Biasing device used in a spinal device

Abstract

The spinal device includes a rod having a first end disposed within the housing and a second end protruding outside the housing through an opening, the rod being movable to protrude more or less from the housing. The biasing device is attached to the rod and includes a plurality of serially connected at least partially wound coils. The first end of the biasing device is positioned to abut the housing, and the second end opposite the first end is attached to the rod.

Description

Technical Field

[0001] The present invention generally relates to spinal implants and orthoses. More particularly, it relates to an accessory or integral biasing device used in a spinal device such as a spinal rod.

Background Art

[0002] Many people are affected by scoliosis, in which the spine is deformed. Current surgical treatments involve fixing a long fixation rod to the spine with pedicle screws. Such a rod system is intended to correct the deformed spine to a healthier position.

[0003] However, such an approach has several drawbacks. That is, the deformation is rarely completely corrected, long-term fixation throughout life is not desired in the clinical setting, and failures are not uncommon.

[0004] U.S. Patent No. 10,245,081 discloses an improved ratchet-type spinal device that includes a rod that is movable externally from a housing. The amount by which the rod protrudes from the housing can be lengthened or shortened by a ratchet mechanism. Using appropriate connectors, the rod can be connected not only to standard pedicle screws but also to other spinal rods and spinal structures.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

[0006] The present invention aims to provide an improved spinal device or an accessory for a spinal device, namely, an accessory or integral biasing device used in a spinal device, which will be described in detail below.

[0007] Thus, according to a non-limiting embodiment of the present invention, the spinal device has a first end provided inside the housing and a second end protruding outside the housing through an opening, and a rod movable so that the protrusion from the housing increases or the protrusion from the housing decreases, and a biasing device including a plurality of at least partially wound coils attached to and continuously connected to the rod. The first end of the biasing device is arranged to abut against the housing, and the second end of the biasing device on the side opposite to the first end is attached to the rod.

[0008] The at least partially wound coil may include a fully wound coil. Instead, it is not fully wound around the rod but is wound at an angle of 360 degrees or less. A pair of adjacent coils among the plurality of at least partially wound coils are each connected by a connecting member, and the connecting members are separated from each other by a circumferential gap, and may include continuously connected partially wound coils.

[0009] In one embodiment of the present invention, the first end of the biasing device is arranged to abut against the housing, and a fixing member for attaching the second end to the rod is provided at the second end of the biasing device on the side opposite to the first end.

[0010] In one embodiment of the present invention, the pre-tension of the biasing device is determined by the axial fixation of the second end.

[0011] In one embodiment of the present invention, the rod is connected to a ratchet mechanism that adjusts the amount by which the rod protrudes from the housing.

[0012] In one embodiment of the present invention, the first multi-axis joint attachment member is provided at the second end of the rod, and the second multi-axis joint attachment member is provided on a part of the housing.

[0013] In one embodiment of the present invention, a method for adjusting spinal curvature includes attaching a biasing device to a rod of a spinal device attached to the spinal structure, where the biasing device includes continuously connected coils, the coils are not fully wound around the rod, but instead are wound at an angle of 360 degrees or less, and a pair of adjacent coils among the plurality of at least partially wound coils are each connected by a connecting member, the connecting members being separated from each other by a circumferential gap, and using the biasing device to bias the rod and the spinal structure.

Brief Description of the Drawings

[0014] The present invention will be fully understood and grasped from the following detailed description and drawings.

Figure 1

Figure 2

Figure 3

Figure 4

Embodiments for Carrying Out the Invention

[0015] Here, reference is made to FIGS. 1-3 showing a spinal device 10 configured and operating in accordance with non-limiting embodiments of the present invention.

[0016] The spinal device 10 has a first end 14 (FIG. 4) provided inside the housing 16 and a second end 18 protruding outside the housing 16 through the opening 19, and includes a rod 12 that is movable so that the protrusion from the housing 16 is increased or the protrusion from the housing 16 is decreased. The term "rod" shall include, throughout, any configuration having a circular or non-circular, regular or irregular outer peripheral surface, although not particularly limited, including rods, bars, lugs, wires, posts, etc.

[0017] As shown in FIG. 4, the rod 12 is connected to a ratchet mechanism 20 that adjusts the amount by which the rod 12 protrudes from the housing 16. The ratchet mechanism 20 may include ratchet teeth 22 formed along a portion of the axis of the rod 12 and a pawl 24 disposed to engage one of the ratchet teeth 22. The pawl 24 may extend from a control element 26 that is attached around the axis 27 and provided with an eccentric cam 28. By the rotation of the eccentric cam 28, the pawl 24 moves to one of the following three positions. a) A position where the pawl 24 engages the teeth 22 such that the rod 12 can gradually move in one direction. b) A position where the pawl 24 engages the teeth 22 in a locked manner so that the rod 12 does not move. c) A position where the engagement with the teeth 22 is disengaged so that the rod 12 can move freely in both directions. Other ratchet mechanisms may be used. Alternatively, a ratchet mechanism may not be used. For example, the rod 12 may be biased by a spring inside the housing 16.

[0018] The device 10 may be provided with two multi-axis joint mounting members 30 (not particularly limited, such as bearing races or simple holes). One may be provided at the second end 18 of the rod 12 and the other may be provided at another portion 21 of the housing 16. Using both multi-axis joint mounting members 30, the device 10 can be attached to the spinal bone structure by a pedicle screw or the like passing through the members 30. Here, as shown in U.S. Patent No. 10,245,081, even after the fixing member is tightened to the member 30, the fixing member securely holds the pedicle screw in its position while allowing multi-axis rotation.

[0019] The device 10 includes a biasing device 32 that can be an accessory attachable to the device 10 before or after being worn by a patient. Alternatively, the manufacturer may provide the biasing device 32 on the device 10.

[0020] The biasing device 32 can include a plurality of continuously connected at least partially wound coils 34 (e.g., coil springs). In one embodiment, the coil 34 is a fully wound coil (fully 360 degrees). In other embodiments, the coil 34 is not fully wound around the rod 12 and instead is wound at an angle less than 360 degrees, and a pair of adjacent coils are each connected by a connecting member 36, which is a partially wound coil. As shown in FIG. 3, the connecting members 36 are separated from each other by a circumferential gap 38. In contrast to a fully wound coil that must be slid from one end of the rod 12 and then slid to a desired axial position (a device having a fully wound coil can be provided by the manufacturer), when the biasing device 32 includes a partially wound coil 34, this coil 34 can be disposed directly on any axial portion of the rod 12. With such a configuration, the biasing device 32 can be attached to the device 10 even after the device 10 has been worn by the patient.

[0021] The first end 40 of the biasing device 32 is disposed to abut against the housing 16. A fixing member 44, such as a set screw for attaching the second end 42 to the rod 12, is provided at the second end 42, which is opposite the first end 40.

[0022] After the device 10 is worn by the patient, the biasing device 32 biases both ends of the device 10, for example, to assist in correcting the patient's spine, according to a patient-specific treatment plan.

Claims

1. A spinal device attached to a spinal structure by a pedicle screw, comprising: a housing; a rod having a first end provided inside the housing and a second end protruding outside the housing through an opening, and being movable such that the protrusion of the rod from the housing increases or the protrusion of the rod from the housing decreases; a biasing device attached to the rod and comprising a plurality of at least partially wound coils that are continuously connected; a first multi-axial joint attachment member and a second multi-axial joint attachment member to which the pedicle screws are respectively connected and comprising wherein the first multi-axial joint attachment member is provided at the second end of the rod; the second multi-axial joint attachment member is provided at an end of the housing on a side away from the second end of the rod; a first end of the biasing device is arranged to abut against the housing; a second end of the biasing device, on the side opposite to the first end, is attached to the rod; the plurality of at least partially wound coils are not completely wound around the rod, but instead are wound at an angle smaller than 360 degrees, and a pair of adjacent coils among the plurality of at least partially wound coils are respectively connected by a connecting member, and the connecting members are separated from each other by a circumferential gap; a spinal device.

2. The spinal device according to claim 1, wherein the pre-tension of the biasing device is determined by axial fixation of the second end of the biasing device.

3. The spinal device according to claim 1, wherein the rod is connected to a ratchet mechanism for adjusting the amount by which the rod protrudes from the housing.

4. The spinal device according to claim 1, wherein the first multi-axial joint attachment member is provided at the second end of the rod, and the second multi-axial joint attachment member is provided at a part of the housing.

5. A spinal device attached to a spinal structure by a pedicle screw, comprising: an implantable housing; an implantable elongate member having a first end of the member disposed within the implantable housing and a second end of the member protruding from the implantable housing An implantable biasing device having a first end of the device that abuts the implantable housing, and a second end of the device connected to the implantable elongate member, and having a plurality of continuously connected partially wound coils that are partially wound around the implantable elongate member and not fully wound, a first multi-axis joint mounting member and a second multi-axis joint mounting member to which the pedicle screws are respectively connected comprising the first multi-axis joint mounting member is provided at the second end of the member, the second multi-axis joint mounting member is provided at an end of the housing on a side away from the second end of the member, a spinal device. **Claim 6** The spinal device according to claim 5, wherein the plurality of continuously connected partially wound coils are wound at an angle less than 360 degrees. **Claim 7** The spinal device according to claim 6, wherein the plurality of continuously connected partially wound coils include a pair of adjacent coils, and the pair of adjacent coils are separated from each other by a circumferential gap. **Claim 8** The spinal device according to claim 7, wherein the implantable elongate member is capable of at least partially extending from the housing and at least partially retracting into the housing. **Claim 9** comprising a ratchet mechanism connected to the implantable elongate member, The spinal device according to claim 8, wherein the ratchet mechanism is operable to cause at least one of extending the implantable elongate member from the housing and retracting the implantable elongate member into the housing.

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