Bolts for bone fixation

Abstract

The objective is to provide an improved device for vertebral fixation that offers means to reduce screw pull-out and screw breakage, and that can resist flexion extension forces, lateral curvature, and / or rotational torque forces. [Solution] This invention relates to a bolt for fixing bones. The bolt has been found to be useful as a bolt for fixing bones such as the vertebrae of the spine, and it can be used in any suitable bone.

Description

Technical Field

[0001] Field of the Invention This invention relates to bolts for bone fixation. The bolts have been found to be useful as bolts for bone fixation, such as for vertebrae of the spine, but can be used in any suitable bone.

Background Art

[0002] Background of the Invention Each vertebra of the spine includes a vertebral body facing forward and a vertebral arch facing backward, which together define a closed foramen that surrounds the vertebral foramen through which the spinal cord passes. The vertebral arch includes two pedicles, two laminae, and seven processes. The pedicles connect the vertebral body and the vertebral arch.

[0003] Pedicle screw fixation is commonly used in spinal instrumentation surgery to correct spinal alignment, stabilize the vertebrae, and connect rods to the vertebrae to achieve arthrodesis. In fact, transpedicle screw fixation is the gold standard for vertebral fixation, and as a result, pedicle screw fixation is common for fixing fixation devices in thoracolumbar spinal surgery to treat various conditions, including degenerative, congenital, tumor, and trauma applications.

[0004] In pedicle screw fixation, the pedicle screw is positioned from the posterior surface of the vertebra. After surgical exposure, anatomical landmarks are identified. The posterior cortical crest of the bone is removed, for example, with bone forceps or a bur, to expose the underlying cancellous bone. The entry point is preferably prepared with a drill. A curved, blunt probe is used to create a passage into the pedicle. The probe must follow the least resistant path without damaging the pedicle wall. If resistance is felt, the entry point and trajectory must be re-evaluated. At any stage, the correct position can be confirmed, for example, by fluoroscopy. Other instruments, such as pedicle fillers or drilling tools (e.g., PediGuard® by SpineGuard), may also be used to assist with positioning and / or trajectory. To enhance bone purchase, a bone tap may be used to prepare the pedicle canal.

[0005] The pedicle screw head has a large U-shaped component for engaging with the posterior vertebral rod. This pedicle screw head may be uniaxial, multiaxial, or uniplane in order to facilitate connection with the posterior metal rod and to promote secure connection with the posterior metal rod. The pedicle screw is inserted to obtain fixation at the pedicle of the subcortical (cancellous) bone and, to a lesser extent, at the cancellous vertebral body.

[0006] The pedicle screw relies largely on a short segment of fixation between the pedicle and the subcortical (cancellous) bone located medially. Great care must be taken to avoid rupturing the cortical wall of the pedicle to prevent entry into the spinal canal and damage to the spinal cord and / or nerve roots. If the cortical bone is ruptured, fixation with the subsequent pedicle screw becomes extremely weak. Fixation can also be difficult in revision surgery and in patients with osteoporosis or pathological bone. Loss of screw fixation (pulling out) or screw breakage typically results from minute movements in the flexion-extension plane, sometimes accompanied by small additional rotational stress.

[0007] To be effective, the pedicle screw must be able to withstand the physiological forces from the load during surgery and from daily activities after surgery. The pedicle screw needs to resist flexion and extension forces, and to a lesser extent, lateral curvature and rotational torque forces. The cross-section of the pedicle is an elongated ellipse, with the vertical dimension being longer than the medial-lateral dimension, but the pedicle screw, by its nature, has a circular cross-section and therefore cannot maximize the anatomical resources of the bone for fixation. [Overview of the project] [Problems that the invention aims to solve]

[0008] The object of the present invention is to provide an improved device for vertebral fixation that provides means for reducing screw pull-out and screw breakage, and that can resist flexural extension forces, lateral curvature and / or rotational torque forces. [Means for solving the problem]

[0009] Summary of the Invention According to a first aspect of the present invention, a bolt for fixing bone is provided, the bolt comprising a body, the outer surface of which at least a portion of the outer surface of the body includes at least one threaded portion.

[0010] According to a second aspect of the present invention, a bolt for fixing bone is provided, the bolt comprising a body having an expandable section.

[0011] According to a third aspect of the present invention, a bolt for fixing bone is provided, the bolt comprising a body having an expandable section and an outer surface having an outer surface in which at least a portion of the outer surface of the body includes at least one threaded portion.

[0012] Optionally, the expandable section is adjacent to the outer surface of the main body.

[0013] Optionally, the expandable sections and the outer surface of the main body are seamlessly connected.

[0014] Optionally, the expandable section and the outer surface of the main body share a common boundary.

[0015] The expandable sections and the outer surface of the main body are integral, either optionally or additionally.

[0016] Optionally, at least a portion of the expandable section includes at least one threaded portion. Furthermore, optionally, at least a portion of the outer surface of the expandable section includes at least one threaded portion.

[0017] Alternatively, at least a portion of the expandable section does not include threads. Further alternative, at least a portion of the outer surface of the expandable section does not include threads. Further alternative, at least a portion of the expandable section is threadless. Further alternative, at least a portion of the outer surface of the expandable section is threadless.

[0018] Preferably, the expandable section is free of threads. More preferably, the outer surface of the expandable section is free of threads.

[0019] The main body optionally has a base end and a tip end.

[0020] Optionally, the expandable section is either adjacent to or located at the tip.

[0021] Optionally or additionally, the outer surface of the main body is adjacent to or located at the base end.

[0022] The term "lead" refers to the distance along the axis, optionally the longitudinal axis, of at least one threaded portion when it rotates, optionally 360°.

[0023] The term "pitch" refers to the distance along the axis, optionally the longitudinal axis, of at least one threaded portion from the first point of a thread to a corresponding point of an adjacent thread.

[0024] Optionally, the lead of the thread portion is greater than the pitch of at least one thread portion.

[0025] Optionally, the lead of the thread portion is at least twice, optionally at least three times, optionally at least four times greater than the pitch of at least one thread portion.

[0026] Preferably, the lead of the thread portion is at least twice greater than the pitch of at least one thread portion.

[0027] Optionally, at least one thread portion includes a thread having at least one lead.

[0028] Optionally, at least one thread portion includes a single-lead thread.

[0029] Optionally, at least one thread portion includes at least two, optionally at least three, optionally at least four threads having leads.

[0030] Optionally, at least one thread portion includes a two-lead, optionally three-lead, optionally four-lead thread.

[0031] Preferably, at least one thread portion includes a thread having two leads.

[0032] Preferably, at least one thread portion includes a two-lead thread.

[0033] Optionally, at least one thread portion includes a thread having at least one start.

[0034] Optionally, at least one thread portion includes a single-start thread.

[0035] Optionally, at least one threaded portion includes threads having at least two, optionally at least three, or optionally at least four starts.

[0036] Optionally, at least one threaded portion includes two, optionally three, or optionally four starting threads.

[0037] Preferably, at least one threaded portion includes a thread having two starts.

[0038] Preferably, at least one threaded portion includes a double start thread.

[0039] Optionally, at least one threaded portion includes at least one thread.

[0040] Optionally, at least one threaded portion includes at least two, optionally at least three, or optionally at least four threads.

[0041] Optionally, at least one threaded portion includes at least one helical thread.

[0042] Optionally, at least one threaded portion includes at least two, optionally at least three, or optionally at least four helical threads.

[0043] Preferably, at least one threaded portion includes two threads.

[0044] Preferably, at least one threaded portion includes two helical threads.

[0045] Optionally, the expandable section has an end and is movable between a contracted position and an expanded position.

[0046] Optionally, the bolt may further include expansion means.

[0047] A fourth aspect of the present invention provides a bolt for fixing bone, the bolt comprising (a) a body having an expandable section and an outer surface having an outer surface having at least a portion of the outer surface of the body having at least one threaded portion, and (b) an expansion means.

[0048] Optionally, the expansion means is operablely associated with the expandable section to displace the expandable section between a contracted position and an expanded position by applying force to each of at least one end of the expandable section so that each of at least one end of the expandable section advances toward each of the opposing ends.

[0049] Optionally, the expansion means is operablely associated with the expandable section to displace the expandable section between a contracted position and an expanded position by applying force to each end of the expandable section so that each end of the expandable section advances toward the opposing end.

[0050] Optionally, the expansion means displaces the expandable section between a contracted position and an expanded position by simultaneously applying force to each end of the expandable section so that each end of the expandable section moves toward the opposing end.

[0051] Optionally, the expansion means is operablely related to the expandable section to displace the expandable section between a contracted position and an expanded position by applying force to each end of the expandable section so that each end of the expandable section can advance independently toward the opposing end.

[0052] Furthermore, optionally, the expansion means is operablely related to the expandable section to displace the expandable section between a contracted position and an expanded position by simultaneously applying force to each end of the expandable section so that each end of the expandable section can advance independently toward the opposing end.

[0053] Optionally, the expandable section is reversibly expandable. More optionally, the expandable section is reversibly expandable under mechanical pressure.

[0054] Optionally, the expandable section is optionally foldable along its longitudinal axis. Furthermore, optionally, the expandable section is optionally foldable radially inward along its longitudinal axis.

[0055] Optionally, the expandable section includes at least two expandable members extending from the longitudinal axis of the bolt under mechanical pressure. More optionally, the expandable members extend radially from the longitudinal axis of the bolt under mechanical pressure.

[0056] Optionally, each expandable member includes a deformable arm.

[0057] Optionally, at least one folding point is provided along each deformable arm.

[0058] Optionally, the folding point or each point may include a weak point, a hinge mechanism, or any mechanism that facilitates the folding of the deformable arm in a desired position.

[0059] Optionally, the extension means includes a connecting means and at least one body that can be attached to the connecting means.

[0060] Optionally, the connecting means includes a shaft. Preferably, the connecting means includes a shaft.

[0061] Optionally, the connecting means includes a shaft adapted to allow bidirectional movement of at least one mountable body relative to the connecting means.

[0062] Optionally, at least one mountable body can be screwed onto the connecting means. Further optionally, a first mountable body can be screwed onto the connecting means and positioned for displacement in response to the rotation of the connecting means to apply mechanical pressure to each of at least one end of the expandable section. The connecting means can be positioned to apply mechanical pressure simultaneously and independently to each of at least one end of the expandable section. At least one mountable body can be displaced in response to the rotation of the connecting means relative to the at least one mountable body.

[0063] Optionally, the connecting means includes at least one screw. Preferably, the connecting means includes a screw.

[0064] Optionally, at least one mountable body is attachable to at least one screw of the connecting means. Preferably, at least one mountable body is attachable to a screw of the connecting means.

[0065] Optionally, at least one mountable body is engageable with at least one of the ends of each of the expandable sections. Furthermore, optionally, at least one mountable body is irreversibly engageable with at least one of the ends of each of the expandable sections.

[0066] Optionally, at least one mountable body defines a portion of the expandable section. Further optionally, at least one mountable body includes a screw located within the portion of the expandable section.

[0067] Optionally, at least one mountable body includes a screw located on at least a portion of the inner surface of the expandable section.

[0068] Preferably, at least one mountable body includes a screw located on at least a portion of the inner surface of the expandable section.

[0069] Optionally, screws located on at least a portion of the inner surface of the expandable section can be attached to at least one screw of the connecting means. Preferably, screws located on at least a portion of the inner surface of the expandable section can be attached to a screw of the connecting means.

[0070] Optionally or additionally, at least one mountable body is immovably mounted to the connecting means. Further optionally, a second mountable body is immovably mounted to the connecting means to apply mechanical pressure to each of at least one end of the expandable section. The connecting means may be arranged to apply mechanical pressure simultaneously and independently to each of at least one end of the expandable section.

[0071] Optionally, at least one mountable body is engageable with at least one of the ends of each of the expandable sections. Furthermore, optionally, at least one mountable body is reversibly engageable with at least one of the ends of each of the expandable sections.

[0072] Optionally, at least one mountable body defines part of the connection means. Further optionally, at least one mountable body includes a fastener located as part of the connection means.

[0073] Optionally, the expansion means includes a connecting means and at least two mountable bodies. Further optionally, the expansion means includes a connecting means and two mountable bodies. Further optionally, the expansion means includes a connecting means and first and second mountable bodies.

[0074] Optionally, the first mountable body may be screwed onto the connecting means. Further optionally, the first mountable body may be screwed onto the connecting means and positioned for displacement in response to the rotation of the connecting means to apply mechanical pressure to each of at least one end of the expandable section. The first mountable body may be displaced in response to the rotation of the connecting means relative to the first mountable body.

[0075] Optionally, the first mountable body is attachable to at least one screw of the connecting means. Preferably, the first mountable body is attachable to a screw of the connecting means.

[0076] Optionally, the first mountable body is engageable with at least one of the ends of the expandable section. Further optionally, the first mountable body is irreversibly engageable with at least one of the ends of the expandable section.

[0077] Optionally, the first mountable body defines a portion of the expandable section. Further optionally, the first mountable body includes a screw located within the portion of the expandable section.

[0078] Optionally, the first mountable body includes a screw located on at least a portion of the inner surface of the expandable section.

[0079] Preferably, the first mountable body includes a screw located on at least a portion of the inner surface of the expandable section.

[0080] Optionally, screws located on at least a portion of the inner surface of the expandable section can be attached to at least one screw of the connecting means. Preferably, screws located on at least a portion of the inner surface of the expandable section can be attached to a screw of the connecting means.

[0081] Optionally or additionally, a second attachable body is immovably mounted to the connecting means. Further optionally, a second attachable body is immovably mounted to the connecting means to apply mechanical pressure to each of at least one end of the expandable section. The connecting means may be arranged to apply mechanical pressure simultaneously and independently to each of at least one end of the expandable section.

[0082] Optionally, the second mountable body is engageable with at least one of the ends of the expandable section. Further optionally, the second mountable body is reversibly engageable with at least one of the ends of the expandable section.

[0083] Optionally, the second mountable body defines part of the connection means. Further optionally, the second mountable body includes a fastener located as part of the connection means.

[0084] Optionally, the bolt further includes at least one joint.

[0085] A fifth aspect of the present invention provides a bolt for fixing bone, the bolt comprising (a) a body having an expandable section and an outer surface having an outer surface in which at least a portion of the outer surface of the body includes at least one threaded portion, (b) an expansion means, and (c) at least one joint.

[0086] Preferably, the bolts include joints.

[0087] Optionally, at least one fitting can be attached to the bolt.

[0088] Optionally, at least one fitting can be reversibly attached to the bolt.

[0089] Optionally, at least one fitting can be fixed to the bolt in a fixed position.

[0090] Preferably, at least one fitting is reversibly attachable to the bolt.

[0091] Optionally, at least one fitting can be attached to the bolt by a pressure fit.

[0092] Optionally, at least one fitting can be reversibly attached to the bolt by a pressure fit.

[0093] Preferably, at least one fitting is reversibly attachable to a bolt by a press-fit.

[0094] Optionally, the bolt includes means for attaching at least one fitting to the bolt.

[0095] A sixth aspect of the present invention provides a bolt for fixing bone, the bolt comprising: (a) a body having an expandable section and an outer surface having an outer surface in which at least a portion of the outer surface of the body includes at least one threaded portion; (b) an expansion means; (c) at least one joint; and (d) an attachment means.

[0096] Optionally, the bolt includes means for reversibly attaching at least one fitting to the bolt.

[0097] Optionally, the bolt includes means for immobilizing at least one fitting to the bolt.

[0098] Preferably, the bolt includes means for reversibly attaching at least one fitting to the bolt.

[0099] Optionally, the bolt includes means for attaching at least one fitting to the bolt by a press-fit.

[0100] Optionally, the bolt includes means for reversibly attaching at least one fitting to the bolt by a press-fit.

[0101] Preferably, the bolt includes means for reversibly attaching at least one fitting to the bolt by a press-fit.

[0102] Optionally, the main body includes at least one joint.

[0103] Optionally, the threaded portion includes at least one joint.

[0104] The main body optionally includes mounting means.

[0105] Optionally, the threaded portion includes mounting means.

[0106] Optionally, the main body includes at least one joint and mounting means.

[0107] Optionally, the threaded portion includes at least one fitting and mounting means.

[0108] Optionally, the base end of the main body includes at least one joint.

[0109] Optionally, the base end of the threaded portion includes at least one joint.

[0110] Optionally, the base end of the main body includes mounting means.

[0111] Optionally, the base end of the threaded portion includes a mounting means.

[0112] Preferably, the base end of the threaded portion includes mounting means.

[0113] Optionally, the base end of the main body includes at least one joint and mounting means.

[0114] Optionally, the base end of the threaded portion includes at least one joint and mounting means.

[0115] Optionally, the mounting means may include a joint.

[0116] Optionally, the mounting means may include a movable joint.

[0117] Optionally, the mounting means may include a pivotable joint.

[0118] Optionally, the mounting means may include a ball joint.

[0119] Optionally, the mounting means may include a ball socket joint.

[0120] Preferably, the mounting means includes a ball socket joint.

[0121] Optionally, the base end of the body includes a socket, and at least one fitting includes a ball.

[0122] Optionally, the base end of the threaded portion includes a socket, and at least one fitting includes a ball.

[0123] Optionally, the base end of the body includes a ball, and at least one fitting includes a socket.

[0124] Optionally, the base end of the threaded portion includes a ball, and at least one fitting includes a socket.

[0125] Preferably, the base end of the body includes a ball, and at least one fitting includes a socket.

[0126] Preferably, the base end of the threaded portion includes a ball, and at least one fitting includes a socket.

[0127] Optionally, the bolt further includes a connecting means.

[0128] A seventh aspect of the present invention provides a bolt for fixing bone, the bolt comprising (a) a body having an expandable section and an outer surface having an outer surface in which at least a portion of the outer surface of the body includes at least one threaded portion, (b) an expansion means, (c) at least one joint, (d) an attachment means, and (e) a coupling means.

[0129] According to an eighth aspect of the present invention, a system for fixing bone is provided, the system comprising (a) a body having an expandable section and an outer surface having an outer surface in which at least a portion of the outer surface of the body includes at least one threaded portion, (b) an expansion means, (c) at least one joint, (d) an attachment means, and (e) a connecting means, including at least one bolt.

[0130] Optionally, the system includes (i) at least one bolt comprising (a) a body having an expandable section and an outer surface having an outer surface in which at least a portion of the outer surface of the body includes at least one threaded portion, (b) an expansion means, (c) at least one joint, and (d) a mounting means, and (ii) a coupling means.

[0131] Optionally, the system includes at least two bolts, optionally at least three bolts, or optionally at least four bolts.

[0132] At least one coupling can be optionally attached to the coupling means.

[0133] At least one coupling can be reversibly attached to the coupling means, at an optional rate.

[0134] Preferably, at least one joint is reversibly attachable to the coupling means.

[0135] Optionally, at least one joint can be attached to the coupling means in a way that prevents movement.

[0136] Optionally, at least one joint is arranged to receive a coupling means.

[0137] Optionally, at least one joint is arranged to reversibly receive the coupling means.

[0138] Optionally, at least one joint includes at least one groove.

[0139] Optionally, it includes at least one groove in which at least one fitting is arranged to receive a coupling means.

[0140] Optionally, at least one joint includes at least one groove positioned to reversibly receive a coupling means.

[0141] Optionally, at least one joint includes at least one arm.

[0142] Optionally, at least one joint includes at least two arms.

[0143] Preferably, at least one joint includes two arms.

[0144] Optionally, at least one joint includes at least two arms, the two arms defining a groove between them.

[0145] Preferably, at least one joint comprises two arms, the two arms defining a groove between them.

[0146] Optionally, at least one coupling includes at least two arms defining a groove between them that is reversibly positioned to receive a coupling means.

[0147] Preferably, at least one coupling comprises two arms, the two arms defining a groove between them that is reversibly positioned to receive a coupling means.

[0148] Optionally, the coupling means may include a rod.

[0149] Optionally, the coupling means may include a linear rod.

[0150] Optionally, the coupling means may include a nonlinear rod.

[0151] Optionally, the coupling means may include a curved rod.

[0152] Optionally, the coupling means may include a cylindrical rod.

[0153] Optionally, the coupling means may include a straight cylindrical rod.

[0154] Optionally, the coupling means may include a non-linear cylindrical rod.

[0155] Optionally, the coupling means may include a curved cylindrical rod.

[0156] Optionally, the coupling means may include a cylindrical rod.

[0157] Optionally, the coupling means may include a linear cylindrical rod.

[0158] Optionally, the coupling means may include a non-linear cylindrical rod.

[0159] Optionally, the coupling means may include a curved cylindrical rod.

[0160] Optionally, the coupling means may include a rod having a non-circular cross-section.

[0161] Optionally, the coupling means includes a linear rod having a non-circular cross-section.

[0162] Optionally, the coupling means includes a nonlinear rod having a non-circular cross-section.

[0163] Optionally, the coupling means may include a curved rod having a non-circular cross-section.

[0164] Optionally, the coupling means includes a rod having a circular cross-section.

[0165] Optionally, the coupling means includes a rod having a linear circular cross-section.

[0166] Optionally, the coupling means includes a rod having a nonlinear circular cross-section.

[0167] Optionally, the coupling means includes a rod having a curved circular cross-section.

[0168] Optionally, at least one joint includes at least one arm, each having an end.

[0169] Optionally, at least one joint includes at least two arms, each arm having its own end.

[0170] Preferably, at least one joint includes two arms, each arm having its own end.

[0171] Optionally, at least one joint includes means for securing the coupling means.

[0172] A ninth aspect of the present invention provides a bolt for fixing bone, the bolt comprising: (a) a body having an expandable section and an outer surface having an outer surface in which at least a portion of the outer surface of the body includes at least one threaded portion; (b) an expansion means; (c) at least one joint; (d) an attachment means; (e) a coupling means; and (f) a fixing means.

[0173] A tenth aspect of the present invention provides a system for fixing bone, the system comprising at least one bolt, the bolt comprising: (a) a body having an expandable section and an outer surface having an outer surface in which at least a portion of the outer surface of the body includes at least one threaded portion; (b) an expansion means; (c) at least one joint; (d) an attachment means; (e) a coupling means; and (f) a fixing means.

[0174] Optionally, the system includes (i) at least one bolt comprising (a) a body having an expandable section and an outer surface having an outer surface in which at least a portion of the outer surface of the body includes at least one threaded portion, (b) an expansion means, (c) at least one joint, and (d) a mounting means, (ii) a coupling means, and (iii) a fastening means.

[0175] Optionally, the fastening means can be attached to at least one joint.

[0176] Optionally, the fastening means can be reversibly attached to at least one joint.

[0177] Optionally, the fixing means can be immovably attached to at least one joint.

[0178] Preferably, the fastening means is reversibly attachable to at least one joint.

[0179] Optionally, the fixing means can be attached to at least one arm having each end.

[0180] Optionally, the fixing means can be reversibly attached to at least one arm having each end.

[0181] Optionally, the fixing means can be immovably attached to at least one arm having each end.

[0182] The fixing means can optionally be attached to at least two arms, each arm having its own end.

[0183] Optionally, the fixing means can be reversibly attached to at least two arms, each having its own end.

[0184] Optionally, the fixing means can be immovably attached to at least two arms, each arm having its own end.

[0185] Preferably, the fixing means is reversibly attachable to at least two arms, each having its own end.

[0186] Optionally, the fastening means may include a set screw.

[0187] Optionally, the fastening means includes a set screw having at least one threaded portion.

[0188] Optionally, each arm includes at least one threaded portion.

[0189] Optionally, each end of each arm includes at least one threaded portion.

[0190] Optionally, each arm includes at least one threaded portion corresponding to at least one threaded portion of a set screw.

[0191] Optionally, each end of each arm includes at least one threaded portion corresponding to at least one threaded portion of a set screw.

[0192] Optionally, the fixing means may include means for rotating a set screw.

[0193] Optionally, the set screw includes means for rotating the set screw.

[0194] Optionally, the fixing means may include means for rotating a set screw.

[0195] Optionally, the rotating means includes a socket.

[0196] Optionally, the rotating means may include a non-circular socket.

[0197] Optionally, the rotating means may include a hexagonal socket.

[0198] Preferably, the rotating means includes a hexagonal socket.

[0199] Optionally, the body has a base portion having a base diameter and a tip portion having a tip diameter, where the base diameter is larger than the tip diameter.

[0200] Optionally, the base diameter is the larger diameter at the base of the main body.

[0201] Optionally, the tip diameter is the largest diameter at the tip of the main body.

[0202] Optionally, the base diameter is the larger diameter of the base end of at least one threaded portion.

[0203] Optionally, the tip diameter is the larger diameter of at least one threaded tip.

[0204] Optionally, the base diameter is the larger diameter of the thread at the base of at least one threaded portion.

[0205] Optionally, the tip diameter is the larger diameter of the thread at the tip of at least one threaded portion.

[0206] Optionally, the base diameter is the smallest diameter at the base of the main body.

[0207] Optionally, the tip diameter is the smallest diameter of the tip of the main body.

[0208] Optionally, the base diameter is the smallest diameter at the base of at least one threaded portion.

[0209] Optionally, the tip diameter is the smaller diameter of the tip of at least one threaded portion.

[0210] Optionally, the base diameter is the smallest diameter of the thread at the base of at least one threaded portion.

[0211] Optionally, the tip diameter is the smallest diameter of the threads at the tip of at least one threaded portion.

[0212] Optionally, the proximal diameter is at least 1.1 times larger than the tip diameter.

[0213] Optionally, the proximal diameter is at least 1.2, optionally at least 1.3, optionally at least 1.4, optionally at least 1.5, optionally at least 1.6, optionally at least 1.7, optionally at least 1.8, optionally at least 1.9, and optionally at least 2.0 times larger than the tip diameter.

[0214] Preferably, the proximal diameter is at least 1.2 times larger than the tip diameter.

[0215] The tip diameter can be optionally up to 6.5 mm.

[0216] Optionally, the tip diameter can be up to 6.5, up to 6.0, up to 5.5, up to 5.0, up to 4.5, up to 4.0, up to 3.5, up to 3.0, up to 2.5, up to 2.0, up to 1.5, up to 1.0, or up to 0.5 mm.

[0217] Preferably, the tip diameter is a maximum of 6.5 mm.

[0218] Optionally, the proximal diameter is at least 1.0 mm.

[0219] Optionally, the proximal diameter is at least 1.5, optionally at least 2.5, optionally at least 3.0, optionally at least 3.5, optionally at least 4.0, optionally at least 4.5, optionally at least 5.0, optionally at least 5.5, optionally at least 6.0, and optionally at least 6.5 mm.

[0220] Preferably, the base diameter is at least 6.5 mm.

[0221] Optionally, the base and tip of the main body form a nonlinear gradient between them.

[0222] Optionally, the base and tip of the threaded portion form a nonlinear gradient between them.

[0223] Optionally, the base and tip of the main body form a linear gradient between them.

[0224] Optionally, the base and tip of the threaded portion form a linear gradient between them.

[0225] Preferably, the base end and tip end of the main body form a linear gradient between them.

[0226] Preferably, the base end and tip end of the threaded portion form a linear gradient between them.

[0227] Optionally, at least one thread in the screw portion is a parallel thread.

[0228] Optionally, at least one thread in the screw portion is a tapered thread.

[0229] Optionally, the bolt further includes at least one washer.

[0230] Optionally, the bolt includes at least two washers.

[0231] Optionally, the bolt includes two washers.

[0232] Optionally, the bolt includes first and second washers.

[0233] Optionally, at least one washer is substantially annular in shape. Furthermore, optionally, at least one washer is substantially annular in shape and defines a washer hole.

[0234] Optionally, at least one washer is sized and sized to receive a connecting means. Furthermore, optionally, at least one washer is sized and sized to receive a connecting means through it. And further optionally, at least one washer is sized and sized to receive a connecting means through a washer hole.

[0235] Optionally, at least one washer can be attached to the connecting means. Furthermore, optionally, at least one washer can be reversibly attached to the connecting means.

[0236] Optionally, the first washer has a substantially annular shape. Furthermore, optionally, the first washer has a substantially annular shape and defines a washer hole.

[0237] The first washer is optionally sized and sized to receive the connecting means. Furthermore, optionally sized and sized to receive the connecting means through it.

[0238] Furthermore, optionally, the size and dimensions of the first washer are determined so as to receive the connecting means through the washer hole. Furthermore, optionally, the size and dimensions of the first washer are determined so as to receive the tip of the connecting means through the washer hole.

[0239] The first washer can be optionally attached to the connecting means. Furthermore, the first washer can be reversibly attached to the connecting means. Furthermore, the first washer can be reversibly attached to the tip of the connecting means.

[0240] Optionally, the first washer is sized and sized to be supported by or at the base end of the main body. Optionally, the first washer is sized and sized to be supported by or at the base end or threaded portion of the main body.

[0241] Optionally, the second washer is substantially annular in shape. Furthermore, optionally, the second washer is substantially annular in shape and defines a washer hole.

[0242] Optionally, the second washer comprises at least two parts. Further optionally, the second washer comprises at least two seamlessly continuous parts. Further optionally, the second washer comprises at least two optionally seamlessly continuous parts, both substantially annular in shape and defining a washer hole. Further optionally, the second washer comprises at least two optionally seamlessly continuous parts, both substantially annular in shape.

[0243] Optionally, the second washer is sized and sized to receive the connecting means. Further optionally, the second washer is sized and sized to receive the connecting means through it. Further optionally, the second washer is sized and sized to receive the connecting means through the washer hole. Further optionally, the first washer is sized and sized to receive the base end of the connecting means through the washer hole.

[0244] Optionally, the second washer can be attached to the connecting means. Further optionally, the second washer can be reversibly attached to the connecting means. Further optionally, the second washer can be reversibly attached to the base end of the connecting means. Further optionally, the second washer can be reversibly attached adjacent to a mountable body including a fastener located on the outer surface of the connecting means. Further optionally, the second washer can be attached between the mountable body including a fastener located on the outer surface of the connecting means and the connecting means.

[0245] Preferably, the bolts are formed from a material suitable for sterilization so that they are provided in sterile packaging for use.

[0246] Preferably, the material is sterilizable by autoclaving.

[0247] Preferably, the material is surgical stainless steel, but it can be found that any material that is suitable for sterilization and can provide the required mechanical strength may be used.

[0248] Optionally, the material is an alloy. Further optionally, the material is titanium. And yet again, optionally, the material is a titanium alloy.

[0249] Any portion of the bolt may be coated or partially coated with a coating that may be hydrophilic and / or lubricating.

[0250] Optionally, the coating is a polymer coating.

[0251] Optionally, the coating is a polymer coating comprising at least two monomers, each monomer comprising a substituted or unsubstituted para-benzenediy ring (-C6H4-) and a 1,2-methanediyl crosslink (-CH2-CH2-). Further optionally, the coating is a polymer coating comprising multiple monomers, each monomer comprising a substituted or unsubstituted para-benzenediy ring (-C6H4-) and a 1,2-methanediyl crosslink (-CH2-CH2-).

[0252] Optionally, the coating comprises parylene. Further optionally, the coating comprises unsubstituted parylene or substituted parylene. Further optionally, the coating comprises chloride (optionally at least one, optionally at least two chlorine substitutions) parylene, fluorinated (optionally at least one, optionally at least two, optionally at least three, optionally at least four fluorine substitutions) parylene, alkyl-substituted (optionally at least one, optionally at least two methyl-, optionally ethyl-substituted) parylene, amine (optionally at least one amine-, optionally methylene-substituted) parylene, ethynyl (optionally at least one ethynyl-substituted) parylene, and combinations and copolymers thereof.

[0253] Furthermore, optionally, the coating may include parylene selected from parylene A, AM, AM-2, AF-4, C, D, E, F, M, N, VT-4, X, and their respective combinations and copolymers.

[0254] For the purposes of this disclosure, the user is the person responsible for operating the bolt during normal use. Typically, this is a medical professional, and normal use includes fixing a patient's bones. When in use, the bolt is oriented to have a proximal end and a tip end relative to the user.

[0255] A patient is defined as someone who will have bolts inserted during a routine surgery.

[0256] Brief explanation of the drawing Embodiments of the present invention are described herein by reference to the accompanying drawings. [Brief explanation of the drawing]

[0257] [Figure 1] This is a perspective view of a bolt with its expandable section in the retracted position. [Figure 2]This is a perspective view of a bolt with an expandable section in the expanded position. [Figure 3] This is a perspective view of the bolt connection mechanism. [Figure 4] This is a perspective view of the bolt body. [Figure 5] This is a disassembled perspective view of the bolt connection mechanism and the main body. [Figure 6] This is a perspective view of the bolt connection means and the main body. [Figure 7] This is a perspective view of a bolted joint. [Figure 8] This is an exploded perspective view of a bolt with a joint. [Figure 9] This is a perspective view of the bolt fastening mechanism. [Figure 10] This is a system perspective view. [Figure 11] This is an exploded perspective view of the bolt connection means and body having at least one washer. [Modes for carrying out the invention]

[0258] Detailed description of the present invention The present invention relates to a bolt (10) for fixing bones.

[0259] In one embodiment, the bolt includes a body (12) having an outer surface, the outer surface of which at least a portion of the outer surface includes at least one threaded portion (14).

[0260] In one embodiment, a bolt comprising a body having an expandable section (16).

[0261] In a preferred embodiment, the bolt (10) includes an expandable section (16) and a body (12) having an outer surface, the outer surface of which at least a portion of the outer surface of the body includes at least one threaded portion (14). The expandable section (16) is movable between a retracted position and an extended position. The retracted position is shown in Figure 1, and the extended position is shown in Figure 2.

[0262] Generally, the expandable section (16) is adjacent to the outer surface of the body (12). The outer surfaces of the expandable section (16) and the body (12) can be continuous without a break and / or share a boundary line, and in a preferred embodiment, the outer surfaces of the expandable section (16) and the body (12) can be formed as a single unit, and may be a single unit but separate but adjacent pieces. In use, the body (12) has a base end (18) and a tip end (20), and generally, the expandable section (16) is adjacent to or at the tip end (20), and the outer surface of the body (12) including the threaded portion (14) is adjacent to or at the base end (18).

[0263] In some embodiments, the lead of the threaded portion (14) is greater than the pitch of the threaded portion (14). The lead of the threaded portion can be more than twice and up to four times greater than the pitch of the threaded portion (14), but in a preferred embodiment, the lead of the threaded portion (14) is more than twice the pitch of the threaded portion (14). The threaded portion (14) may include a thread (or single-lead thread) having at least one lead or a thread (including double, triple, or quadruple-lead threads) having up to four or more leads, and in a preferred embodiment, the threaded portion (14) may include a thread (also known as a double-lead thread) having two leads. The threaded portion (14) may include a thread (or single-start thread) having at least one start or a thread (including double, triple, or quadruple-start threads) having up to four or more starts, and in a preferred embodiment, the threaded portion (14) may include a thread (also known as a double-start thread) having two starts. The threaded portion (14) generally includes helical threads, and in some embodiments it may include up to four or more helical threads, but in a preferred embodiment the threaded portion (14) includes two helical threads.

[0264] At least a portion of the expandable section (16) may include a threaded portion which may be the same as or different from the threaded portion (14) on the outer surface of the body (12). In such embodiments, the outer surface of the expandable section (16) includes at least one threaded portion. However, in preferred embodiments, the expandable section (16) or its outer surface does not include a threaded portion. In such embodiments, the expandable section (16) or its outer surface excludes the threaded portion. Thus, a preferred embodiment of the bolt (10) includes a body (12) having an expandable section (16) which excludes the outer surface including the threaded portion and the threaded portion (14).

[0265] The bolt (10) further includes an expansion means (22) operably associated with the expandable section (16) to displace the expandable section (16) between a retracted position and an extended position by applying force to one or both of the respective ends of the expandable section (16) so that one or both of the respective ends of the expandable section (16) advance toward the respective opposing ends. The expansion means (22) can displace the expandable section (16) between a retracted position and an extended position by simultaneously applying force to each of the respective ends of the expandable section (16), so that each of the respective ends of the expandable section (16) advances toward the respective opposing ends.

[0266] In this manner, the expandable section (16) may, in some embodiments, be reversibly expandable under mechanical pressure, such as from a mechanical pressure expansion means (22) or from an external force on the surrounding fixed bone. In such embodiments, the expandable section (16) may be foldable, for example, along the longitudinal axis, and the expandable section (16) may fold radially inward to a contracted position along the longitudinal direction.

[0267] The expandable section (16) includes at least two expandable members (24) extending from the longitudinal axis of the bolt (10) under mechanical pressure. During use, the expandable members (24) can extend radially from the longitudinal axis of the bolt (10) under mechanical pressure, for example, mechanical pressure applied by an expansion means (22). Each of the expandable members generally includes a deformable arm. At least one folding point (26) may be provided along each deformable arm. The folding point may be a weak point, a hinge mechanism, or any mechanism that facilitates the folding of the deformable arm in a desired position.

[0268] The expansion means (22) generally includes a connecting means (28) and at least one mountable body (30). The connecting means (28) is a shaft, which is not required but preferably includes a shaft adapted to allow bidirectional movement of the connecting means (28), for example, the mountable body (30) relative to the shaft. The mountable body (30) can be screwed onto the connecting means (28) and can be arranged to apply mechanical pressure simultaneously and independently to one or both of the respective ends of the expandable section (16). In such embodiments, the mountable body (30) can be displaced in response to the rotation of the connecting means (28). For example, the connecting means (28) may include a screw so that the mountable body (30) can be attached to the screw of the connecting means (28). In some embodiments, the mountable body (30) may be engageable with each end of the expandable section (16) and may even be irreversibly engageable with each end of the expandable section (16). In a preferred embodiment, the mountable body (30) defines a portion of the expandable section (16), for example, the mountable body (30) may include screws located on a portion of the expandable section (16), such as screws located on at least a portion of the inner surface of the expandable section (16). The screws located on the inner surface of the expandable section (16) are mountable to screws of the connecting means (28).

[0269] Optionally or additionally, attachable bodies may be immovably attached to the connecting means (28). For example, a second attachable body (32) may be immovably attached to the connecting means (28) to apply mechanical pressure to each end of the expandable section (16). The connecting means (28) may be arranged to apply mechanical pressure to each end of the expandable section (16) simultaneously and independently. This attachable body (32) is engageable with each end of the expandable section (16) and is generally reversibly engageable with each end of the expandable section (16). In a preferred embodiment, this attachable body (32) defines a portion of the connecting means (28), for example, the attachable body (32) includes a fastener located on the outer surface of the connecting means (28).

[0270] In such a preferred embodiment, the expansion means (22) includes a connecting means and two mountable bodies (30, 32) - a first mountable body (30) and a second mountable body (32). The first mountable body (30) can be screwed onto the connecting means (28) such that the first mountable body (30) can be displaced relative to the first mountable body (30) in response to rotation of the connecting means (28). In such an embodiment, the first mountable body (30) is mountable to at least one screw of the connecting means (28). In this embodiment, the first mountable body (30) defines a portion of the expandable section (16) by including a screw located on the inner surface of the expandable section (16). The second mountable body (32) may define a portion of the connecting means (28) by including a fastener that is immovably mounted to the connecting means (28) and located on a portion of the connecting means (28).

[0271] In a preferred embodiment, the bolt (10) further includes a joint (34) which may be attachable to the bolt (10) and may be immovably attached to the bolt (10), but preferably is reversibly attachable to the bolt (10). The joint (34) may be attachable to the bolt, for example, by interference fit, thereby making the joint (34) reversibly attachable to the bolt (10).

[0272] The bolt (10) may include means (36) for attaching the joint (34) to the bolt (10). The bolt (10) may include means (36) for reversibly attaching the joint (34) to the bolt (10) or for immovably attaching the joint (34) to the bolt (10). In a preferred embodiment, the bolt (10) includes means (36) for reversibly attaching the joint (34) to the bolt (10), for example by a pressure fit. In an embodiment, the body (12) includes the joint (34), and in an embodiment, the threaded portion (14) includes the joint (34). Similarly, in an embodiment, the body (12) 20 includes mounting means (36), and in an embodiment, the threaded portion (14) includes mounting means (36). In this manner, the base end (18) of the body (12) of the threaded portion (14) includes the joint (34). Similarly, the base end (18) of the main body (12) of the threaded portion (14) includes a mounting means (36).

[0273] The mounting means (36) may include a joint that may be, for example, a movable joint, for example, a pivotable joint. In such embodiments, the mounting means (36) includes a ball joint, and preferably the mounting means (36) includes a ball socket joint. The base end (18) of the body (12) or threaded portion (14) may include a socket, and the coupling (34) may include a ball, but in a preferred embodiment, the base end (18) includes a socket (38) and the coupling (34) includes a ball (36). In such embodiments, the body (12) and optionally the base end (18) of the threaded portion (14) include a ball (36), and the coupling (34) includes a socket (38).

[0274] A bolt (10) may include a coupling means (40). In this manner, a system is provided comprising a coupling means (4), at least one bolt (10), each bolt (10) having a body (12) having an expandable section (16) and an outer surface, the outer surface of which at least a portion of the outer surface includes at least one threaded portion (14), an expansion means (26), a joint (34), and a mounting means (36). The system may include any number of bolts (10), including at least two, three, four, or five or more bolts (10).

[0275] The coupling means (40) may include a rod that is linear or nonlinear, such as a curved rod. The coupling means (40) may include a cylindrical (e.g., cylindrical) rod that is straight or nonlinear or curved. In some embodiments, the coupling means (40) includes a rod having a non-circular cross-section, which may be a linear or nonlinear rod having a non-circular cross-section. However, in some embodiments, the coupling means (40) includes a rod having a circular cross-section, such as a linear or nonlinear (e.g., curved) rod having a circular cross-section.

[0276] The joint (34) is attachable to the coupling means (40) and may be attachable to the coupling means (40) reversibly or immovably, but preferably reversibly attachable to the coupling means (40). In this way, the joint (34) is positioned to receive or reversibly receive the coupling means (40). For example, the joint (34) may include a groove (42) which can be positioned to receive or reversibly receive the coupling means (40). In a preferred embodiment, the joint (34) includes two arms (44). The arms (44) can define a groove (42) between them, i.e., the groove (44) can be defined between the arms (44). In this way, the two arms (44) defining the groove (42) are positioned to receive or reversibly receive the coupling means (40) between them and within the groove (42).

[0277] The joint (34) includes means for securing the coupling means (40). The fixing means (46) is attachable to the joint (34) and may be attachable to the joint (34) reversibly or immovably, but preferably reversibly. In a preferred embodiment, the fixing means (46) is attachable to one or both arms (44), each having its own end. The fixing means (46) may include a set screw having a threaded portion (48).

[0278] Correspondingly, each arm (44) preferably includes a threaded portion (50) at each end of each arm (44). The threaded portion (50) of the arm (44) corresponds to the threaded portion (48) of the set screw (46). The fixing means (46), for example, the set screw, may include means (52) for rotating the fixing means (46) (e.g., a female thread). The rotating means (52) may be a socket that is not circular, for example, a hexagonal socket.

[0279] In one embodiment, the body (12) has a base end (18) having a base diameter and a tip end (20) having a tip diameter, wherein the base diameter is larger than the tip diameter. The base diameter may be the larger diameter of the base end (18) of the body (12) or the threaded portion (14). The tip diameter may be the larger diameter of the tip end (20) of the body (12) or the threaded portion (14). Alternatively, the base diameter may be the smaller diameter of the base end (18) of the body (12) or the threaded portion (14). The tip diameter may be the smaller diameter of the tip end (20) of the body (12) or the threaded portion (14). The base diameter may be at least 1.1 times, for example, at least 1.2, at least 1.3, at least 1.4, at least 1.5, at least 1.6, at least 1.7, at least 1.8, at least 1.9, or at least 2.0 times larger than the tip diameter. In the embodiment, the tip diameter is up to 6.5 mm, for example, up to 6.5, up to 6.0, up to 5.5, up to 5.0, up to 4.5, up to 4.0, up to 3.5, up to 3.0, up to 2.5, up to 2.0, up to 1.5, up to 1.0, and up to 0.5 mm. The base diameter may be at least 1.0 mm, for example, at least 1.5, at least 2.5, at least 3.0, at least 3.5, at least 4.0, at least 4.5, at least 5.0, at least 5.5, at least 6.0, and at least 6.5 mm.

[0280] The base end (18) and tip end (20) of the main body (12) or threaded portion (14) may form a nonlinear or linear gradient between them, but preferably the base end (18) and tip end (20) of the main body (12) or threaded portion (14) include a linear gradient between them.

[0281] The threads of the threaded portion (14) may be parallel threads or tapered threads.

[0282] In any of the embodiments described, the bolt (10) may further include at least one washer (54, 56). In some embodiments, the bolt includes a first washer (54) and a second washer (56). Each washer (54, 56) is substantially annular in shape and defines a washer hole. Each washer (54, 56) is sized and sized to receive the connecting means (28) so that the connecting means (28) can pass through there, i.e., through the washer hole. Each washer (54, 56) is attachable to the connecting means (28), and optionally reversibly attachable.

[0283] The first washer (54) may be substantially annular in shape and is sized and sized to receive the tip of the connecting means (28) through the washer hole. In this way, the first washer (54) is reversibly attachable to the connecting means (28), preferably by the tip of the connecting means (28). The first washer (54) may also be sized and sized to be received by or at the base end (18) of the body (12) or the threaded portion (14). Thus, during use, the first washer (54) can be positioned by or at the base end (18) of the body (12) or the threaded portion (14) and can receive the tip of the connecting means (28) through the washer hole.

[0284] The second washer (56) may be substantially annular in shape and may define a washer hole. In a preferred embodiment, the second washer (56) may be two parts, which may be two seamlessly continuous parts, and which together are substantially annular in shape, i.e., two parts that together form an annular band defining a washer hole. The second washer (56) is attachable to the base end of the connecting means (28), and optionally reversibly attachable. Preferably, the second washer (56) is reversibly attachable adjacent to an attachable body (32) including a fastener located on the outer surface of the connecting means (28). The second washer (56) may be reversibly attachable between the attachable body (32) including the fastener and the connecting means (36).

[0285] Each washer may be coated or partially coated with a coating that may be hydrophilic and / or lubricating to reduce friction impedance or increase lubrication between any moving parts of the bolt.

Claims

1. A bolt for fixing bones, (a) The main body, (i) an expandable section having each end and being movable between a contracted position and an expanded position, (ii) an outer surface wherein at least a portion of the outer surface of the main body includes at least one threaded portion A main body having, (b) an expansion means operably associated with the expandable section so as to displace the expandable section between the retracted position and the extended position A bolt containing a bolt.

2. The bolt according to claim 1, wherein the extension means includes a connecting means and at least one body attachable to the connecting means, and the connecting means includes a shaft adapted to allow bidirectional movement of the at least one attachable body relative to the connecting means.

3. The bolt according to claim 2, wherein a first attachable body is screwed onto the connecting means, and a second attachable body is fixed to the connecting means so as not to move.

4. The bolt according to claim 3, wherein the first mountable body includes a screw located on at least a portion of the inner surface of the expandable section and attachable to the screw of the connecting means, and the second mountable body includes a fastener located on a portion of the connecting means.

5. The bolt according to any one of claims 1 to 4, wherein the expandable section is reversibly expandable.

6. A bolt according to any one of claims 1 to 5, further comprising at least one fitting that can be attached to the bolt.

7. The bolt according to claim 6, wherein the bolt includes a ball socket joint for attaching the at least one fitting to the bolt, the body including the ball, and the at least one fitting including the socket.

8. The bolt according to claim 6 or 7, wherein the bolt further includes a coupling means, the at least one joint is attachable to the coupling means, and optionally the coupling means includes a linear rod or a nonlinear (curved) rod.

9. The bolt according to claim 8, wherein at least one joint includes at least one groove disposed to receive the coupling means.

10. The bolt according to claim 9, wherein the at least one joint includes at least two arms, each arm having its own end and defining the groove between them.

11. The bolt according to claim 10, wherein the at least one joint includes means for fixing the coupling means, the fixing means is attachable to the at least two arms, each arm having its respective end.

12. The bolt according to claim 12, wherein the fixing means includes a set screw having at least one threaded portion, and each end of each arm includes at least one threaded portion corresponding to the at least one threaded portion of the set screw.

13. The bolt according to any one of claims 2 to 12, further comprising at least one washer which is substantially annular in shape, is attachable to the connecting means, and is sized and dimensioned to be received by or thereat the base end of the body or the threaded portion.

14. The bolt according to any one of claims 1 to 13, wherein at least a portion of the bolt is coated or at least partially coated with a hydrophilic and / or lubricating coating.

15. A system for fixing bone, the system comprising at least one bolt, the system comprising: (a) a body, (i) an expandable section having respective ends and being operable between a contracted position and an expanded position, (ii) an outer surface having at least a portion of the outer surface of the body including at least one threaded portion, (b) an expansion means operablely related to the expandable section to displace the expandable section between the contracted position and the expanded position, (c) at least one joint, (d) mounting means, (e) coupling means, and (f) fixing means.

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