Abstract: An implant assembly includes a screw body, including anchor portion and proximal head portion, and a cradle movably mounted in the screw body to allow for controlled angulation between a spinal connection element disposed in the cradle and the screw body. The cradle is pivotable in one or more selected directions about one or more axes relative to the screw body. The cradle may be generally, substantially spherical in shape and allow for unrestricted movement in one or more directions around one or more axis.

Abstract: An implant assembly includes a screw body, including anchor portion and proximal head portion, and a cradle movably mounted in the screw body to allow for controlled angulation between a spinal connection element disposed in the cradle and the screw body. The cradle is pivotable in one or more selected directions about one or more axes relative to the screw body. The cradle may be generally, substantially spherical in shape and allow for unrestricted movement in one or more directions around one or more axis.

Abstract: An instrument for engaging a bone anchor may include a first implant engaging member having a proximal end and a distal end and a second implant engaging member having a proximal end and a distal end. The second implant engaging member may be integrally connected to the first implant engaging member by a pair of opposed integral spring members located proximal to the distal ends of the first and second implant engaging members. Manipulation of the proximal ends of the first and second implant engaging member can cause each of the distal ends to rotate about the pair of opposed spring members to engage at least a portion of a bone anchor. A rod adjusting tool may be connectable to the bone anchor engaging tool and may be axially adjustable relative to the bone anchor tool to adjust a spinal rod relative to the bone anchor.

Abstract: An instrument for engaging a bone anchor may include a first implant engaging member having a proximal end and a distal end and a second implant engaging member having a proximal end and a distal end. The second implant engaging member may be integrally connected to the first implant engaging member by a pair of opposed integral spring members located proximal to the distal ends of the first and second implant engaging members. Manipulation of the proximal ends of the first and second implant engaging member can cause each of the distal ends to rotate about the pair of opposed spring members to engage at least a portion of a bone anchor. A rod adjusting tool may be connectable to the bone anchor engaging tool and may be axially adjustable relative to the bone anchor tool to adjust a spinal rod relative to the bone anchor.

Abstract: An instrument for engaging a bone anchor may include a first implant engaging member having a proximal end and a distal end and a second implant engaging member having a proximal end and a distal end. The second implant engaging member may be integrally connected to the first implant engaging member by a pair of opposed integral spring members located proximal to the distal ends of the first and second implant engaging members. Manipulation of the proximal ends of the first and second implant engaging member can cause each of the distal ends to rotate about the pair of opposed spring members to engage at least a portion of a bone anchor. A rod adjusting tool may be connectable to the bone anchor engaging tool and may be axially adjustable relative to the bone anchor tool to adjust a spinal rod relative to the bone anchor.

Abstract: An instrument for manipulating a spinal fixation element relative to a bone anchor includes a bone anchor grasping mechanism, a first adjustment mechanism, and a second adjustment mechanism. The bone anchor grasping mechanism includes a first arm having a distal end configured to engage an opening provided in the bone anchor. The first adjustment mechanism includes a second arm pivotally connected to the first arm. The second arm has a distal end configured to engage an opening provided in the bone anchor and is operable to adjust a spinal fixation element in a first direction upon pivoting relative to the first arm. The second adjustment mechanism is removably and replaceably coupled to the bone anchor grasping mechanism and is movable relative to the bone anchor grasping mechanism to adjust the spinal fixation element in a second direction, perpendicular to the first direction, relative to the bone anchor.

Abstract: An implant assembly includes a screw body, including anchor portion and proximal head portion, and a cradle movably mounted in the screw body to allow for controlled angulation between a spinal connection element disposed in the cradle and the screw body. The cradle is pivotable in one or more selected directions about one or more axes relative to the screw body. The cradle may be generally, substantially spherical in shape and allow for unrestricted movement in one or more directions around one or more axis.

Abstract: A screw placement guide tool for use in minimally invasive surgery has a proximal handle portion, an extension member extending distally from the handle portion, and an alignment element connected transversely to a distal portion of the extension member and having a screw placement guide located thereon. In this aspect of the invention, the tool is configured so that a surgeon may operate the tool using the handle portion external to a patient's body to align the alignment element with implanted screws so that the screw placement guide indicates a desired position for implantation of an additional screw. Systems and methods for placing a rod receiving screw are also provided.

Abstract: An instrument for manipulating a spinal fixation element relative to a bone anchor includes a bone anchor grasping mechanism, a first adjustment mechanism, and a second adjustment mechanism. The bone anchor grasping mechanism includes a first arm having a distal end configured to engage an opening provided in the bone anchor. The first adjustment mechanism includes a second arm pivotally connected to the first arm. The second arm has a distal end configured to engage an opening provided in the bone anchor and is operable to adjust a spinal fixation element in a first direction upon pivoting relative to the first arm. The second adjustment mechanism is removably and replaceably coupled to the bone anchor grasping mechanism and is movable relative to the bone anchor grasping mechanism to adjust the spinal fixation element in a second direction, perpendicular to the first direction, relative to the bone anchor.

Abstract: An instrument for engaging a bone anchor may include a first implant engaging member having a proximal end and a distal end and a second implant engaging member having a proximal end and a distal end. The second implant engaging member may be integrally connected to the first implant engaging member by a pair of opposed integral spring members located proximal to the distal ends of the first and second implant engaging members. Manipulation of the proximal ends of the first and second implant engaging member can cause each of the distal ends to rotate about the pair of opposed spring members to engage at least a portion of a bone anchor. A rod adjusting tool may be connectable to the bone anchor engaging tool and may be axially adjustable relative to the bone anchor tool to adjust a spinal rod relative to the bone anchor.

Abstract: A bone screw is provided having a head and a shank with opposed first and second helical threads extending there around. In one embodiment, the shank has a proximal portion with a constant minor diameter, and a distal portion with a minor diameter that decreases in a proximal-to-distal direction to form a taper. The opposed first and second helical threads preferably define a thread depth that remains constant along the length of the shank. In an exemplary embodiment, a major diameter of the shank at a distal tip of the shank is equal to or less than the minor diameter of the proximal portion of the shank.

Abstract: An instrument for engaging a bone anchor may include a first implant engaging member having a proximal end and a distal end and a second implant engaging member having a proximal end and a distal end. The second implant engaging member may be pivotally connected to the first implant engaging member about a pivot point located proximate the distal ends of the first and second implant engaging members. Manipulation of the proximal ends of the first and second implant engaging member can cause each of the distal ends to rotate about the pivot point to engage at least a portion of a bone anchor.

Abstract: An instrument for engaging a bone anchor may include a first implant engaging member having a proximal end and a distal end and a second implant engaging member having a proximal end and a distal end. The second implant engaging member may be pivotally connected to the first implant engaging member about a pivot point located proximate the distal ends of the first and second implant engaging members. Manipulation of the proximal ends of the first and second implant engaging member can cause each of the distal ends to rotate about the pivot point to engage at least a portion of a bone anchor.

Abstract: A fastener cartridge installs clamping fasteners, e.g., a set screw and a lock nut, to fix a linking rod or cable in the head of an anchor assembly. The cartridge carries one or more fasteners, or pairs of inner and outer fasteners, and applies them onto the anchor head without cross-threading. A separate holder mechanism aligns and guides the cartridge with a centering body into which the fastener cartridge fits. One cartridge has a box wrench that externally grips and turns the nut, and a central shaft coaxial with the box wrench that positions and rotates a clamp screw in coordination with the nut. Preferably, these are configured, by springs, detents or offset positioning surfaces, to install the inner lock screw coaxially with but ahead of the outer nut to fix a linking member anchor assemblies prior to fitting, e.g., compressions and distractions of the spine and final tightening.

Abstract: A fastener cartridge installs clamping fasteners, e.g., a set screw and a lock nut, to fix a linking rod or cable in the head of an anchor assembly. The cartridge carries one or more fasteners, or pairs of inner and outer fasteners, and applies them onto the anchor head without cross-threading. A separate holder mechanism aligns and guides the cartridge with a centering body into which the fastener cartridge fits. One cartridge has a box wrench that externally grips and turns the nut, and a central shaft coaxial with the box wrench that positions and rotates a clamp screw in coordination with the nut. Preferably, these are configured, by springs, detents or offset positioning surfaces, to install the inner lock screw coaxially with but ahead of the outer nut to fix a linking member anchor assemblies prior to fitting, e.g., compressions and distractions of the spine and final tightening.