formations slidably matable with the tongue-like protuberances. In this regard, the connecting portion 14 may comprise a head portion 30. Together the head portion 30 and the planar surface 17 define the laterally opposed connector formations 29. In some embodiments, the head portion 30 of the connecting portion 14 has a head width 31 and head length 32 configured to correspondingly and slidably mate with the laterally opposed plate formations 28. The second end 22 of the elongate aperture 20 is configured to receive the head width 31 and the head length 32 such that, after receiving the head portion 30 via the second end 22, the bone plate 15 may be linearly displaced as at arrow 128 so as to migrate the head portion 30 toward the first end 21 for mated engagement with the bone plate 15 via the plate formations 28 and the connector formations 29. In some applications, the bone plate 15 may be proximally displaced as at arrow 128 so as to migrate the head portion 30 toward the distal first end 21 for mated engagement with the bone plate 15.

[0099] In some embodiments, the pallet portion 23 further comprises an outer or upper pallet surface 33 configured to mate with an inner plate surface 34 of a fixation plate 35 configured to cover at least a majority of the bone plate 15. In this regard, the reader is further directed to reference FIGS. 33 - 36 and 38 - 43 particularly depicting the fixation plate 35. In some embodiments, the connecting portion 14 is configured to be fixated at the bone side surface 104 by way of both the bone plate 15 and the fixation plate 35 such that fixation plate 35 at least partially covers the bone plate 15 and the connecting portion 14. In some embodiments, the upper pallet surface 33 may have a curvature that that mimics or approximates the outer surface curvature 120 of the bone side surface 104 in some embodiments. This may reduce or prevent the risk of irritation in overlying tendons and / or muscles.

[0100] By fixating the connecting portion 14 with both the bone plate 15 and the fixation plate 35, the resulting modular bone implant arrangement may provide an optimal long term bone fixation. In some embodiments, the fixation plate 35 may comprise an outer plate surface 41 having a curvature that that mimics or approximates the outer surface curvature 120 of the bone side surface 104. Optionally, outer surface 41 is smooth. This may reduce or prevent the risk of irritation in overlying tendons and / or muscles.

[0101] In some embodiments, the fixation plate 35 fully covers the connecting portion 14 and fastens to the bone plate 35 via the at least one fastener 24 (e.g., a screw fastener) receivable through the fixation plate 35 by way of at least one fastener-receiving aperture 36 axially aligned with the fastener- receiving aperture 22. In some embodiments, the fixation plate 35 may comprise one or more additional apertures 37. Optionally, the additional apertures are axially aligned with the one or more additional apertures 36 along the length of the fixation plate 35 for receipt of one or more screw fasteners 27 therethrough. The one or more additional apertures 36 formed in the fixation plate 35 and screw fasteners 27 provide for enhanced fixation of the ensemble at the side surface anchor site. When affixed to a bone 100, the anchor seat 11 is spatially and structurally configured to be non-parallel to the bone plate 15 and the fixation plate 35.

[0102] In some embodiments, the fixation plate 35 may comprise laterally offset apertures 38 along the length of the fixation plate 35 for receipt of two or more fasteners 27 (e.g., screw fasteners) therethrough. In some embodiments, the laterally offset apertures 38 are formed at a distal end 39 of the fixation plate 35 and the apertures 36 and 37 are aligned along a main plate plane 121 extending medially through the fixation plate 35 defining laterally opposed portions thereof. The apertures 36 and 37 are formed at a proximal end 40 of the fixation plate 35 in some embodiments. In some embodiments, the screw fasteners 27 received in the laterally offset apertures 38 are obliquely angled relative to the main plate plane 121 and the screw fasteners 24 and 27 received in the apertures 36 and 37 are axially aligned with the main plate plane 121. The modular bone implant 10 may further comprise at least one fixating element 42. In the examples shown, the modular bone implant 10 comprises a pair of fixating elements 42. It is noted that other embodiments may include a different number of fixating elements, e.g., 3, 4, 5 fixating elements or a larger number. In those embodiments deploying a pair or fixating elements 42, the fixating elements 42 are positioned laterally opposite one another and together with the elongate stem 16 provide a triangular stance as generally depicted in FIG. 37 at triangle pattern 129. The triangular stance or pattern 129 may improve stability of the modular bone implant 10 as mounted to the bone 100.

[0103] The fixating elements 42 extend from the anchor seat 11 adjacent the elongate stem 16. In some embodiments, the fixating elements 42 are integrally or monolithically formed with the anchor seat 11. Each fixating element 42 has a fixator long axis 122 that extends in parallel relation to the stem long axis 110 in some embodiments as generally depicted in FIGS. 11 and 13. The fixating elements 42 further comprise a length 123 shorter than that of the elongate stem 16. In some embodiments the length 123 of each fixating element 42 is equal to the other and less than half the length of the elongate stem 16. The use of fixating element(s) 42 which are significantly shorter than the elongate stem 16 may be advantageous in that less of the bone volume is occupied by the fixating elements 42 (e.g., as compared to fixating elements which are substantially similar in length to the stem), thereby potentially imposing less interference on blood flow, bone growth, and the like.

[0104] The elongate stem 16 and the fixating elements 42 extend into the bone end 105 obliquely relative to the bone long axis 103. In other words, the fixator long axes 122 and the stem long axis 110 extend parallel to one another and obliquely relative to the bone long axis 103 in some embodiments. The elongate stem 16 may comprises a non-circular transverse cross-section along the stem long axis 110 in some embodiments. In this regard, the reader is again directed to FIG. 37. From a consideration of FIG. 37, the reader will there see the elongate stem 16 may comprise a rectangular transverse cross-section in some embodiments. Similarly, the fixating elements 42 may comprises a non-circular transverse cross-section along the fixator long axes 122 in some embodiments. Each of the fixating elements 42 may also comprise a generally rectangular transverse cross-section in some embodiments. Although not specifically illustrated, the transverse cross-sections of the elongate stem 16 and the fixating elements 42 may take other forms. A potential advantage of a non-circular cross section profile of a stem and / or of a fixating element, e.g., a rectangular cross section profile, may include reducing a likelihood of rotation (pivoting) of the stem and / or of the fixating element inside the bone. It is noted that other crosssection profiles, e.g. squared, triangular, trapezoidal or others are also contemplated.

[0105] Noting that the anchor seat 11 abuts the bone end 105 and the elongate stem 16 and fixating elements 42 extend therethrough in a direction toward the bone side surface 104, the reader will further consider the bone end 105 or epiphysis may be characterized as comprising cancellous bone filled with bone marrow responsible for producing blood cells. Interruption of these tissues by extension of the elongate stem 16 and fixating elements 42 therethrough may interrupt blood cell production. In this regard, it is noted that a complexly contoured outer surface profiles of structures extending within this portion of the bone 100 may be advantageous for supporting regrowth of tissue around the extended structures. In this regard, the outer surfaces of the elongate stem 16 and the fixating elements 42 may be non-smooth or rough at least along a portion thereof in some embodiments. In some embodiments, the elongate stem 16 and the fixating elements 42 may comprise at least one planar surface that is smooth at least along a portion thereof. In the case of the elongate stem 16, the elongate stem 16 may comprise a ventral stem side 44 opposite the (dorsal) bone side surface 104 in some embodiments. In some embodiments, the ventral stem side 44 is planar and smooth. In the case of the fixating elements 42, the fixating elements 42 may each comprise a medial fixator surface 45, which medial fixator surfaces 45 face one another and are planar and smooth in some embodiments. The ventral stem side 44 and the medial fixator surfaces 45 are planar and smooth at least along a portion thereof in some embodiments may ease insertion of the elongate stem 16 and fixating elements 42 into and through the bone 100.

[0106] The elongate stem 16 may further comprise laterally opposed stem sides 46 and a dorsal stem side 47 opposite the ventral stem side 44 in some embodiments. The laterally opposed stem sides 46 and the dorsal stem side 47 may comprise serrations 48 at least along a portion thereof in some embodiments. The fixating elements 42 may each comprise at least one cavity formation 49 at a cavitied surface 50 thereof in some embodiments. In some examples, as shown, the cavitied surface 50 of each fixating element 42 is positioned laterally relative to the medial fixator surface 45 and the cavity formation 49 formed therein may extend along the fixator long axis 122. In some embodiments, the cavity formations 49 are positioned in laterally opposite positions relative to one another in some embodiments.

[0107] In some embodiments, the fixating elements 42 may each comprise opposed surfaces 51 extending intermediate the medial fixator surface 45 and the cavitied surface 50. The opposed surfaces 51 may comprise stepped portions 52 at least along a portion thereof. In some embodiments, the stepped portions 52 at each opposed surface 51 of each fixating element 42 correspond to one another such that the thickness of the fixating element 42 periodically increases from ends thereof toward the anchor seat 11. The serrations 48 formed upon the elongate stem 16 and the cavity formations 49 and stepped portions 52 formed upon the fixating elements 42 respectively provide a complexly contoured outer surface profile for the elongate stem 16 and fixating elements 42 extending within this portion of the bone 100 operable to support regrowth of bone and fatty tissue therearound. The complexly-contoured outer surface can generally include a rough or rugged texture, which may enhance grip as well as support bone growth.

[0108] Referring now to the selectively mountable connecting portion 14’, as introduced hereinabove, the modular bone implant 80 comprises a mountable connecting portion 14’ comprising a first directional geometrical locking mechanism 81 that mounts to the proximal end 12 of elongate stem 16’. The connecting portion 14’ may be mounted to the elongate stem 16’ after implantation of the radial part or elongate stem 16’. In this regard, the reader is directed to FIGS. 17 - 19 generally depicting the modular bone implant 80. In some embodiments, the mountable connecting portion 14’ may be inserted and rotated or slid into a locked configuration. The first directional geometrical locking mechanism is supported by the bone 100 after assembly and cannot be disassembled, and is arranged such that natural forces (e.g tension and compression) which act on the implant, for example on the stem, are not expected to disassemble the locking mechanism 81.

[0109] The connecting portion 14’ comprises head portion 30 and upper portions of laterally opposed channel-like formations 29. When mounted to the planar surface 17 of the elongate stem 16’, the head portion 30 and the planar surface 17 further define the laterally opposed groove-like formations 29. To mount the connecting portion 14’ to the planar surface 17, in some examples, an oblong aperture 82 is formed in the planar surface 17 at the proximal end 12 of the elongate stem 16’ as generally depicted and referenced in FIGS. 18 and 19. The connecting portion 14’ further comprises a first directional geometrical locking mechanism 81 characterized in some embodiments by a spindle portion 83 and an oblong cam portion 84 extending from the connecting portion 14’ opposite the head portion 30. The spindle portion 83 defines a spindle axis of rotation 130 and the oblong cam portion 84 extends along a cam long axis angled relative to the head length 31 of the head portion 30.

[0110] The oblong aperture 82 formed through the planar surface 17 of the elongate stem 16’ is configured to receive the oblong cam portion 84 when oriented in a first rotational orientation and directed as at arrow 135 as generally depicted in FIG. 18. Once the oblong cam portion 84 is received through the oblong aperture 82, the connecting portion 14’ may be rotated as at arrow 136 about the spindle axis of rotation 130 through the angle between the cam long axis and the head length 31 to lock the connecting portion 14’ to the planar surface 17. In this regard, it will be noted the connecting portion 14’ comprises an axis of rotation 130 orthogonal to the planar surface 17 about which the connecting portion 14’ may be rotated to fix or mount the connecting portion 14’ to the proximal end 12. In some embodiments, the ventral stem side 44 of the elongate stem 16’ comprises a cavity portion 85 to receive cam ends 86 of the oblong cam portion 84 when rotated into the locking configuration of the connecting portion 14’ as generally depicted in FIGS. 17 and 19.

[0111] Referencing FIGS. 20 - 22 the reader will there further consider modular bone implant 90. The modular bone implant 90 comprises a connecting portion 14 integrally formed with a stem attachment portion 91 having a planar surface 17 at the proximal end 12 thereof and a second directional geometrical locking mechanism 92 at a distal end 93 thereof. Basically, the second directional geometrical locking mechanism 92 structurally connects to the elongate stem 16” which is abbreviated in length as compared to the elongate stems 16 / 16’ such that a length of the stem attachment portion 91 and the length of the elongate stem 16” together provide a length for positioning the connecting portion 14 at the bone side surface 104.

[0112] The modular bone implant 90 is configured such that the stem attachment portion 91 is connected to the elongate stem 16” before implantation. The junction site between the stem attachment portion 91 and the proximal end 94 of the elongate stem 16” may contribute to isolation of distal portions of the of the modular bone implant 90 from forces acting on the proximal end 12.

[0113] The elongate stem 16” comprises laterally opposed sides 46 and a dorsal stem side 47 and a ventral stem side extending intermediate the laterally opposed sides 46 in some embodiments. In some embodiments, the dorsal stem side 47 and the ventral stem side 44 may comprise planar surfaces and are smooth at least along a portion thereof. A proximal end 94 of the elongate stem 16” comprises a medial slotted portion 95 extending along the stem long axis 110 configured to receive a medial tabbed portion 96 of the stem attachment portion 91. The lateral sides 46 each comprise a lateral slotted portion 97 and a protuberance-receiving aperture 98. Together the protuberance-receiving apertures 98 define an axis 134. The medial tabbed portion 96 comprises laterally opposed oblong protuberances 99 the centers of which define a stem axis of rotation 131 alignable with the axis 134.

[0114] The medial slotted portion 95 is configured to receive the medial tabbed portion 96 and the lateral slotted portions 97 are configured to receive the medial tabbed portions 96 when the stem attachment portion 91 is axially aligned along the stem long axis 110 and in a mounting rotational configuration as comparatively depicted in FIGS. 21 and 22. The stem attachment portion 91 may then be directed into engagement with the proximal end 94 as at arrow 132 in FIG. 22.

[0115] The stem attachment portion 91 may then be rotated as at arrow 133 about stem axis of rotation 131 into a second rotational configuration such that the protuberance-receiving apertures 98 receive the laterally opposed oblong protuberances 99 thereby locking the stem attachment portion 91 to the elongate stem 16”. In this regard, it will be noted the connecting portion 14 as integrally formed with the stem attachment portion 91 may be said to comprise an axis of rotation as at axis 131 orthogonal to the stem long axis 110 about which the connecting portion 14 may be rotated to fix or mount the connecting portion 14 to the elongate stem 16”. The ensemble may thereafter be inserted through the bone 100 such that the proximal end 12 may be selectively positioned at the bone side surface 104 for anchored attachment thereto as variously described herein.

[0116] In some embodiments, the stem attachment portion 91 is rotated into a linear alignment with the elongate stem 16”, and locked at that alignment. In other embodiments, it can be possible to lockably position the stem attachment portion 91 at an angle with respect to the long axis of the elongate stem 16”. For example, referring to FIG. 22, instead of rotating the stem attachment portion 91 by a 90-degree angle (into a linear alignment with the elongate stem 16”), the stem attachment portion 91 can be rotated by an angle of between 0-180 degrees, and optionally locked at a selected angle. This may be advantageous, for example, in situations in which the radius bone was fractured and is in an offset alignment, requiring the implant to be adapted to that alignment.

[0117] In general, the bi-cortical connection between the proximal end 12 variously anchored at the side surface anchor site and the anchor seat 11 is bolstered by at least the elongate stem 16. In some embodiments, the elongate stem 16 extends centrally relative to the cortical bone 101 at the one bone side surface 104 via at least one oblique bore or channel formed in the bone 100 from the bone side surface 104 to the articulating surface 119 at the bone end 105. In some embodiments, the presently disclosed subject matter contemplates a modular bone implant kit, which may include at least one tool for forming at least one such oblique bore or channel through the bone for receiving the elongate stem 16 and fixating elements 42.

[0118] The bone implant kit according to the presently disclosed subject matter may be said to essentially include a bone implant comprising anchor seat 11 having inner seat surface 13 configured for abutting the bone end surface 119 and an elongate stem as variously exemplified having proximal end 12 and stem long axis 110 such that the elongate stem (for example, elongate stem 16) is extendable through a bone 100 from the anchor seat 11 toward bone side surface 104. The bone implant kit may further comprise a connecting portion (for example, connecting portion 14’) for selectively mounting onto the proximal end of the elongate stem for enabling the attachment of bone plate 15 to the bone implant via the connecting portion. The connecting portion may comprise a directional geometrical locking mechanism as described hereinabove or alternatively a threaded lock, a snap-fit lock or similar other directional geometrical locking mechanism configured for locking the connecting portion to the proximal end of the elongate stem. As generally referred to herein, a directional geometrical locking mechanism may include any suitable components for fixedly coupling the connecting portion (e.g. in implant 80) or the stem attachment portion (e.g. in implant 90) to the proximal end of the elongate stem. Directional locking mechanism may include, for example, a bayonet mount type coupling, a dovetail joint, a ratchet mechanism, spline couplings, snap fit mechanism, or other suitable mechanism. The oblique bores or channels are pre-formed in the bone 100 once select placement(s) of the anchor seat 11 and side surface anchor site are determined by the surgical team. In some applications, the elongate stem 16 and the fixating elements 42 extends through at least a portion of cancellous bone within the medullary cavity 102 and at least a portion of cortical bone 101 through which the preformed oblique bores or channels extend. The bone end 105 to which the anchor seat 11 may be affixed is distally located in certain embodiments. The bone side surface 104 can be surgically selected to be deep to at least one of superficial radiocarpal tendon(s) and musculature.

[0119] In some embodiments, the implant arrangements, e.g., including the bone plate and the fixation plate, are generally constructed to have a low-profile and remain close to the natural outer contour of the bone. In some applications, for example, the bone side surface 104 is rounded in transverse cross-section and the bone plate 15 may comprise a generally convex inner plate surface or curvature 19 and a convex outer plate surface as at upper pallet surface 33 for mimicking the rounded cortical bone surface at the bone side surface 104. Similarly, the fixation plate 35 may comprise a generally concave inner plate surface as at 34 and a generally convex outer plate surface as at 41. In flat bone applications, the inner plate surface of the bone plate 15 and the inner plate surface of the fixation plate 35 may be generally flat to correspond with the underlying bone surface for minimizing the profile and reducing irritation to overlying anatomy. The outer plate surfaces of the bone plate 15 and the fixation plate 35 are preferably smooth, for example, for least interfering with overlying tissue and tendons in some embodiments.

[0120] In some embodiments, as also noted above, the bone implant kit can be provided with one or more surgical tools required for implantation and / or assembly of the implant. For example, a bone drill which is configured to form a bore in the bone having a cross-sectional profile which matches that of the stem and / or of the fixation elements, e.g., a rectangular cross section profile. In another example, tools such as clamping means for grasping and rotationally locking connecting portion 14’ (in the configuration of bone implant 80) or for rotationally aligning portion 91 (in the configuration of bone implant 90) can be provided.

Claims

What is claimed is:

1. A modular bone implant for affixation to a bone having a bone end surface and a bone side surface oriented in an angle with respect to each other, said implant comprising: an anchor seat having an inner seat surface configured for abutting the bone end surface; an elongate stem extending from the anchor seat, the elongate stem comprising a proximal end portion, a distal end portion and a stem long axis extending between the proximal and distal end portions; the proximal end portion comprising a planar surface obliquely angled relative to the stem long axis, the planar surface being configured for positioned placement under the bone side surface and in proximity thereto; and at least one fixating element extending from the anchor seat adjacent the stem, the at least one fixating element having a fixator long axis parallel to the stem long axis, and a length shorter than that of the stem.

2. The modular bone implant according to claim 1 comprising a pair of fixating elements which together with the stem provide a triangular stance.

3. The modular bone implant according to claims 1 or 2, wherein each fixating element comprises at least one cavity formation at an outer surface thereof.

4. The modular bone implant according to any one of the preceding claims, wherein each fixating element comprises a non-circular transverse cross-section.

5. The modular bone implant according to any one of the preceding claims comprising a connecting portion which is integrally or selectively mounted to the planar surface, the connecting portion being configured to breach the bone side surface, at least partially.

6. The modular bone implant according to claim 5, wherein the connecting portion is matable with a bone plate.

7. The modular bone implant according to claim 6, wherein the bone plate comprises a pallet portion formed with an inner pallet curvature which corresponds to a surface curvature of the bone side surface.

8. The modular bone implant according to claims 6 or 7, wherein the bone plate comprises at least one elongate aperture defined within the pallet portion, the elongate aperture having a first end and a second end located along a pallet long axis of the pallet portion, the elongate aperture being configured to slidably receive at least a part of the connecting portion.

9. The modular bone implant according to claim 8, wherein the at least a part of the connecting portion abuts against the pallet portion at the first end of the elongate aperture, a remaining area of the elongate aperture being configured to receive at least one fastener therethrough, which fixates the pallet portion to the bone and prevents the at least a part of the connecting portion from slipping out of the elongate aperture.

10. The modular bone implant according to according to any one of claims 6 through 9, wherein the bone plate has a distal plate end and a proximal plate end, the distal plate end including the at least one elongate aperture and being matable with the at least a part of the connecting portion, and the proximal plate end being fastenable to the bone side surface.

11. The modular bone implant according to any one of claims 6 through 10 comprising a fixation plate configured to be mounted on top of the bone plate and to cover at least a majority of the bone plate and the at least a part of the connecting portion.

12. The modular bone implant according to claim 11, wherein the fixation plate is configured to fasten to the bone plate.

13. The modular bone implant according to any one of the preceding claims, wherein the stem comprises serrations at least along a portion of an outer surface thereof.

14. The modular bone implant according to any one of the preceding claims, wherein the stem comprises a non-circular transverse cross-section along the stem long axis.

15. The modular bone implant according to any of the preceding claims wherein the anchor seat is configured to provide a hemiarthroplasty basis.

16. The modular bone implant according to claim 15, wherein the bone is a radius bone, the anchor seat providing a radiocarpal hemiarthroplasty basis.

17. A modular bone implant arrangement for selective affixation to a bone having a bone end surface and a bone side surface, said implant arrangement comprising: an anchor seat defining an imaginary anchor seat plane and configured for abutting the bone end surface; an elongate stem extending from the anchor seat, the elongate stem comprising a proximal end portion, a distal end portion and a stem long axis extending between the proximal and distal end portions, the stem long axis extending obliquely relative to the imaginary anchor seat plane; and a connecting portion at the proximal end portion of the stem, the connecting portion being configured to: be fixated at the bone side surface by way of a bone plate; orbe fixated at the bone side surface by way of the bone plate and a fixation plate, said fixation plate at least partially covering the bone plate and the connecting portion.

18. The modular bone implant arrangement according to claim 17 comprising a pair of fixating elements which together with the stem provide a triangular stance.

19. The modular bone implant arrangement according to claim 18, wherein each of the fixating elements comprises at least one cavity formation at an outer surface thereof.

20. The modular bone implant arrangement to any one of claim 18 or 19, wherein each of the fixating elements comprise a non-circular transverse cross-section.

21. The modular bone implant arrangement according to any one of claims 18 through 20, wherein the proximal end portion comprises a planar surface, the connecting portion being integrally or selectively mounted to the planar surface, the connecting portion being configured to breach the bone side surface, at least partially.

22. The modular bone implant arrangement according to claim 21, wherein the planar surface is obliquely angled relative to the stem long axis and is positionable within a cortical layer under the bone side surface.

23. The modular bone implant arrangement according to any one of claims 17 through 22, wherein the bone plate has a distal plate end and a proximal plate end, the connecting portion being matable with the distal plate end, the proximal plate end being fastenable to the bone side surface.

24. The modular bone implant arrangement according to any one of claims 17 through 23, wherein the bone plate comprises a pallet portion formed with an inner pallet curvature which corresponds to a surface curvature of the bone side surface.

25. The modular bone implant arrangement according to any one of claims 17 through 24, wherein the bone plate comprises at least one elongate aperture defined within the pallet portion, the elongate aperture having a first end and a second end located along a pallet long axis of the pallet portion, the elongate aperture being configured to slidably receive the proximal end.

26. The modular bone implant arrangement according to claim 25, wherein the proximal end abuts against the pallet portion at the first end of the elongate aperture, a remaining area of the elongate aperture being configured to receive at least one screw fastener therethrough, which fixates the pallet portion to the bone and prevents the proximal end from slipping out of the elongate aperture.

27. The modular bone implant arrangement according to any one of claims 17 through 26, wherein the fixation plate is configured to cover at least a majority of the bone plate and the connecting portion and fasten to the bone plate.

28. The modular bone implant arrangement according to any one of claims 17 through 27, wherein the stem comprises serrations at least along a portion of an outer surface thereof.

29. The modular bone implant arrangement according to any one of claims 17 through 28, wherein the stem comprises a non-circular transverse cross-section along the stem long axis.

30. The modular bone implant arrangement according to any one of claims 17 through 29, wherein the anchor seat is configured to provide a hemiarthroplasty basis.

31. A bone plate for fixation of a bone implant, the bone implant having an elongate stem which extends through the bone and ends with a connecting portion positionable at an outer bone surface of the bone, the bone plate comprising: a pallet portion formed with an inner pallet curvature corresponding to a surface curvature of the outer bone surface;at least one elongate aperture defined within the pallet portion, the elongate aperture having a first end and a second end located along a pallet long axis of the pallet portion; wherein the elongate aperture is configured to slidably receive at least a portion of the connecting portion such that when the connecting portion abuts against the pallet portion at the first end of the elongate aperture, a remaining area of the elongate aperture is configured to receive at least one fastener therethrough which fixates the pallet portion to the bone and prevents the connecting portion from slipping out of the elongate aperture.

32. The bone plate according to claim 31 comprising one or more additional apertures along the length of the bone plate for receipt of fasteners therethrough.

33. The bone plate according to claim 32, wherein the one or more additional apertures are aligned along a pallet long axis of the pallet portion.

34. The bone plate according to any one of claims 31 through 33 comprising a distal plate end and a proximal plate end, the distal plate end being matable with the connecting portion and the proximal plate end being fastenable to the outer bone surface.

35. The bone plate according to any one of claims 31 through 34, wherein the pallet portion comprises an outer pallet surface configured to mate with an inner plate surface of a fixation plate configured to cover at least a majority thereof.

36. The bone plate according to claim 34, wherein the first end of the elongate aperture comprises laterally opposed plate formations and the connecting portion comprises laterally opposed connector formations matable with the laterally opposed plate formations.

37. The bone plate according to claim 36, wherein the connecting portion comprises a head portion defining the laterally opposed connector formations and having a head width and head length configured to correspondingly mate with the laterally opposed plate formations.

38. The bone plate according to claim 37, wherein the second end of the elongate aperture is configured to receive the head width and head length, the bone plate being linearly displaceable so as to migrate the head portion toward the first end of the elongate aperture for slidably mating with the bone plate.

39. A bone implant kit, comprising: a bone implant comprising:an anchor seat having an inner seat surface configured for abutting a bone end surface; and an elongate stem extending from the anchor seat, the elongate stem comprising a proximal end portion, a distal end portion and a stem long axis extending between the proximal and distal end portions; a connecting portion for selectively mounting to the proximal end portion of the stem for enabling the attachment of a bone plate to the bone implant via the connecting portion; the connecting portion comprising a directional geometrical locking mechanism configured for locking the connecting portion to the proximal end of the stem.

40. The bone implant kit according to claim 39, wherein the connecting portion is configured to at least partially protrude from the bone side surface when mounted onto the proximal end portion of the stem.

41. The bone implant kit according to claims 39 or 40, wherein the proximal end portion of the stem comprises a planar surface, the connecting portion being mountable to the planar surface.

42. The bone implant kit according to claim 41, wherein the planar surface is obliquely angled relative to the stem long axis and is positionable within a cortical layer under the bone side surface.

43. The bone implant kit according to any one of claims 39 through 42, wherein the connecting portion is mountable to the proximal end portion of the stem after implantation of the bone implant.

44. The bone implant kit according to any one of claims 41 through 43, wherein the connecting portion comprises an axis of rotation orthogonal to the planar surface about which the connecting portion may be rotated to fix the connecting portion to the proximal end portion.

45. The bone implant kit according to any one of claims 39 through 42, wherein the connecting portion is mountable to the proximal end portion of the stem before implantation of the bone implant.

46. The bone implant kit according to claim 45, wherein the connecting portion comprises an axis of rotation orthogonal to the stem long axis about which the connecting portion may be rotated to fix the connecting portion to the stem.

47. The bone implant kit according to any one of claims 39 through 46 further comprising a pair of fixating elements which together with the stem provide a triangular stance at the anchor seat.

48. The bone implant kit according to claim 47, wherein each of the fixating elements comprises at least one cavity formation at an outer surface thereof.

49. The bone implant kit according to claim 42, wherein the bone plate is formed with an elongate aperture in which the connecting portion is receivable, the elongate aperture being configured to slidably receive the connecting portion.

50. The modular bone implant according to claim 49, wherein the connecting portion abuts against a first end of the elongate aperture when slidably received, a remaining area of the elongate aperture being configured to receive at least one screw fastener therethrough operable to fix the bone plate to the bone and prevent the connecting portion from slipping out of a second end of the elongate aperture.

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