Abstract: Methods and apparatus for providing correction of one or more maladies or conditions of the spinal column of a living being. In one embodiment, the apparatus includes an implant delivery instrument and an implant for use therewith. In one variant, the implant delivery instrument includes a non-detachable distraction member for distraction of the disc space and a track for slidable delivery of an implant to the distracted disc space. In another variant, the implant delivery instrument includes a detachable distraction member for distraction of the disc space and a track for slidable delivery of an implant to the distracted disc space. In the latter variant, the distraction member is co-implanted in the disc space with the implant.

Abstract: An instrument includes a sleeve extending between proximal and distal ends. The sleeve defines a passageway. The distal end defines an engagement portion including an engagement surface extending from a first end to a second end. A peg extends outwardly from the first end. An opening that is in communication with the passageway extends through the second end. A knob is coupled to the proximal end. A shaft includes a proximal end and an opposite distal end. The distal end of the shaft includes a mating portion. The mating portion extends through the opening. The proximal end of the shaft is coupled to the knob. The knob is rotatable relative to the sleeve to rotate the shaft relative to the sleeve. Methods of use are disclosed.

Abstract: A spinal implant comprises an implant body extending between an anterior surface and a posterior surface, and including a first vertebral engaging surface and a second vertebral engaging surface. The implant body includes an inner surface that defines at least a first cavity and a second cavity. The cavities are oriented to implant fasteners in alignment with an oblique surgical pathway relative to a bilateral axis of a subject body and adjacent an anterior portion of an intervertebral space of the subject body. Systems and methods are disclosed.

Abstract: A spinal-correction system having (i) a receiver including a base and opposing arms extending proximally from the base forming a rod-receiving cavity, (ii) a pair of extender tabs, each extender tab having threaded inner walls for receiving threads of a setscrew, (iii) a pair of tab extenders each being connectable releasably to one of the extender tabs, (iv) a cap instrument connectable releasably to the tab extenders, and (v) a pair of breakoff sections, each connecting one of the extender tabs to one of the receiver arms, and each being readily breakable for separating the extender tab from the receiver arm. The distal base defines a bonescrew cavity to receive a bonescrew head so that the head can move relative to the base. Each receiver arm has threaded inner walls for receiving setscrew threads. The rod-receiving cavity has geometry corresponds to geometry of the setscrew and a spinal-correction rod.

Abstract: The present application is directed a Joint Revision Surgery Apparatus which includes a blade guide block which has a plurality of blade guide slots and a central cavity. The blade guide block central cavity is positioned over the trunnion end of the existing prosthesis to be removed and secured to the prothesis. Straight, curved and compound curved knife blades are guided by the blade guide slots to cut the prothesis free. The securing of the guide blade block support apparatus against the femur is accomplished by the means of a male threaded T handle screw or male threaded eyebolt threading into one of the female threaded orifices in the blade guide block frame. The guide blocks in varying sizes and configurations, straight and curved knifes blades and related accessories may be sold as a complete kit. The Joint Revision Surgery Apparatus facilitates rapid, efficient and complete removal of an existing prosthesis during joint revision surgery.

Abstract: An implantable tendon protection system includes a body adapted to be implanted within a bursa overlying a tendon of a patient to protect the tendon. The body may be fixed to the tendon with adhesive, sutures, staples, and/or anchors. A surgical kit is provided with such a tendon protection system and an insertion cannula. Methods of protecting a tendon of a patient are also disclosed.

Abstract: The present application provides a tool for minimally invasive surgical procedures. The tool includes a first and second portion where each portion has an outer blade and an inner blade that is slidable along the outer blade. A removable connector connects the first and second portions. When removed, the first and second portions are separated by a gap extending the length of the tool.

Abstract: Disclosed are devices and methods used to customize the length of fasteners used during orthopedic surgeries, comprising creating a hole of the desired depth in a bone, measuring the depth of the hole using a depth measuring device, calculating, using the depth measuring device, the optimal length dimension of the fastener, transferring the calculated fastener optimal length dimension to a fastener cutting device, inserting a fastener having a length exceeding the optimal length dimension into the fastener cutting device, and cutting the fastener to the optimal length dimension using the fastener cutting device.

Abstract: A surgical coupling member includes a shaft defining an axis and including at least one thread having an external thread form. The external thread form having a leading flank and a trailing flank. The external thread form defines a pitch and a crest, the crest having a width in a range of about 35% to about 50% of the pitch of the external thread form, wherein the leading flank and the trailing flank are angled in a proximal orientation relative to the thread axis, and wherein the external thread form is configured to interlock with an internal thread form of an implant receiver. Systems, spinal constructs, implants and methods of use are disclosed.

Abstract: The present invention is directed to a system comprising a medical instrument (e.g. cup implant, 3) and a holding device (2) that interacts with said medical instrument to form a sealable cavity within the combined arrangement of components. An impaction device (1) is also provided, preferably which provides means to allow fluid to be expelled from the cavity but which prevents further fluid from entering the cavity.

Abstract: Provided is a novel rod reducing device including a screw jack mechanism that is moveably engaged with an elongated grasping fork assembly, the screw jack mechanism having an elongated threaded portion, the elongated threaded portion being connected at its most distal end to a rod contact member, which is positioned in sliding circumferential contact with each of the two opposing elongated grasping members and the most proximal end of the elongated threaded portion terminating in a controlling member, which can be activated in a measured and controlled manner. A method of using the device is also provided.

Abstract: A device and a method of treatment for osteoarthritis of a joint, such as the hip. The implant is an extensible cap that is placed over the femoral head.

Abstract: A bone fusion method, system and device for insertion between bones that are to be fused together and/or in place of one or more of the bones, such as, for example, the vertebrae of a spinal column. The bone fusion device comprises one or more extendable tabs having a central rib. The bone fusion device includes one or more support channels configured to receive an insertion instrument that is then secured to the bone fusion device via a coupling mechanism. As a result, the coupled device is able to be securely positioned between vertebrae using the insertion instrument with minimal risk of slippage.

Abstract: Devices and methods for the removal of bone implant tips from within a bony structure in a body. The device or method includes a shaft with an internal grasping feature capable of being inserted while remaining in an un-expanded, un-deployed state. This permits a surgeon or operator to insert the device while in a small profile state, avoiding or reducing damage to adjacent bone tissue during insertion. Upon insertion of the shaft to the proper position within a patient's bone, the grasping feature may then be expanded or deployed from the distal end of the shaft by a surgeon or operator using an actuator in a handle attached to the proximal end of the shaft. Following deployment, the grasping feature may be used to manipulate and/or remove a bone implant tip from a patient's bone tissue. Embodiments of the grasping feature include one or more hooks, wires, articulating fingers, and/or net-based designs formed of metal, polymer, composite, or a combination thereof.

Abstract: Implant inserters and related methods are disclosed herein, e.g., for delivering a fusion cage or other implant to a spinal disc space and for rotating or articulating the implant within the disc space. An exemplary instrument can include a slider that is slidably mounted to a body to define an implant clamp. A locking mechanism can allow the slider to be quickly disassembled from the body and for fast and convenient loading and unloading of an implant to the instrument. An actuation knob can be moved between a first position in which the implant is locked from rotating relative to the instrument and a second position in which the implant is retained to the instrument but allowed to rotate relative to the instrument.

Abstract: An intervertebral device comprises a plurality of struts that are rotatably associated with each adjacent strut to form a modifiable inner volume V for bone graft containment.

Abstract: A geared cam expandable spinal implant. Rotational motion of a rotating portion is translated into linear motion of a yoke, which moves geared cams at the distal end of the implant to mate with, and walk along, teeth of corresponding racks. The walking of the gear cam teeth along the rack teeth creates a regular rate of implant expansion, reduces initial excessive expansion force applied to the implant, and provides fine adjustment of the expansion rate and force.

Abstract: A system and method for allowing any surgeon, including those surgeons who perform a fewer number of a replacement procedure as compared to a more experienced surgeon who performs a greater number of procedures, to provide an improved likelihood of a favorable outcome approaching, if not exceeding, a likelihood of a favorable outcome as performed by a very experienced surgeon with the replacement procedure. Force sensing is included to aid in quantifying installation of an implant, particularly a cup into a pelvic bone.

Abstract: An inserter includes a knob at its proximal end. The knob actuates linear motion of a slide at the distal end of the inserter. The linear motion of the slide separates two pins that project from a distal end of the inserter. The pins engage and release corresponding holes defined in the faceplate of an implant. The pins can project at an oblique angle from the longitudinal axis of the inserter. The angle of projection of each pin can be different so that a jaw-like action is provided, which securely grasps the implant via the holes in the faceplate.

Abstract: A system and method for improving installation of a prosthesis. Devices include prosthesis installation tools, prosthesis assembly tools, site preparation systems, and improved power tools used in implant site preparation, the tools including a secondary motion that preferably includes an ultrasonic vibration.

Abstract: The instant disclosure is directed to methods of improving bone-soft tissue healing using biocompatible electrospun polymer fibers. In one embodiment, a method may include locating a portion of a subject's bone, affixing a tendon or ligament to the bone using a hardware fixture, and placing a patch comprising at least one electrospun polymer fiber in physical communication with both the bone and the tendon or ligament. In some embodiments, the bone may be a humerus, and the tendon or ligament may be a supraspinatus tendon. In certain embodiments, the patch may comprise substantially parallel electrospun polymer fibers, and may be placed such that the fibers are also substantially parallel with the long axis of the tendon or ligament.

Abstract: A screw extension assembly for use in minimally invasive spinal surgery, the assembly has an inner slotted shaft and an outer shaft, a rod reducer and a removable nut. The combination when assembled is configured to move a spinal fixation rod into a slotted rod receiving spinal implant where it is seated and affixed thereto. The screw extension assembly further has a locking knob rotationally coupled to a proximal end of the outer shaft, wherein the inner shaft has one or more cam grooves and the locking knob has a pin extending into and guided by said cam groove causing the outer shaft to translate longitudinally upon rotation of the locking knob relative to the inner shaft toward an engaged position locking the deflectable legs in the coupled position to the slotted rod receiving implant.

Abstract: 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.

Abstract: A modular inserter assembly for use in inserting an interbody fusion cage into the disc space between opposing vertebrae comprises a depth stop and a modular inserter tip releasably attached thereto. The modular inserter assembly includes a cage attachment surface for releasable attachment to an interbody fusion cage, the depth stop including a movable stop axially movable relative to the inserter tip and being sized and configured to engage an exterior surface of one of the vertebrae to establish the depth to which the interbody fusion cage is to be inserted in the disc space. A plurality of modular inserter tips, each being configured for selective releasable attachment to differently sized interbody fusion cages are provided in a kit with the depth stop.

Abstract: A method for inserting an intervertebral disc prosthesis into a space between two vertebrae involves inserting the prosthesis partway into the space under constraint to prevent endplates of the prosthesis from articulating, releasing the prosthesis from constraint, and inserting the unconstrained prosthesis farther into the space. In some embodiments, the method involves grasping the prosthesis with a grasping device to insert the prosthesis partway under constraint, loosing the grasping device to release the prosthesis from constraint, and pushing the prosthesis farther into the disc space using the grasping device and/or one or more separate pusher devices. A system includes a grasping device, at least one separate pushing device, and optionally a vertebral spreading device and/or a vertebral midline indicator device.

Abstract: A surgical instrument apparatus includes an elongate tubular body having a proximal end and a distal end and a bore extending through the tubular body; an actuator link extending through and configured to move longitudinally within the bore, the actuator link including a first end connected to a first actuator at the proximal end of the tubular body and a second end terminating in a coupler, wherein the first end of the first actuator causes the actuator link to selectively move between an extended state and a retracted state.

Abstract: Methods and apparatus for holding and maneuvering a valve during preparation and attachment to patient, providing increased visibility of the prosthetic valve and the sewing ring to prevent suture entanglement. A handle attachment is spaced from the valve for improved visibility of the sewing ring and the outlet end of the valve during attachment. Commissure posts are bent inward at the tips while preventing crashing of the commissure posts into each other causing damage. A release force needed to remove the holder and unthread the holder sutures is reduced. The holder and related methods can provide a kink free holder suture path to reduce suture entanglement and prevent damage to the implanted valve during holder removal by reducing the release force needed to remove the holder sutures by up to 30%.

Abstract: A system, method, and computer program product for allowing any surgeon, including those surgeons who perform a fewer number of a replacement procedure as compared to a more experienced surgeon who performs a greater number of procedures, to provide an improved likelihood of a favorable outcome approaching, if not exceeding, a likelihood of a favorable outcome as performed by a very experienced surgeon with the replacement procedure, such as by understanding the prosthesis installation environment (e.g., cup/cavity interface) and to provide intelligent and interactive tools and methods to standardize the installation process and provide feedback regarding a quality of insertion/installation. Force sensing is included to aid in quantifying installation of an implant, particularly a cup into a pelvic bone.

Abstract: Apparatuses and systems including at least one of mounting and removal of a femoral component on a femur are disclosed. The instrument can include a handle, a plunger, first and second arms and a knob. The handle can define a recess. The recess can extend along a portion of an elongate length of the handle. The plunger can be moveably disposed within the recess and can be configured to extend through an opening in a distal end of the handle to engage a pad to contact the pad against the femoral component. The first and second arms can be pivotally coupled to the handle and can be pivotable relative to one another. The first and second arms can each have at least one coupling feature configured to engage with a corresponding second coupling feature in the femoral component. The knob can be configured to operatively actuate the plunger to move the plunger proximal/distal within the recess to engage the plunger with and disengage the plunger from the pad.

Abstract: A method and system for performing bone fusion and/or securing one or more bones, such as adjacent vertebra, are disclosed. The screw includes a threaded distal piece fixedly attached connected to an inner post. Both the inner post and the proximal piece have non-cylindrical receptacles at their proximal ends for engagement with driving tools. Independent rotation of the proximal piece and the distal piece enables for compression or decompression to modify the gap between two bones or bone fragments. During use, the distal piece of the bone screw is placed at least partially within a distal bone, the proximal piece is placed at least partially within a proximal bone, and one of two pieces is rotated while the other is held in a fixed position, causing movement of the proximal and distal bones relative to each other.

Abstract: Guides, implants, devices, instruments, systems, and assemblies for achieving bone fusion are disclosed. A bone fusion system, including an implant template, a guide wire for insertion through the implant template, a plate for receiving the guide wire, and an alignment guide apparatus for coupling to the plate. Methods of using a bone fusion system for achieving bone fusion are also disclosed.

Abstract: An intervertebral scaffolding system is provided having a central beam having a proximal portion having an end, a grafting portion having a top and a bottom, a distal portion having a end, a central beam axis, a graft distribution channel having an entry port at the end of the proximal portion, a top exit port at the top of the grafting portion, and a bottom exit port at the bottom of the grafting portion. These systems can also include a laterovertically-expanding frame operable for a reversible collapse from an expanded state into a collapsed state. The expanded state, for example, can be configured to have an open graft distribution window that at least substantially closes upon the reversible collapse.

Abstract: An orthopedic instrument in the form of an acetabular cup extractor system for reliably and efficiently extracting an acetabular cup implant from an acetabulum. The system includes a handle assembly, an extractor attachable to a distal end of the handle, and a dome guide assembly having a hemi-spherical dome for engaging the extractor and a centering body extending distally from the hemi-spherical dome for engaging an acetabular implant. The extractor includes a curved, concave guide and a curved blade. The curved, concave guide is sized and shaped to substantially matingly engage with and cover a substantial portion of the hemi-spherical dome. As a result of such an arrangement, a uniform cut is achieved by the curved blade thereby resulting in a minimum of bone being extracted from the acetabulum around the acetabular cup implant during a surgical procedure.

Abstract: An ultra-sonic medical dissector includes a vibration generator and a wire that defines a cutting loop remote from a first end and a second end. The wire is coupled to the vibration generator in a cutting configuration, and a cutting surface is located on an inner curvature of the cutting loop. A vibration is generated by the vibration generator is transmitted to the cutting loop by the wire when the wire is in tension. The cutting loop can free an embedded end of a vena cava filter from a vessel wall to ease retrieval.

Abstract: New surgical instruments and methods used to implant elements of a reverse hip prosthesis in a patient are described. The instruments are impactors which are struck with a hammer at their proximal ends after the instrument has been used to position the implant element in the patient. An acetabular cup impactor has inclination and anteversion rods which are used to position the acetabular cup optimally in the acetabulum. An acetabular ball impactor affixes the acetabular ball in the acetabular cup by means of a Morse taper. And a femoral cup impactor affixes the femoral cup in the femoral stem by means of a Morse taper.

Abstract: Surgical trays and tools for use in hip revision surgery wherein the implanted prosthesis is a reverse prosthesis comprising an acetabular ball and a femoral cup. A set of trays is provided having tools for i) separating a femoral cup from an acetabular ball, ii) separating a femoral cup from a femoral implant and iii) separating an acetabular ball from an acetabular cup. A tool for removing an acetabular cup from an acetabulum is also described. A surgical method is also provided wherein the acetabular ball and femoral cup are separated first followed by, in any order, separating the femoral cup from the femoral implant and separating the acetabular ball from the acetabular cup.

Abstract: A femoral head press can comprise: a frame having first end second ends; a clamp connected to the first end to define a holding plane; a mechanical drive mechanism mounted to the second end and having a drive axis; a ram connected to the second end; and a femoral head cup connected to the ram; wherein the mechanical drive mechanism is configured to drive the ram along the drive axis substantially perpendicular to the holding plane to advance the femoral head cup toward the clamp. A method for assembly a femoral head to a stem neck can comprise: attaching a clamp of a frame of a femoral head press to a neck of a femoral stem; connecting a femoral head to a cup connected to a ram slidably engaged with the frame; and actuating a mechanical drive mechanism coupled to the frame to advance the cup toward the neck.

Abstract: An intervertebral insert member and an instrument for positioning the insert in a space between vertebral bodies in vivo. The insert member is advanced by the instrument into a prepared site located between adjacent vertebral bodies. Upon reaching the appropriate insertion point, the sleeve is retracted and a pivotal motion is imparted to the insert. The insert member is pivotally attached to the distal end of the delivery instrument such that it can be articulated about a pivot point that is located on the insert member until it is properly positioned. The positioning instrument is then released from the insert member and removed from the space between the vertebral bodies. An adjustment screw is available to expand the surfaces of the insert member by displacement of a wedge member within the insert.

Abstract: New surgical instruments and methods used to implant elements of a reverse hip prosthesis in a patient are described. The instruments are impactors which are struck with a hammer at their proximal ends after the instrument has been used to position the implant element in the patient. An acetabular cup impactor has inclination and anteversion rods which are used to position the acetabular cup optimally in the acetabulum. An acetabular ball impactor affixes the acetabular ball in the acetabular cup by means of a Morse taper. And a femoral cup impactor affixes the femoral cup in the femoral stem by means of a Morse taper.

Abstract: Hair Graft Placement Apparatus Used for Hair Transplantation. This invention is related to a hair graft placement apparatus that enables the placement of previously obtained hair grafts into incisions made on a bald scalp during the hair transplantation process. The invention consists of wall thickness (1), end region (2), narrow channel (3), wide channel (4), metal tube (5), handle grip (6) and finger slot (7).

Abstract: A surgical instrument and method for inserting a spinal implant in the intervertebral disc space between two adjacent vertebrae and an anchor engageable with the implant and an adjacent vertebra are provided. The instrument includes an inserter having an engagement portion including a distal engagement surface for interfacing with the implant and a handle portion. The engagement portion includes a track for slidably translating the anchor toward the engagement surface. A kit is provided including the inserter and a tamp to force the anchor into engagement with the implant and the adjacent vertebra. The kit may also include a cutter for piercing the adjacent vertebra.

Abstract: Provided are modular implant delivery systems, devices and methods. In some embodiments, spinal implant delivery devices and methods are provided. An exemplary delivery device may include a head supported by a handle. The head may have an opening defining an insertion axis. The handle may have a handle axis that traverses the insertion axis. The head may also be configured to releaseably couple one or more blades.

Abstract: The present invention is directed to methods and instrumentation for performing surgery on the spine along its lateral aspect (side) and generally by a lateral, anterior or an anterolateral surgical approach, such that the instruments enter the body from an approach that is other than posterior and make contact with the spine along its lateral aspect. The present invention provides for the entire surgical procedure to be performed through a relatively small incision and may be performed in either the thoracic or lumbar spine.

Abstract: A kit includes a number of femoral prostheses of different sizes and shapes. Each femoral prostheses in the kit includes a femoral stem including a proximal end portion defining a proximal stem axis, a femoral neck portion including a lateral shoulder extending distally and laterally at an angle relative to the proximal stem axis, such that when projected onto a coronal plane including the proximal stem axis, the lateral shoulder is not parallel to the proximal stem axis. Each prostheses further includes an insertion/extraction cavity extending distally from a proximal surface of the neck portion, the cavity defining an insertion/extraction cavity axis which, when projected on to the coronal plane, is not parallel with the proximal stem axis, and the lateral shoulder of each femoral prosthesis is oriented at an angle relative to the proximal stem axis that is different from the angle of each of the other femoral prostheses.

Abstract: The present invention provides an expandable fusion device capable of being installed inside an intervertebral disc space to maintain normal disc spacing and restore spinal stability, thereby facilitating an intervertebral fusion. In one embodiment, the fusion device includes a body portion, a first endplate, and a second endplate, the first and second endplates capable of being moved in a direction away from the body portion into an expanded configuration or capable of being moved towards the body portion into an unexpanded configuration. The fusion device is capable of being deployed and installed in both configurations.

Abstract: A system for fusing together opposing vertebra of a spine that defines a disc space therebetween. The system comprises a disc preparation instrument and an inserter assembly for use in the interbody fusion procedure. Disc preparation instrument comprises an elongate handle supporting a trial device at one end thereof. Inserter assembly comprises an elongate inserter supporting at one end thereof an interbody cage implant for insertion into the disc space. Disc preparation instrument provides a scoring element that scribes vertebral endplates at an appropriate scored location for anchor blades on the cage implant to engage the vertebral bodies. Inserter is used to introduce cage implant with anchor blades into the disc space to an appropriate depth so that the blades will be precisely positioned at the scored location created by the scoring element for penetration into the vertebral endplates.

Abstract: An intervertebral cage and intervertebral cage apparatus and a method for using the intervertebral cage and/or the intervertebral cage apparatus. The intervertebral cage can be any desired material including a memory material. The intervertebral cage apparatus can include the intervertebral cage and one or both of a variable volume pouch and a deployment cable. The variable volume pouch can be inserted into an internal volume of the intervertebral cage and affixed to the intervertebral cage. The variable volume pouch can be filled with material to achieve an expanded state. The variable volume pouch can assist in the deployment of the intervertebral cage. The deployment cable can be attached to the intervertebral cage and can include features to facilitate that attachment. The deployment cable can apply a force to the intervertebral cage to deploy the intervertebral cage, and can include features to lock the intervertebral cage in the deployed configuration.

Abstract: Described herein are reusable surgical needles having a resiliently collapsible rear loop that captures a suture as it is passed through an object and resiliently expands upon exiting the object to release the suture. Also described are suture spool assemblies that include a rigid housing and a rotatable spool of suture material suspended within the housing so that a plurality of sutures can be dispensed from the assembly in succession during a surgery. Also described are annular pledgets having diametrical dimensions similar to an outer ring of a cardiac implant such that a single annular pledget can be used with a plurality of sutures that secure the cardiac implant to native tissue around the perimeter of the cardiac implant. Related methods of suturing cardiac implants are also disclosed.

Abstract: Spinal implant trials are provided having various configurations and sizes that aid the selection of spinal implants having similar configurations and sizes. A surgeon during surgery can insert various configurations and sizes of the spinal implant trials into a disc space between two adjacent vertebral bodies of a patient to enable the selection of a spinal implant configured and sized to fit the patient's disc space. Fluoroscopic images can be used in aiding the selection of an appropriately configured and sized spinal implant corresponding to one of the spinal implant trials. The spinal implant trials include features that reveal on the fluoroscopic images whether the spinal implant trials are properly located and oriented in the disc space and include features corresponding to different sizes of spinal implants also revealed on the fluoroscopic images.

Abstract: A system for fusing together opposing vertebra of a spine that defines a disc space therebetween. The system comprises a disc preparation instrument and an inserter assembly for use in the interbody fusion procedure. Disc preparation instrument comprises an elongate handle supporting a trial device at one end thereof. Inserter assembly comprises an elongate inserter supporting at one end thereof an interbody cage implant for insertion into the disc space. Disc preparation instrument provides a scoring element that scribes vertebral endplates at an appropriate scored location for anchor blades on the cage implant to engage the vertebral bodies. Inserter is used to introduce cage implant with anchor blades into the disc space to an appropriate depth so that the blades will be precisely positioned at the scored location created by the scoring element for penetration into the vertebral endplates.