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EP-4736794-A2 - BIASING DEVICE FOR SPINAL DEVICE

EP4736794A2EP 4736794 A2EP4736794 A2EP 4736794A2EP-4736794-A2

Abstract

A spinal device includes a rod which has a first end disposed in a housing and a second end which protrudes out of the housing through an aperture and which is movable to protrude more out of the housing or less out of the housing. A biasing device, mounted on the rod, includes a series of connected at-least partial coils. A first end of the biasing device is arranged to abut against the housing and a second end of the biasing device, opposite to the first end, is affixed to the rod.

Inventors

  • ARNIN, URI

Assignees

  • Apifix Ltd.

Dates

Publication Date
20260506
Application Date
20201220

Claims (8)

  1. A spinal device, comprising: a rod; and an biasing device coupled to said rod, said biasing device including a series of connected partial coils extending partially and not completely around said rod.
  2. The spinal device according to claim 1, wherein said series of connected partial coils subtends an angle of less than 360°.
  3. The spinal device according to claim 2, wherein said series of connected partial coils includes pairs of connected neighboring coils, and wherein said pairs of connected neighboring coils are circumferentially separated from one another by a circumferential gap.
  4. The spinal device according to claim 3, comprising: a polyaxial-joint attachment member, wherein said rod extends from said polyaxial-joint attachment member.
  5. The spinal device according to claim 4, comprising: a fastener affixing said biasing device to said rod, wherein said biasing device includes an end portion, and said fastener affixes said end portion of said biasing device to said rod.
  6. The spinal device according to claim 5, wherein said fastener is a set screw.
  7. The spinal device according to claim 3, comprising: a fastener affixing said biasing device to said rod, wherein said biasing device includes an end portion, and said fastener affixes said end portion of said biasing device to said rod.
  8. The spinal device according to claim 7, wherein said fastener is a set screw.

Description

FIELD OF THE INVENTION The present invention relates generally to spinal implants and prostheses, and particularly to an add-on or integral biasing device for a spinal device, such as a spinal rod. BACKGROUND OF THE INVENTION Scoliosis is a spinal deformity affecting many people. Current surgical treatment involves affixing long fusion rods to the spine by pedicle screws. The rod system is intended to force the deformed spine into a more healthy position. Unfortunately, there are severe shortcomings to this procedure; the deformation is rarely perfectly corrected, the long fusion for life is not a desired clinical situation and failures are not uncommon. US Patent 10245081 to Arnin describes an improved ratcheted spinal device that includes a rod that can move out of a housing. The amount the rod protrudes out of the housing can be lengthened or shortened using a ratchet mechanism. The rod can be connected to standard pedicle screws as well as to other spinal rods or spinal structure, using appropriate connectors. SUMMARY OF THE INVENTION The present invention seeks to provide an improved spinal device or accessory for a spinal device, namely an add-on or integral biasing device for a spinal device, as is described more in detail hereinbelow. There is thus provided in accordance with a non-limiting embodiment of the present invention a spinal device including a rod which has a first end disposed in a housing and a second end which protrudes out of the housing through an aperture and which is movable to protrude more out of the housing or less out of the housing, and a biasing device, mounted on the rod, which includes a series of connected at-least partial coils, wherein a first end of the biasing device is arranged to abut against the housing and a second end of the biasing device, opposite to the first end, is affixed to the rod. The at-least partial coils may include full coils, or instead, a series of connected partial coils that do not extend completely around the rod but instead subtend an angle of less than 360° and each pair of neighboring coils of the partial coils are connected by a connection member and the connection members are separated from one another by a circumferential gap. In accordance with an embodiment of the present invention a first end of the biasing device is arranged to abut against the housing and a second end of the biasing device, opposite to the first end, is provided with a fastener to affix the second end to the rod. In accordance with an embodiment of the present invention axial fixation of the second end determines a pretension of the biasing device. In accordance with an embodiment of the present invention the rod is coupled with a ratchet mechanism for controlling an amount the rod protrudes out of the housing. In accordance with an embodiment of the present invention a first polyaxial-joint attachment member is at the second end of the rod and a second polyaxial-joint attachment member is at a portion of the housing. In accordance with an embodiment of the present invention a method for adjusting curvature of a spine includes mounting a biasing device on a rod of a spinal device which is installed on spinal structure, the biasing device including a series of connected partial coils that do not extend completely around the rod but instead subtend an angle of less than 360° and each pair of neighboring coils of the partial coils are connected by a connection member and the connection members are separated from one another by a circumferential gap, and using the biasing device to apply an urging force to the rod and to the spinal structure. BRIEF DESCRIPTION OF DRAWINGS The present invention will be understood and appreciated more fully from the following detailed description, taken in conjunction with the drawings in which: Fig. 1 is a simplified pictorial illustration of a spinal device, constructed and operative in accordance with an embodiment of the invention;Fig. 2 is a simplified enlarged illustration of a biasing device of the spinal device of Fig. 1;Fig. 3 is another simplified illustration of the biasing device, showing circumferential gaps between ends of partial coils of the biasing device; andFig. 4 is a simplified sectional illustration of the spinal device. DETAILED DESCRIPTION OF EMBODIMENTS Reference is now made to Figs. 1-3, which illustrate a spinal device 10, constructed and operative in accordance with a non-limiting embodiment of the invention. Spinal device 10 includes a rod 12 which has a first end 14 (Fig. 4) disposed in a housing 16 and a second end 18 which protrudes out of housing 16 through an aperture 19 and which is movable to protrude more out of housing 16 or less out of housing 16. The term "rod" throughout encompasses any element with a round or non-round, regular or irregular perimeter, such as but not limited to, a rod, bar, lug, wire, post and others. As seen in Fig. 4, rod 12 may be coupled with a ratchet mechanism 20 for controlling