AU2016203422B2 - Flexible plate fixation of bone fractures - Google Patents

Description

FLEXIBLE PLATE FIXATION OF BONE FRACTURES

Cross Reference to Related Applications [0001] The present application claims priority to U.S. Provisional Patent Application No. 61/428,745 filed December 30, 2010, entitled “FLEXIBLE PLATE FIXATION OF BONE FRACTURES,” and to U.S. Provisional Patent Application No. 61/357,855 filed June 23, 2010, entitled “FLEXIBLE PLATE FIXATION OF BONE FRACTURES,” the disclosures of which are hereby incorporated by reference in their entirety.

[0001a] The present application is a divisional application of Australian Application No. 2014265031, which is incorporated in its entirety herein by reference.

Technical Field [0002] Embodiments herein relate generally to devices for fixation of a fractured bone.

Background [0003] Osteosynthesis plates for stabilization of bone fractures typically are applied with bone screws. Traditionally, bone screws compress a plate onto the bone surface to provide stable fixation. More recently, locking plates have been introduced, which typically have threaded receiving holes for positive, angle-stable engagement with the threaded head portion of a locking screw. These locking plates may provide more stable fixation in the ends of weak, osteoporotic bone compared to traditional, non-locking plates.

[0004] Clinically, plate osteosynthesis constructs face two principal challenges. First, an osteosynthesis construct may alter the load distribution in bone, which may either cause bone resorption in cases exhibiting load shielding, or bone fracture due to implant-induced stress risers. Second, the high stiffness of a plate osteosynthesis construct may suppress relative displacement between bone fragments, whereby this interfragmentary motion is important to promote the natural cascade of fracture healing by callus formation.

[0004a] Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of common general knowledge in the field.

Summary of the Invention [0004b] According to a first aspect, the present invention provides a device comprising: a bone plate having an outer surface and a bone-facing surface, the bone plate comprising one or more spiral-shaped slots extending through the plate from the outer surface to the bone-facing surface, the one or more spiral-shaped slots forming a non-perpendicular angle with the outer surface and the bone-facing surface of the bone plate, and the one or more spiral-shaped slots at least partially circumscribing a periphery of one or more receiving holes located in the bone plate and not penetrating through a longitudinal edge of the bone plate, the longitudinal edge of the bone plate extending between the outer surface and the bone-facing surface, wherein the one or more spiral-shaped slots form a spring element, the spring element at least partially surrounding the receiving hole and permitting axial translation of the bone plate relative to the one or more receiving holes within a plane that is substantially parallel to the outer surface or the bone-facing surface of the bone plate, but substantially preventing motion of the bone plate relative to the one or more receiving holes in a direction that is substantially perpendicular to the outer surface or the bone-facing surface of the bone plate.

[0004c] According to a second aspect, the present invention provides a device comprising: a bone plate having an outer surface and a bone-facing surface, the bone plate comprising two or more slots extending through the plate from the outer surface to the bonefacing surface, each of the two or more slots circumscribing a periphery of one or more receiving holes at least once and not penetrating through a longitudinal edge of the bone plate, wherein the two or more slots form a spring element, the spring element at least partially surrounding the receiving hole and permitting axial translation of the bone plate relative to the one or more receiving holes within a plane that is substantially parallel to an upper or lower surface of the bone plate, but substantially preventing motion of the bone plate relative to the one or more receiving holes in a direction that is substantially perpendicular to the upper or lower surface of the bone plate; wherein the two or more slots defining each spring element comprise two or more spiral segments, and wherein the two or more spiral segments circumscribe the one or more receiving holes one or more times.

[0004d] Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise”, “comprising”, and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to”.

Brief Description of the Drawings fOOOSJ Embedments will be readily understood by the following detailed description in conjunction with the accompanying brewings. Embodiments are illustrated by Way of example and not by way of Ornitatjon in the figures of the accompanying drawings.

[¢0063 Figure 1Ά illustrates a top view, a tongitudinai cross~sacfIonai view, and a transverse cross-sectional view of an example of a bone plate having a rivet: paired with symmetrically arranged elastic segments and a nort-circular, quasl-rectangular fhrougH hole, in accordance with various embodiments; [OOOfJ Figure 1B illustrates bottom, perspective and side views of an example of a rivet tor use with the bone plate illustrated in Figure 1AS wherein the rivet has a generally circular head and-a-lhraaded, non-circular expansion portion, in accordance with various embodiments; [0008] Figure 2A illustrates a perspective assembly view of a bone plate hay|ng a rivet, a locking screw, and a plate section with symmetrically arranged elastic segments, in accordance with various embodiments; [0009! Figure 2B illustrates a partial perspective assembly view of tee bone plate illustrated in Figure 2A, having a rivet, a Socking screw, and a plate section with symmetrically arranged elastic segments, in accordance with various embodiments:; [00103 Figure,2$ illustrates $ top view of a bene piste having a rectangular rivet, a screw, and a plate section with symmetrically arranged elastic segments flanking the screw receiving hole on either side, In accordance with various embodiments; [0011! Figure 2D illustrates a cross-sectional view of the bone plate Of Figure 2C, in accordance with various embodiments; [08123 Figure 2E illustrates an exploded perspective view of the done plate of Figure 2C, in accordance with various embodiments; [0013| Figure 3A illustrates a side view of an example of a screw with a thread that has a consistent core diameter, but an increased outer diameter in the vicinity of the screw head, in accordance with various embodiments] {(10143 Figure 3B fustrates a top view of a bone piate having a corresponding thread in the plate hole that extends across the motion gap into the plate, in accordance with various embodiments; [081SJ Figure 3C illustrates a transverse cross-sectional view of a bone plate having a corresponding thread in the plate hoie that extends across the motion gap into the piste, in accordance with various embodiments; [00103 Figure 4& illustrates a perspective assembly view of an embodiment of a bone plate assembly that limits deflection of the screw hole member out of the plane of the plate, while ailowing for a controlled amount of translation of the screw hole member In the direction of the plate longitudinal axis, in accordance with various embodiments; [001?| Figure 4B illustrates a lransverse cross-sectional view of the bone plate- assembly Illustrated in Figure 4A, showing that the threaded feature of the screw heacl extends across the motion gap and into the plate tb limit deflection of the screw hole member out of the plane of the plate, while allowing for a controlled amount of translation of the screw hole member In the direction of the plate longitudinal axis, in accordance with various embodiments; {001 $| Figure 40 illustrates a partial iongitudinai perspective view of the bone plate assembly illustrated in Figure 4A, in accordance with various embodiments; {0010| Figure 40 illustrates a partial transverse perspective view of the bone plate assembly lilustrated In Figure 4A, in accordance with various embodiments; [0O20J Figure 0A illustrates a top view of an example of a bohe plate in which the motion gaps adjacent to the screw hoie diverge from the top surface to the lower surface of the plate, in accordance with various embodiments; [0021] Figure 5B illustrates a bottom view of the bone plate shown in Figure 5A, in accordance with various embodiments; {00223 Figure SC illustrates a perspective view of the bone plate shown in Figure 6Λ., in accordance with various embodiments; [0023J Figure 50 illustrates a transverse cross-sectional view of the bone plate shown in Figure SA, in accordance with various embodiments; {00243 Figure 6A illustrates a top view of another example of a bone plate for elastic fixation of a bone: fracture, in accordance with various embodiments; [0O2SJ Figure 6B Illustrates a top view of another bone plate for elastic fixation of a bone fracture for use in combination with cylindrical bone segments, in accordance with various embodiments; {00203 Figure 7A illustrates a top view and a cross-sectional side view of an example of a bone plate for elastic fixation of a bone, shown in functions! but unloaded association with a bone screw affixed to a cylindrical bone, In accordance with various embodiments; {0027J Figure 7B illustrates a fop view and a cross-sectionai side view of an example of a bone plate for elastic fixation of a bone, shown in functional loaded association with a bone screw affixed te a cylindrical bone, in accordance with various embodiments; [0028J Figure 8A illustrates a top view of an embodiment of a C-shaped flexible element, in accordance with various embodiments; [00203 Figure SB illustrafes a top view of another embodiment of a C~ shaped flexible el ament whereto elastic beam elements are narrow to reduce stiffness, in:accordance: with various embodiments; [00303 Figure SC iiiustrat.es a top view of another embodiment of a C-shaped flexible element wherein the elastic beam elements are elongated to reduce stiffness, in accordance with various embodiments; [00313 Figure SB illustrates a top view of an E~shaped flexible element wherein elastic beam elements are narrow to reduce stiffness, In accordance with various embodiments; [0032] Figure EE illustrates a top view of a flexible element that includes one E-shaped slot in combination with multiple linear slots, In accordance with various embodiments; [0033] Figure 9A illustrates a top view of a flexible element that includes a curvilinear E-shaped slot in combination with multiple linear slots, In accordance with various embodiments; [0034] Figure OB illustrates a perspective view of a bone plate for elastic fixation of a bone fracture, incorporating the flexible elements shown in Figure M, in accordance with various embodiments; [0035] Figure ISA illustrates a top view of a flexible element that includes a singie spiral-shaped slot, In accordance with various embodiments; [0036] Figure 10B iliustrates a lop view of a flexible eiement that includes a single spiral-shaped slot with curvilinear and round elements on the outside and inside spiral ends, respectively, in accordance with various embodiments; [0037] Figure 100 illustrates a top view of a flexible element that includes a single spiral-shaped slot having a thin beam, in accordance with various embodiments; [0033] Figure 10D illustrates a top view Of a flexible eiement that; includes a pair of interlaced spiral-shaped slots, wherein the flexible element is offset from the midline of the bone plate, |n accordance with various embodiments; [0030] Figure 16E illustrates a top view of a flexible eiement that includes a pair of interlaced spiral-shaped slots, wherein the flexible element: is positioned at the midiine of the bone plate, In accordance with various embodiments; [P40] Figure 10F illustrates a top view of s flexible element that includes three interlaced spiral-shaped slots, in accordance with venous embodiments; [3341] Figure 11A illustrates a side view· of a bone plate wherein the flexible element is a separate, removable element that is configured to be inserted into an enlarged receiving hoie, in accordance with various embodiments; |0β42| Figure 11B Illustrates a top view of the flexible element of Figure 11A, In accordance with various embodiments; i:004|| Figure 110 illustrates a perspective view of the flexible element of Figure 11A wherein the flexible element is a separate, removable element that is configured to be Inserted into an eh!arged receiving hole, in accordance with various embodiments; [00443 Figure 12 illustrates a cross -sectional perspective view of a flexible element, showing the ratio of beam width to plate height, in accordance with various embodiments; [00453 Figure 13A illustrates sevefa! views ot a flexible element coupled with a rivet configured to protect the flexible element from excessive deformation perpendicular to the plane of the plate, In accordance with various embodiments; [004S3 Figure 13B illustrates several views of a flexible element coupled with a halfmivet configured to protect the flexible element from excessive deformation perpendicular to the plane of the plate, in accordance with various embodiments; [004?3 Figure 13C illustrates a perspective view of a half rivet configured to protect the flexible eiement from excessive deformation perpendicular to the plane of the plate, wherein the hait-rivet is coupled with a customised bone screw, in accordance with various embodiments; [0048] Figure 14A illustrates a cross-sectionai view of a rivet elastically suspended inside a receiving hole In a bone plate using a discrete spring eiement, In accordance: with various embodiments;; [00403 Figure 14B illustrates a perspective view of a rivet elastically: suspended inside a receiving hole in a bone plate using a discrete spring element, in accordance with various embodiments; [00303 Figure 1SA illustrates a transverse cross-sectional view of a threaded Insert that is suspended with spring elements in a central position within a receiving holes whereby the spring elements are rigIdly; coupled to or part of a· threaded insert, in accordance with various embodiments; [0O513 Figure 158 illustrates a top view of the device shown in Figure ISA, in accordance with various embodiments; [0Q52j Figure 15G illustrates a partial cutaway view of the device shown in Figure I SA, showing placement of an Insert, in accordance with various embodiments; [00533 Figure 15B illustrates a planar cross-sectional view of the device shown in Figure 15A, in accordance with various embodiments; [00543 Figure ISA illustrates a top view of a threaded insert that is generated from the bone plate by Introducing a slot that circumscribes the receiving hole, in accordance with various embodiments; [00553 Figure 168 Illustrates a schematic view of the device shown in Figure 18A, in accordance with various embodiments; [00563 Figure 16€ illustrates a longitudinal cross-sectional view of the device shown in Figure 16A, in accordance with various embodiments; [0O57J Figure 16D illustrates a transverse cross-sectional view of the device shown in Figure 10A, in accordance with various embodiments; [0058J Figure 17A illustrates a transverse cross-sectional view of a threaded insert formed by the introduction of a slot fiat circumscribes fhe receiving hole in an; anti parallel manner and suspended [centered) inside a bone plate using'flexible· elements, in accordance with various embodiments; [0069J Figure 17B illustrates a top view of the device illustrated in Figure 17A, in accordance with various embodiments;; [0060| Figure 1?C illustrates a longitudinal cross-sectional view of the device illustrated in Figure 17A, in accordance with various embodiments; [00613 Figure 1SA illustrates a cross-sectional side view of a bone plate for elastic fixation of a bone fracture, shown in functional but unloaded association with locking bone screws for spanning a; bone fracture in a cylindrical bone, In accordance with various embodiments; [0062J Figure 188 illustrates a cross-sectional side view of a bone plate for elastic fixation of a bone fracture, shown in functional association with locking bone screws lor spanning a bone fracture in a cylindrical bone, wherein axial compression of the cylindrical bone segments induces parallel motion at the fracture, in accordance with various embodiments; [00633 Figure 19A illustrates a cross-sectional side view of a bone plate for elastic compressk>h of a bone fracture, shown in functional association with non-locking bone screws for spanning a bonefacture in a cylindrical bone, wherein bone screws are inserted in an eccentric manner, in accordance with various embodiments; [0064J Figure 19B illustrates a cross-sectional side view of a bone plate for elastic compression of a bone fracture, wherein tightehing of eccentrically inserted bone screws Induces elastic compression across a bone fracture by deformation of elastic beam elements that connect the plate holes to the plate member, in accordance with: various embodiments; and J0O65J Figure 20 is a graph comparing axial stiffness of a standard plate with that of a plate with spring eleiti#d^CS*Plate”) in accordance with embodiments herein.

Detailed Description of Disclosed Embodiment [OOiSJ Sn the following detailed description, reference Is made te the accompanying drawings which form a part hereof, and in which are shown by way of illustration embodiments that may be practiced. It is to be understood that other embodiments may be utilised and structural or logical changes may be made without departing from the scope. Therefore, the following detailed description Is not to be taken In a limiting sense, and the scope of embodiments is defined by the appended claims and their equivalents.

[0067| Various operations may toe described as multiple discrete operations id turn, in a manner that may be helpful in understanding embodiments; however, the order of description should not be construed to imply that these operations we order dependent.

[0068J The description may use perspective-based descriptions such as up/down, backdront, andtop/toottom. Such descriptions are merely used to facilitate the discussion and are not intended to restrict the application of disclosed embodiments, [Οββί] The terms "coupled” and "connected;' along with their derivatives* may be used, It should be understood that these terms are not intended as synonyms for each other. Rather, in particular embodiments, “connected” may be used to indicate that two or more elements are in direct physical contact with each other. "Coupied” may mean that two or mere elements are in direct physical or electrical contact. However, "coupled'' may also mean that two or more elements are not in direct contact with each other, but yet still cooperate or interact with each other.

[OQTOJ For the purposes of the description, a phrase in the form or in the form "A and/or B” means (A), (B), or (A and B). For the purposes of ^.description, a phrase in the form "at least one of A, 8, and 0“ means (A), (B), P), (A and B), (A and G), 0 and G|, or (A, B and G). For the purposes of the descriplion, a phrase in the form %A)S” means (B) or (AB) that is, A is an optional element, fdpTIJ The description may use the terms “embodiment" or “embodiments,” which may each refer to one or more of the same or different embodiments, Furthermore, the terms “comprising,” including “having," and the like, as used with respect to embodiments, are synonymous. |0072| In various embodiments, methods, apparatuses, and systems for fixation of a fractured Pone are provided. In various embodiments, the systems and plates may provide elastic suspension of receiving holes relative to an osteosynthesis plate. In various embodiments, this elastic suspension may promote load distribution between screws that connect a bone segment to the plate, (hereby reducing stress risers and the load shielding effect in addition, in various embodiments, stress at the screw holes, and within the construct as a whole, may bo reduced by incorporation of these elastic elements in the plate. Additionally, in some embodiments, for instance if fracture healihg by callus formation is desired , elastic suspension of the receiving holes relative to the osteosynthesis plate may enable smalt, controlled amounts of relative motion between bone fragments, connected by the plate, which may promote fracture healing by callus formation. In some embodiments, relative motion between bone fragments enabled by the elastic elements may be substantially parallel to an upper or lower surface of the bone plate, or substantially parallel to a bone surface, |G073J Unlike other devices, bone plates In accordance with certain embodiments disclosed herein may be configured to be suspended above the surface of the bone, so that a gap Is present between the lower surface of the plate and the upper surface of the bone. In various embodiments, this may be accomplished by using Socking screws that are designed to engage with a threaded hole in the bone plate. In. various embodiments, the coupling of a locking screw with a corresponding portion of a bone plate may ensure that the locking screw: is only inserted to a certain extent, lor instance the point where the screw locks Into the hoie of the bone plate. In another embodiment, the receiving hole elements may extend through the lower surface of the bone piafe .for instance so tbaf tbe plate remains suspended oyer the bone surface even if a bone fastener is used to compress the receiving hole element; to the one bone. £018743 In other embodiments, for instance if direct fracture healing is desired, elastic suspension of the receiving holes relative to the osteosynthesis plate may promote elastic compression across a fracture site, whereby the1 plate may be affixed to the bone with non-locking screws inserted in an eccentric manner in order to induce compression across the: fracture. Thus, in various embodiments, it may be beneficial and desirable to· a.-lx>he'fmc|M.re:%ith a plate as disclosed herein to enhance load distribution between screws, to pmmote fracture site motion when fracture healing by osilus formation is desired, and/or to induce prolonged compression across a fracture when direct fracture healing is desired. £00753 Figure 1A iustrates a top view, a longltudinai cross-sectional view, and a frahsverse cross-sectional view of a specific, non-iimltshg example of a bone plate· having .a rivet paved with symmetrically arranged elastic segments and a non-circular, quashrectanguiaf through hole; Figure 1B illustrates bottom, perspective and. side views of an example of a rivet for use with the bone plate illustrated in .'Figure 1A> wherein the rivet has a generally circular head and a threaded, non-circular expansion portion; Figures 2A and 28 illustrate a perspective assembly view and a cross-sectional assembly view of a bone plate haying a rivet, a locking screw, and a plate section with symmetncaily arranged elastic segments, all in accordance with various embodiments. In the example illustrated in Figures 1A, IB, 2A, and 2B, the bone plate 101 may include a rivet 160 with generally symmetrically-arranged elastic segments 108 and a non-circular, quasi-rectangular through hole 186, As illustrated, elastic segments (also referred to herein as elastic elements, elastic beam elements, and spring elements) 108 formed by'slots or channels 106 may be generally symmetrically-arranged in proximity of the screw hole 108, for example to enable translation of the screw hole member 105a in a principally axial direction. In various embodiments. screw hole member 105a may include quasi-rectangular through hole 136, In various embodiments, a lower rivet member 160 with a rivet head 148 and a rectangular expansion element 186 may be inserted from the lower plate surface 103 into rectangular through hole 136 of screw hole member 165a, In some embodiments, rivet 160 may be secured in screw hole member 105a by press-fit, whereas in other embodiments, rivet 160 may be secured in screw hole member 105a using a retaining feature that may be adapted to engage with a corresponding receiving feature in quasi-rectangular through hole 136. In various embodiments, rivet head 148 may be sufficiently large to extend laterally across the motion gap 107 of elastic segments 108. In various embodiments, rivet 168 may be configured to protect elastic segments 108 from excessive deformation perpendicular to the plane of plate 161.

[60763 In various embodiments; the circular through-hole 105 of rivet 180 may be threaded, and the threads may extend into quasi-rectangular through hole 136 of screw hole member 105a. In various embodiments, a screw 118 with matching threads may be inserted from: the upper plate surface 102 through the rivet 160, and the screw locking feature 169 may be sufficiently laro® to exteiid laterally across motion gap 10T of elastic segments 108. Thus, in various embodiments, the screw locking feature 100 may therefore limit deflection of screw hole member iOSa toward lower plate surface 103, Additionally or alternatively, in some embodiments, the rivet head 148 may limit deflection of screw hole member 105a toward upper plate surface 182. Thus, the 'illustrated example may enable controlled translation of screw hole member 105a relative to the longitudinal axis of the plate, yet may limit translation relative to the plane of bone plate 101 when screw hole member 1D5a Is guided between the screw locking feature 189 and rivet head 14S> 10077] Another example of a bone plate 201 that includes a rivet 268 is shown to Figures 2C, 20, and 2E, which illustrate a top view (Figure 2€), a cross-sectional view Figure 2D)S and an exploded perspective view (Figure 2E) of a bone plate having a rectangular rivet 260, a screw 218, and a plate 201 with generally symmetrically arranged elastic segments 288 flanking the screw receiving hole oneither side, ail in accordance with various embodiments, in this embodiment, rivet 280 may have a rectangular or square shape, and may be recessed in to the top and or bottom surfaces of bone plate 281, in some embodiments, rivet 288 may include a separate center shat portion 288, and one or two shoulder portions 248 coupled thereto. In various embodiments, the upper and/or lower shoulder portions 248 of rivet 260 may limit translation of receiving hole 288 ib a direction that Is substantially perpendicular to the upper or lower plane of bone plate 281.

In other words, rivet 268 may constrain cut-oApiane motion, while still allowing axial (e.g., in-plane) translation of receiving hole 205re!ative to bone plate 201 (or vice versa). In some embodiments, screw 218 may he a looking screw, for instance, a screw having a threaded head portion, or It may be a non-locking screw, in some embodiments, a non-locking screw may compress shoulder portions 248 and center shaft portion 268 of rivet 268 onto th bone, while plate 281 may retain an axially flexible connection with the bone vis elastic segments 208.

[0078] Figures 3A, 3B, and 3€ illustrate a side view, a top view, and a transverse eross-sectiona) view, respectively, of an example of a screw wife a threadlhat has a consistent core diameter, but an increased outer diameter in vicinity of the screw head, and Figures 4A, 4B, 4C, and 40 iilustrate a perspective assembly view, a transverse cross-sectional view, a partial longitudinal perspective view, and a partial transverse perspective view, respectively, of an embodiment of a bone plate assembly 301, showing that the threaded feature of the screw head extends across the motion gap and into the plate to limit deflection of the screw hole member out of the plane of the plate, while allowing ter controlled amount of translation of the screw hole member in the direction of the plate longitudinal.axis,, ail in accordance with various embodiments.

[0079J As discussed above and as Illustrated in Figures 3 and 4, a bone plate in accordance with the present disclosure may Include elastic segments 308 that may be symmetrically arranged in proxirnity with the screw hole 305, for instance to enable translation of the screw hole member 305a in a principally axial direction. In some embodiments, screw hole member 305a may be guided to remain within the piano of the plate by a thread 321fhat may extend from screw hole 385, across the motion gap 307, and Into fee-plate member 381, In some embodiments, thread 321 may be characterized by an outer diameter that is considerably larger than the core diameter. For example, a suitable core diameter Is in the range of 2 to 5 and a SMltabie outer diameter is in fee range of 4 to 10.

[0080] in various embodiments, fee looking screw 318 may include a correspondingly threaded head segment 318 with an outer diameter that is considerably larger than the core diameter. However, In various embodiments, the outer diameter of the thread 31§of the screw head segment 318 may be smaller than the outer diameter of thread 321 in screw bole member 305a. in various embodiments, fee outer diameter of thread 310 in screw head segment 318 may remain large enough to extend across the motion gap 387 and Into the plate member 301, once inserted into the screw hole 305, In some embodiments, screw head 328 may include a locking feature 309 at may enable rigid fixation of screw head 328 inside screw hole member 305a. In particular embodiments, once screw 310 is fixed to screw hole member 305a, screw hole member 305a may translate in aprincipally axial direction relative to the plate iongitudinaf axis, for instance, due to the difference in outer diameters between screw head 328, thread 319, and plate thread 321, However, in some embodiments, extension of screw head thread 319 across motion gap 307 and into plate member 301 may limit deflection of screw hole member 388a outside the plane of plate 301.

[00811 Figures 5A, SB, 30, and 80 illustrate a top view, a bottom view, a perspective view, and a transverse cross-sectional view, respectively, of an example of a bone plate SOI in which the motion gaps 307 adjacent to the screw hole SOS diverge from the top surface 302 to the lower surface 303 of plate 801, In accordance with various embodiments. In the illustrated example, elastic segments 508 may be symmetrically arranged in proximity with screw hole 505^ for instance, to enable translation of the screw hole member 505a in a principally axial direction. In various embodiments, rndtldn gaps 807 connecting symmetrically arranged elastic segments 508 may diverge from (angle away from) the upper plate surface 502 toward the lower plate surface 503. In various embodiments, these divergent motion gaps 307 may limit deflection of screw hole member 505a through upper surface 502 of the plate member 301. in some embodiments, the head diameter of the corresponding locking screw 510 may be sufficiently large to extend over motion gap 507 on upper surface 502 of plate member 501, For example, the head may extend over motion gap, when: at rest, by about 0.1 mm- 3 mm, tor example, about 1mm, in various embodiments, the locking feature 309 may thereby limit deflection of screw hole member 505a through bottom surface 503 of plate member 301.

[0082] Figure iA illustrates a top view of another example of a bone plate for elastic fixation of a bone fracture, and Figure 8i illustrates a top view of a further bone plate for elastic fixation of a bone fracture for use in combination with cylindrical bone segments, in accordance with various embodiments- In these embodiments, the bone plate 601 may have an upper surface 602 and a Pone contacting surface 603, and it may define a longitudinal axis 604. in some embodiments, at least one receiving bole 60S for a fixation element may extend through the upper surface 602 and the bone contacting surface 603. in some embodiments, receiving hole 605 may he threaded for rigid engagement of a locking screw with a threaded head portion, or it may have a concave recess to accommodate a conventional compression screw, in some embodiments, receiving holes 605 may be disposed along the longitudinal axis 604 as shown in Figure 8A. in other embodiments, receiving holes 605 may be spaced from the longitudinal axis 604, as shown in Figure 68, [00833 Also included in some embodiments, in the vicinity of receiving hole 606 are one or more slots 606 extending from the upper surface 602 to the bone contacting surface 603. in various embodiments, at least one substantially Shaped, E-sbaped, or semi circular slot 806 may extend around a substantial portion of receiving hole 808. In some embodiments, a corresponding slot 606a may extend from the opposite side of the periphery around receiving hole 606. In some embodiments, the end segments of slot 806 may overlap, but not intersect the end segments of corresponding slot 606a. Thus, in various embodiments, the overlapping slots 606 and 666a may enclose elastic beam: elements (e.g,, spring elements} 60S that may enable elastic translation of receiving hole 605 relative to bone plate 601 in a direction principally parallel to the longitudinal axis 604 of bone plate 601, [80843 In the embodiment illustrated in Figure 68, elastic beam elements 608 may be formed by combining at least one substantially C-shaped, E~shaped or semi-circular slot 606 with one or more substantially linear slots 806a extending from the periphery of bone plate 801 in an essentially perpendicular manner to overlap but not intersect with the ends of slots 666, [00853 Figures ?A and 78 Illustrate top and cross-sectional side views of an example of a bone plate 701 for elastic fixation of a bone, shown in functional but unloaded (Figure 7Ά) association with a bone screw 710 affixed to a cylindrical bone 72$, and shown in functional loaded (Figure 7B) association with a bone screw 710 affixed to a cylindrical bone, in accordance with various embodiments. In the illustrated; embodiment, a locking bone screw 710 is Illustrated that may have a threaded Head segment 718 for rigid engagement with receiving hole 705. in various embodiments, the screw 710 may be furthermore engaged in first cortex 713 and/or second cortex 714 of a substantially cylindrical bone 72S. Figure 7A illustrates an example of an unloaded construct, and Figure 7B Illustrates an example of how a load acting through bone 726 and onto locking screw 710 may induce translation of receiving hole 705 relative id the bone plate 751 by elastic deformation of elastic beam elements 70S between receiving hole 705 and bone plate 701, [0086] In various embodiments, the dimensions, and/dr the configuration of the spring elements (e.g.»elastic beam elements) and/or slots may be varied in order to achieve a desired stiffness and range of elastic displacement of the bone plate reiative to the receiving holes. Figure 8Ά depicts an embodiment with thicker beam elements 808 as compared to beam elements 808 shown in Figure SB, the iatter aiiowing for more flexible displacement of receiving hole 805 relative to bone plate member 801, Another example of a way to decrease the stiffness of the elastic eiements Is depicted in Figure 8C, wherein the length of slot 808 is increased in order to increase the effective length of beam eiements 888, Yet another example of a way to decrease the stiffness of the elastic element is depicted in Figure 80, wherein slots 808 are configured in a substantiaily E-shaped formation, which may yield an increased effective length of elastic beam elements SOS, Another alternative embodiment of an elastic element is depicted in Figure 8E> wherein receiving hoie 805 is located in vicinity of plate edge 823. in this example, two slots 808 may overlap but not intersect each end of reshaped slot 806 to form elastic beam eiements 808, [00871 Figure 9A illustrates a top view of a flexible element that includes a curvilinear E-snaped slot in combination with multiple linear slots 90S, and Figure 9B illustrates a perspective view of a bone plate 901 for elastic fixation of a bone fracture that incorporates the flexible elements 008 shown in Figure 0Λ,, in accordance with various embodiments. As Illustrated in Figure 94, some embodiments of bone plates 901 may Include one curvilinear E-shaped slot 906b in combination with multiple linear slots 966a; which together form elastic beam elements 908, In some ernbodiments, the curvilinear slots 906a may reduce peak stress and provide a more even strain distribution when loaded along the longitudinal axis of a bone plate 901, "TThis:©mi?o€lin^erjfc··ϊ^· -«ihowii in Figure 80, in that the elastic beam elements 968 may be folded back on themselves, in some embodiments, each of the two folded elastic beams 908 associated with a receiving hole 965 may be oriented in opposite directions, wherein the folded and of one elastic beam element 908 may be oriented toward the edge of the; bone plate 901, and the folded end of the other elastic beam element may be oriented toward the bone plate 961 midline. In various embodiments, the ourvillinear fold of the elastio beam element 908 may fit closely within the E»sheped slot 906b, which arrangement may contribute to: a stable association of receiving hole 966 with plate 901, while still allowing Ibr controlled axial trensiation of receiving hole 905 relative to plate 901, Figure 9B illustrates a perspective view of a bone plate having the curvilinear E-shaped slots 9G6bshown in Figure §4. In this embodiment, the receiving holes 966 may be offset from the longitudinal axis,· which may contribute to the stability and stiffness of bone plate 961, [06883 Some embodiments of the flexible fixation bone plates may Include curvilinear and/or spiral-shaped slots. Figure 164 itiusbates a top view of a flexible element that includes of a single spiral-shaped slot 1666, Figure 16B illustrates a top view of a flexible element that includes a single spiral-shaped slot 1006 with curvilinear 1616 and round elements 1618 on the outside and inside spiral ends, respectively, Figure 10C illustrates a top view of a flexible element that includes a single spiral-shaped slot 1666 having a thin elastic beam element 1068, Figure 10D illustrates a top view of a flexible element that includes a pair of interlaced spiral-shaped slots 1696, wherein the flexible element is offset from the midiine of the bone plate 1601,

Figure 10E illustrates a top view of a flexible element that includes a pair of interlaced spiral-shaped slots 1006, wherein the flexible element is positioned at the mldline of the bone plate 1001., and Figure 10F Illustrates a top view of a flexible element that includes three interlaced spiral-shaped slots 1O06, all in accordance with various embodiments. 10009] Figure 10A depicts another embodiment of an elastic element. In this embodiment:, a single spiral-shaped slot 1006 may be positioned around receiving hole 1000, In various embodiments, the spiral slot 1006 may circumscribe receiving hole 1005 once or multiple times, creating elastic beam element 1008 where it overlaps, in various embodiments, in order to reduce stress concentrations at the spiral ends, circular 1018 or curvilinear 1016 elements may be added to the ends of slot 1006 as shown in Figure 108, or the beam elements 100$ may be tapered. As with the embodiments shown in Figure BA and 8B, in various embodiments, beam elements 1008 may he configured to be thinner, as shown in Figure 10C, aiiowing for more flexible displacement of receiving bole 1005 relative to bone plate member 1001 - In various embodiments, increasing the length of spiral beam element 1008 also may allow for increased flexibility.

[0000] As shown In Figures 100 and 10E, receiving hoies 1005 maybe located along the midline of plate 1001, or at a distance from the longitudinal axis of plate 1801. For example, In various embodiments, if receiving holes 1005 are arranged in an alternating staggered pattern relative to the longitudinal mldline of plate 1001, they may provide multi-planar fixation to improve the strength of the fixation between plate 1001 and the underlying bone. Both Figures 10B and 10E illustrate spiral slots 1006 that include two interlaced spirals. One of skill in the art will appreciate that additional spiral slots 1006 may be used, such as the three-slot 1006 arrangement depicted in Figure 10F, [0091] Figures 11 A, 11B, and 11C illustrate three views of another embodiment of a flexible element, in this embodiment of bone plate 1101, slot 1106 and elastic beam element 1108 may be located on a separate, removable plug element 1120 that may be adapted to be inserted into an enlarged receiving hole 1130. In an alternate embodiment, removable plug element 1120 may be an integral component of an enlarged head of a bone screw that engages the correspondingly enlarged receiving hole 1136, [0092] Figure 12 depicts a cross-sectional perspective view of another embodiment, showing the dimensions of beam element 1268 and slot 1206. Generally, beam elements 1206 may be considerably higher {thicker} than they are wide. For instance, in some embodiments, the ratio of the beam height 1264 to the beam width 1266 may vary from about 2 {2 to 1) to about 12 {12 to 1), for instance from about 6 (6 to 1} to about 9 (9 to 1}. In various embodiments, receiving holes 1206 associated with flexible elements as described herein may or may not have features for positive locking of a bone screw or fastener. For instance, in embodiments Sacking positive locking mechsnlsmsf the flexible spring element may actio relieve stress at the plate-bone interface. In embodiments having positive locking mechanisms, the flexible element may provide flexible plate fixation to allow small relative motion between the plate and the bone, which in turn may induce interfragmentary motion and promote bone heating, |d093| In -further embodiments, Figure '13 A illustrates several views of a flexible element 1308 used in conjunction with a rivet 134δ configured to protect the flexible element 1308 from excessive deformation perpendicular to the plane of the plate 1361, Figure 13B illustrates several views of a flexible element 1308 used in conjunction with a haif-hvet 1360 configured to protect the flexible element 1368 from excessive deformation perpendicular to the plane of the plate 1361, and Figure 13C illustrates a perspective view of a half rivet 1360 configured to protect the flexible element 1308 from excessive deformation perpendicular to the plane of the plate 1381, wherein the half-rivet 1360 is used together with a customized bone screw 1310, all in accordance with various embodiments, [0094J As illustrated in Figure 13A, the elastic element 1306 may include a spira l-shaped slot 1306 positioned: around receiving hole 1305 , and the spiral slot 1306 may eircumscribe receiving hole 1306 once or multiple times, creating elastic beam element 1308 where it overlaps. In this embodiment, a rivet 1338 may be provided in receiving hole 130$, and may be configured to protect elastic beam element 1308 from excessive deformation perpendicular to the plane of plate 1301 , In various embodiments, rivet 1338 may have a shoulder 1343 on each side of a centra! cylinder 1343 to restrict flexion of elastic beam element 1303 that may occur within the plane of plate 1301, In embodiments, the inner diameter of the central cylinder 1340 of rivet 1330 may be threaded for rigid locking with the threaded head of a bone screw 1310, Depending on plate 1301 thickness, the rivet shoulders 1348 may rest on the surface of the plate 1331, dr may be recessed into the plate 1301, in various embodiments wherein shoulder 1348 is recessed, the longitudinal dimension of the recess may be larger than the corresponding dimension of rivet shoulder 1348 to allow rivet translation along the plate 1331 longitudinal axis, while constraining rivet 1338 translation in a transverse direction, [3095J In various embodiments, tor assembly, rivet 1338 may include two parts that may be inserted from opposite sides into receiving bole 1308, and the two parts may be rigidly coupled to each other; tor instance by laser welding or by a thread feature between central cylinder 1348 and shoulder 1348, Alternatively, as illustrated in Figure 13B, rivet 1338 may have only one shoulder 1348 to form a “half -rivef 1380, which may limit deformation of elastic beam element 1308 in only one direction. In various embodiments, half-rivet 1380 may include an externally threaded central cylinder 1340 for rigid engagement to elastic beam element 1308, Alternatively, in some embodiments, hatf-rivet 1380 may be attached to elastic beam element 1308 using a press fit between central cylinder 1340 and elastic beam element 1308, In embodiments, half-rivet 1380 may be used in combination with a customized bone screw 1310 as shown in Figure 13C, which may include a head that incorporates a corresponding shoulder element 1382. Thus, In various embodiments, upon screw insertion, elastic beam element 1308 may be confined between shoulder 1348 of half-rivet 1380 and the corresponding shoulder 1382 of the screw head, with the remainder of the screw head resting inside central cylinder 1340 of half-rivet 1388.

[86961 In various other embodiments shown in figures 14A and 1:4.8, rivet 1438 may be elastically suspended inside receiving hole 1436 using a discrete spring element 1458. In some embodiments, spring element 1458 may include a corrugated metal strip 1444, that may circumscribe central cylinder 1448; of rivet 1438, and that may center rivet 1438 inside receiving hole 1436, v#siie allowing for elastic translation of rivet 1438 within the plane of plate 1481, In some embodiments, spring element 1458 may further retain rivet 1438 Inside the plane of plate 1481, The inner diameter of central cylinder 1448 of rivet 1438 may be threaded In some embodiments for rigid locKihg with the threaded head of a bone screw.

[86971 Figures 15 A, 158, 150, and 150 illustrate a cross-sectional view, a top view, a partial cutaway view showing placement of an insert 1546, and a planar cmss-sectional view, respectively, of another embodiment, in which a threaded insert 1548, once inserted into insert receiving hole 1536, may translate along the longitudinal plate axis within the plane of plate 1581. In various embodiments, threaded insert 1546 may bo suspended with spring elements (eg,, flexible elements) 1548 in a central position within insert receiving hole 1538, whereby spring elements (e.g., flexible elements) 1548 may be ngidly coupled to or part ofthreaded insert 1548. In some embodiments, opposite sides of threaded insertl 548 may have a convex .cylindrical surface 1550 adapted to securely retain threaded insert 1546 within the plane of plate 1561, In various embodiments, tor installation, threaded insert 1548 may be first rotated perpendicular to the plate surface, then inserted into insert receiving hole 1538, and finally rotated by 90 degrees so that: its Upper surface is parallel to the: upper surface of plate 1501, in some embodiments, spring elements (e.g,., flexible elements) 1548 may engage with |e,g., snap into) a corresponding recess 1542 in plate 1581 to ensure that upon insertion, threaded insert 1546 remains rotationally secured within the plane of plate 1501.

[86981 in further embodiments, Figure 18A illustrates a fop view of a threaded insert 1848 that is generated from the bone plate 1601 by introducing a slot 1606 that circumscribes the receiving hole 1685, Figure 18B illustrates a schematic view of the device shown in Figure liA, Figure 16C illustrates a longitudinal cross-sectional view of the device shown in Figure 16A. and Figure 16D Illustrates a transverse cross-sectional view of the device shown in Figure 16A, ail in accordance with various embodiments, As illustrated in various embodiments, a threaded insert 1646 may be generated from plate 1601 by introducing a slot 1606 that circumsen bes receiving hole 160S. in various embodiments, slot 1606 may be introduced in an anti-parallel manner, whereby two opposing sections 1662 of slot 1606 converge toward the lower side 1663 of plate 1661 > while two other opposing sections 1664 diverge toward the lower side 1603 of plate 1601, Hence, in these embodiments, the anti-parallel slot 1606 may enable threaded Insert 1646 to translate relative to plate 1601 within the confines of the slot width, and without being able to disassociate from plate 1661.

[669S| In stiil other embodiments, Figure 17A illustrates a transverse cross-sectional view.-of a threaded insert 1746 formed by the introduction of a siot 1766 that circumscribes the receiving hole 1766 in an anti-parallel manner and Suspended (centered) inside a bone plate 1701 using flexible elements 1768, Figure 17B iiiustrates a fop view of the device illustrated in Figure 17A, and Figure 17C iiiustrates a longitudinal cross-sectional view of the device illustrated in Figure 17A, all in accordance with various embodiments. As illustrated in Figures 17A-C, threaded insert 1746 may be formedby the introduction of a slot 1766 that circumscribes receiving hole 1766 in an antiparaliel manner as described above, and threaded insert 1746 may be suspended (centered) Inside plate 1761 using flexible elements 1786, In an exemplary embodiment, these flexible elements 1768 may be cylindrical in shape and comprised of a polymer, and may provide a flexible connection between threaded ihsert 1746 and plate 1761, while the anti-parallel slot ensures that threaded Insert 1748 remains securely captured in plate 1761.

[66166| in other embodiments, Figure 18A iiiustrates a cross-sectional side view of a bone plate for elastic fixation of a bone fracture, shown in functional but unloaded association with locking bone screws tor spanning a bone fracture in a cylindrical bone, and Figure 18B illustrates a cross-sectional side view of a bone plate for elastic fixation of a bone fracture, shown in functional association with locking bone screws for spanning a bone fracture in a cylindrical bone, wherein axial compression of the cylindrical bone segments induces parallel motion at toe fracture, both In accord a nee with various embodimen ts.

[00101] Thus, in order to illustrate a method for elastic fixation of a bone fracture. Figure 18& depicts a cross-secfional view of an embodiment for elastic fixation of a bone fracture 1824 with a bone plate 1881 that may be attached to two bone segments 1828. In this configuration, each bone segment 1828 may be connected by one or more locking bone screws 1810 to receiving holes 1805 that may he connected with elastic elements 1808 to bone plate 1801, in embodiments, the screw heads 1828 of bone screws 1810 may be rigidly connected to receiving holes 1805, for instance by matching thread features on screw heads 1828 with those on the receiving boles 1888. |n embodiments, this locking mechanism between screw heads 1:828 and receiving holes 1805 may enable bone plate 1801 to remain elevated above bone surface 1830, while providing elastic fixation between bone segments 1828.

[801021 in order to illustrate a method for inducing principally parailei axial motion across a bone fracture, Figure 18B depicts a emss-sectiona! view of an embodiment tor eiastic fixation of a bone fracture subjected to axial loading, as may foe the case In patients that start weight bearing of a fractured extremity that has been stabilized with bone plate 1801. In various embodiments, the toad acting on bone segments 1828 and onto locking screws 1810 may induce elastic translation of receiving holes 1805 relative to bone plate 1801, which In turn may cause generally parailei motion between bone segments 1828 at bone fracture 1824. In this configuration, axial loading of bone segments 1828 may cause elastic deformation of elastic beam elements 1808, wherein siot segments 1832 located at the aspect of receiving hole 1805 facing fracture 1824 become narrower, while slot segments 1834 located at the receiving hole aspect facing away from fracture 1824 become wider, [60183] in various other embodiments* Figure 19& illustrates a cross-seciional side view of a bone plate for elastic com press ion of a bone fracture, shown in functional association with non-locking bone screws for spanning a bone factum in a cylindrical bone, wherein bone screws are Inserted in an eccentric manner* and Figure 19B illustrates a crose-sectiohal side view of a bone plate for elastic compression of a bone fracture, wherein tightening of eccentrically inserted bone screws induces elastic compression across a bone fracture by deformation of elastic beam elements that connect the plate holes to the plate member, both in accordance with various embodiments, [60104] Thus, in order to illustrate a method for Inducing elastic compression across a bone fracture, Figures 19Ά and 198 depict cross-sectional views of an embodiment of a bone plate 1961 applied to bridge and to elastically compress a fracture 1924 in a substantially cylindrical bone. Figure 19A depicts bone screws 1916 being partially inserted through receiving holes 1965 into bone segments 1926. in various embodiments, screws 1916 may be Inserted eccentrically in receiving holes 1985, at a small distance'from'the center-line 1922 of receiving hole 1985 In an opposite direction from fracture 1924. Figure 19B depicts the embodiment in a cross-sectional view after complete insertion Of screws 1916, Since screws 1916 were inserted eccentrically relative to receiving hole 1965, once screw heads 1928 are contacting bone plate 1901 during insertion, screws 1918 may be forced to translate toward the center of receiving holes 1965, This in turn causes bone segment 1926 attached to screws 1918 to translate relative to bone plate 1901 toward fracture 1924, thereby inducing compression across fracture 1924. Once fracture 1924 is fully compressed, any further translation may be accommodated by deformation of elastic beam elements 1908 connecting receiving holes 19051ο bone plate 1961. in embodiments, this elastic deformation may induce additional compressive forces at fracture 1924, [00105] As illustrated in Figure 20, the introduction of elastic elements in a tone plate as described elsewhere herein (referred to in Figure 20 as an S-piato) may reduce axial stiffness of the plate as compared to a standard plate without the etostic elements, Notably, there is little to no impact da the bending stiffness of the plate due to the introduction of the elastic elements, [00106] Thus, in some embodiments, having an opening with a major dimension in a transverse direction may effectively reduce the bending strength of tone plates, which may to in bending. Thus in various embodiments, the flexible elements described herein may not have a major dimension extending in transverse direction. This orientation may cause the bone piato to retain a substantial amount of bending strength. As described elsewhere herein, it is desirable to maintain the bending strength of the construct while reducing the axial stiffness of plate, and additionally reducing stress at the screw hotels) and in the construct as a whole, in various embodiments, stress at the screw hoie(s) may cause undesirable or detrimental deforrnation of the hoie(s).

[5010?] in other embodiments, if the cantilever beam were located transversely In-line’ with the screw hole, the transverse opening may extend over a substantial ./portion of the plate in order to derive flexibility, which in turn may reduce the bending strength of the plate. Thus, various embodiments disclosed herein employ a combination of two or more cantilever beams located above and below the screw hole (e.g., in the longitudinal plate direction), which may preserve bending strength of the plate, [00108] in still Other embodiments described herein, one or more pairs of cantilever beams may be employed, wherein the beams of each cantilever pair are located oh opposite sides of the screw hole in longitudinal direction, rather than one cantilever beam element that extends in a principally transverse direction to either one or both sides of the screw hole (lug), depending if the screw hole is located offset tom or located on the longitudinal plate msdiine, respectively.

[00109] Other embodiments disclosed herein use pairs of slots that extend through the plate edge, rather than a slot that defines the transverse opening and that surrounds the beam and lug element, wherein the slot remains wlthinthe plate surface and does not extend through the plate edge.

[00110] Still other embodiments include a set of slots per screw hole, wherein the set combines a central slot that partially surrounds the screw hole without extending thFough the plate edge with peripheral slots that penetrate through the longitudinal plate edge, rather than one continuous slot per screw hole, whereby the slot defines the transverse open ing and Surrounds the beam and fug element, [00111] Various other embodiments disclosed herein employ a set of slots to form a principally S-shaped spring element having an upper and a lower cantilever element that Is diagonally connected by a central segment that contains the screw hole, rather than a generally l-shaped cantilever beam, tor instance; Still other embodiments described herein employ cantilever elements of a width that is substantially smaller than the plate thickness, rather than a cantilever elemant of a width that is larger than the plate thickness. This may ensure a desired bending direction of the cantilever beam within the plane of the plate rather than out of the plane of the plate, [00112] It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. Specifically, the disclosed invention may be practiced for fixation of a bone plate to one side of a fracture only, whereby the corresponding side of a fractured bene: may be applied tc the one plate by alternative means for flexible: or rigid fixation. It is understood, therefore, that this disclosure is not limited to the particular embodiments disclosed, but it Is intended to cover modifications within the spirit and scope of the present disclosure as defined by the appended claims.

[00113] Although certain embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a wide variety of alternate and/or eguivalent embodiments or implementations calculated to achieve the same purposes may be substituted for the embodiments shewn and described without departing from the scope, Those with skill in the art will readily appreciate that embodiments may be implemented in a very wide variety of ways. This application is Intended to cover any adaptations or variations of the embodiments discussed herein. Therefore, it Is manifestly intended that embodiments be limited only by the claims and the equivalents thereof.

Claims (18)

1. Claims

   1. A device comprising: a bone plate having an outer surface and a bone-facing surface, the bone plate comprising one or more spiral-shaped slots extending through the plate from the outer surface to the bone-facing surface, the one or more spiral-shaped slots forming a non-perpendicular angle with the outer surface and the bone-facing surface of the bone plate, and the one or more spiral-shaped slots at least partially circumscribing a periphery of one or more receiving holes located in the bone plate and not penetrating through a longitudinal edge of the bone plate, the longitudinal edge of the bone plate extending between the outer surface and the bone-facing surface, wherein the one or more spiral-shaped slots form a spring element, the spring element at least partially surrounding the receiving hole and permitting axial translation of the bone plate relative to the one or more receiving holes within a plane that is substantially parallel to the outer surface or the bone-facing surface of the bone plate, but substantially preventing motion of the bone plate relative to the one or more receiving holes in a direction that is substantially perpendicular to the outer surface or the bone-facing surface of the bone plate.
2. 2. The device of claim 1, wherein the spring element comprises a single spiral-shaped slot that circumscribes the periphery of the receiving hole at least once.
3. 3. The device of claim 2, wherein the spiral-shaped slot includes an inside spiral end and an outside spiral end, the outside spiral end positioned further away from the receiving hole in a radial direction, wherein at least one of the inside spiral end and the outside spiral end includes a curvilinear segment or an enlarged rounded segment configured to reduce stress concentration.
4. 4. The device of claim 1, wherein the spring element comprises two or more spiral-shaped slots that at least partially circumscribe the receiving hole.
5. 5. The device of claim 4, wherein each of the spiral-shaped slots circumscribes the periphery of the receiving hole at least once.
6. 6. The device of claim 1, wherein the spring element comprises three or more interlaced spiral-shaped slots, each of the spiral-shaped slots circumscribing less than an entirety of the periphery of the receiving hole.
7. 7. The device of claim 1, wherein at least one of the one or more receiving holes is located in a plug or rivet disposed within the bone plate, wherein the plug or rivet is configured to permit axial translation of the receiving hole relative to the bone plate.
8. 8. The device of claim 7, wherein the spring element associated with the receiving hole is located in the plug or rivet.
9. 9. The device of claim 8, wherein the receiving hole in the plug or rivet comprises a threaded receiving hole.
10. 10. The device of claim 7, wherein the spring element is formed in the bone plate and surrounds an enlarged hole configured to receive the plug or rivet having the receiving hole therein.
11. 11. The device of claim 7, wherein the plug or rivet includes a shoulder.
12. 12. The device of claim 11, wherein the shoulder is configured to rest on the bone-facing surface of the bone plate.
13. 13. A device comprising: a bone plate having an outer surface and a bone-facing surface, the bone plate comprising two or more slots extending through the plate from the outer surface to the bonefacing surface, each of the two or more slots circumscribing a periphery of one or more receiving holes at least once and not penetrating through a longitudinal edge of the bone plate, wherein the two or more slots form a spring element, the spring element at least partially surrounding the receiving hole and permitting axial translation of the bone plate relative to the one or more receiving holes within a plane that is substantially parallel to an upper or lower surface of the bone plate, but substantially preventing motion of the bone plate relative to the one or more receiving holes in a direction that is substantially perpendicular to the upper or lower surface of the bone plate; wherein the two or more slots defining each spring element comprise two or more spiral segments, and wherein the two or more spiral segments each circumscribe the one or more receiving holes one or more times.
14. 14. The device of claim 13, wherein the two or more spiral segments define two or more elastic beam elements.
15. 15. The device of claim 14, wherein the two or more elastic beam elements include a beam height, measured between the outer surface and the bone-facing surface of the bone plate, and a beam width, measured in a direction transverse to the beam height, wherein the beam height is greater than the beam width.
16. 16. The device of claim 15, wherein a ratio of the beam height to the beam width is between 2:1 and 12:1.
17. 17. The device of claim 16, wherein the ratio of the beam height to the beam width is between 6:1 and 9:1.
18. 18. The device of claim 13, wherein at least one of the one or more receiving holes is located in a plug or rivet, wherein the plug or rivet is configured to permit axial translation of the receiving hole relative to the bone plate.