Abstract: An apparatus and method is disclosed for securing tissue to a bone comprising a novel screw anchor for insertion into a bone by a novel rotational driver. The screw anchor and rotation driver enables the screw to be completely embedded into the bone while permitting a suture to be threaded through a transverse aperture in the screw. The rotation driver facilitates insertion and engagement of a capture with one of a series of protuberance formed along a length of a suture. In addition, the method is disclosed of forming the series of protuberance.

Abstract: The present invention relates to the field of medical devices, and more specifically to a radiolucent surgical handle system which utilizes properties of silicone and channel geometry to create a more responsive and stable medical instrument. Channel geometry is utilized to stabilize the outer silicone gripping layer, thus preventing axial, planar, lateral or angular movement of the silicone gripping layer under conditions of torque force during a surgical operation.

Abstract: A sleeve clamp has a body with a through bore for receiving a sleeve, and a clamping element. The clamping element includes a clamping edge and may be arranged at the body so as to be movable between two positions, i.e. a neutral position and a deflected position. In the neural position, the clamping edge protrudes laterally into a lumen which is occupied by the sleeve when the sleeve is received in the through bore. In the deflected position, the clamping element may be elastically deformed and the clamping edge does not protrude into the lumen which is occupied by the sleeve when the sleeve is received in the through bore.

Abstract: A telescopic insertion assembly is configured to insert a pedicle screw into a vertebral body. The insertion assembly includes an attachment fixture having one end configured to mate with the pedicle screw and another end having a ridged portion. A center tube is provided having one end slidably attached to the attachment fixture and another end having an internally ridged portion. A telescoping member has one ridged end configured to slidably attach to the center tube and another end having a yoke. The telescoping member is configured to extend the yoke to different distances from the center tube. An alignment member is configured to hingeably attach to the yoke of the telescoping member. The alignment member is configured to rotate from a first position to a second position. The second position of the alignment member is above a top surface of a patient's skin.

Abstract: A minimally invasive fixation system and installation method is provided. The system includes a rod having an anchor fixation head, an anchor system for anchoring the rod using the anchor fixation head, and a guide system configured to attach to the anchor fixation head of the rod for the insertion of the additional anchor systems. In one embodiment, a method for placing a spinal fixation element relative to a vertebra is provided.

Abstract: A helicoil interference fixation system comprising: a helicoil comprising a helical body comprising a plurality of turns separated by spaces therebetween, the helical body terminating in a proximal end and a distal end, and at least one internal strut extending between at least two turns of the helical body; and an inserter for turning the helicoil, the inserter comprising at least one groove for receiving the at least one strut; the helicoil being mounted on the inserter such that the at least one strut of the helicoil is mounted in the at least one groove of the inserter, such that rotation of the inserter causes rotation of the helicoil.

Abstract: A tool set for implanting bone screws in a human spine, followed by the implantation of a longitudinal connecting member into the bone screws includes a pair of independently mountable and manipulatable elongate guide tools that form a unitary tool guide when desired. Each guide tool includes attachment structure for independent operable connection of the guide tool to an arm of the bone screw. The bone screw/guide tool attachment includes an undercut and/or recess so as to resist separation of the guide tool member from an attached bone screw. Further tools include a removable stabilizer, a cooperating bone screw driver with an attached stabilizer, a closure starter/reduction tool, a closure driver and a counter torque tool.

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 blade assembly has a blade body and a blade body surround. A retractor attachment structure is attached to the blade body at the first end portion thereof extending from an exterior surface thereof. The retractor attachment structure is configured for having one of the blade body mounting structures of the retractor engaged therewith in a manner whereby the blade body is independently pivotable about and translatable along the blade body mounting structure. An alignment member protrudes from an interior surface of the blade body adjacent its first end portion. A slot extends through the blade body at its first end portion. The blade body surround and the blade body jointly form a generally cylindrical-shaped structure when the blade body is in a seated position within the slot. The cylindrical structure defines a central passage extending between the first and second end portions of blade body surround.

Abstract: Procedures and instruments for preparing and transplanting osteochondral allograft plugs to a host bone to repair an articular cartilage defect. An allograft bone plug having a cartilage plate and cancellous bone tissue attached thereto is removed from a donor bone. The allograft plug is further shaped by removing or cutting away cancellous bone tissue to form a cancellous stalk extending from the cartilage plate. At the recipient site of the host bone, a cutout is formed corresponding in shape to the allograft plug. The allograft plug is inserted into the cutout such that the cancellous stalk is retained in the host bone and the cartilage plate aligns with the condyle surface of the host bone.

Abstract: A screwdriver for actuating bone screws which have a shaft and a fork head for holding a vertebral rot or the like, includes a central shaft, which at its distal end is provided with a formfitting or force-fitting profile for engagement in a corresponding counter profile on the bone screw for turning the bone screw, a distal sleeve which rotatably engages around the shaft and is provided with connecting means for holding the screwdriver on the fork head of the bone screw, a handle provided at the proximal end of the screwdriver and a turn handle which is connected with the distal sleeve, and an adjustment device for axial adjustment of the relative position of the central shaft relative to the distal sleeve in at least two different predefined positions which are adjusted for different sizes and shapes of bone screws.

Abstract: A device, system and method for orthopedic spine surgery using a novel screw-based retractor, disclosed herein, that allows for access to the spine through a minimally or less invasive approach. The retractor device is designed as a co-molded part of the tulip of a pedicle screw assembly with opposed arms of the retractor spread apart to open the wound proximally. The arms are removed by separating the arms from the tulip and removing them from the incision. The retractor device is intended to be made of a relatively stiff material, sterile packaged and disposable after one use. A system and method for using the retractor and performing a minimally invasive spine surgical procedure are also disclosed.

Abstract: A device for handling a bone screw to be connected with a vertebral rod includes an essentially cylindrical and hollow housing and an adjustment tool which axially traverses the housing and which has a section provided with an outer threading and is screwed into an internal threading of the housing, wherein the housing is constructed pliers-like and has a first and a second jaw which relative to the user each have a proximal and a distal end, wherein the distal ends engage at the head of the bone screw, wherein the two jaws are pivotably connected with each other via a pivot axis which is situated between the distal and proximal ends and extends orthogonally in relation to the longitudinal axis of the housing, and wherein the internal threading of the housing is provided on a proximal end of a single one of the jaws.

Abstract: A positioning and installation tool for a fixation implant is inserted through a single, simple drill hole and positioned in place. The device controls the degree to which the implant is deployed and prevents accidental disengagement of the device from the implant before deployment has completed. The device also guides the components of the implant involved in active tendon compression at the aperture of the bone tunnel. The implant is deployed simply by rotating a knob, thereby creating an anchor point of high stiffness and fixation strength. When deployment has completed, the inserter is disengaged from the affixed implant by simply pulling a release mechanism.

Abstract: A system for guiding an implant to an optimal placement within a patient includes a trajectory guide for guiding instruments along a selected trajectory and a trajectory fixation device for fixing the trajectory guide in a selected position. The trajectory guide defines a path configured to align with the selected trajectory. A movable support mounts the trajectory guide and selectively moves the trajectory guide to align the trajectory guide with the selected trajectory prior to fixing the trajectory guide in the selected position. After fixing the trajectory guide, instruments can be inserted along the trajectory through the path defined by the trajectory guide.

Abstract: A tool and a method are provided for driving a bone pin into a fractured bone to stabilize the fractured bone by maintaining the fractured bone in a reduced state. The tool may be a handheld device including a cartridge having at least one passageway that receives the bone pin. The tool may also include a pneumatically-powered piston having a needle that is sized for receipt within the passageway of the cartridge, the needle applying sufficient force to the bone pin to drive the bone pin out of the cartridge and into the fractured bone.

Abstract: Apparatus, methods, systems, and kits related to surgical procedures and instruments are disclosed. In one aspect, a method for securing a fixation device to a driver for use in a surgical procedure is disclosed. The method comprises engaging a first portion of the driver with the fixation device to limit rotational movement of the fixation device relative to the driver; and engaging a second portion of the driver with the fixation device to limit axial movement of the fixation device relative to the driver; wherein engaging the second portion of the driver with the fixation device comprises actuating an actuator of the driver to cause the second portion of the driver to move relative to the first portion of the driver. In other aspects, surgical drivers, surgical kits, and surgical procedures are disclosed.

Abstract: A pedicle screw driver is provided and includes an inner shaft and outer shell. The shell includes a sidewall defining an inner cavity and has a slot formed on the sidewall. The slot includes a narrowed slot portion. The inner shaft includes a narrowed shaft portion. The narrowed shaft portion is sized to fit through the narrowed slot portion, but not other wider portion of the slot. The shell includes apertures that can permit gas and fluids to access the inner cavity of the outer shell.

Abstract: A facet fixation device formed from an anchor screw and a collet or facet screw that is secured to adjacent pedicles. The anchor screw having an aperture for receipt of a first end of guide wire or polyaxial based facet screw. The collet includes a unidirectional attachment mechanism wherein a wire can be drawn to a desired position to fix the distance between the anchor screw and the collet. Excess wire can then be removed.

Abstract: Bone anchors and surgical instruments (e.g., bone taps, drivers, etc.) are disclosed herein that include integrated guide tips. Use of these anchors or instruments can eliminate one or more of the steps in a conventional bone anchor installation procedure, improving surgical efficiency and safety. For example, a surgical instrument can include a guide projection configured for insertion through a cannulation formed in a bone anchor when the surgical instrument is coupled to the bone anchor. The surgical instrument can also include various mechanisms for adjusting the position of the guide projection relative to the bone anchor. The guide projection can replace the needle, stylet, and guidewire used in typical insertion procedures. The bone anchor can also include integrated tapping features to eliminate the need for a separate bone tap instrument. Thus, in some embodiments, targeting, tapping, and driving the bone anchor can be performed in a single step.

Abstract: An orthopedic implant screw driver includes drive shaft. A first gear is operably coupled to the drive shaft and in meshing engagement with a hollow gear which rotates in response to rotation of the drive shaft. The hollow gear includes a passage defining an inwardly facing screw engagement periphery configured to receive and drivingly rotate a threaded portion of the screw. A method of securing an orthopedic implant to a bone includes positioning a screw within the passage which is configured to drivingly engage a threaded portion of the screw and rotating a drive shaft in driving engagement with the gear causing the gear to engage the screw along the threaded portion of the screw and rotatably drive the screw via the threaded portion.

Abstract: An implant driver assembly includes an assembly for advancing a threaded implant over a wire. The assembly may include a driver tool with a proximal end, a distal end and a first engagement surface that has a first thread. The driver tool may also include a first wire passage. The assembly may further include a wire locking mechanism with a second engagement surface having a second thread. The second thread is engaged with the first thread to rotatably couple the wire locking mechanism with the driver tool. The wire locking mechanism may further include a second wire passage. The second wire passage may be substantially coaxially aligned with the first wire passage.

Abstract: Bone anchors and surgical instruments (e.g., bone taps, drivers, etc.) are disclosed herein that include integrated guide tips. Use of these anchors or instruments can eliminate one or more of the steps in a conventional bone anchor installation procedure, improving surgical efficiency and safety. For example, a surgical instrument can include a guide projection configured for insertion through a cannulation formed in a bone anchor when the surgical instrument is coupled to the bone anchor. The surgical instrument can also include various mechanisms for adjusting the position of the guide projection relative to the bone anchor. The guide projection can replace the needle, stylet, and guidewire used in typical insertion procedures. The bone anchor can also include integrated tapping features to eliminate the need for a separate bone tap instrument. Thus, in some embodiments, targeting, tapping, and driving the bone anchor can be performed in a single step.

Abstract: The disclosure provides examples of an open architecture anchor for securing soft tissue to bone, for example, to repair a torn rotor cuff. The anchor includes a helical screw thread having a base and two sidewalls that are non-linear. The non-linear sidewalls extend from opposing ends of the base and meet at a peak. The non-linear sidewalls are circumscribed within a triangle defined by the peak and ends of the base. Compared to the standard triangle profile, the helical screw thread profile has a smaller cross-sectional surface area and, consequently, removes less bone. The helical screw thread having the reduced cross-sectional area preserves bone stock and enhances the holding strength of the anchor in bone.

Abstract: An instrument for limiting torque can include a method for limiting torque that is transferred from a handle of the instrument through a torque transfer member to a shaft that extends relative to the handle. The method can include applying a torque to the handle along a direction relative to the shaft. The method can include transmitting the applied torque from the handle through the torque transfer member to the shaft when the applied torque is less than a limited torque value. When the applied torque is greater than the limited torque value, at least one of the torque transfer member and the handle deforms so as to allow the handle to rotate along the direction relative to both the torque transfer member and the shaft.

Abstract: Surgical instruments and devices including drivers, inserters, and reducers. The driver includes a ratcheting mechanism configured to provide uni-directional motion when engaged. The inserter includes a rack, pinion, and cam system designed to secure an implant and release an implant in-situ. The reducer includes a geared system for persuading together surgical components and aligning misaligned vertebrae.

Abstract: A rod reduction tool assembly includes an outer tube with outer tangs for engaging a bone anchor, an inner partially tubular pin support and a threaded cap mated to the outer tube and engaging the inner pin support.

Abstract: An instrument assembly can include a handle and an instrument. The handle can include an inner member and an outer member. The inner member can include a rod and a first tip. The outer member can include a second tip and can define a cannulation. The instrument can define a pocket configured to receive the second tip of the outer member. The handle can be adjustable at a desired angle relative to the instrument when the second tip of the outer member is disposed in the pocket and the first tip of the inner member is positioned in the cannulation spaced apart from the second tip. The first tip can be configured to expand the second tip radially outward such that the second tip engages the pocket and locks the handle at the desired angle when the first tip is positioned in the cannulation in engagement with the second tip.

Abstract: A surgical instrument includes a first member defining a longitudinal axis and including a drive interface engageable with a first surface of a bone fastener. The first surface is configured for penetrating a sacrum. A second member includes a drive interface engageable with a second surface of the bone fastener to translate the second surface relative to the first surface such that the second surface engages an outer non-articular surface of an ilium to draw separated articular surfaces of the sacrum and the ilium into fixation. In some embodiments, systems and methods are disclosed. Systems and methods are disclosed.

Abstract: Method to attach two sections of bone together in which a telescoping screw system is positioned through a hole of a fixation device attached to a first section of bone while the screw system is in a closed configuration in which the screw body is telescoped inside the screw barrel. The screw body is then advanced relative to the screw barrel to cause penetration of the forward, threaded end of the screw body into a second section of bone, and thereby bring the screw system toward an open configuration in which the screw body is telescoped outside the screw barrel. The screw barrel is also engaged to the fixation device via a cooperating engagement mechanism.

Abstract: Embodiments of the present invention provide a cannulated screw driver assembly which includes a rigid guide pin such that the assembly can be used to assist the surgeon in inserting and positioning the rigid guide pin and an interference screw within a bone graft tunnel. Once the screw is properly placed, screw driver assembly components to include the rigid guide pin, the driver and the handle can be removed while the screw remains in the tunnel to secure the graft. In one embodiment, the interference screw can be removed from the distal end of the driver and the driver and handle can be removed from the screw's proximal end. Embodiments of the inventions also include an interchangeable driver to mate with different size and types of interference screws.

Abstract: A device for removable attachment to a bone of a living patient, useful as a mounting support for a trackable part of a computerized surgical navigation system and a method for attaching an object removably to a bone of a living patient. A shaft having a self drilling, self-tapping screw tip can be inserted transversely of the bone and securely screwed into the cortex. A screw drives a sharp-edged sleeve along the shaft to engage the near cortex. A stepping mechanism allows incremental angular movement of a portion of an adjustment mechanism and indicates when the sleeve is securely engaged by resisting further tightening.

Abstract: A surgical implant driver includes a member defining an engagement portion including a wall having a circumference and a plurality of lobes disposed thereabout. The lobes are curved toward an interior of the circumference and are connected by a plurality of arcuate portions that are curved toward the interior of the circumference.

Abstract: A method for performing spinal fixation and instrumentation. A first incision may be made through the skin and a passageway may be created to the spine. A screw may be inserted through the passageway and into a vertebrae. The screw may have a head portion including a channel. An insertion guide may be operable connected to the screw. The insertion guide may have first and second longitudinal slots. Additional screws may each be inserted through separate incisions or through the first incision. Insertion guides may be operably connected to a head portion of each screw. A sleeve may be positioned into one insertion guide in a first position to guide a rod through at least one other insertion guide. The sleeve may be rotated to a second position to allow the rod to move down the slots of the insertion guide(s) and into the head portion of the screw.

Abstract: A tool for holding or driving an implant member having a recess is provided including an elongate tool shaft having a distal head portion for being received in the recess and a securing mechanism that keeps the head portion in the drive recess and which is disposed proximally up along the tool shaft from the distal head portion. In one form, the securing mechanism includes a plurality of resilient leg member having distal end locking portions. In another form, a drive system includes a drive tool and a driven member. The drive tool has a generally annular flange portion that is radially larger than the drive head portion. The driven member has a generally annular securing portion for receiving the flange portion in releasably locked engagement so that the circumferential extent of the locking engagement is maximized relative to the smaller radial size of the drive head portion.

Abstract: A locking peg includes a head and a shaft. The head is at the proximal end of the locking peg, and a shaft extends distally from the head to a distal end of the locking peg. The shaft has a threaded proximal portion and an unthreaded distal portion. A length of the unthreaded distal portion of the shaft is greater than a length of the threaded proximal portion of the shaft. When the locking peg is inserted into a bone through a bone plate, the threaded proximal portion of the shaft extends into the bone. This extended threading provides additional axial force to help explant the locking peg during removal of the locking peg.

Abstract: The present invention relates to a connector including a body having a helix configured to change circumferentially in response to a change in force applied to the connector, the connector characterised in that the helix has at least one portion with a tapered circumference.

Abstract: A programmable screw driver and method for affixing screws into bone is disclosed. The screw driver includes a torque sensor for measuring torsional input during screw insertion, a rotational motion sensor for measuring the rotation of the screw driver, and a microprocessor. Once a surgeon rotates a screw to be affixed to the bone, the torque sensor measures the torque and sends this information to the microprocessor. Once a predetermined torque level is attained, the microprocessor begins to measure subsequent rotation of the screw driver until a predetermined rotational limit, thereby causing a signal to be sent to alert the surgeon to stop tightening.

Abstract: A device for facilitating implantation of an intramedullary nail includes a coupling portion extending from a first end configured to couple to a proximal end of an intramedullary nail to a joint portion and a radiolucent handle coupled to the joint portion and extending distally therefrom along a path which, when the coupling portion is coupled to an intramedullary nail in a desired orientation, extends substantially parallel to a longitudinal axis of a proximal portion of the nail, the radiolucent part including first and second radiopaque markers positioned and oriented so that, when the nail is coupled to the coupling portion in the desired orientation, the first and second markers align with edges of the proximal portion of the nail.

Abstract: A nail cap cannula for directing a nail cap useable with an intramedullary nail system including an intramedullary nail and a targeting guide.

Abstract: A medical screwdriver configured to avoid disengaging from a screw during implantation of the screw at a surgical site, the screwdriver including an outer shaft having a housing in which is located a piston and a spring, an inner shaft, and a collar. When the collar is rotated in a first direction the collar is positioned at a first position and the inner shaft is rotationally coupled to the outer shaft. When the collar is rotated in a second direction opposite the first direction, the collar moves to a second position and the inner shaft is unlocked from the outer shaft.

Abstract: A distance indicator for indicating the distance that a device has traveled includes an elongate housing with a guidewire connector configured for operative connection to a guidewire to hold the housing stationary with respect thereto. A plunger is operatively connected to the housing for longitudinal motion with respect to the housing. A first plunger end is configured to operatively contact the device. As the guidewire connector is holding the housing stationary with respect to the guidewire, the first plunger end is placed into operative contact with the device with the plunger and housing in a first relative plunger/housing position. The device moves longitudinally. The plunger moves into a second relative plunger/housing position assisted by the operative connection between the first plunger end and the device. The longitudinal difference between the first and second relative plunger/housing positions indicates a distance that the device has moved longitudinally with respect to the guidewire.

Abstract: A guide and method for cutting bones adjacent a joint at locations referenced to the joint anatomy is presented.

Abstract: The device incorporates multiple implants for the attachment of prosthetic equipment, and is characterized by the fact that it incorporates multiple identical implants (1) positioned in alignment and connected to each other at their front (1a) and rear (1b), in a temporary manner, such that the said implants have a screw-form external configuration, and such that each implant has a longitudinal internal cavity (1c) of triangular cross-section extending fully from end to end, that constitutes the housing for a means of pre-positioning (3) configured to have a triangular imprint with a spiked-form end part (3a), such that the interconnection of the implants at the respective front and rear of two successive implants is a temporary connection, and such that the multiple implants constitute an assembled set intended to be inserted into a loader unit associated with the ancillary insertion device.

Abstract: An interlock driving instrument is configured to be releasably lockable to a fastener, such as a bone anchor. A bone anchor can be locked to the interlock driving instrument by inserting an expandable distal end of the shaft of the interlock driving instrument into the driving opening of the bone anchor and expanding the distal end within the driving opening by translating an expansion member into the expandable distal end. Alternatively, the bone anchor can be locked to the interlock driving instrument by inserting the distal end of the shaft of the interlock driving instrument into the driving opening of the bone anchor and translating a sliding member along a sloped surface defined in a channel extending into the shaft.

Abstract: A drive tool for accepting and rotationally locking the head portion of an orthopedic screw, such as a dental implant, to impart driving torque to the screw. In one exemplary embodiment, the drive tool includes an elongate body having an opening at its proximal end which is sized to receive the head portions of at least two different dental implants, the head portions of the dental implants being oriented at different angles with respect to the implant body portions. When the head portion of an implant is received within the opening, the drive tool is rotationally locked with respect to the implant. In this position, the body of the drive tool remains oriented so that same is substantially colinear with the body portion of the implant. Although the invention is described in the context of a drive tool used with a dental implant having a body portion and a head portion or abutment portion, the invention is more broadly applicable to drive tools which may be used with other types of orthopedic screws.

Abstract: A Lisfranc injury between a second metatarsal and medial cuneiform is repaired by gaining access to the injury site and placing two arm members of a novel drill guide around the two neighboring bones at the injury site, drilling a guide wire through the two bones guided by the drill guide to a desired depth, measuring the depth of the guide wire to determine the proper length for a bone screw for securing the two bones, drilling a cannulated drill bit into the two bones to a drill depth using the guide wire as a guide, and threading a bone screw into the two bones.

Abstract: A plate puller device can include a head portion and extension rod portion. The device enables the fastener receiving member to be pulled against a bone surface before a head section of the fastener is advanced within the fastener receiving member into a locked position. The head portion can be positioned between the head section of the fastener and a surface of the fastener receiving member not adjacent to the bone surface. Also, a plate puller device can include a screwdriver, a grasper portion and a grasper sleeve. The grasper portion and grasper sleeve can be threadingly mated wherein rotation of the grasper sleeve forces a head portion of the grasper portion to grip the head section of the fastener to prevent the head section from advancing within the fastener receiving member.

Abstract: An instrument for provisionally tightening a screw body member to a head of a polyaxial bone screw includes a barrel body, an inner shaft, a handle and lever, and a load link assembly. The barrel body includes a distal end with a pair of rotatable tangs configured to engage the screw body member. The inner shaft includes a distal end configured to engage a bushing within the screw body member. The lever pivotally couples to one of the handle and the barrel body. The load link assembly couples to the inner shaft and the lever. Actuation of the lever towards causes the load link assembly to longitudinally displace the inner shaft toward the distal end to contact the bushing and advance the bushing into frictional fit between the screw body member and the head of the polyaxial bone screw.

Abstract: A modular dynamic pedicle screw system including anchoring device having a threaded shank for anchoring within a vertebra, an intermediate element and a head portion configured to receive and secure a rigid or non-rigid stabilization rod. The threaded shank, the intermediate element and the head portion of the anchoring device are cannulated to permit percutaneous implantation of the device. The intermediate portion is designed to be removable from the threaded shank portion subsequent to implantation of the anchoring device to enable substitution of another intermediate element having different dynamic characteristics. The dynamic stabilization system includes an adjustable torque limiting device that is interchangeable between a tap device and a screw driver. The torque device provides information relative to the patient's bone quality inter-operatively in order to determine the appropriate modulus of elasticity for the dynamic pedicle screw.