A method of treating a spinal column shape deformation includes fixing at least two fixation screw assemblies to respective vertebrae, sliding a rod between the arm extensions on each of the fixation screw assemblies, swinging the channels of the screw assemblies relative to the fixation screws so that the channels become less inclined to the axes of the fixation screws, and so that the rod is located generally posteriorly of the spinal column, locking the channel against swinging relative to the screw, rotating the rod about its axis relative to at least one of the channels, and locking the rod against movement relative to the channel.

A bone screw assembly includes an anchor portion and a head portion, such as a rod-receiving portion, movably mounted to the anchor portion to allow for controlled angulation between the anchor portion and the head portion. The anchor portion is pivotable in one or more selected directions about an axis relative to the head portion. A restriction member, which may be a rod seat, prevents the anchor portion from pivoting in one or more different directions about another axis relative to the head portion and/or a spinal fixation element received in the head portion. The restriction member may be inserted in the head portion to control direction that the anchor portion pivots relative to the head portion. The restriction member may also serve as a compression member and/or rod seat for seating a spinal rod coupled to the bone screw assembly.

A uniplanar bone anchor including a housing and a bone screw is provided. The lower region of the housing defines mating elements that mate with engaging elements on the bone screw to limit movement of the housing relative to the bone screw to a single plane.

A bone fastener assembly including a bone screw, a receiver, a crown, a first retaining ring, and a second retaining ring is provided. The crown is received in an interior cavity of the receiver, and the first retaining ring is provided to hold the crown in the receiver. At least a portion of a head portion is received in the interior cavity of the receiver, and the second retaining ring is provided to hold at least a portion of the head portion in the receiver. The crown, the first retaining ring, and/or the second retaining ring can be manufactured using a 3D printing process that provides a higher surface finish (Ra).

A polyaxial bone screw for attaching a rod to a vertebra comprises a fastener having a threaded shank and a head. A yoke has a rod receiving channel for receiving the rod. A screw support rotatably attached to the yoke has a cavity articulatingly and rotatably supporting the fastener head, a hole receiving the threaded fastener shank therethrough, and a plurality of slots for maximum screw angulation. A crown has an upper rod receiving surface, a lower surface in contact with the fastener head and a projecting surface in contact with the yoke. A biasing element between the screw support and the yoke applies biasing forces among the fastener, the crown, and the yoke to provide sufficient friction to retain the yoke in a manipulable position relative to the fastener. A set screw is supported by the yoke to overcome the bias and to rigidly secure the components.

A pivotal bone screw assembly includes a receiver having a base defining a lower portion of a central bore, and a pair of upright arms extending upward from the base to define an open channel configured to receive an elongate rod. The uprights arms include opposed internal surfaces with a guide and advancement structure configured for engagement with a closure top, and side outer surfaces opposite the internal surfaces with tool engagement grooves extending horizontally and circumferentially to the front and back faces of the receiver. The assembly further includes a shank having a head and an anchor portion configured for attachment to the bone, with the head being positionable into the central bore of the receiver with the shank extending downward through the lower opening. The lower opening is configured to provide for increased pivotal movement of the shank with respect to the receiver in at least one direction.

Systems, assemblies, components and methods for correcting alignment of one or more vertebrae of a spine are provided. A first elongate derotator member includes a first elongate element having a first proximal end portion and a first distal end portion. The first distal end portion is releasably engageable with a first implant implanted in one of the vertebrae. A second elongate derotator member comprising a second elongate element is releasably engageable with a second implant implanted in the same vertebra. A transverse member is engageable with the first and second elongate elements. A first channel extends axially through the first elongate element and a second channel extends axially through the second elongate element such that a proximal end portion of the first implant can be accessed from a proximal end portion of the first elongate element by inserting a tool through the first channel and a proximal end portion of the second implant can be accessed from a proximal end portion of the second elongate element by inserting the tool or another tool through the second channel.

An orthopedic implant kit comprising a lockable poly-axial screw, a tissue dilatation sleeve, a screw driver, a screw extender, a rod, rod-reduction device, a set screw driver, a torque limiting device and a screw releasing device.

The present invention provides a pedicle screw, which includes a screw head, a screw body, a screw rod and a screw cap. The screw body includes a ball-liked arc-shaped buckle portion and a column-liked thread portion. The screw head includes a semi-sphere part with an arc-shaped dimple on one end and a U-shaped cavity on the other end. The U-shaped cavity connects with the arc-shaped dimple. Furthermore, the Arc-shaped dimple connects with the arc-shaped buckle portion. The Arc-shaped dimple includes an opening on its top to allow the screw body passing through. The U-shaped cavity includes an opening, which includes a female thread to fix the screw rod in the U-shaped cavity by a male thread on the screw cap.

A spinal fixation device for securing two stabilizing rods to bone, such as the spine, pelvis or cranium, has a threaded shaft configured for fastening to bone, a first (primary) rod coupling head and a secondary rod coupling head. The threaded shaft has a longitudinal axis and the first rod coupling head is connected to the threaded shaft. The first rod coupling head has a side wall and a cavity for receiving a rod, the cavity being open toward a top of the first rod coupling head. In a neutral position of the first rod coupling head, the first rod coupling head extends symmetrically around the longitudinal axis of the threaded shaft. The second rod coupling head is rotatably connected to the first rod coupling head, around an axis of rotation. The axis of rotation is disposed at an angle that is not perpendicular to the longitudinal axis of the threaded shaft when the first rod coupling head is in the neutral position. This allows for two rods to be manipulated independently through different axis planes at any single point of bony fixation.