Extendable spinal rod devices and systems

Abstract

An extendable spinal rod device includes a housing, a bearing nut rotatably disposed within the housing, an extendable rod extending from the housing and threadingly engaged within the bearing nut such that the bearing nut is rotated in response to axial movement of the extendable rod relative to the housing, and first and second one-way ratchet interfaces associated with the housing and the bearing nut, respectively. The one-way ratchet interfaces are configured to engage one another to permit rotation of the bearing nut in a first rotational direction corresponding to axial extension of the extendable rod from the housing and to inhibit rotation of the bearing nut in a second rotational direction corresponding to axial retraction of the extendable rod into the housing such that axial extension of the extendable rod from the housing is permitted while axial retraction of the extendable rod into the housing is inhibited.

Description

A0012380W001 (10259BS-502-PCT)EXTENDABLE SPINAL ROD DEVICES AND SYSTEMS CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of, and priority to, U.S. Provisional Patent Application No. 63 / 721,697, filed on November 18, 2024, the entire contents of which are hereby incorporated herein by reference.FIELD

[0002] The present disclosure relates to spinal surgery and, more particularly, to extendable spinal rod devices and systems for treating disorders of the spine.BACKGROUND

[0003] Spinal disorders such as scoliosis and other curvature abnormalities, kyphosis, degenerative disc disease, disc herniation, osteoporosis, spondylolisthesis, stenosis, tumors, and fracture may result from trauma, disease, and / or degenerative conditions and may cause patient pain, deformity, nerve damage, and / or loss of mobility.

[0004] Surgical treatment of such spinal disorders includes correction, fusion, fixation, discectomy, laminectomy and / or implantable prosthetics. With respect to correction, for example, surgical treatment may include implantation of a system of rods and screws to provide spinal stabilization and maintain spinal curve correction.

[0005] While surgical treatments for spinal correction are generally effective, spinal correction is challenging in children due to the need to account for skeletal growth, while maintaining the corrections over time and minimizing the need for repeat surgeries until skeletal maturity.SUMMARY

[0006] Any or all of the aspects described herein, to the extent consistent, may be used in conjunction with any or all of the other aspects described herein.

[0007] Provided in accordance with aspects of the present disclosure is an extendable spinal rod device including a housing, a bearing nut rotatably disposed within the housing and having internal threading, an extendable rod extending from the housing, and first and second one-way ratchet interfaces associated with the housing and the bearing nut, respectively. The extendable rod includes a threaded portion having external threading. The bearing nut is disposed about the threaded portion of the extendable rod with the internal and external threadings engaged with one another such that the bearing nut is rotated within the housing in response to axial movement of the extendable rod relative to the housing.A0012380W001 (10259BS-502-PCT)The first and second one-way ratchet interfaces are configured to engage one another to permit rotation of the bearing nut in a first rotational direction corresponding to axial extension of the extendable rod from the housing and to inhibit rotation of the bearing nut in a second rotational direction corresponding to axial retraction of the extendable rod into the housing such that axial extension of the extendable rod from the housing is permitted while axial retraction of the extendable rod into the housing is inhibited.

[0008] In an aspect of the present disclosure, the internal and external threadings define non-thread lock threadforms, e.g., high helix threadforms, configured to inhibit self-locking and thereby enable axial extension of the extendable rod from the housing in response to application of an axial force urging the extendable rod from the housing.

[0009] In another aspect of the present disclosure, at least one bearing is disposed between the housing and the bearing nut to facilitate rotation of the bearing nut relative to the housing.

[0010] In another aspect of the present disclosure, the first one-way ratchet interface is disposed on an end of a bushing tube disposed within the housing and the second one-way ratchet interface is disposed on an end of the bearing nut. In such aspects, at least one of the bushing tube or the bearing nut may be biased towards the other of the bushing tube or the bearing nut to maintain engagement between the first and second one-way ratchet interfaces.

[0011] In still another aspect of the present disclosure, a cap is engaged with an open end of the housing to retain the bearing nut within the housing. The extendable rod extends through the cap.

[0012] In another aspect of the present disclosure, each of the housing and the threaded portion of the extendable rod includes a curved section extending along at least a portion of a length thereof.

[0013] In yet another aspect of the present disclosure, a first access opening is defined through a side wall of the housing to expose a portion of the extendable rod. In such aspects, a tool is configured for insertion through the first access opening and into engagement with the portion of the extendable rod to enable manual axial extension of the extendable rod. More specifically, in aspects, the portion of the extendable rod includes a gear rack and the tool includes a gear driver configured to engage the gear rack and drive axial extension of the extendable rod in response to rotation of the gear driver. Alternatively or additionally, a suitable tool may be utilized to operably engage the bearing nut to drive rotation of theA0012380W001 (10259BS-502-PCT)bearing nut, thereby driving axial extension of the extendable rod in response to rotation of the bearing nut.

[0014] In still yet another aspect of the present disclosure, at least one of the first or second one-way ratchet interfaces is axially movable relative to the other from an engaged position, permitting axial extension of the extendable rod while inhibiting axial retraction of the extendable rod, to a disengaged position, permitting both axial extension and axial retraction of the extendable rod. In such aspects, a second access opening may be defined through a side wall of the housing to expose a portion of the bearing nut and a tool may be configured for insertion through the second access opening and into engagement with the bearing nut to move the second one-way ratchet interface from the engaged position to the disengaged position.

[0015] In another aspect of the present disclosure, a fixed rod body extends from the housing opposite the extendable rod. The fixed rod body, in aspects, may extend coaxially from the housing or in offset, parallel relation relative to the housing.

[0016] In another aspect of the present disclosure, a second bearing nut is rotatably disposed within an opposite end of the housing or within a second housing oriented in an opposite direction relative to the housing and a second extendable rod extends from the opposite end of the housing or from the second housing in the opposite direction relative to the housing. The second extendable rod and second bearing nut are in accordance with any of the aspects above or otherwise detailed herein. Further, another first one-way ratchet interface associated with the housing or the second housing and another second one-way ratchet interface associated with the second bearing nut are provided. Thus, axial extension of the second extendable rod from the housing or the second housing is permitted while axial retraction of the second extendable rod into the housing or the second housing is inhibited.

[0017] An extendable spinal rod system provided in accordance with the present disclosure includes a first screw assembly configured to anchor in a first vertebrae of a patient’s spine, a second screw assembly configured to anchor in a second vertebrae of a patient’s spine, and an extendable spinal rod device according to any of the aspects above or otherwise detailed herein.

[0018] In an aspect of the present disclosure, the internal and external threadings define non-thread lock threadforms, e.g., high helix threadforms, configured to inhibit self-locking and thereby enable axial extension of the extendable rod from the housing in response to application of an axial force urging the extendable rod from the housing. In such aspects,A0012380W001 (10259BS-502-PCT)growth of the patient may provide the axial force urging the extendable rod from the housing.

[0019] In another aspect of the present disclosure, at least one bearing is disposed between the housing and the bearing nut to facilitate rotation of the bearing nut relative to the housing.

[0020] In yet another aspect of the present disclosure, the first one-way ratchet interface is disposed on an end of a bushing tube disposed within the housing and the second oneway ratchet interface is disposed on an end of the bearing nut.

[0021] In still another aspect of the present disclosure, a first access opening is defined through a side wall of the housing to expose a portion of the extendable rod and a tool is configured for insertion through the first access opening and into engagement with the portion of the extendable rod to enable manual axial extension of the extendable rod.

[0022] In still yet another aspect of the present disclosure, at least one of the first or second one-way ratchet interfaces is axially movable relative to the other from an engaged position, permitting axial extension of the extendable rod while inhibiting axial retraction of the extendable rod, to a disengaged position, permitting both axial extension and axial retraction of the extendable rod.

[0023] In another aspect of the present disclosure, each of the housing and the threaded portion of the extendable rod includes a curved section extending along at least a portion of a length thereof.BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The above and other aspects and features of the present disclosure will become more apparent in light of the following detailed description when taken in conjunction with the accompanying drawings wherein like reference numerals identify similar or identical elements.

[0025] FIG. 1 illustrates a system for treating disorders of the spine in accordance with the present disclosure installed on a patient’s spine;

[0026] FIGS. 2 A and 2B are perspective views of an extendable spinal rod device provided in accordance with the present disclosure and configured for use with the system of FIG. 1, shown defining first and second lengths, respectively;

[0027] FIG. 3 is an exploded, perspective view of the extendable spinal rod device of FIGS. 2 A and 2B;A0012380W001 (10259BS-502-PCT)

[0028] FIG. 4 is an enlarged, perspective, partially transparent view of a portion of the extendable spinal rod device of FIGS. 2A and 2B;

[0029] FIG. 5 is cross-sectional view taken along section line “5-5” of FIG. 4;

[0030] FIG. 6 is a perspective view illustrating engagement of the extendable rod, bearing nut, and bushing tube of the extendable spinal rod device of FIGS. 2 A and 2B;

[0031] FIGS. 7A-7C are side views illustrating extension of the extendable spinal rod of the extendable spinal rod device of FIGS. 2 A and 2B relative to the bearing nut and bushing tube of the extendable spinal rod device of FIGS. 2A and 2B;

[0032] FIG. 8A is a perspective, partially transparent view of a portion of the extendable spinal rod device of FIGS. 2A and 2B including a tool engaged therewith for manually extending the extendable rod;

[0033] FIG. 8B is a perspective view of another configuration of the portion of the extendable spinal rod device of FIGS. 2 A and 2B for engagement with a gear assembly for extending the extendable rod;

[0034] FIG. 9 is an enlarged, perspective view of a portion of the extendable spinal rod device of FIGS. 2A and 2B including a tool positioned for insertion through an engagement slot defined through the stationary rod;

[0035] FIGS. 10A and 10B are perspective partially transparent and longitudinal cross-sectional views, respectively, of a portion of the extendable spinal rod device of FIGS. 2A and 2B incorporating a biasing spring;

[0036] FIGS. 11-14 illustrate various different bearing configurations for use with the extendable spinal rod device of FIGS. 2A and 2B;

[0037] FIGS. 15-17 are perspective views of other extendable spinal rod devices provided in accordance with the present disclosure and configured for use with the system of FIG. 1 or any other suitable system;

[0038] FIG. 18 is longitudinal, cross-sectional view of a portion of another extendable spinal rod device provided in accordance with aspects of the present disclosure;

[0039] FIG. 19 is a perspective view of the extendable rod of the extendable spinal rod device of FIG. 18; and

[0040] FIG. 20 is an enlarged, longitudinal, cross-sectional view of a portion of the extendable spinal rod device of FIG. 18 illustrating off-axis tilting of a bearing nut to accommodate a curvature of the extendable rod.A0012380W001 (10259BS-502-PCT)DETAILED DESCRIPTION

[0041] Referring to FIG. 1, a system for treating disorders of the spine in accordance with the present disclosure is generally identified by reference numeral 10 and shown installed on a patient’s spine “S ” System 10 includes one or more extendable spinal rod devices 100 and one or more screw assemblies 200. System 10 may additionally or alternatively include connectors, fixed length spinal rods, and / or any other suitable components. Each screw assembly 200 is anchored in a vertebrae “V” of the patient’s spine “S ” Each extendable spinal rod device 100 (and each fixed length spinal rod, if provided) is received within one or more screw assemblies 200 and generally extends along at least a portion of a length of the patient’s spine “S ” Extendable spinal rod devices 100, as described in greater detail below, are passively extendable in length in response to lengthening of the patient’s spine “S”, e.g., due to patient growth (natural or assisted), without requiring surgical intervention. Further, and as also described in greater detail below, extendable spinal rod devices 100 are actively adjustable to vary the length thereof by a surgeon in minimally invasive fashion, e.g., for active (surgeon-driven) growth.

[0042] Screw assemblies 200 may be anchored in pedicle bone, cortical bone, or any other suitable bone, whether vertebral or otherwise. Further, screw assemblies 200 may be include one or more polyaxial screw assemblies, uniaxial screw assemblies, fixed angle screw assemblies, and / or any other suitable screw assemblies used in any suitable location(s) and / or trajectory(s), e.g., a sagittal trajectory or a transverse trajectory.

[0043] Turning to FIGS. 2A-5, an extendable spinal rod device 100 provided in accordance with the present disclosure and configured for use with system 10 (FIG. 1) or any other suitable system for treating disorders of the spine is shown. Extendable spinal rod device 100 includes a stationary rod 110, a cap 120, a bushing tube 130, an extendable rod 140, a bearing nut 150, and one or more bearings 160.

[0044] Stationary rod 110 includes a body 112 and a housing 114 that are arranged end-to-end along the length of stationary rod 110 and fixed relative to one another, e.g., monolithically formed, welded, or otherwise fixed relative to one another. Body 112 defines a first free end of stationary rod 110, may be solid or at least partially solid of any suitable diameter, and may be configured similar to any suitable spinal rod. Housing 114 defines a substantially hollow interior configured to receive, as detailed below, bushing tube 130, at least a portion of extendable rod 140, bearing nut 150, and the one or more bearings 160. Housing 114 includes a base portion 116 connected to and extending from body 112 and a head portion 118 extending from base portion 116 to a second free end of stationary rodA0012380W001 (10259BS-502-PCT)110. Base portion 116 of housing 114 defines a diameter greater than the diameter of body 112, and head portion 118 defines a diameter greater than the diameter of base portion 116. Tapered portions 113, 115 may be defined between body 112 and base portion 116 of housing 114 and between base portion 116 of housing 114 and head portion 118 of housing 114, respectively, to define smooth transitions between the different diameter portions of stationary rod 110. Housing 114 of stationary rod 110 further includes first and second access openings 117, 119 defined through base portion 116 and head portion 118, respectively, thus enabling access to components within the interior of housing 114 from the exterior of stationary rod 110, as detailed below.

[0045] Cap 120 is configured to engage head portion 118 of housing 114 at the second free end of stationary rod 110 to retain the internal operable components of extendable spinal rod device 100 within housing 114 of stationary rod 110, as detailed below. Cap 120 may be welded to head portion 118 of housing 114 or engaged therewith in any other suitable manner. Cap 120 defines an aperture 122 therethrough that is configured to receive extendable rod 140 to enable extendable rod 140 to extend from housing 114 of stationary rod 110 through cap 120.

[0046] Continuing with reference to FIGS. 2A-5, and with additional reference to FIGS.6 and 7A-7C, bushing tube 130 is configured for positioning, in fixed longitudinal and rotational relation, within base portion 116 of housing 114 of stationary rod 110. Bushing tube 130, more specifically, may be fixed within base portion 116 of housing 114 of stationary rod 110 via complementary fit engagement, snap-fit engagement, adhesives, welding, combinations thereof, and / or in any other suitable manner. Bushing tube 130 defines at least one open end 132 providing access to the interior thereof. Bushing tube 130 is configured to receive extendable rod 140 to enable extendable rod 140 to extend therefrom, e.g., through open end 132 of bushing tube 130. An annular ratchet interface 134 of bushing tube 130 surrounds open end 132 of bushing tube 130. Annular ratchet interface 134 includes a plurality of one-way ratchet teeth 136, e.g., each having an angled cam surface oriented in a first circumferential direction and a perpendicular stop surface oriented in a second, opposite circumferential direction, to enable rotation of a corresponding ratchet interface engaged with annular ratchet interface 134 in a first rotational direction and inhibit rotation of the corresponding ratchet interface in a second, opposite rotational direction while the corresponding ratchet interface is engaged with annular ratchet interface 134. Bushing tube 130 further includes a window 138 defined through a side wall thereof to provide access to the interior of bushing tube 130. WhenA0012380W001 (10259BS-502-PCT)bushing tube 130 is engaged within base portion 116 of housing 114 of stationary rod 110, window 138 is at least partially aligned with first access opening 117 of base portion 116 of housing 114 of stationary rod 110, thus enabling access to the interior of bushing tube 130 from the exterior of stationary rod 110.

[0047] Extendable rod 140 includes a threaded portion 142 and a rod portion 144 that are arranged end-to-end along the length of extendable rod 140 and fixed relative to one another, e.g., via monolithic formation, welding, or in any other suitable manner. Extendable rod 140, led by threaded portion 142, is configured for partial positioning within bushing tube 130 and housing 114 of stationary rod 110 with at least a portion of rod portion 144 of extendable rod 140 extending from housing 114 of stationary rod 110 and through cap 120 to extend longitudinally away from housing 114 of stationary rod 110. Threaded portion 142 includes helical threading 146 disposed about the outer periphery thereof. Helical threading 146 defines a non-thread lock threadform such as, for example, a high helix threadform, e.g., having a larger helix angle than standard screw threads, to inhibit self-locking and thereby facilitate, with bearing nut 150 threadingly engaged about threaded portion 142 of extendable rod 140, axial translation of extendable rod 140 through and relative to bearing nut 150 in response to application of an axial pulling force on extendable rod 140, thereby extending extendable rod 140 from housing 114 of stationary rod 110 in response to the application of the axial pulling force on extendable rod 140.

[0048] Threaded portion 142 of extendable rod 140 includes a longitudinal channel 148 recessed into a side wall of threaded portion 142. Longitudinal channel 148 includes a gear rack 149 extending longitudinally along an inner wall defining longitudinal channel 148. With extendible rod 140 disposed within bushing tube 130 and housing 114 of stationary rod 110, longitudinal channel 148 is oriented to at least partially overlap with window 138 of bushing tube 130 and first access opening 117 of base portion 116 of housing 114 of stationary rod 110, thus enabling access to longitudinal channel 148 from the exterior of extendable spinal rod device 100.

[0049] With continued reference to FIGS. 2A-5, bearing nut 150 is configured for positioning within head portion 118 of housing 114 of stationary rod 110 in end-to-end relation relative to bushing tube 130 and is retained within housing 114 of stationary rod 110 between bushing tube 130 and cap 120. Bearing nut 150 defines a threaded interior having helical threading 152 disposed about the inner periphery thereof. Helical threading 152 is complementary to helical threading 146 of threaded portion 142 of extendable rod 140 to enable threaded engagement of bearing nut 150 about threaded portion 142 ofA0012380W001 (10259BS-502-PCT)extendable rod 140. Helical threading 152, more specifically, defines a non-thread lock threadform such as, for example, a high helix threadform, e.g., having a larger helix angle than standard screw threads, to inhibit self-locking and thereby facilitate, with bearing nut 150 threadingly engaged about threaded portion 142 of extendable rod 140, axial translation of extendable rod 140 through and relative to bearing nut 150 in response to application of an axial pulling force on extendable rod 140, while bearing nut 150 is rotated about extendable rod 140.

[0050] Bearing nut 150 further includes an annular ratchet interface 154 surrounding an open end 155 thereof. Annular ratchet interface 154 includes a plurality of one-way ratchet teeth 156 that are complementary to one-way ratchet teeth 136 of annular ratchet interface 134 of bushing tube 130, e.g., each having an angled cam surface oriented in a first circumferential direction and a perpendicular stop surface oriented in a second, opposite circumferential direction. With bushing tube 130 and bearing nut 150 disposed within housing 114 of stationary rod 110, annular ratchet interfaces 134, 154 are biased into engagement with one another. As a result, rotation of bearing nut 150 is permitted in the first rotational direction and inhibited in the second, opposite rotational direction while annular ratchet interfaces 134, 154 remain engaged with one another. Thus, with threaded portion 142 of extendable rod 140 extending through and threadingly engaged within bearing nut 150, application of the above-detailed axial pulling force on extendable rod 140, e.g., urging extendable rod 140 away from stationary rod 110, axially translates extendable rod 140 to extend extendable rod 140 from housing 114 of stationary rod 110 while bearing nut 150 is rotated in the first rotational direction. However, application of an axial pushing force on extendable rod 140, e.g., urging extendable rod 140 towards stationary rod 110, does not result in axial translation of extendable rod 140 because rotation of bearing nut 150 is inhibited by the interaction between one-way ratchet teeth 136, 156 of annular ratchet interfaces 134, 154, respectively. Accordingly, passive extension of extendable rod 140 is permitted while passive retraction of extendable rod 140 is inhibited.

[0051] With particular reference to FIGS. 4 and 5, bearing nut 150 also includes first and second annular channels 158a, 158b defined about the outer periphery thereof in longitudinally spaced relation relative to one another. First annular channel 158a is configured to align with a corresponding annular channel 159 defined on the inner periphery of head portion 118 of housing 114 of stationary rod 110 to capture the one or more bearings 160 therebetween. The one or more bearings 160 may include a plurality of ball bearings 162, for example, to facilitate smooth and reduced friction rotation of bearing nut 150 withinA0012380W001 (10259BS-502-PCT)and relative to head portion 118 of housing 114 of stationary rod 110. Receipt of ball bearings 162 within annular channels 158a and / or 159 may also maintain annular ratchet interfaces 134, 154 (see FIGS. 7A-7C) in engagement with one another while the relative diameters of ball bearings 162 and either or both of annular channels 158a, 159 are selected so as to enable axial movement of bearing nut 150 within and relative to housing 114, thereby allowing camming of one-way ratchet teeth 136, 156 relative to one another as well as disengagement of ratchet interfaces 134, 154 from one another, as detailed below. Additional or alternative bearing configurations are detailed below (see FIGS. 11-14). In other aspects, a bearing configuration is not provided; rather, substantially open space may be defined between the inner periphery of head portion 118 of housing 114 of stationary rod 110 and bearing nut 150.

[0052] Second annular channel 158b of bearing nut 150 is positioned to at least partially overlap with second access opening 119 of head portion 118 of housing 114 of stationary rod 110 when bearing nut 150 is disposed within head portion 118 of housing 114 of stationary rod 110, thus enabling access to second annular channel 158b of bearing nut 150 from the exterior of expandable spinal rod device 100.

[0053] Referring to FIGS. 7A-7C, in conjunction with FIGS. 2A-6, as detailed above, annular ratchet interfaces 134, 154 of bushing tube 130 and bearing nut 150, respectively, enable one-way ratcheted extension of extendable rod 140 from stationary rod 110. That is, from the initial position shown in FIG. 7A, and in response to an axial pulling force on extendable rod 140 in the axial direction “A,” bearing nut 150 is rotated in the rotational direction “R” such that the angled cam surfaces of one-way ratchet teeth 136, 156 of annular ratchet interfaces 134, 154, respectively, enable one-way ratchet teeth 136, 156 to incrementally cam over one another, as shown in FIG. 7B, before dropping into engagement with the next one-way ratchet teeth 136, 156, as shown in FIG. 7C, thereby incrementally advancing extendable rod 140 in the axial direction “A” progressively from FIG. 7 A to FIG.7C.

[0054] However, and as also detailed above, the abutment of the perpendicular stop surfaces of one-way ratchet teeth 136, 156 of ratchet interfaces 134, 154, respectively, inhibit rotation of bearing nut 150 in a rotational direction opposite the rotational direction “R” such that extendable rod 140 is locked out from retracting back into stationary rod 110 after each incremental extension of extendable rod 140 from stationary rod 110. Thus, passive extension in length of extendable spinal rod device 100 is enabled in response to lengthening of the patient’s spine “S” (FIG. 1), e.g., due to patient growth (natural orA0012380W001 (10259BS-502-PCT)assisted), without requiring surgical intervention, wherein the above-detailed axial pulling force is provided by the lengthening of the patient’s spine “S” (FIG. 1) during growth. More specifically, with momentary reference back to FIG. 1, with body 112 of stationary rod 110 fixed relative to one vertebrae “V” of the patient’s spine “S”, e.g., via a screw assembly 200, and with rod portion 144 of extendable rod 140 fixed relative to another vertebrae “V” of the patient’s spine “S”, e.g., via another screw assembly 200, patient growth whereby the distance between the vertebrae “V” is increased causes one or both screw assemblies 200 to apply an axial pulling force to extendable rod 140 and / or stationary rod 110 and, as detailed above, extendable spinal rod device 100 is configured to accommodate this growth by enabling passive extension in length of extendable rod 140 from stationary rod 110 without allowing subsequent retraction.

[0055] With reference to FIG. 8A, in addition to the above-detailed passive extension in length of extendable rod 140 from stationary rod 110, extendable spinal rod device 100 also enables active length adjustment by a surgeon in minimally invasive fashion. More specifically, in order to enable active length adjustment, an adjustment tool 800 having a shaft 810 and a gear driver 820 at the distal end of shaft 810 is inserted minimally invasively through the patient’s tissue to the implanted extendable spinal rod device 100, through first access opening 117 of housing 114 of stationary rod 110, through window 138 of bushing tube 130, and into longitudinal channel 148 of threaded portion 142 of extendable rod 140, whereby gear driver 820 engages gear rack 149 of longitudinal channel 148 of threaded portion 142 of extendable rod 140. With adjustment tool 800 engaged in this manner, adjustment tool 800 may be rotated (or otherwise actuated) to rotate gear driver 820 such that, by the engagement of gear driver 820 with gear rack 149, an axial pushing force is applied to extendable rod 140 to urge extendable rod 140 to extend farther from stationary rod 110, thereby lengthening extendable spinal rod device 100. Similarly as with the passive lengthening detailed above, bearing nut 150 is rotated in response to the translation of extendable rod 140 in the lengthening direction and, due to the one-way engagement of bearing nut 150 with bushing tube 130, rotation of bearing nut 150 in the opposite direction is inhibited and, thus, translation of extendable rod 140 in a retracting direction is likewise inhibited.

[0056] As an alternative or in addition to adjustment tool 800 engaging longitudinal channel 148 of threaded portion 142 to urge extendable rod 140 to extend farther from stationary rod 110, thereby lengthening extendable spinal rod device 100, a suitable tool (e.g., adjustment tool 800 or another tool (not shown)) may be utilized to operably engageA0012380W001 (10259BS-502-PCT)an exposed portion of bearing nut 150, e.g., extending from cap 120 or in place of cap 120, to drive rotation of bearing nut 150, thereby urging extendable rod 140 to extend farther from stationary rod 110 and lengthening extendable spinal rod device 100. In such configurations, the tool and bearing nut 150 may include complementary gear features, e.g., bevel gear features, or other suitable engagement features configured to enable the tool to drive rotation of bearing nut 150, as detailed below with reference to FIG. 8B.

[0057] Turning to FIG. 8B, in aspects, in addition or as an alternative to length adjustment via engagement of gear driver 820 of adjustment tool 800 with gear rack 149 of longitudinal channel 148 of threaded portion 142 of extendable rod 140 (see FIG. 8 A), bearing nut 150 may include a helical gear 830 defined annularly about an outer circumferential portion thereof. In such aspects, an access opening (not shown) defined through head portion 118 of housing 114 (see FIGS. 3-4) may be provided to expose a portion of helical gear 830. In such aspects, an adjustment tool 840 including a gear assembly 850 and a driver 860 may be provided to engage helical gear 830 to drive rotation of bearing nut 150 such that an axial pushing force is applied to extendable rod 140 to urge extendable rod 140 to extend farther from stationary rod 110, thereby lengthening extendable spinal rod device 100 (FIG. 8 A). Similarly as detailed above, bearing nut 150 is only rotatable in the rotatable direction corresponding to lengthening due to the one-way engagement of bearing nut 150 with bushing tube 130 (FIG. 8A); rotation of bearing nut 150 in the opposite direction is inhibited and, thus, retraction of extendable rod 140 is likewise inhibited.

[0058] Adjustment tool 840, as noted above, includes gear assembly 850 and driver 860. Gear assembly 850 includes an axle 852 supporting a helical gear 854 and a bevel gear 856 (separately or together as a compound gear) and configured for positioning in substantially parallel orientation relative to the longitudinal axis of bearing nut 150. Helical gear 854 is configured to extend through the access opening (not shown) defined through head portion 118 of housing 114 (see FIGS. 3-4) and into meshed engagement with helical gear 830 of bearing nut 150 such that rotation of helical gear 854 rotates helical gear 830.

[0059] Driver 860 includes a shaft 862 supporting a bevel gear 864 at a distal end portion thereof. Driver 860 is configured for positioning in substantially perpendicular orientation relative to the longitudinal axis of bearing nut 150 and with bevel gear 864 of driver 860 disposed in meshed engagement with bevel gear 856 of gear assembly 850. In this configuration, rotational driving of driver 860 about its longitudinal axis (substantially perpendicular to the longitudinal axis of bearing nut 150) drives rotation of bevel gear 856A0012380W001 (10259BS-502-PCT)and, thus, axle 852 and helical gear 854 substantially parallel to the longitudinal axis of bearing nut 150 to thereby rotate bearing nut 150 to lengthen extendable spinal rod device 100 (FIG. 8 A). In aspects, rather than perpendicular orientation, bevel gears 856, 864 may be configured to engage one another at any other suitable angle of approach, e.g., from about 45 degrees to about 135 degrees.

[0060] Referring to FIG. 9, in conjunction with FIGS. 3 and 6, as noted above, extendable spinal rod device 100 is configured to permit incremental lengthening, e.g., passively or actively, but is configured to one-way lock after each incremental lengthening to inhibit retraction or shortening of extendable spinal rod device 100. However, there may be instances where shortening of extendable spinal rod device 100 is desired. As such, extendable spinal rod device 100 enables disengagement of annular ratchet interfaces 134, 154 (FIGS. 7A-7C) of bushing tube 130 and bearing nut 150, respectively, to thereby allow for shortening of extendable spinal rod device 100. More specifically, a disengagement tool 900 having a shaft 910 and a wedge 920 at the distal end of shaft 910 is inserted minimally invasively to extendable spinal rod device 100 and through second access opening 119 of head portion 118 of housing 114 of stationary rod 110 such that wedge 920 is engaged at least partially within second annular channel 158b of bearing nut 150. Wedge 920 is then manipulated to urge bearing nut 150 away from bushing tube 130, disengaging annular ratchet interfaces 134, 154 of bushing tube 130 and bearing nut 150, respectively, from one another. With annular ratchet interfaces 134, 154 disengaged, an axial pushing force may be applied to extendable rod 140 to enable extendable rod 140 to retract back into housing 114 of stationary rod 110 while bearing nut 150 is rotated in the second, opposite rotational direction. Upon removal of disengagement tool 900, bearing nut 150 is returned towards bushing tube 130 to reengage ratchet interfaces 134, 154, thereby returning to the one-way ratcheting condition wherein extension of extendable rod 140 is permitted but retraction of extendable rod 140 is inhibited. As an alternative or in addition to disengagement tool 900 extending through second access opening 119 to engage bearing nut 150, bearing nut 150 may include an exposed portion, e.g., extending from cap 120 or in place of cap 120, configured to be engaged by a tool (e.g., tool 900 or another tool (not shown)) to enable disengagement of annular ratchet interfaces 134, 154 of bushing tube 130 and bearing nut 150, respectively, from one another. In aspects where bearing nut 150 includes gear features or other suitable engagement features to enable a tool to drive rotation of bearing nut 150 from the exterior of stationary rod 110, the same tool or a different tool may be utilized toA0012380W001 (10259BS-502-PCT)disengage annular ratchet interfaces 134, 154, e.g., to enable retraction of extendable rod 140.

[0061] Turning to FIGS. 10A and 10B, as noted above, bearing nut 150 may be biased towards or otherwise retained in close proximity with bushing tube 130 to maintain the engagement of annular ratchet interfaces 134, 154 of bushing tube 130 (see FIGS. 7A-7C) and bearing nut 150, respectively, with one another in the absence of a force, e.g., from disengagement tool 900 (FIG. 9), sufficient to overcome the bias. This bias may be provided, in aspects, by a spring 1000 which may be a wave spring (as shown) or other suitable spring disposed between bearing nut 150 and cap 120. Alternatively or additionally, a spring (not shown) may be disposed between bushing tube 130 and base portion 116 of housing 114 to thereby provided the bias from bushing tube 130 towards bearing nut 150 for similar purposes.

[0062] With reference to FIGS. 11-14, in aspects, as an alternative or in addition to the one or more bearings 160 including ball bearings 162 (see FIGS. 3 and 4), other suitable bearings may be provided. For example, as shown in FIG. 11, a pin 1110 mounted within housing 114 of stationary rod 110 (see FIG. 3) and extending transversely relative to bearing nut 150 may extend partially into first annular channel 158a to function as a bearing to facilitate smooth and reduced friction rotation of bearing nut 150 within housing 114 of stationary rod 110 (see FIG. 3).

[0063] As another example, FIGS. 12A and 12B illustrate a bearing 1200 including an outer ring 1210 formed by or engaged with to housing 114, an inner ring 1220 formed by or engaged with bearing nut 150, and a plurality of ball bearings (not shown; see ball bearings 162 (FIG. 3)) captured between inner and outer rings 1210, 1220. Bearing 1200 facilitates smooth and reduced friction rotation of bearing nut 150 within housing 114. As bearing 1200 retains the ball bearings between outer and inner rings 1210, 1220, respectively, the need for annular channels defined in bearing nut 150 and housing 114 is obviated and, thus, these annular channels can be omitted.

[0064] As shown in FIG. 13, an O-ring bearing 1300 may be provided for positioning within first annular channel 158a of bearing nut 150 to function as a bearing to facilitate smooth and reduced friction rotation of bearing nut 150 within housing 114 of stationary rod 110 (see FIG. 3). O-ring bearing 1300 may be formed from a relatively hard material to inhibit compression or flexion of O-ring bearing 1300 in use. Further, in aspects where O-ring bearing 1300 is used, the annular channel defined within housing 114 may be omitted (or, alternatively, may be provided).A0012380W001 (10259BS-502-PCT)

[0065] FIG. 14 illustrates another bearing in the form of a self-lubricating material 1400 overmolded or otherwise disposed on bearing nut 150 and protruding therefrom (e.g., protruding from the outer surface thereof or protruding from an annular channel defined within the outer surface) to facilitate smooth and reduced friction rotation of bearing nut 150 within housing 114 of stationary rod 110 (see FIG. 3).

[0066] Referring to FIGS. 15-17, other extendable spinal rod devices 1500, 1600, 1700 provided in accordance with the present disclosure are shown. To the extent consistent, extendable spinal rod devices 1500, 1600, 1700 may include any of the features detailed above with respect to extendable spinal rod device 100 (FIGS. 2 A and 2B) and, thus, only differences therebetween are described in detail hereinbelow for purposes of brevity.

[0067] With particular reference to FIG. 15, extendable spinal rod device 1500 is similar to extendable spinal rod device 100 (FIGS. 2 A and 2B) except that, rather than the stationary rod including a fixed body extending from one end thereof and an extendable rod operably coupled at the other end thereof to enable extension of the extendable rod relative to the housing of the stationary rod as with extendable spinal rod device 100 (FIGS. 2 A and 2B), extendable spinal rod device 1500 includes a central stationary housing 1514 having first and second extendable rods 1540a, 1540b operably coupled to opposing ends of central stationary housing 1514 to enable independent extension of each extendable rod 1540a, 1540b relative to central stationary housing 1514. As such, the above-detailed operable components to enable one-way ratcheting extension of each extendable rod 1540a, 1540b, e.g., the features of central stationary housing 1514, the cap 1520, the bushing tube (not shown, see bushing tube 130 (FIG. 3)), the bearing nut (not shown, see bearing nut 150 (FIG. 3)), and the one or more bearings (not shown, see bearing 160 (FIG. 3)), are provided at each end of central stationary housing 1514 to enable bi-directional extension of extendable rods 1540a, 1540b from central stationary housing 1514.

[0068] Referring to FIG. 16, extendable spinal rod device 1600 is similar to extendable spinal rod device 1500 (FIG. 15) except that, rather than extendable rods operably coupled to and extending from opposing ends of a single central stationary housing as with extendable spinal rod device 1500 (FIG. 15), extendable spinal rod device 1600 includes first and second stationary housings 1614a, 1614b oriented in opposite directions with each having an extendable rod 1640a, 1640b operably coupled thereto to enable independent extension of each extendable rod 1640a, 1640b relative to the corresponding stationary housing 1614a, 1614b, with each stationary housing 1614a, 1614b including the abovedetailed internal operable components to enable bi-directional extension of extendable rodsA0012380W001 (10259BS-502-PCT)1640a, 1640b. Stationary housings 1614a, 1614b may be welded to one another or engaged to one another in any other suitable manner, including permanent engagements as well as releasable engagements.

[0069] With reference to FIG. 17, extendable spinal rod device 1700 is similar to extendable spinal rod device 100 (FIGS. 2 A and 2B) except that, rather than the stationary rod including a fixed rod body extending coaxially from the housing of the stationary rod, stationary rod 1710 includes a fixed rod body 1712 coupled to housing 1714 of stationary rod 1710 in offset, parallel relation via a connector 1790. Connector 1790 may be configured to releasably engage fixed rod body 1712 to housing 1714 and / or may be permanently or removably engaged with housing 1714.

[0070] Turning to FIGS. 18-20, another extendable spinal rod device 1800 provided in accordance with the present disclosure and configured for use with system 10 (FIG. 1) or any other suitable system for treating disorders of the spine is shown. Extendable spinal rod device 1800 is similar to and may include any or all of the features of any of the extendable rod devices detailed above, e.g., extendable spinal rod device 100 (FIGS. 2A-6), except that at least a portion of extendable spinal rod device 1800 defines one or more curvatures along its length. Accordingly, only differences between extendable spinal rod device 1800 and the extendable rod devices detailed above are described in detail hereinbelow while similarities are summarily described or omitted entirely for purposes of brevity.

[0071] Extendable spinal rod device 1800 includes a stationary rod 1810, a cap (not shown, similar to cap 120 (FIGS. 2A-2B)), a bushing tube 1830, an extendable rod 1840, a bearing nut 1850, and one or more bearings (not shown, similar to bearings 160 (FIG. 3)). Stationary rod 1810 of extendable spinal rod device 1800 includes a body 1812 and a housing 1814. At least a portion of housing 1814 and, in aspects, at least a portion of body 1812, defines a curved configuration wherein at least a section along the length thereof is curved to define a curvature in one or more directions.

[0072] Housing 1814 of stationary rod 1810 defines a substantially hollow interior configured to receive bushing tube 1830, at least a portion of extendable rod 1840, bearing nut 1850, and the one or more bearings. Housing 1814 includes a base portion 1816 and a head portion 1818, wherein head portion 1818 defines a diameter and length sufficient to enable axial translation and off-axis tilting, e.g., angulation, of bearing nut 1850 within and relative to housing 1814.

[0073] Bushing tube 1830 of extendable spinal rod device 1800 may define a shortened configuration relative to bushing tube 130 of extendable spinal rod device 100 (see FIG. 3)A0012380W001 (10259BS-502-PCT)such that bushing tube 1830 may extend along a linear axis despite the curvature of housing 1814 of stationary rod 1810, although other configurations are also contemplated. Bushing tube 1830 defines an annular ratchet interface 1834.

[0074] Extendable rod 1840 includes a threaded portion 1842 and a rod portion 1844. At least a section of threaded portion 1814 along its length and, in aspects, at least a section of rod portion 1844 along its length, defines a curvature in one or more directions. Extendable rod 1840 is generally cylindrical in configuration except that threaded portion 1842 includes one or more flats 1843 extending longitudinally along at least a portion of the length of threaded portion 1842. The one or more flats 1843 of threaded portion 1842 of extendable rod 1840 provide sufficient play between threaded portion 1842 of extendable rod 1840 and bearing nut 1850 when threaded portion 1842 of extendable rod 1840 is threadingly engaged within bearing nut 1850 to accommodate the curvature of threaded portion 1842 of extendable rod 1840 through bearing nut 1850 and facilitate off-axis tilting of bearing nut 1850 relative to head portion 1818 of housing 1814 of stationary rod 1810. Thus, the threaded engagement of threaded portion 1842 of extendable rod 1840 within bearing nut 1850 is maintained despite threaded portion 1842 of extendable rod 1840 defining a curvature relative to bearing nut 1850 and / or tilting of bearing nut 1850. In aspects, bearing nut 1850 defines along a substantially linear longitudinal axis.

[0075] With continued reference to FIGS. 18-20, bearing nut 1850, as noted above, is configured for positioning within head portion 1818 of housing 1814 of stationary rod 1810 in end-to-end relation relative to bushing tube 1830. Bearing nut 1850 includes an annular ratchet interface 1854 complementary to annular ratchet interface 1834 of bushing tube 1830 such that, when annular ratchet interfaces 1834, 1854 are engaged with one another, rotation of bearing nut 1850 is permitted in a first rotational direction and inhibited in a second, opposite rotational direction. Thus, with threaded portion 1842 of extendable rod 1840 extending through and threadingly engaged within bearing nut 1850, application of a force urging extendable rod 1840 away from stationary rod 1810 axially translates extendable rod 1840 to extend extendable rod 1840 from stationary rod 1810 while bearing nut 1850 is rotated in the first rotational direction. However, application of a force urging extendable rod 1840 towards stationary rod 1810 does not result in axial translation of extendable rod 1840 because rotation of bearing nut 1850 is inhibited by the interaction between annular ratchet interfaces 1834, 1854, respectively.

[0076] Further, where a linear section of threaded portion 1842 of extendable rod 1840 passes through bearing nut 1850, bearing nut 1850 remains in substantially fixed angularA0012380W001 (10259BS-502-PCT)position within head portion 1818 of housing 1814 of stationary rod 1810 such that annular ratchet interfaces 1834, 1854 remain engaged with one another. However, as extendable rod 1840 extends from stationary rod 1810 and a curved section of extendable rod 1840 passes through bearing nut 1850, bearing nut 1850 is tilted off-axis relative to head portion 1818 of housing 1814 of stationary rod 1810 to thereby disengage or permit disengagement of annular ratchet interfaces 1834, 1854, thus allowing extension of extendable rod 1840 from stationary rod 1810. On the other hand, if extendable rod 1840 is urged to retract into stationary rod 1810 with a curved section of extendable rod 1840 passing through bearing nut 1850, bearing nut 1850 is returned from the titled position into axial alignment relative to head portion 1818 of housing 1814 of stationary rod 1810 to thereby engage annular ratchet interfaces 1834, 1854 and inhibit the retraction of extendable rod 1840 into stationary rod 1810.

[0077] The non-thread lock threadforms of threaded portion 1842 of extendable rod 1840 and bearing nut 1850, together with the annular ratchet interfaces 1834, 1854 and tilting of bearing nut 1850, enable the above-detailed one-way translation of extendable rod 1840 relative to stationary rod 1810 in curved extendable spinal rod device 1800. In order to enable retraction of extendable rod 1840 into stationary rod 1810, a disengagement tool may be utilized, similarly as detailed above with respect to extendable spinal rod device 100 (FIGS. 2A-6).

[0078] Aspects of this disclosure may be further described by reference to the following numbered paragraphs:

[0079] Example 1. An extendable spinal rod device, comprising: a housing; a bearing nut rotatably disposed within the housing, the bearing nut having internal threading; an extendable rod extending from the housing, the extendable rod including a threaded portion having external threading, wherein the bearing nut is disposed about the threaded portion of the extendable rod with the internal and external threadings engaged with one another such that the bearing nut is rotated within the housing in response to axial movement of the extendable rod relative to the housing; a first one-way ratchet interface associated with the housing; and a second one-way ratchet interface associated with the bearing nut, wherein the first and second one-way ratchet interfaces are configured to engage one another to permit rotation of the bearing nut in a first rotational direction corresponding to axial extension of the extendable rod from the housing and to inhibit rotation of the bearing nut in a second rotational direction corresponding to axial retraction of the extendable rod intoA0012380W001 (10259BS-502-PCT)the housing such that axial extension of the extendable rod from the housing is permitted while axial retraction of the extendable rod into the housing is inhibited.

[0080] Example 2. The extendable spinal rod device according to example 1, wherein the internal and external threadings define non-thread lock threadforms configured to inhibit self-locking and thereby enable axial extension of the extendable rod from the housing in response to application of an axial force urging the extendable rod from the housing.

[0081] Example 3. The extendable spinal rod device according to any preceding numbered example, further comprising at least one bearing disposed between the housing and the bearing nut to facilitate rotation of the bearing nut relative to the housing.

[0082] Example 4. The extendable spinal rod device according to any preceding numbered example, wherein: the first one-way ratchet interface is disposed on an end of a bushing tube disposed within the housing, and the second one-way ratchet interface is disposed on an end of the bearing nut.

[0083] Example 5. The extendable spinal rod device according to example 4, wherein at least one of the bushing tube or the bearing nut is biased towards the other of the bushing tube or the bearing nut to maintain engagement between the first and second one-way ratchet interfaces.

[0084] Example 6. The extendable spinal rod device according to any preceding numbered example, wherein each of the housing and the threaded portion of the extendable rod includes a curved section extending along at least a portion of a length thereof.

[0085] Example 7. The extendable spinal rod device according to any preceding numbered example, further comprising a first access opening defined through a side wall of the housing to expose a portion of the extendable rod, wherein a tool is configured for insertion through the first access opening and into engagement with the portion of the extendable rod to enable manual axial extension of the extendable rod.

[0086] Example 8. The extendable spinal rod device according to example 7, wherein the portion of the extendable rod includes a gear rack and wherein the tool includes a gear driver configured to engage the gear rack and drive axial extension of the extendable rod in response to rotation of the gear driver.

[0087] Example 9. The extendable spinal rod device according to any preceding numbered example, wherein at least one of the first or second one-way ratchet interfaces is axially movable relative to the other from an engaged position, permitting axial extension of the extendable rod while inhibiting axial retraction of the extendable rod, to a disengaged position, permitting both axial extension and axial retraction of the extendable rod.A0012380W001 (10259BS-502-PCT)

[0088] Example 10. The extendable spinal rod device according to any preceding numbered example, further comprising a second access opening defined through a side wall of the housing to expose a portion of the bearing nut, wherein a tool is configured for insertion through the second access opening and into engagement with the bearing nut to move the second one-way ratchet interface from the engaged position to the disengaged position.

[0089] Example 11. The extendable spinal rod device according to any preceding numbered example, further comprising a fixed rod body extending from the housing opposite the extendable rod.

[0090] Example 12. The extendable spinal rod device according to example 11, wherein the fixed rod body extends coaxially from the housing or in offset, parallel relation relative to the housing

[0091] Example 13. The extendable spinal rod device according to any one of examples 1-10, further comprising: a second bearing nut rotatably disposed within an opposite end of the housing or within a second housing oriented in an opposite direction relative to the housing; a second extendable rod extending from the opposite end of the housing or from the second housing in the opposite direction, the second extendable rod including a threaded portion having external threading, wherein the second bearing nut is disposed about the threaded portion of the second extendable rod with the internal and external threading engaged with one another such that the second bearing nut is rotated within the housing or the second housing in response to axial movement of the second extendable rod relative to the housing or the second housing; another first one-way ratchet interface associated with the housing or the second housing; and another second one-way ratchet interface associated with the second bearing nut, wherein the another first and second one-way ratchet interfaces are configured to engage one another to permit rotation of the second bearing nut in the second rotational direction corresponding to axial extension of the second extendable rod from the housing or the second housing and to inhibit rotation of the second bearing nut in the first rotational direction corresponding to axial retraction of the second extendable rod into the housing or the second housing such that axial extension of the second extendable rod from the housing or the second housing is permitted while axial retraction of the second extendable rod into the housing or the second housing is inhibited.

[0092] Example 14. An extendable spinal rod system, comprising: a first screw assembly configured to anchor in a first vertebrae of a patient’s spine; a second screw assembly configured to anchor in a second vertebrae of a patient’s spine; and an extendableA0012380W001 (10259BS-502-PCT)spinal rod device, including: a housing fixed relative to the first screw assembly; a bearing nut rotatably disposed within the housing, the bearing nut having internal threading; an extendable rod fixed relative to the second screw assembly and extending from the housing, the extendable rod including a threaded portion having external threading, wherein the bearing nut is disposed about the threaded portion of the extendable rod with the internal and external threadings engaged with one another such that the bearing nut is rotated within the housing in response to axial movement of the extendable rod relative to the housing; a first one-way ratchet interface associated with the housing; and a second one-way ratchet interface associated with the bearing nut, wherein the first and second one-way ratchet interfaces are configured to engage one another to permit rotation of the bearing nut in a first rotational direction corresponding to axial extension of the extendable rod from the housing and to inhibit rotation of the bearing nut in a second rotational direction corresponding to axial retraction of the extendable rod into the housing such that axial extension of the extendable rod from the housing is permitted while axial retraction of the extendable rod into the housing is inhibited.

[0093] Example 15. The extendable spinal rod system according to example 14, wherein the internal and external threadings define non-thread lock threadforms configured to inhibit self-locking and thereby enable axial extension of the extendable rod from the housing in response to application of an axial force urging the extendable rod from the housing.

[0094] Example 16. The extendable spinal rod system according to example 15, wherein growth of the patient provides the axial force urging the extendable rod from the housing.

[0095] Example 17. The extendable spinal rod system according to any one of examples 14-16, further comprising at least one bearing disposed between the housing and the bearing nut to facilitate rotation of the bearing nut relative to the housing.

[0096] Example 18. The extendable spinal rod system according to any one of examples 14-17, wherein: the first one-way ratchet interface is disposed on an end of a bushing tube disposed within the housing, and the second one-way ratchet interface is disposed on an end of the bearing nut.

[0097] Example 19. The extendable spinal rod system according to any one of examples 14-18, further comprising a first access opening defined through a side wall of the housing to expose a portion of the extendable rod, wherein a tool is configured for insertion throughA0012380W001 (10259BS-502-PCT)the first access opening and into engagement with the portion of the extendable rod to enable manual axial extension of the extendable rod.

[0098] Example 20. The extendable spinal rod system according to any one of examples 14-19, wherein at least one of the first or second one-way ratchet interfaces is axially movable relative to the other from an engaged position, permitting axial extension of the extendable rod while inhibiting axial retraction of the extendable rod, to a disengaged position, permitting both axial extension and axial retraction of the extendable rod.

[0099] Example 21. The extendable spinal rod system according to any one of examples 14-20, wherein each of the housing and the threaded portion of the extendable rod includes a curved section extending along at least a portion of a length thereof.

[0100] While several aspects of the disclosure have been detailed above and are shown in the drawings, it is not intended that the disclosure be limited thereto, as it is intended that the disclosure be as broad in scope as the art will allow and that the specification be read likewise. Therefore, the above description and accompanying drawings should not be construed as limiting, but merely as exemplifications of particular aspects. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto.

Claims

A0012380W001 (10259BS-502-PCT)WHAT IS CLAIMED IS:

1. An extendable spinal rod device, comprising:a housing (114);a bearing nut (150) rotatably disposed within the housing (114), the bearing nut (150) having internal threading (152);an extendable rod (140) extending from the housing (114), the extendable rod (140) including a threaded portion (142) having external threading (146), wherein the bearing nut (150) is disposed about the threaded portion (142) of the extendable rod (140) with the internal and external threadings (152, 156) engaged with one another such that the bearing nut (150) is rotated within the housing (114) in response to axial movement of the extendable rod (140) relative to the housing (114);a first one-way ratchet interface (134) associated with the housing (114); and a second one-way ratchet interface (154) associated with the bearing nut (150), wherein the first and second one-way ratchet interfaces (134, 154) are configured to engage one another to permit rotation of the bearing nut (150) in a first rotational direction corresponding to axial extension of the extendable rod (140) from the housing (114) and to inhibit rotation of the bearing nut (150) in a second rotational direction corresponding to axial retraction of the extendable rod (140) into the housing (114) such that axial extension of the extendable rod (140) from the housing is permitted while axial retraction of the extendable rod (140) into the housing (114) is inhibited.

2. The extendable spinal rod device according to claim 1, wherein the internal and external threadings (152, 156) define high helix threadforms configured to inhibit self-locking and thereby enable axial extension of the extendable rod (140) from the housing (114) in response to application of an axial force urging the extendable rod (140) from the housing (H4).

3. The extendable spinal rod device according to claim 1 or 2, further comprising at least one bearing (160, 1110, 1200, 1300, 1400) disposed between the housing (114) and the bearing nut (150) to facilitate rotation of the bearing nut (150) relative to the housing (114).A0012380W001 (10259BS-502-PCT)4. The extendable spinal rod device according to any preceding claim, wherein:the first one-way ratchet interface (134) is disposed on an end (132) of a bushing tube (130) disposed within the housing (114), andthe second one-way ratchet interface (154) is disposed on an end (155) of the bearing nut (150).

5. The extendable spinal rod device according to claim 4, wherein at least one of the bushing tube (130) or the bearing nut (150) is biased towards the other of the bushing tube (130) or the bearing nut (150) to maintain engagement between the first and second one-way ratchet interfaces (134, 154).

6. The extendable spinal rod device according to any preceding claim, wherein each of the housing (1814) and the threaded portion (1842) of the extendable rod (1840) includes a curved section along at least a portion of a length thereof.

7. The extendable spinal rod device according to any preceding claim, further comprising a first access opening (117) defined through a side wall of the housing (114) to expose a portion of the extendable rod (140), wherein a tool (800) is configured for insertion through the first access opening (117) and into engagement with the portion of the extendable rod (140) to enable manual axial extension of the extendable rod (140).

8. The extendable spinal rod device according to claim 7, wherein the portion of the extendable rod (140) includes a gear rack (149) and wherein the tool (800) includes a gear driver (820) configured to engage the gear rack (149) and drive axial extension of the extendable rod (140) in response to rotation of the gear driver (820).

9. The extendable spinal rod device according to any preceding claim, wherein at least one of the first or second one-way ratchet interfaces (134, 154) is axially movable relative to the other from an engaged position, permitting axial extension of the extendable rod (140) while inhibiting axial retraction of the extendable rod (140), to a disengaged position, permitting both axial extension and axial retraction of the extendable rod (140).

10. The extendable spinal rod device according to any preceding claim, further comprising a second access opening (119) defined through a side wall of the housing (114) to expose a portion of the bearing nut (150), wherein a tool (900) is configured for insertion through theA0012380W001 (10259BS-502-PCT)second access opening (119) and into engagement with the bearing nut (150) to move the second one-way ratchet interface from the engaged position to the disengaged position.

11. The extendable spinal rod device according to any preceding claim, further comprising a fixed rod body (112, 1712) extending from the housing (114, 1714) opposite the extendable rod (140).

12. The extendable spinal rod device according to claim 11, wherein the fixed rod body (112, 1712) extends coaxially from the housing (114) or in offset, parallel relation relative to the housing (114, 1714).

13. The extendable spinal rod device according to any one of claims 1-10, further comprising:a second bearing nut rotatably disposed within an opposite end of the housing (1514) or within a second housing (1614b) oriented in an opposite direction relative to the housing (1514, 1614a);a second extendable rod (1540b, 1640b) extending from the opposite end of the housing (1514) or from the second housing (1614b) in the opposite direction, the second extendable rod (1540b, 1640b) including a threaded portion having external threading, wherein the second bearing nut is disposed about the threaded portion of the second extendable rod (1540b, 1640b) with the internal and external threadings engaged with one another such that the second bearing nut is rotated within the housing (1514) or the second housing (1614b) in response to axial movement of the second extendable rod (1540b, 1640b) relative to the housing (1514) or the second housing (1614b);another first one-way ratchet interface associated with the housing (1514) or the second housing (1614b); andanother second one-way ratchet interface associated with the second bearing nut, wherein the another first and second one-way ratchet interfaces are configured to engage one another to permit rotation of the second bearing nut in the second rotational direction corresponding to axial extension of the second extendable rod (1540b, 1640b) from the housing (1514) or the second housing (1614b) and to inhibit rotation of the second bearing nut in the first rotational direction corresponding to axial retraction of the second extendable rod (1540b, 1640b) into the housing (1514) or the second housing (1614b) such that axial extension of the second extendable rod (1540b, 1640b) from the housing (1514)A0012380W001 (10259BS-502-PCT)or the second housing (1614b) is permitted while axial retraction of the second extendable rod (1540b, 1640b) into the housing (154) or the second housing (1614b) is inhibited.

14. An extendable spinal rod system, comprising:a first screw assembly (200) configured to anchor in a first vertebrae (“V”) of a patient’s spine (“S”);a second screw assembly (200) configured to anchor in a second vertebrae (“V”) of a patient’s spine (“S”); andwherein the housing (114) is fixed relative to the first screw assembly (200) and the extendable rod (140) is fixed relative to the second screw assembly (200).

15. The extendable spinal rod system according to claim 14, wherein the internal and external threadings (152, 146) define high helix threadforms configured to inhibit selflocking and thereby enable axial extension of the extendable rod (140) from the housing (114) in response to application of an axial force urging the extendable rod (140) from the housing (114), and wherein growth of the patient provides the axial force urging the extendable rod (140) from the housing (114).

Images