Abstract: A system and method is provided for distracting opposite surfaces from the interior of a bone, such as a vertebral body. A working channel cannula provides a working channel through which an inserter and an injection cannula can simultaneously pass. The inserter transports a plurality of wafers into the interior of the bone to form a load-bearing stack bearing against the opposite surfaces. The injection cannula is used to inject a fluent material into and/or around the stack. In certain embodiments, the fluent material is a load-bearing or hardenable material, such as bone cement. In other embodiments, the fluent material can be a BMP, HAP, or other osteo-inductive, osteo-conductive, or pharmaceutical compositions. A syringe containing the fluent material is engaged to the injection cannula and is operable to inject the fluent material into the vertebral body under controlled pressure.

Abstract: An apparatus and method is provided for distracting, in a given direction, and supporting opposing vertebral bodies. A plurality of wafers are consecutively inserted between the vertebral bodies to create a column of wafers. The column of wafers is oriented between the vertebral bodies so as to expand in the given direction as the wafers are consecutively added to the column.

Abstract: An apparatus for detecting the presence of a connecting rod during percutaneous spinal surgery comprises a tubular member and an elongate strip extending therethrough. The strip has a flag at the proximal end and an elastically flexible rod detection tip projecting outwardly from the distal end for contacting a connecting rod. The strip is supported in the tubular member for pivoting movement relative to the longitudinal axis of the member. A biasing member biases the strip to a first position in which the flag is adjacent a first side of the tubular member and the detection tip at the distal end is adjacent an opposite second side. Upon application of a force to elastically flex the detection tip, in which the force is sufficient to overcome the bias, the flag is shifted to a second position adjacent the second side of the tubular member.

Abstract: A system and method is provided for distracting opposite surfaces from the interior of a bone, such as a vertebral body. A working channel cannula provides a working channel through which an inserter and an injection cannula can simultaneously pass. The inserter transports a plurality of wafers into the interior of the bone to form a load-bearing stack bearing against the opposite surfaces. The injection cannula is used to inject a fluent material into and/or around the stack. In certain embodiments, the fluent material is a load-bearing or hardenable material, such as bone cement. In other embodiments, the fluent material can be a BMP, HAP, or other osteo-inductive, osteo-conductive, or pharmaceutical compositions. A syringe containing the fluent material is engaged to the injection cannula and is operable to inject the fluent material into the vertebral body under controlled pressure.

Abstract: An expandable interbody fusion device includes superior and inferior plates that are configured to receive a sequentially inserted stack of expansion members or wafers. The superior and inferior plates include features that at least initially interlock the two plates until the superior plate is dislodged by pressure from the growing wafer stack. The wafers include features on their top and bottom surfaces that interlock the wafers in multiple degrees of freedom so that the wafer stack is not disrupted when the fusion device is fully expanded. Each wafer also includes features that interlock with the inferior plate until the wafer id dislodged by sequential introduction of another wafer.

Abstract: An introducer is provided for inserting a connecting rod into tissue of a spine that comprises an outer sleeve with an actuatable rod attachment portion at a distal end thereof to releasably pivotally attach to a connecting rod, and an elongate inner shaft movable translationally within the outer sleeve. The proximal end of the shaft is coupled to an actuation mechanism for selectively translating the inner shaft. The distal end of the shaft includes a rod engagement surface that is movable y the actuation mechanism to a first position to engage a cooperative engagement surface on the rod to hold the rod in a selected locked orientation, to a second position to space the rod engagement surface from the cooperative engagement surface of the rod to allow pivoting of the rod, and to a third position to release the rod from the outer sleeve.

Abstract: A spinal fixation system includes an elongated rod sized to extend between at least two vertebrae and a number of anchor devices for anchoring the rod to the spine. The anchor devices include a bone engaging fastener having a head defining a spherical socket. A ball insert is configured to be placed within the socket and rotated so that a spherical surface of the ball insert is juxtaposed with the spherical surface of the socket. The insert has a first dimension less than the socket opening and a second dimension that upon rotation causes the insert to be captively retained in the socket. The anchor device further includes a yoke defining a yoke channel for receiving the rod and including a stem that is engaged to the ball insert when the insert is captured within the socket. A sleeve is disposed between the yoke channel and the fastener head for supporting the rod thereon. A set screw is threaded into the yoke channel for clamping the rod against the sleeve.

Abstract: A system for percutaneously fixing a connecting rod to vertebrae comprises first and second bone screws, each with a corresponding hollow bone screw extension mounted thereto, and a connecting rod of length sized for subcutaneous receipt in the yokes of the bone screws. A rod introducer is provided for inserting the connecting rod into slots of the screw extensions and into the yokes of the bone screws. A rod persuader may also be provided that is attachable to at least one of the screw extensions, the rod persuader being operable to engage the connecting rod and urge the rod into the slot of the yoke of the corresponding bone screws. A rod detector may also be provided for insertion one of the screw extensions, the rod detector having an indicator sensing the presence of a rod in the slot of the yoke of at least one of the bone screws.

Abstract: An apparatus and method is provided for interbody fusion including distracting, in a given direction, and supporting opposing vertebral bodies. A plurality of wafers are consecutively inserted between the vertebral bodies to create a column of wafers. The column of wafers is oriented between the vertebral bodies so as to expand in the given direction as the wafers are consecutively added to the column.

Abstract: Improvements are provided for a syringe-to-syringe mixing system to improve the mixing characteristics of the system. In one embodiment, a mixing apparatus includes opposite fittings for mounting to a pair of syringes. The mixing apparatus defines a fluid passageway therethrough and includes a flow modifying element disposed within the passageway. The flow modifying element is configured to increase the flow velocity, disrupt the fluid flow or introduce turbulence into the fluid flow between the two syringes. In another embodiment, a nozzle element is disposed within the tip of the syringe, the element configured to increase the fluid flow therethrough. The nozzle element can be a nozzle insert removably mounted within the tip, or an integrally formed nozzle within the tip.

Abstract: A method of attaching an extension to a bone anchor for use in percutaneous spinal surgery is provided that comprises the steps of: providing a bone anchor including a first portion for attachment to a vertebra and a second portion for attachment to a connecting element, the bone anchor including an extension coupling surface; providing an elongate hollow extension having a distal end and a proximal end, the extension having a rotationally movable anchor engaging member projecting radially from the distal end thereof; placing the distal end of the extension adjacent the bone anchor; and rotating the anchor engaging member to engage the extension coupling surface on the anchor and couple the extension and the bone anchor.

Abstract: A surgical instrument for the distraction or compression of bones or bone portions comprises a pair of elongate cross members pivotally coupled for relative movement having at one end a respective pair of handles and at the other end a respective pair of jaws. The jaws are generally parallel to each other and define a first plane within which the jaws are relatively movable, the space on both sides of the plane defining a work space between the jaws. The instrument further comprises a fulcrum supported by at least one of the cross members projecting into the work space and having an axis spaced from the jaws.

Abstract: A method of attaching a curved rod to a plurality of pedicle screws in the thoracic region of the spine is disclosed. Preferably, the method is practiced in a procedure for percutaneously fixing the rod to the pedicle screws through slots formed through a plurality of screw extensions releasably attached respectively to the pedicle screws. The method includes the steps of releasably and pivotally attaching the curved rod to a rod introducer having a handle and holding the rod initially in a fixed position. The rod is introduced in the fixed position through the slots in the extensions with the rod curvature defining a lordotic angle relative to the spine. The rod is released from the fixed position without separating the rod from the introducer. While the rod is in the released position the handle is rotated 180° thereby rotating the rod to a kyphotic angle relative to the thoracic region of the spine.

Abstract: A bone screw extension assembly for use in placing a connecting rod percutaneously into tissue of a patient comprises a multi-axial bone screw and a screw extension releasably coupled to yoke of the bone screw. The screw extension includes coaxially disposed outer sleeve and inner sleeves that are rotatable relative to each other. A screw engaging member projects radially from the distal end the inner sleeve and is configured to engage an extension coupling surface on the outer sleeve upon relative. A securement member including cooperative surfaces is defined adjacent the distal end of the inner and outer sleeves that is operable upon relative radially secure the sleeves together to thereby maintain the engagement of the screw engaging member and the bone screw.

Abstract: A system for percutaneously fixing a connecting rod to vertebrae comprises first and second bone screws, each with a corresponding hollow bone screw extension mounted thereto, and a connecting rod of length sized for simultaneous receipt in the yokes of the bone screws. A rod introducer is provided for inserting the connecting rod into slots of the screw extensions and into the yokes of the bone screws. A rod persuader may also be provided that is attachable to at least one of the screw extensions, the rod persuader being operable to engage the connecting rod and urge the rod into the slot of the yoke of the corresponding bone screws. A rod detector may also be provided for insertion one of the screw extensions, the rod detector having an indicator sensing the presence of a rod in the slot of the yoke of at least one of the bone screws.

Abstract: A screwdriver for driving a multi-axial bone screw into a vertebra of the spine in one configuration includes an elongate shaft defining a driving tip at its distal end for engaging the head of the bone screw for joint rotational movement. The screw driver also includes an outer sleeve within which the inner shaft rotates freely. The outer retention sleeve releasably attaches to the yoke of the bone screw. Rotation of the inner shaft enables rotation of the bone screw threaded shank while the outer sleeve and yoke remain fixed. In another configuration, instead of the outer retention sleeve the screwdriver comprises a screw engagement member affixed to the shaft for joint rotational movement therewith, the screw engagement member comprising a stop sized to seat within a slot of the bone screw yoke, the stop being configured to rotate the yoke upon rotation shaft. A releasable retention member is provided on the screw engagement member for releasably attaching the screwdriver to the bone screw.

Abstract: An introducer is provided for inserting a connecting rod into tissue of a spine that comprises an outer sleeve with an actuatable rod attachment portion at a distal end thereof to releasably pivotally attach to a connecting rod, and an elongate inner shaft movable translationally within the outer sleeve. The proximal end of the shaft is coupled to an actuation mechanism for selectively translating the inner shaft. The distal end of the shaft includes a rod engagement surface that is movable y the actuation mechanism to a first position to engage a cooperative engagement surface on the rod to hold the rod in a selected locked orientation, to a second position to space the rod engagement surface from the cooperative engagement surface of the rod to allow pivoting of the rod, and to a third position to release the rod from the outer sleeve.

Abstract: An apparatus for detecting the presence of a connecting rod during percutaneous spinal surgery comprises a tubular member and an elongate strip extending therethrough. The strip has a flag at the proximal end and an elastically flexible rod detection tip projecting outwardly from the distal end for contacting a connecting rod. The strip is supported in the tubular member for pivoting movement relative to the longitudinal axis of the member. A biasing member biases the strip to a first position in which the flag is adjacent a first side of the tubular member and the detection tip at the distal end is adjacent an opposite second side. Upon application of a force to elastically flex the detection tip, in which the force is sufficient to overcome the bias, the flag is shifted to a second position adjacent the second side of the tubular member.

Abstract: An apparatus and method for distracting, in a given direction, and supporting two tissue surfaces. A plurality of wafers are consecutively inserted between the two tissue surfaces to create a column of wafers. The column of wafers is oriented between the tissue surfaces so as to expand in the given direction as the wafers are consecutively added to the column.

Abstract: A dynamic stabilization device includes end caps that define a bore for receiving a corresponding bone screw therethrough. A spacer is engaged between each end cap and a cable passes through each of the components and is placed in tension to couple the spacer between the two end caps. The spacer is formed of a material that allows some flexible movement after implantation. An alternative stabilization device includes a spacer over-molded about two bushings defining the bores. According to a method of use, a stabilization device is passed along guide wires through a small incision. Once the device is in contact with the vertebrae, the bone screws are advanced along the guide wires and driven into the bone. One fastener bore may include a camming surface that causes distraction of the vertebrae as the bone screw is threaded into the vertebral bone.