Abstract: A receiver assembly includes a receiver with a base defining a central bore for receiving the head of a bone anchor and upright arms defining a channel for receiving a rod, with the central bore having through apertures extending outwardly to outer side surfaces of the receiver and the upright arms having top surfaces, opposite front and back surfaces, vertical tool-engaging slots extending downward from the top surfaces to the through apertures for slidably receiving an insert compression tool, and horizontal tool-engaging grooves on either side of the vertical slots that extend laterally to a front or back surface of the upright arm. The assembly also includes an insert positionable within the central bore with an upward-facing outer engagement surface located within a through aperture and aligned with a vertical tool-engaging slot, and which is configured for compressive engagement by the insert compressing tool to independently lock a position of the receiver with respect to the bone anchor.

Abstract: A method for securing a longitudinal connection member assembly into multiple bone anchors by inserting the assembly into the bone anchors before or after the assembly is tensioned. The assembly includes a tensionable cord, an outer end blocker, and a set screw. The cord has a first end portion fixedly connected to a first structure, extends through a through-bore of a second structure, and has a second end portion that extends through a blocker through-bore of the outer end blocker. The outer end blocker has oppositely spaced lateral external planar surfaces and a threaded closed bore. The set screw is releasably engageable to the outer end blocker via the threaded closed bore. The method further includes tensioning the cord from the second end portion, holding the planar surfaces during tensioning of the cord within the blocker, and securing the tensioned cord to the outer end blocker by the set screw.

Abstract: A fail-safe release mechanism for use with patient positioning support apparati having a base structure and a patient support structure, to prevent collapse of the patient support structure during disconnection of the patient support structure from the base structure at outboard ends thereof.

Abstract: A pivotal bone anchor assembly includes a receiver having an axial bore with a seating surface adjacent a lower opening and an open channel for receiving a cylindrical rod. The assembly also includes a shank having an anchor portion and a capture portion with a drive socket, a planar top surface surrounding the drive socket, and a partially spherical lower surface curving upwardly and outwardly from a neck portion, and a central bore for a guide wire extending distally from the drive socket to a distal tip of the anchor portion. The assembly further includes an insert having an upper surface for engaging the cylindrical rod, a lower surface for transferring a downward force toward the capture portion to lock the assembly, and a central aperture providing access to the drive socket.

Abstract: A method of securing a rod to a receiver via a closure top. The receiver is configured to be used with a bone anchor and includes a pair of upright arms that define an open channel configured to receive the rod, a discontinuous helically wound receiver guide and advancement structure formed into the interior surfaces of the upright arms, and horizontally-elongated tool-engaging structures formed on the outer surface of the upright arms. The method further includes positioning the rod within the open channel of the receiver and securing the rod to the receiver by threadably advancing the closure top to secure the rod and within the receiver body of the receiver. The method further includes rotatably attaching a lower end of a tool to the receiver.

Abstract: A pivotal bone screw assembly includes a threaded shank body having an integral upper portion receivable in a receiver, with the receiver having an upper channel for receiving a longitudinal connecting member and a lower cavity cooperating with a lower opening. The assembly also includes a downloadable compression insert with a side arm extension for engagement and compression by a vertically-translating insert side compressing member so as to lock the assembly independent of the closure top.

Abstract: A pivotal bone anchor assembly includes a receiver having a central bore with a spherical seating surface adjacent a bottom opening and upright arms defining a channel for receiving a rod. The upright arms include side outer surfaces with horizontal tool engagement grooves spaced below top surfaces and having downwardly-facing upper groove surfaces and upwardly-facing lower groove surfaces that extend to front and back planar surface portions of the upright arms. The upright arms also include vertical tool engagement slots extending into and downward across the side outer surfaces from the top surfaces through to at least the upper groove surfaces of the horizontal tool engagement grooves. The assembly also includes a shank having an anchor portion for attachment to patient bone and a capture portion with a curvate lower surface configured for slidable engagement with the spherical seating surface of the receiver prior to locking the assembly with a closure.

Abstract: A modular bone anchor system includes a plurality of bone anchors, with each bone anchor comprising a capture portion at a proximal end, an anchor portion at a distal end, and a neck portion integral with the capture portion and the anchor portion. The system also includes a plurality of pivoting and non-pivoting receiver sub-assemblies, with each receiver sub-assembly including a receiver having a channel for receiving a rod and a central bore that extends upwardly from a bottom opening through the channel to a top of the receiver, and either a capture portion-engaging retainer or a rod-engaging insert positioned within the central bore. The capture portion of each bone anchor has a single predetermined size and shape that is common with the other bone anchors and is configured for uploading into either the pivoting or non-pivoting receiver sub-assemblies through the bottom opening of the receiver.

Abstract: A pivotal bone anchor assembly includes a receiver having a central bore with an integral downward facing surface below a helically wound guide and advancement structure and a first interference surface, and a compression insert configured for top-loading into the central bore into a first position and then being rotatable about the receiver longitudinal axis into a second position defined by an engagement between a second protuberant interference surface of the compression insert and a first interference surface of the central bore. The compression insert further includes radially offset upwardly facing surfaces configured for biased engagement with a downward facing surface of the central bore upon completion of rotation to the second position, and the receiver further includes one or more inwardly extending integral non-resilient structure positionable into one or more outer alignment grooves of the compression insert, also upon the completion of rotation to the second position.

Abstract: A soft dynamic stabilization assembly includes a core, typically in the form of a tensioned cord, at least one pair of bone anchors, a spacer surrounding the core located between the bone anchors, typically, at least one elastic bumper and at least one fixing or blocking member. The core is slidable with respect to at least one of the bone anchors and cooperating spacer.

Abstract: A method of assembling a pivotal bone anchor assembly includes positioning a retaining structure into a central bore of a receiver having a planar seating surface above a lower opening, the retaining structure being operably slidably coupled with the planar seating surface and having a central opening, the receiver including upright arms defining an open channel configured to receive a rod and exterior surfaces comprising opposite cylindrical upper side surfaces defining a first width and opposite lower side surfaces below the upper side surfaces defining a second width. The method also includes positioning a partially spherical head of a shank into the central opening of the retaining structure, with the retaining structure being slidably movable along the planar seating surface of the receiver to provide for increased articulated movement between the shank and the receiver in at least one direction relative to a vertical centerline axis of the receiver prior to locking the assembly with a closure.

Abstract: A receiver assembly includes a receiver with upright arms extending upward from a base to define an open channel for receiving a rod, and a central bore communicating with a bottom of the base through a bottom opening and having a discontinuous guide and advancement structure proximate the tops of the upright arms. Each upright arm further includes one or more tool engagement grooves extending horizontally and circumferentially below the top of the upright arm to a front or back outer face the receiver.

Abstract: A dynamic fixation medical implant having at least two bone anchors includes a longitudinal connecting member assembly having rigid sleeves for attachment to the bone anchors, at least one spacer engaging the bone anchors and the sleeves, and in some embodiments, an end elastic bumper. A flexible cord is initially slidingly received within the rigid sleeves, the spacer and the bumper. The spacer may include an optional inelastic inner liner, with at least one of the sleeves having an extension slidingly receivable within the liner. Some sleeves include apertures for receiving a closure top portion for locking the cord against the sleeve, or alternatively receiving a closure top that does not extend into the aperture, the slip or grip option provided by the aperture in each sleeve resulting in an overall connector with variable segmental stiffness.

Abstract: A receiver assembly for securing an elongate rod to a bone anchor includes a receiver having pair of upright arms that define an open channel configured to receive the elongate rod, a discontinuous helically wound receiver guide and advancement structure formed into the interior surfaces of the upright arms, and horizontally-elongated tool engaging grooves formed into upper portions of the outer surface of the upright arms. The receiver assembly further includes a closure configured for positioning within the open channel to secure the elongate rod to the receiver in a locked configuration, with the closure having an outer surface with a mating continuous helically wound closure guide and advancement structure configured to resist a tendency toward splaying between the upright arms upon a screwing in of the closure within the open channel by rotatable engagement with the receiver guide and advancement structure.

Abstract: A receiver assembly includes a receiver with a central bore and a bottom opening, a channel for receiving a rod, and a discontinuous horizontal recess and one or more vertically-aligned side pockets formed into sidewall surfaces of the central bore. The assembly also includes a pressure insert with an upwardly-open rod-seating surface, opposite flanges projecting radially outward from an upper portion of an outer cylindrical surface, and one or more side protuberances projecting radially outward below the opposite flanges. The pressure insert is positionable into the central bore in a first position and then rotatable from the first position to a second position in which the side protuberances are interferingly forced into the side pocket recesses to inhibit further rotation of the pressure insert and the opposite flanges are rotated under downwardly-facing surfaces of the horizontal recess to inhibit upward movement of the pressure insert within the central bore.

Abstract: A receiver assembly includes a receiver having a first channel, a through-space with internal recesses beneath a guide and advancement structure, and internal ridges projecting inwardly below the internal recesses. The assembly also includes an insert having a second channel, side structures protruding laterally outward below top surfaces, and opposed lower extensions extending downwardly below the second channel, with the insert being loadable into the through-space with the second channel in non-alignment with the first channel. The insert is the non-threadably rotatable within the through-space to align the second channel with the first channel and to move the side structures into the internal recesses above the internal ridges, with a subsequent forced downward displacement of the insert within the through-space causing the side structures to frictionally engage the internal ridges to inhibit the insert from moving upward within the through-space.

Abstract: A pivotal bone anchor assembly includes a receiver having an axial bore with a lower seating surface adjacent a bottom opening, and a bone anchor having a capture portion uploadable through the bottom opening with a spherical outer surface and a pair of opposite planar side surfaces. The assembly also includes a multi-part retainer comprising at least two discrete retainer parts, each having an internal planar surface for engaging a planar side surface of the capture portion within the axial bore, and a compression insert having a lower curvate surface for engaging the spherical outer surface of the capture portion and opposite parallel planar side surfaces for engagement by rotation blocking structures extending into the axial bore. Upon an application of downward force onto the multi-part retainer, outer surfaces of the retainer parts frictionally engage the lower seating surface to lock an angular orientation of the bone anchor with respect to the receiver.

Abstract: A pivotal bone anchor assembly includes a receiver having a central bore with a seating surface adjacent a bottom opening and a downward-facing surface above the seating surface, and a shank having a head portion positionable within the axial bore. The assembly also includes a compression insert positionable within the central bore above the head portion and having an upper portion with a notch formed therein to define a resiliently compressible structure extending over the notch. When the head portion of the shank and the compression insert are positioned together in the central bore of the receiver, the engagement between the resiliently compressible structure and the downward-facing surface is configured to provide an axially directed resilient biasing force for a pre-lock friction fit of the pivotal bone anchor assembly prior to securing the longitudinal connecting member in the open channel with the closure.

Abstract: A patient support apparatus for supporting a patient in a prone position during a surgical procedure is provided, including an open fixed frame suspended above a floor and a pair of spaced opposed radially sliding joints cooperating with the frame, each joint including a virtual pivot point and an arc of motion spaced from the virtual pivot point, the joints being movable along the arc providing a pivot ship mechanism for a pair of pelvic pads attached to the joints. A base for supporting and suspending a patient support structure above the floor, for supporting a patient during a surgical procedure, the base including a pair of spaced opposed vertical translation subassemblies reversibly attachable to a patient support structure, a cross-bar, and a rotation subassembly having two degrees of rotational freedom; wherein a location of each vertical translation subassembly is substantially constant during operation of the patient support structure.

Abstract: A method for securing an elongate rod to a bone of a patient with a pivotal bone anchor assembly. The method includes providing a splay limiting closure, providing an open bone anchor receiver with horizontal curvate extending instrument engaging grooves. The method further includes rotatably advancing the closure within an open channel of the receiver so as to secure the elongate rod to the receiver in a locked configuration.