Abstract: A dynamic stabilization, motion preservation spinal implant system includes an anchor system, a horizontal rod system and a vertical rod system. The systems are modular so that various constructs and configurations can be created and customized to a patient.

Abstract: A dynamic stabilization, motion preservation spinal implant system includes an anchor system, a horizontal rod system and a vertical rod system. The systems are modular so that various constructs and configurations can be created and customized to a patient.

Abstract: A spinal stabilization system, apparatus, and method are disclosed which include an interconnection mechanism for engaging stabilization members to one another. In one embodiment, the interconnection mechanism comprises a locking member having first and second threaded segments. An anchor member is provided having an upper segment and a lower segment, wherein the lower segment is structurally configured for engagement with a respective bone segment. A first stabilization member is connected to the upper segment of the anchor member. A locking member is engaged with the anchor member such that the first stabilization member is fixedly secured to the anchor member by a lower portion of the locking member having a first threaded segment. A second stabilization member is connected to an upper portion of the locking member by a cap that is threaded onto a second threaded segment of the locking member.

Abstract: A locking mechanism for locking a rod in a screw and rod fixation assembly includes a cap having a sidewall and a locking element extending from at least a portion of the sidewall. Locking mechanism cooperates with a receiver component for a spinal fixation rod to lock the rod in the receiver without requiring application of torque. A method of locking a spinal fixation member in a receiver of a screw fixation assembly includes the steps of placing the spinal fixation member into a channel of a receiver, axially advancing a locking cap into the receiver toward the spinal fixation member without application of any torque, and securing the locking cap in a locked position above the spinal fixation member without application of any torque.

Abstract: An elongated rod for insertion into a bowed canal of a bone such as a femoral medulla of a femur bone, wherein the canal is bowed in one plane. The rod has a longitudinal axis disposed on a first plane and one or more cutouts formed in at least a portion of a length of the rod and on opposite sides of the first plane. The rod is flexible along a second plane which is co-planar with the bowed canal plane and which is disposed on the longitudinal axis and perpendicular to the first plane.

Abstract: A fastening system for bone screws used in spinal fixation systems for reshaping the spine of a patient. The bone screw has threads on one end for anchoring in the spine. The other end has a spherical head with a multi sided recess formed therein for engagement with an appropriate driving tool. The system includes a stabilizing rod, a saddle member, a cap member and a set screw with at least one bone screw having a outer diameter that exceeds the diameter of a cavity formed in the saddle, wherein placement of the bone screw is made possible by matching the threads of the set screw to the threads of the bone screw. The head of the bone screw providing proper positioning of the stabilization rod within the patient.

Abstract: Posterior spinal stabilization devices and methods include first and second elongate elements engageable along the spinal column and a spinous process replacement body positionable between the elongate elements. Connection mechanisms are provided to adjustably connect the spinous process replacement device to the elongate elements so that the spinous process replacement device can be moved to the desired location between the connecting elements and secured in the desired location.

Abstract: A femoral hip stem explant system has an alignment body which is attached to two locations of a femoral bone and has several lockable collet type adjustment features to set the shaft of a reamer or end mill exactly in coincidence with the femoral bone cavity axis. The shaft of the end mill or reamer is supported by a sleeve member, which is inserted into a drill guide central aperture. The drill guide aperture is adjusted first and locked to be in line with the femoral bone cavity. Each of the sleeve members has the same mating outer diameter, which fits into the drill guide central aperture. Accordingly, the sleeve members can be interchanged into the drill guide aperture with shafts of differently sized reamers or end mills.

Abstract: A method for effecting reduction, stabilization and enhancement of fusion of the human cranio-cervical junction, which may be performed in order to relieve mechanical stresses imparted to the spinal cord and brainstem as a result of an abnormal clivo-axial angle, includes steps of achieving the correct craniocervical relationship, of effecting a fusion of a first portion of a bone forming material based structural member to a human cranium, and effecting fusion of a second portion of the bone forming material based structural member to a least one portion of a human cervical spine. Fusion of the bone forming material based structural member to the human cranium may be promoted through the use of plate member that is shaped to define a graft accommodation space between the plate member and the cranium.

Abstract: There is provided a modular pedicle screw assembly that includes various components which may be configured in various manners so as to provide different functionalities to the pedicle screw assembly. This advantageously decreases surgery time, reduces repetitive and tedious surgical steps, and allows for streamlining inventory of expensive medical equipment. In one embodiment, a pedicle screw assembly includes a pedicle screw, a rod holding element, an insert, a rod, and a set screw. The pedicle screw includes a threaded shaft and a cap. The rod holding element includes a screw hole, an insert bearing area, a chamber, chamber walls, a saddle area, and a threading area. The insert is disposed within the chamber, and the insert defines a bearing surface, an upper surface, side walls and a receiving area.

Abstract: The design of a rod is disclosed that can serve in general structural applications or as an orthopedic spinal implant to retain formation or stimulate the reduction of deformity as occurring in scoliosis and kyphosis. Different from common solid rod implants, the here-disclosed rod is curvature-adaptable in three dimensions to the actual or desired curvature or shape of the spine and can be provided with elasticity in order to serve as support or agent for curvature correction. The curvature adaptation of the proposed rod can be done with minimal force before or after implantation by means of the simple rotation of always only one in a pair of wedge shaped washers inserted between rod segments while leaving full mechanical strength or elasticity to the rod after curvature adaptation. The rotation of the washers can be done by various means, either once before implant or subsequently in the implanted state.

Abstract: A method for effecting reduction, stabilization and enhancement of fusion of the human cranio-cervical junction, which may be performed in order to relieve mechanical stresses imparted to the spinal cord and brainstem as a result of an abnormal clivo-axial angle, includes steps of achieving the correct craniocervical relationship, of effecting a fusion of a first portion of a bone forming material based structural member to a human cranium, and effecting fusion of a second portion of the bone forming material based structural member to a least one portion of a human cervical spine. Fusion of the bone forming material based structural member to the human cranium may be promoted through the use of plate member that is shaped to define a graft accommodation space between the plate member and the cranium.

Abstract: A bone retractor that may be used as a femoral elevator. The bone retractor includes a clamp for attaching the bone retractor to an operating room bed rail, a post attached to the clamp via a hinged joint, a mount slidably attached to the post and a hook coupled to the mount which in turn is attached to the post. A shaft passes through the interior of the post and attaches to clamp. The clamp has a lower jaw and an upper jaw. An opening is formed in the lower jaw and an end of the shaft is engaged in the opening. The shaft has two sections with a universal joint connecting these two sections. The born retractor is attached to the operating room bed rail by applying clamp to the bed rail. With bone retractor attached to the bed rail, the post is lowered towards the wound. The hook is placed under the bone, and the bone exposed by holding the hook or the post and lifting the bone out of the wound.

Abstract: The present invention may provide for an adaptable medical tool removal device and method for removing medical instruments seized in vivo. The removal tool may comprise a clamping mechanism. The clamping mechanism may comprise a locking member, a pivotal clamp member, and a connector clamp member. The pivotal clamp member may be pivotally attached to the connector clamp member. The pivotal clamp member may pivot between an opened and a closed position. The locking member may lock the pivotal clamp member in a closed position around a tool adaptor device. The tool adaptor device may attach to a seized medical instrument. The removal tool may further comprise a sliding weight able to impart an impact force to the seized medical instrument through the tool adaptor device. An embodiment of the tool adaptor device may comprise hooks to connect to a t-shaped handle of a seized medical instrument.

Abstract: The present invention relates to a rod capable of securely connecting pedicle screws in a pedicle screw system for correcting a damaged or transformed spine and a method and an apparatus for fabricating the same and, more particularly, to a flexible pedicle rod with superelasticity in order to provide a flexibility to a fixation between spine segments and a method and an apparatus capable of fabrication the same in mass production.

Abstract: A minimally invasive, percutaneous system that allows for dynamic stabilization of the spine is provided, together with methods of using the system. The system comprises a first bone anchoring member that is anchored in a first vertebra, and a second bone anchoring member that is anchored in a second, adjacent, vertebra. The first and second bone anchoring members include a first head portion and second head portion, respectively, that are designed to hold first and second ends of a flexible, elongated member, or cord. In certain embodiments, the cord is provided with a stiffened, relatively inflexible, end portion that is fixedly attached to the cord and that facilitates threading of the cord through the first and second head portions.

Abstract: A pull-locking rotational action needle driver that comprises an ergonomically designed handle and an integrated locking system that permits left and right handed surgeons to perform the surgical suturing procedure in a less complicated and more secure way by allowing more control over the suturing needle and the area to be stitched, even when the suturing area is small, deep, and/or restricted.

Abstract: A ligament graft-fixing apparatus has a rod-shaped shaft and a ligament graft-fixing unit that can be removably mounted on the rod-shaped shaft. The ligament graft-fixing unit has a screw part which drills a bone to form a tunnel therein to hold the ligament graft-fixing unit in the bone tunnel; a ligament graft-holding part; and a mounting tunnel in which the rod-shaped shaft is mounted. The mounting tunnel and the rod-shaped shaft have a torque transmission mechanism which transmits a rotational force imparted to the rod-shaped shaft to the ligament graft-fixing unit; and a removal prevention mechanism which holds the ligament graft-fixing unit on the rod-shaped shaft.

Abstract: A force applying surgical system is provided for use to assist in the insertion and/or removal of a surgical tool or a device attached thereto from an orthopedic structure. This surgical system comprises a medical impacting device that mates with a surgical tool such that the impacting device can be manually reciprocated along an axis of the tool to forcefully impact the impacting device on a portion of the tool. The impacting device can generate a distally directed force for inserting the tool (and/or an attached device) into an orthopedic structure, or it can generate a proximally directed force to remove the tool (and/or attached device) from an orthopedic structure.

Abstract: A medical instrument impacting tool that is useful for mating to a medical instrument used during spinal surgery is provided. The impacting tool is effective to apply a force to the medical instrument to efficiently and effectively prepare a bone structure, insert or remove a trial implant, insert or remove an implant, or to remove a medical instrument positioned between adjacent bone structures. In general, the medical instrument impacting tool includes a hollow tube, a handle slidably disposed around the tube, and a mass connected to the handle and slidably disposed within the tube.

Abstract: An implant may be formed in a disc space during a spinal fusion procedure. The implant may include implant members and connectors. The connectors may include sections with removed material that allow for some flexibility of the connectors. The connectors may include limiters that limit the amount of flexibility of the connectors. The ability of the connectors to flex may allow stress to be applied to bone growth material positioned in the implant. Stress may promote desirable bone growth.

Abstract: An instrumentation set may include insertion instruments for forming an implant between bone structures. The insertion instruments may include a spreader and a separator. The bone structures may be vertebrae. Implant members may be attached to the spreader and positioned between the bone structures. The separator may be inserted into the spreader to establish a desired separation distance between the implant members. Connectors may be inserted into the implant members to join the implant members together and form the implant. The insertion instruments may be removed. A seater may be used to set the position of the connectors relative to the implant members to inhibit disassembly of the implant.

Abstract: An installation tool is provided for the efficient and effective placement of an implant between adjacent bone structures, preferably adjacent vertebral bodies, and for the subsequent removal of the device without displacement of the implant. The installation tool generally includes a pair of opposed levers, a pusher assembly disposed between the levers, and an installation tool removing element having a mass slidably disposed with respect to at least a portion of the pusher assembly. The levers are effective to separate adjacent bone structures, such as adjacent vertebrae, upon insertion of an implant. The pusher assembly is slidably movable with respect to the levers, and is effective to insert an implant between the adjacent bone structures. Once the implant is positioned between the adjacent vertebrae, the mass can be used to apply a proximally directed force to the opposed levers, thereby removing the instrument from the space between the adjacent bone structures.

Abstract: A medical instrument impacting tool that is useful for mating to a medical instrument used during spinal surgery is provided. The impacting tool is effective to apply a force to the medical instrument to efficiently and effectively prepare a bone structure, insert or remove a trial implant, insert or remove an implant, or to remove a medical instrument positioned between adjacent bone structures. In general, the medical instrument impacting tool includes a hollow tube, a handle slidably disposed around the tube, and a mass connected to the handle and slidably disposed within the tube.

Abstract: An installation tool is provided for the efficient and effective placement of an implant between adjacent bone structures, preferably adjacent vertebral bodies, and for the subsequent removal of the device without displacement of the implant. The installation tool generally includes a pair of opposed levers, a pusher assembly disposed between the levers, and an installation tool removing element having a mass slidably disposed with respect to at least a portion of the pusher assembly. The levers are effective to separate adjacent bone structures, such as adjacent vertebrae, upon insertion of an implant. The pusher assembly is slidably movable with respect to the levers, and is effective to insert an implant between the adjacent bone structures. Once the implant is positioned between the adjacent vertebrae, the mass can be used to apply a proximally directed force to the opposed levers, thereby removing the instrument from the space between the adjacent bone structures.

Abstract: A force applying surgical system is provided for use to assist in the insertion and/or removal of a surgical tool or a device attached thereto from an orthopedic structure. This surgical system comprises a medical impacting device that mates with a surgical tool such that the impacting device can be manually reciprocated along an axis of the tool to forcefully impact the impacting device on a portion of the tool. The impacting device can generate a distally directed force for inserting the tool (and/or an attached device) into an orthopedic structure, or it can generate a proximally directed force to remove the tool (and/or attached device) from an orthopedic structure.

Abstract: An instrument for inserting a graft fixation device. The fixation device is useful for affixing a tissue graft to a bone or other body surface. The graft fixation device comprises two implantation members connected by a connecting member. The fixation device can be combined with insertion members. The implantation members have longitudinal passageways therethrough. The instrument has a hammer handle slidably mounted to a slide rod. The slide rod is mounted at an angle to a mounting member. A mounting rod having an angulated distal end is mounted to the mounting member. Prongs extend longitudinally out from the angulated distal end. The longitudinal axis of the slide rod is parallel to the longitudinal axis of the angulated distal end. The prongs are optionally removably mounted in an end housing mounted to the angulated distal end.

Abstract: In a surgical instrument for the mechanical removal of bone cement (2), comprising a longitudinal housing (4) with a cylinder (6) in which a piston element can be reciprocated by a drive means (14), wherein the piston element on the distal end (18) of the cylinder (6) exerts an impact on a chisel tool supported axially in the housing (4), it is provided that the piston element (10) comprises a projectile (10) adapted to be accelerated to a high final speed and inducing a shock wave into the chisel tool comprising a metallic shock wave transmission probe (22), the probe tip (26) of the chisel tool transmitting the shock wave to the bone cement (2) at a low movement amplitude of the probe tip (26).

Abstract: A device for driving a wire pin, and in particular a Kirschner wire, into bone material, comprising a propelling device that acts upon the wire pin which may be inserted into the device from the free front end thereof, said propelling device being driven by periodically repeated impact strokes applied thereupon by an impacting member. The propelling device acts upon the wire pin without any clamping means being involved, which is achieved by the propelling device being designed as a transmitting member against which the free end face of the wire pin may evenly abut and which may transmit the impact strokes of the impacting member as impact pulses into the wire pin through the free end face thereof, with the impact pulses propagating through the wire pin as periodic compression waves so that the wire pin is successively driven into the bone material.

Abstract: An instrument for seating taper junctions of modular implants engages two components and provides a sustained assembly force along the junction axis with great mechanical advantage. In one embodiment the instrument comprises a lever mechanism for generating the mechanical advantage. In another embodiment, the instrument provides for an indicator of the amount of force being applied to the junction. In another embodiment, the instrument engages the components for such that both assembly and disassembly can be accomplished.

Abstract: A profile gauge for use with an acetabular cup loading tube provided with a skirt or flange characterized by adjustable means for measuring and indicating the diametric profile of the mouth of the rim area adjacent thereto of an acetabular socket into which an acetabular cup is to be implanted and includes means for removably locating said adjustable means on a loading tube to indicate on the skirt thereof the measured diameter profile.

Abstract: A method and tool for inserting a prosthetic stem component in an aligned position into a prepared bone cavity. The bone is prepared by removing bone material from the bone canal and preferably also machining an entry opening of a predetermined shape and desired orientation in the bone, or marking the plane of the joint on the bone end. The tool includes an upper component that engages the top of the prosthesis stem to fix its rotational alignment, and an arm that extends to the opening in the bone and is aligned at its distal end. The upper component rides along the arm, and orients the stem with respect to the bone as the stem is inserted. The tool may include a lower element that engages the machined or marked bone and holds the arm to orient the head of the prosthesis. Optionally, the lower element may guide the distal stem. Alternatively, the guide may include an arm that simply points to, contacts or fastens at the bone end, orienting the prosthesis insertion without sighting errors.

Abstract: Hand operable pneumatically driven medical actuator and method of use preferably utilized for orthopedic or orthodontic manipulation in a user enabled pulse modulated mode. In one form, the medical actuator includes a free piston moveable within the body of the actuator responsive to pressurized gas selectively injected through a valve controlled by the hand supporting the actuator. The valve is operable in both pulse width and pulse frequency modulation modes, initiating corresponding pneumatic forces and acceleration effects on the free piston. A piston stop attached to a shaft extending from the medical actuator converts piston momentum into pulses of force transferable through the shaft to a translation device external to the medical actuator. The force pulses conveyer to the orthopedic or orthodontic translation device act upon teeth, bones, implants, or the like. Pulse modulation in a single hand operating mode permits the user to impart precise dynamic forces to the thing being manipulated.

Abstract: A temporary non-weight bearing prosthesis to be placed inside an implant area of a joint replacement patient. The prosthesis is impregnated with an antibiotic agent which leaches out to the surrounding tissue to fight infection in the implant area. While the infection is being overcome, the prosthesis maintains the joint spacing of the implant area against the contractive force of the surrounding muscles and tendons by fully occupying the space in which a primary prosthesis had once been.

Abstract: Set of ancillary equipment for the implantation of acetabular cups (1) of hip prostheses, of the type having a substantially hemispherical corolla, consisting of expandable petals (2) which are provided with external barbs (5). The set comprises an obturator (7) for closing the petals, under elastic radial stress, in a position in which they are drawn together, elements (8, 9) for holding this obturator on the edges of the petals by connection with the bottom of the acetabular cup, an ancillary impaction device with which it is possible to impact the acetabular cup, freeing its petals by extraction of the obturator.

Abstract: The invention is directed to an orthopaedic apparatus 24, 80, 380, 480, 580 for positioning an implant 22, 322, 422 relative to an end of a bone. The implant has at least one extractor opening 30, 330, 430 and a shoulder 26, 326, 426 with a slot therein. The positioning apparatus includes a shaft 32, 82, 382, 482 having a fixed impactor tip at an end thereof. The impactor tip is configured to be received within the implant slot. At least one clamping jaw is connected to the shaft, and includes a projection which is configured to be received in the at least one extractor opening. The at least one clamping jaw is preferably detachably connected to the shaft.

Abstract: A device and method for the insertion and removal of an internal fracture fixation implant are disclosed. The device includes a slide rod having a tubular body with first and second ends and a bore for receiving the implant, a securing element located on the first end of the slide rod for maintaining the implant in the bore, a handle on the second end of the slide rod for manipulation of the device, and a slap hammer having a body member configured and dimensioned to be releasably and slideably connected to the slide rod so that displacement against the securing element results in impaction while displacement against the handle results in extraction of the implant. Removing the slap hammer from the slide rod when it is not needed facilitates use of the device. In a preferred embodiment, the slap hammer has a grip and the slap hammer body member has a channel for receiving the slide rod and at least one retaining element for maintaining the slide rod in the channel.

Abstract: An intraosseous device having an elongated shaft and handle with a syringe attached to the shaft is disclosed. The syringe can be filled with an intraosseous liquid suspension which is made of a hydroxyapatite, a carbonated apatite, a calcium ion source, and a hormone mixture. The shaft includes a frusto-conical connector for releasable interconnection with cortical bone, and the handle facilitates turning the shaft to interconnect it to the bone.

Abstract: An impactor apparatus and method for assembling modular orthopedic prosthesis parts includes a base member that can be for example an instrument from a tray or an instrument tray lid. The base member defines a plane and provides a plurality of components extending away from the plane. The tray components include a pair of spaced apart supports. An impactor tool can be removably supported upon the supports in a fixed position relative to the base member, preferably generally parallel thereto. The components include an impact driver tool actuator that pivotally attaches to the base member. A pair of prosthesis parts or components are connectable at a taper lock connection defined by respective tapered annular portions of the prosthesis parts. The components and impact driver tool support the prosthesis parts adjacent the base and axial alignment with the impact driver tool, the prosthesis parts being generally positioned in between the pair of spaced apart supports.

Abstract: A punch system is provided for preparing a keel cavity in a tibial bone for implantation of a prosthesis. The system provides a modular punch system providing a logical step-to-step approach to cutting, punching, and/or forming the tibial bone. The system of a preferred embodiment includes a quick release punch guide for attaching to a tibial tray trial component of a surgical instrument system for implanting artificial knees, and a universal quick release handle for attaching or detaching a punch from a handle or slap hammer.

Abstract: The extraction tool comprises a sleeve part (13) which can be coupled to a neck portion (6) of a shaft which is to be withdrawn, and a coupling element (15) in the form of a collet which can be fitted onto the neck portion (6). The collet has an elongate section with wall segments (16a) which can be clamped against the neck portion (6), and comprises fittings (23) which can be guided into a constriction (24) of the neck portion (6), and a head part (17) which projects beyond the neck portion (6), wherein the head part (17) can be clamped against the sleeve part (13) via a bias screw (18). The coupling element (15) is loosely connected to the sleeve part (13) and fitted onto the neck portion (6). It can then be clamped by approaching the bias screw (16) against the sleeve part (13) and against the neck portion (6). A rigid yet easily releasable connection between the extraction tool and the shaft to be withdrawn is thus achieved in a simple manner.

Abstract: An implant fixture is built up of a titanium body, a titanium cover that is threadedly engaged with the body, a support having a columnar form of protuberance to be loosely fitted into a small hole in the head of the cover, and a connector spring member including a cylindrical body having spring action that enables it to take hold of the outer surface of the cover through a flange provided at one end. A forceps is built up of two frames, each provided at one end with a finger ring having a claw and at the other end with a holding surface for holding a second shaft of the support in parallel with the axial direction, and a guide rod which extends axially from one frame and has a slidable weight.

Abstract: A prosthetic socket implant installation apparatus and method combines holding, impacting, and aligning functions in a modular device. The apparatus comprises an installation tool that firmly engages a feature around the inner rim of a prosthetic socket implant so that the shell does not disengage during the installation process. An implant engaging arrangement on the installation tool is capable of extending to properly engage and hold implants in a broad range of sizes. The tool provides both axial and angular alignment references to facilitate the correct alignment of a prosthetic socket implant during installation. A mechanically isolated impacting rod slideably attaches within an opening along the longitudinal axis of the tool thus facilitating impact at the proper location and angle and allowing the alignment and impacting to be performed by one person.

Abstract: A knockout tool for joint prostheses has a curved tool head, which has a passage for receiving a prosthesis shaft and has a locking device which releasably blocks the prosthesis shaft in the passage, characterized in that the locking device has a blocking element engaging the passage, whose engagement position is adjustable for the sake of adaptation to various prosthesis shaft diameters, wherein an adjusting force, serving to adjust the engagement position and acting upon the blocking member, is transmitted along the curved tool head.

Abstract: An acetabular cup having an outer shell of a hard material defining a cavity circumscribed by an annular surface, and a bearing insert of a material which is softer than the material of the outer shell, the bearing insert being disposed within the cavity of the shell, and coupling tracks disposed on the annular surface for coupling a tool to the outer shell, the tool being used for installing the cup in a patient's acetabulum, the coupling tracks operating to prevent the tool from damaging the bearing insert during the installation of the cup.

Abstract: A surgical tool for driving a K-wire into bone fragment or bone with gentle but forceful precision is described. The tool provides for the driving of the K-wire with a slap hammer action while rotating the wire. The tool is of simple construction.

Abstract: An improved instrument for removing thermoplastic bone cement by applying a heater tip of heating wire to the cement to melt the bone cement inserting the hot heater tip into the bone cement, allowing it to cool embedded in the bone cement and to pull the instrument and, through the embedded heater tip, pull the bone cement from the bone.

Abstract: A pneumatic inertia tool for applying a cyclic percussive force to an orthopedic article via a reciprocating shuttle comprising a passageway extending between a first port and a second port. The shuttle travels within the passageway and strikes an anvil, imparting its momentum to the orthopedic article. The mass of the shuttle and its velocity at impact are selected to fix a bone relative to the orthopedic article via the existing inertia of the bone. The shuttle reciprocates within the passageway by alternating pressure and vacuum forces applied at the first port and at the second port.

Abstract: According to the invention there is provided surgical instrumentation for implanting an orthopedic prosthesis comprising a handle having opposed longitudinal ends and a head assembly situated at one end of the handle. The head assembly includes an external impact surface for transmitting force to an orthopedic instrument or prosthesis. A spring and sliding shaft arrangement are disposed within the head assembly for dampening the force from the impact surface. The head assembly is adjustable for varying the force absorbed by the spring and sliding shaft arrangement.

Abstract: A tool driver having a shaft with a longitudinal axis and opposite ends. A boss is positioned at one of the ends. A tool collet is positioned at the other of the ends. The boss has a bore extending axially thereof forming debris cavity. An actuator on the shaft. A pair of oppositely disposed pins on the actuator. The pins are movable in relation to the boss in response to movement of the actuator. The actuator and the pins move as a unit axially of the boss between an at rest position and a static position. The pins are movable between an extended position and a retracted position as the actuator moves between an at rest position and a static position, whereby a tool can be positioned on the tool driver when the actuator is in its static position and held in operable position on the tool driver when the actuator is in its at rest position.