Device and method for generating orthopedic impaction forces using a rotary-driven magnetic adapter

Abstract

An adapter (100) converts rotary motion from a powered surgical rotary driver (300) into controlled reciprocating impaction forces for orthopedic surgery. The adapter (100) includes a housing with a proximal attachment mechanism (130) for coupling to the driver (300) and a distal attachment mechanism (150) for coupling to orthopedic instruments such as broaches, osteotomes, chisels, or implant inserters. Internally, a drive shaft (215) transmits rotary motion to at least one diametrically magnetized rotating cylindrical permanent magnet (210), which interacts magnetically with an axially aligned sliding cylindrical permanent magnet (213) constrained against rotation by a guide structure (214) but free to translate axially. Alternating magnetic attraction and repulsion drive the sliding magnet (213) in reciprocation, transmitting periodic axial impacts via transfer rods (216) and an impactor plate (217) to the orthopedic instrument. In one embodiment, distal and proximal rotating magnets (210, 222) coupled to respective rotation limiter mechanisms (225) enable bidirectional impact and extraction forces simply by reversing the rotational direction of the driver (300).

Description

[0001] Docket Number: MA-2025.1-PCT TITLE

[0002] DEVICE AND METHOD FOR GENERATING ORTHOPEDIC IMPACTION FORCES USING A ROTARY-DRIVEN MAGNETIC ADAPTER BACKGROUND

[0003] Without limiting the scope of the invention, its background is described in connection with tools used in orthopedic surgery. More particularly, the invention describes an adapter for generating reciprocating impaction forces using a conventional rotary driver or drill.

[0004] Orthopedic procedures such as total hip arthroplasty, knee arthroplasty, and other reconstructive surgeries routinely require repetitive impaction of osteotomes, chisels, broaches, and implant inserters to prepare bone and to seat trial and definitive components. Manual surgical mallets have traditionally been used for these tasks, with the surgeon delivering a sequence of strikes to the instrument handle to achieve the desired depth, alignment, and press-fit. Although familiar and widely available, this approach has inherent limitations that become more problematic as procedural volumes, implant complexity, and expectations for reproducible outcomes increase. First, manual impaction is fundamentally operator-dependent. The magnitude, direction, and consistency of each strike vary between surgeons and even between successive strikes by the same surgeon. This variability can translate into inconsistent bone preparation and implant seating, with individual blows sometimes being too forceful, risking intraoperative fracture, or too weak, leading to inadequate seating and the need for additional impaction. Off-axis blows can introduce unintended bending moments and torsional forces at the bone-instrument or bone-implant interface, potentially altering alignment or generating microcracks in the surrounding bone. As implants and surgical techniques move toward tighter tolerances and more precise biomechanical reconstructions, the lack of control and repeatability inherent in manual mallet techniques becomes increasingly undesirable.

[0005] Second, manual mallet use imposes significant ergonomic and physical burdens on surgeons. Repetitive high-force hammering, often performed from awkward body positions dictated by patient anatomy and operating room constraints, contributes to cumulative musculoskeletal strain in the hands, wrists, elbows, shoulders, neck, and back. Over the course of a day with multiplearthroplasty procedures, or over a surgical career, these repetitive stresses can lead to fatigue, discomfort, and even chronic occupational injuries. Fatigue can also degrade the surgeon’s fine motor control and consistency of strikes as a case progresses, further increasing variability in impaction forces and potentially prolonging operative time.

[0006] Third, reliance on manual mallet techniques can increase procedure time and reduce efficiency. Achieving adequate broach advancement or implant seating often requires numerous iterative strikes with interim assessments of position and stability. This incremental process, combined with occasional “over-hits” that must be corrected or “under-hits” that require additional cycles, can prolong the impaction phase of the procedure. Longer operative times translate into increased anesthesia duration, higher costs, and reduced throughput for busy operating rooms.

[0007] To address these issues, powered orthopedic impactors have been introduced to provide more consistent, controlled impaction forces and to reduce the physical demands on the surgeon. Existing systems, however, tend to be specialized capital devices with dedicated handpieces, consoles, or proprietary power sources. They may incorporate complex internal hammering, cam, or spring mechanisms that add cost, size, weight, and maintenance requirements. In many cases, these systems arc optimized for specific steps (c.g., acetabular cup seating or femoral stem insertion) and are not readily adaptable as general-purpose adapters that can interface with standard powered surgical rotary drills already present in the operating room. As a result, adoption can be limited by cost, logistical complexity, and the need to integrate yet another powered platform into the surgical workflow.

[0008] Furthermore, many known powered impactors are not designed to exploit simple, robust magnetic interactions to convert continuous rotary motion directly into controlled reciprocating motion along the tool axis. Mechanical hammer-and-anvil or cam mechanisms can be noisy, subject to wear, and more sensitive to lubrication and debris. They may also be designed primarily to provide impaction in one axial direction, with limiied or no capability for generating controlled extraction forces along the same axis using the same device. In procedures such as femoral broaching, however, there is a practical need not only to drive a broach into bone with controlled, repeatable impacts, but also, when necessary, to extract the broach safely and predictably without resorting to ad hoc reverse malleting or additional instrumentation.

[0009] Accordingly, a need exists for a compact, sterilizable device that can be attached to a conventional powered surgical rotary driver and that utilizes magnetic interactions to convert rotary motion intoreciprocating linear motion that produces periodic axial impacts on an orthopedic instrument. Such a device should be capable of delivering substantially consistent impact magnitudes aligned with the instrument axis, thereby reducing variability associated with manual mallet strikes and mitigating the risk of off-axis loading and unintended bone damage. It should reduce surgeon fatigue and ergonomic strain by shifting the physical work of impaction from the surgeon's upper extremities to a powered rotary driver that is already familiar and widely used in orthopedic surgery. Desirably, the device should also provide the capability to generate impact forces in opposite axial directions simply by reversing the direction of rotation of the powered driver — allowing, for example, a first rotational direction to be used to drive a broach into bone with a series of controlled axial impacts and an opposite rotational direction to be used to extract the broach from bone with a series of controlled axial impacts in the reverse direction. Providing these capabilities in the form of an adapter that can interface with standard surgical drills and a variety of orthopedic instruments addresses an unmet need for a flexible, cost-effective, and ergonomically favorable impact-generating tool for orthopedic surgery.

[0010] SUMMARY

[0011] A first objective of the present invention is to provide a device and method that converts rotary motion from a standard powered surgical rotary driver into reciprocating linear motion that delivers periodic axial impacts to an orthopedic instrument. This objective encompasses the ability to translate continuous rotary input into controlled, discrete impact events along the instrument axis.

[0012] Another objective is to replace manual mallet-based impaction with a powered impact-generating adapter, thereby reducing surgeon fatigue and cumulative musculoskeletal strain associated with repetitive hammering. By shifting the primary work of impaction from the surgeon’s upper extremities to a powered driver, the invention seeks to improve ergonomics and the surgeon's well-being.

[0013] A further objective is to provide more consistent, repeatable, and substantially axially aligned impaction forces than manual techniques, improving the precision of bone preparation and the reliability of implant seating. In particular, the invention aims to reduce variability in force magnitude and direction, and to mitigate off-axis loading that can compromise implant stability or cause bone damage.

[0014] Another objective is to provide an adapter that can be removably coupled to commonly usedpowered surgical rotary drivers and to a range of orthopedic instruments, such as osteotomes, broaches, chisels, and implant inserters, without requiring dedicated capital equipment or proprietary consoles. In this way, the invention is intended to integrate readily into existing operating room workflows and to leverage tools already available to surgeons.

[0015] A farther objective is to utilize magnetic interactions, rather than complex mechanical hammering or cam systems, to convert continuous rotary motion into controlled reciprocating motion, thereby simplifying the internal mechanism, reducing wear, and facilitating sterilization. The use of permanent magnets configured to alternate between attraction and repulsion is intended to provide a robust, low-maintenance impact-generating mechanism.

[0016] Another objective is to provide the capability to generate impact forces selectively in opposite axial directions by reversing the direction of rotation of the powered driver, so that the same device can be used both to drive an instrument into bone and to extract it from bone when required. This objective includes the ability to generate distal impact forces for broach insertion and proximal impact forces for broach extraction using a single adapter.

[0017] A farther objective is to enable embodiments in which multiple magnet pairs act in concert to increase delivered impact energy, while maintaining a compact form factor and compatibility with standard surgical workflows. By arranging multiple magnet pairs along the axis and combining their reciprocating motions, the invention seeks to provide scalable impact performance within a practical surgical device.

[0018] In one aspect, the invention provides an adapter configured to be coupled proximally to a powered surgical rotary driver and distally to an orthopedic instrument. The adapter includes a housing defining an axis, a rotary input member driven about the axis by the surgical driver, and an output member arranged to transmit reciprocating motion along the axis to the orthopedic instrument. Within the housing, one or more cylindrical permanent magnets are arranged along the axis in magnetically interacting pairs, with at least one magnet of each pair fixed to rotate with the rotary input member and at least one magnet constrained against rotation but free to translate axially. Magnet shapes other than cylindrical are also contemplated to be included in the scope of the claims, as the invention is not limited in this regard. Each cylindrical permanent magnet is magnetized such that opposite magnetic polarities occupy respective halves of its volume separated by a plane intersecting the longitudinal axis of the magnet. As the rotary input member rotates, the relative angular orientation of each rotating magnet and its corresponding slidingmagnet changes, causing alternating magnetic attraction and repulsion that drive the sliding magnet back and forth along the axis. The sliding magnet is mechanically coupled, for example via one or more transfer rods and an impactor plate, to the output member, which applies periodic axial impacts to the connected orthopedic instrument. In this manner, continuous rotary motion from the powered surgical driver is converted into a sequence of controlled, substantially axially aligned impact events at the distal interface.

[0019] In another aspect, the invention provides embodiments employing a distal rotating cylindrical permanent magnet and a proximal rotating cylindrical permanent magnet spaced apart along the axis, with an impacting cylindrical permanent magnet disposed between them and constrained to translate axially without rotation. Each rotating magnet is magnetized in a diametric fashion, and the impacting magnet is similarly magnetized, so that rotation of a given rotating magnet produces alternating attractive and repulsive interactions with the impacting magnet to generate reciprocating motion. Rotation limiter mechanisms are coupled to the rotating magnets such that each rotating magnet is permitted to rotate only in one respective rotational direction. When the powered driver rotates in a first rotational direction, only the distal rotating magnet turns with the rotary input member and interacts with the impacting magnet to produce a series of axial impacts in a first axial direction, suitable, for example, for driving a broach distally into bone. When the powered driver rotation is reversed to the opposite rotational direction, only the proximal rotating magnet turns and interacts with the impacting magnet to produce a series of axial impacts in the opposite axial direction, thereby providing controlled extraction forces to withdraw the broach from bone. This bidirectional impact capability is achieved simply by reversing the direction of rotation of the same powered driver, without changing instruments or adapters.

[0020] In yet another aspect, the invention provides embodiments including a plurality of rotating cylindrical permanent magnets spaced along the axis and a corresponding plurality of sliding cylindrical permanent magnets disposed between adjacent rotating magnets. Each sliding magnet is constrained to translate along the axis and prevented from rotating, and each magnet pair is magnetized to produce alternating attraction and repulsion as the rotary input member turns. The sliding magnets are coupled to a common output structure so that their individual reciprocating motions combine to produce enhanced impact energy transmitted to the orthopedic instrament. This configuration allows the overall impact-generating capability of the adapter to be scaled by adjusting the number, size, and arrangement of magnet pairs, while preserving a compact, generally tubular form factor suitable for attachment to standard powered surgical rotary driversand for use with standard orthopedic instruments in a sterile surgical environment.

[0021] BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Subject matter is particularly pointed out and distinctly claimed in the concluding portion of the specification. The foregoing and other features and advantages of the present disclosure will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. In the drawings:

[0023] FIG. 1 is a side view of a first embodiment of an adapter configured to convert rotary motion from a powered surgical rotary driver into reciprocating motion of an orthopedic instrument.

[0024] FIG. 2 is a side view of the adapter of FIG. 1, shown coupled proximally to a powered surgical rotary driver and distally to a surgical broach or similar orthopedic instrument.

[0025] FIG. 3 is a side view of a second embodiment of the adapter having an alternative external housing configuration.

[0026] FIG. 4 is a side view of another embodiment of the adapter, including a distal impaction surface configured to contact an impact interface or connector of an orthopedic instrument.

[0027] FIG. 5 is a side view of the adapter illustrating distal attachment mechanisms for coupling to various orthopedic instruments.

[0028] FIG. 6 is a side view of an example powered surgical rotary driver suitable for use with the adapter. FIG. 7 is a side view of the adapter of FIG. 1 with the outer body removed to show internal components of the power unit.

[0029] FIG. 8 is a longitudinal sectional view of the adapter illustrating a single rotating cylindrical permanent magnet and a single sliding cylindrical permanent magnet in an impaction configuration.

[0030] FIG. 9 is a longitudinal sectional view of the adapter illustrating the rotating and sliding cylindrical permanent magnets in an extraction configuration.

[0031] FIG. 10 is a side view of a second internal magnet configuration with the outer body removed, illustrating an embodiment utilizing three magnets.FIG. 11 is a longitudinal sectional view of the second embodiment of FIG. 10 showing the magnets in a neutral configuration.

[0032] FIG. 12 is a longitudinal sectional view of the second embodiment illustrating the magnets in an impaction configuration generating axial impacts in a first axial direction.

[0033] FIG. 13 is a longitudinal sectional view of the second embodiment illustrating the magnets in an extraction configuration generating axial impacts in an opposite axial direction.

[0034] FIG. 14 is a longitudinal sectional view of another embodiment of the adapter including multiple sets of rotating and sliding cylindrical permanent magnets arranged along the axis.

[0035] DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

[0036] The following description sets forth various examples along with specific details to provide a thorough understanding of the claimed subject matter. It will be understood by those skilled in the art, however, that claimed subject matter may be practiced without one or more of the specific details disclosed herein. Further, in some circumstances, well-known methods, procedures, systems, components and / or circuits have not been described in detail in order to avoid unnecessarily obscuring claimed subject matter. In the following detailed description, reference is made to the accompanying drawings, which form a part hereof. In the drawings, similar symbols typically identify similar components, unless context dictates otherwise. The illustrative embodiments described in the detailed description, drawings, and claims are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented here. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the figures, can be arranged, substituted, combined, and designed in a wide variety of different configurations, all of which arc explicitly contemplated and make part of this disclosure.

[0037] The following description sets forth example embodiments of the invention with reference to the accompanying drawings. The embodiments are provided by way of illustration and are not intended to limit the scope of the claims.

[0038] Overview of the DeviceIn general, the invention provides an adapter configured to convert rotary motion from a powered surgical rotary driver into reciprocating linear motion that delivers periodic axial impacts to an orthopedic instrument. The adapter includes a main body or housing, a proximal attachment mechanism for coupling to a powered surgical rotary driver, a distal attachment mechanism for coupling to one or more orthopedic instruments, and an internal power unit that uses magnetic interactions to generate impact-producing reciprocating motion along a longitudinal axis. The device is sized and shaped to be compatible with standard powered surgical drills used in orthopedic operating rooms, and its proximal and distal attachment interfaces are configured to accept both common drill chuck connections and a variety of orthopedic instrument connectors from different manufacturers. In some embodiments, the body is generally tubular in form, allowing internal components to be assembled coaxially along the longitudinal axis in a compact arrangement that minimizes the overall length and weight added to the surgical workflow.

[0039] First Embodiment — Single Rotating Magnet Configuration (FIGS. 1, 2, 7-9)

[0040] Referring to FIGS. 1 and 2, a device 100 in a first embodiment includes a main power unit 110 received within a tubular body that defines a longitudinal axis. The proximal end of the body carries an attachment mechanism 130 configured to mechanically and rotationally couple the device 100 to a standard powered surgical rotary driver 300, such as a battery-powered surgical drill having a rotary output shaft. The attachment mechanism 130 may include any suitable quickconnect interface, chuck, collet, keyed coupling, or proprietary connection compatible with standard surgical drill platforms. The attachment mechanism 130 also includes a stabilizer bracket or anti-rotation feature configured to engage a fixed part of the powered driver 300, such as its housing or a designated stabilization port, so that the body of the device 100 does not rotate during operation. This rotational stability is important to ensure that the impaction force is delivered in a controlled, axially aligned manner without the body spinning relative to the surgeon's hand or the patient. The distal end of the body carries an impaction mechanism 140 and a distal attachment mechanism 150 configured to couple the device to an orthopedic instrument, such as a broach, osteotome, chisel, or implant inserter, via a suitable connector. The distal attachment mechanism 150 may include a variety of instrament-specific connectors, adaptors, or interfaces, allowing the device 100 to be used with standard surgical instruments and implant systems from different manufacturers.

[0041] In one embodiment, the adapter further comprises a stabilizer mechanism coupled to the exterior of the housing and configured to prevent rotation of the housing relative to the powered surgicaldriver 300 during operation. The stabilizer mechanism may comprise a rigid arm, bracket, or clip that extends from the housing and is configured to engage a corresponding feature on the body of the powered surgical driver, such as a handle grip, a side rail, a designated mounting slot, or a stabilization port provided on the driver for this purpose. The stabilizer mechanism is preferably designed to engage the driver body in a manner that permits the drive shaft to rotate freely while holding the housing of the adapter rotationally fixed. In this way, the impaction forces generated by the adapter are directed along the axis of the orthopedic instrument rather than being dissipated in unintended rotation of the adapter housing. The stabilizer mechanism may be integrally formed with the housing, permanently attached, or configured as a removable accessory that can be connected to the housing prior to use and removed for cleaning and sterilization. Different stabilizer mechanism configurations may be provided to accommodate different powered surgical driver models and their respective anti-rotation features.

[0042] Referring to FIG. 7, with the outer body removed to expose the internal components, the power unit 110 is seen to include a drive shaft 215 aligned with the longitudinal axis and mechanically coupled at its proximal end to the rotary output shaft of the powered surgical driver 300. The drive shaft 215 is a solid or hollow rod or a bar (as well as other non-circular but preferably axisymmetric shapes) formed from a suitable high-strength material, such as stainless steel or titanium, and is configured to transmit rotary torque from the driver to the rotating magnet assembly without significant flexion or torsional deformation. The drive shaft 215 passes through one or more internal components, including magnet brackets and end caps, via central axial passages defined in those components, ensuring that the shaft remains centered along the axis during rotation.

[0043] At an internal location within the body, a rotating magnet assembly is provided, including a first cylindrical permanent magnet, referred to herein as the rotating magnet (RM) 210, and a rotating magnet case (RM case) 211. The rotating magnet 210 is a cylindrical permanent magnet magnetized diametrically, meaning that its magnetization axis is perpendicular to the cylindrical axis, so that a first half of the magnet volume on one side of a plane containing the cylindrical axis exhibits a first magnetic polarity (for example, north) and the opposite half exhibits the opposite magnetic polarity (for example, south). In a preferred embodiment, the rotating magnet 210 is a neodymium (NdFeB) permanent magnet chosen for its high magnetic energy density, which allows a compact magnet size to generate sufficient magnetic force for the intended impaction application. The rotating magnet 210 is received within the rotating magnet case 211 , which is astructural housing that is fixed to the drive shaft 215 by a keyed engagement, press fit, adhesive, set screws, or other suitable means, so that the rotating magnet 210 rotates unitarily with the drive shaft. In one embodiment, the RM case 211 is directly attached to the drive shaft 215. In another embodiment, the RM case 211 is connected to the drive shaft 215 via a rotation direction limiter component, described further below, which allows the RM to be selectively engaged or disengaged from the rotary motion of the drive shaft depending on the direction of rotation. The rotating magnet case 211 rotates freely within a rotating magnet bracket (RM bracket) 212 that is secured to the interior of the body. The RM bracket 212 provides a coaxial platform or journal bearing surface that supports the rotating magnet assembly and allows it to rotate smoothly about the longitudinal axis. The RM bracket 212 also defines openings or passages that permit the transfer rods 216 to pass generally parallel to the axis on either side of the rotating magnet assembly.

[0044] Axially spaced from the rotating magnet 210, in the distal direction, is a second cylindrical permanent magnet, referred to as the impacting magnet (IM) 213, received within an impacting magnet bracket (IM bracket) 214. The impacting magnet 213 is also a cylindrical permanent magnet, preferably a neodymium magnet of the same or similar configuration as the rotating magnet, magnetized diametrically so that opposite magnetic polarities occupy respective halves separated by a plane intersecting the longitudinal axis. The impacting magnet bracket 214 is a structural housing that supports the impacting magnet 213 and couples to the transfer rods 216. The IM bracket 214 is mounted within the body in a manner that prevents its rotation about the longitudinal axis but permits free axial translation within the body interior. This constraint against rotation and freedom of axial translation may be achieved by any suitable guide structure, such as longitudinal guide rails, slots, or keying features between the IM bracket and the interior of the body or a dedicated guide sleeve, which engages corresponding features on the IM bracket. The impacting magnet 213 itself also has a central axial passage through which the drive shaft 215 passes, allowing the shaft to extend through the center of the impacting magnet without mechanical interference. Similarly, the rotating magnet 210 has a central axial passage for the same purpose, permitting the drive shaft to extend coaxially through both magnets and the internal mechanism.

[0045] The guide structure constraining the second cylindrical permanent magnet (and, in other embodiments, the impacting cylindrical permanent magnet) against rotation while permitting axial translation comprises, in combination, the impacting magnet bracket 214 and the internalfeatures of the housing body with which it engages. Specifically, the impacting magnet bracket 214 includes one or more anti-rotation features, such as flat surfaces, keyways, fins, or tabs, that engage corresponding longitudinal guide rails, slots, or grooves formed in the interior wall of the housing body. These cooperating features together constitute the guide structure: the internal housing features define the axial travel path and prevent rotation, while the impacting magnet bracket forms the moving element of the guide structure that carries the impacting magnet along that path. It will be understood that the impacting magnet bracket thus both houses the impacting magnet and forms an integral part of the guide structure.

[0046] Each of the first cylindrical permanent magnet 210 (rotating magnet) and the second cylindrical permanent magnet 213 (impacting magnet) includes a central axial passage extending through the magnet along its longitudinal axis. These passages are coaxially aligned with the longitudinal axis of the device and are dimensioned to receive the drive shaft 215, which passes through the interior of both magnets. The central axial passage in the rotating magnet 210 allows the drive shaft to extend distally through the rotating magnet case 211 and into the region of the impacting magnet assembly, while the passage in the impacting magnet 213 permits the same drive shaft to continue through the impacting magnet bracket 214 and toward the distal end of the housing. In this coaxial arrangement, the drive shaft 215 and the magnets share the same longitudinal axis, enabling a compact, space-efficient internal layout while maintaining the magnetic alignment necessary for the alternating attraction-repulsion mechanism.

[0047] Transfer rods 216 extend generally parallel to the longitudinal axis between the IM bracket 214 and the impactor plate 217. At their proximal ends, the transfer rods 216 are attached to the IM bracket 214, and at their distal ends, they are attached to the impactor plate 217. The transfer rods 216 may be provided as individual cylindrical rods, for example, two or more rods symmetrically disposed around the axis, or in one embodiment as a single tubular or cylindrical member with cutouts or openings formed to clear the rotating magnet bracket 212 and other internal features. The function of the transfer rods 216 is to transmit axial translation of the IM bracket 214 directly to the impactor plate 217, ensuring that the full axial displacement of the impacting magnet 213 is delivered to the output end of the device. The impactor plate 217 is a disc or plate-shaped structural member disposed near the distal end of the body and configured to translate axially within the body interior. The impactor plate 217 is oriented transversely to the axis so that its distal face impacts one or more impactor bolts 218 that are disposed at the distal interface. One or more impactor bolts 218 are attached to the proximal end of impaction mechanism 140, for example,by threaded engagement, press fit, or welding, and project distally from the impactor plate toward the distal end of the housing. The impactor bolts 218 are positioned and dimensioned to engage a corresponding connector structure associated with the orthopedic instrument, such as a broach connector, instrument adaptor plate, or other coupling element that is received within or through the distal end cap 221 of the housing. During each distal stroke of the impactor plate 217, the impactor bolts 218 contact and strike the connector, transferring the impaction force from the magnetic power unit through the output member and the bolts to the orthopedic instrument. In embodiments where multiple impactor bolts are used, they are arranged symmetrically around the axis to distribute the impaction force evenly across the connector interface, reducing the risk of off-axis loading at the instrument connection point.

[0048] One or more distal extractor bolts 223 are provided at the distal interface of the impaction mechanism 140 to transmit proximally directed axial forces from the output member to the connected orthopedic instrument during extraction. Each distal extractor bolt 223 is a structural pin, post, or rod attached, for example, by threaded engagement, press fit, or welding, to a proximal-facing connector structure associated with the orthopedic instrument, such as a broach connector or instrament adaptor received within or through the distal end cap 221. The distal extractor bolt 223 extends proximally from the connector structure into the interior of the housing, where its proximal end is positioned in axial alignment with the proximal face of the impactor plate 217. During normal impaction operation, when the impactor plate 217 translates distally, the distal face of the impactor plate 217 strikes the impactor bolts 218 to deliver forward impaction force to the orthopedic instrument, and the proximal face of the impactor plate 217 moves away from the distal extractor bolt 223 without engagement. During extraction operation, when the magnetic power unit drives the impacting magnet 213 and the output member 216, 217 in the proximal direction, the proximal face of the impactor plate 217 contacts and bears against the proximal end of the distal extractor bolt 223, applying a proximally directed axial force through the bolt 223 to the instrament connector and thereby to the connected orthopedic instrument. In this manner, the distal extractor bolt 223 couples the proximal translational motion of the impactor plate 217 to the orthopedic instrument, enabling the device to withdraw the instrument, for example, to extract a femoral broach from the medullary canal, in a controlled and axially aligned manner. In embodiments where multiple distal extractor bolts 223 are used, they are arranged symmetrically around the axis to distribute the extraction force evenly across the connector interface, reducing the risk of off-axis loading or tilting of the instrument during withdrawal. The distal extractor bolt 223 thus complements the impactor bolt 218 by providing a dedicated loadpath for extraction forces, keeping the impaction and extraction force transmission paths structurally independent while sharing the same output member 216, 217.

[0049] At the proximal side of the IM bracket 214, one or more proximal extractor bolts 219 are positioned to receive force from the IM bracket during proximal translation. The proximal extractor bolts 219 are disposed on the proximal side of the impactor plate or at another proximal location, and they serve to transmit proximally directed axial forces from the impacting magnet assembly to the connected orthopedic instrament when the device is operating in an extraction mode, for example, pulling a broach out of bone. A proximal end cap 220 encloses the proximal end of the body, supports the attachment mechanism 130 to the powered surgical driver, and provides a sealing surface. A distal end cap 221 encloses the distal end of the body and defines a central opening through which the broach connector or other instrument connector passes. The end caps may be threaded, press-fit, or otherwise secured to the body and can be removed for cleaning and sterilization.

[0050] Different versions of the first embodiment are contemplated. Examples include the presence of only one set of either distal extractor bolts 223 or proximal extractor bolts 219, or the use of both the distal and proximal extractor bolts 223 and 219.

[0051] Operating Principle — Single Rotating Magnet Configuration (FIGS.8 and 9)

[0052] Referring to FIGS. 8 and 9, the operating principle of the first magnet configuration is illustrated. When the powered surgical driver 300 rotates the drive shaft 215 and, with it, the rotating magnet 210 about the longitudinal axis, the magnetization plane of the rotating magnet 210 rotates relative to the fixed magnetization plane of the impacting magnet 213. As the rotating magnet completes successive 180-degree increments of rotation, the facing polarities of the two magnets alternate between a like-polarity (repulsion) configuration and an opposite-polarity (attraction) configuration. In the attraction configuration (FIG. 8), the north half of one magnet faces the south half of the other, and the resulting magnetic attractive force draws the impacting magnet 213 and IM bracket 214 toward the rotating magnet 210, moving the transfer rods 216 and impactor plate 217 in the proximal direction. As the rotating magnet continues to turn and the like-polarity (repulsion) configuration is reached, the mutually repulsive force between the magnets drives the IM bracket 214 and transfer rods 216 distally, propelling the impactor plate 217 into contact with the impactor bolts 218 and delivering an axial impact to the orthopedic instrument (FIG. 8, impaction status). In the subsequent attraction phase, the impacting magnet 213 is drawn backproximally, setting up the next impact cycle (FIG. 9, extraction status). Each complete rotation of the rotating magnet 210 produces one complete cycle of attraction and repulsion, and thus one impact event. The frequency of impact events is therefore equal to the rotational speed of the drive shaft in revolutions per second, and the surgeon can modulate the impact rate by adjusting the speed of the powered driver.

[0053] Second Embodiment — Dual Rotating Magnet Configuration with Directional Impaction and Extraction (FIGS. 10-13)

[0054] Referring to FIGS. 10 through 13, a second embodiment of the device provides directional impaction and extraction using a three-magnet arrangement comprising a distal rotating cylindrical permanent magnet, a proximal rotating cylindrical permanent magnet, and an impacting cylindrical permanent magnet disposed between them along the axis.

[0055] The distal rotating magnet is fixedly coupled via a distal RM case to the rotary input member for rotation at a distal position along the axis, and is magnetized diametrically in the same manner as described for the first embodiment. The proximal rotating magnet has the same construction as the distal rotating magnet, but is assembled in reverse orientation relative to the distal rotating magnet. This reverse orientation is essential for keeping the distance between the proximal RM and IM magnet at a minimum to maximize the attraction force and generated impaction force. Each rotating magnet case is coupled to the drive shaft 215 via a rotation limiter mechanism 225, sometimes referred to herein as a one-way rotational coupling or directional clutch. The rotation limiter mechanism 225 is configured to permit each rotating magnet to rotate freely in one permitted rotational direction while arresting or preventing rotation in the opposite direction. In one embodiment, the rotation limiter mechanism includes a spring clutch, a ratchet-and-pawl arrangement, a roller-and-wedge one-way clutch, a sprag clutch, or any other suitable unidirectional coupling device. The rotation limiter mechanism for the distal rotating magnet is oriented to permit rotation in a first rotational direction (for example, clockwise as viewed from the proximal end) and to prevent rotation in the opposite second rotational direction. Conversely, the rotation limiter mechanism for the proximal rotating magnet is oriented to permit rotation in the second rotational direction (counterclockwise) and to prevent rotation in the first rotational direction. In each case, when the drive shaft rotates in the direction opposite to the permitted direction of a given rotating magnet, the rotation limiter prevents the magnet from rotating beyond approximately 180 degrees, stopping the magnet in a fixed angular position relative to the body.In this manner, when the drive shaft rotates in the first direction, only the distal rotating magnet turns with the shaft, while the proximal rotating magnet remains rotationally static. When the drive shaft rotates in the second direction, only the proximal rotating magnet turns with the shaft, while the distal rotating magnet remains static.

[0056] Referring to FIG. 11 (neutral configuration), FIG. 12 (impaction configuration), and FIG. 13 (extraction configuration): when the driver rotates in the first rotational direction (FIG. 12), the distal rotating magnet rotates with the drive shaft and alternately attracts and repels the impacting magnet, driving it distally in a series of axial impacts. These distal impacts are transmitted through the transfer rods, impactor plate, and impactor bolts to the connected orthopedic instrument, for example, to drive a femoral broach progressively into the medullary canal during hip arthroplasty. The proximal rotating magnet remains stationary and does not contribute to the motion of the impacting magnet in this direction of rotation. When the driver rotation is reversed to the second rotational direction (FIG. 13), the distal rotating magnet is arrested by its rotation limiter and remains stationary, while the proximal rotating magnet begins to rotate with the drive shaft. Because the proximal rotating magnet is mounted in reverse orientation relative to the distal rotating magnet, its rotation produces alternating attraction and repulsion on the opposite side of the impacting magnet, driving it proximally in a series of axial impacts in the opposite axial direction. These proximal impact forces are transmitted through the IM bracket to the proximal extractor bolts 219, which in turn apply extraction forces to the connected orthopedic instrument, for example, to withdraw the broach from the bone when revision is required during the surgical procedure. In another embodiment, the proximal impact forces are transmitted through the impactor plate 217 to the distal extractor bolt 223 and in turn apply extraction forces to the connected orthopedic instrument, for example, to withdraw the broach from the bone when revision is required during the surgical procedure.

[0057] This bidirectional configuration provides an important clinical advantage: the surgeon can seamlessly switch between broach insertion and broach extraction simply by pressing forward or reverse trigger (in dual-trigger models) or the reverse button on the same powered surgical drill, without having to change instruments, reposition the patient, or switch to a separate extraction tool. The impact forces in both directions are controlled, repeatable, and substantially axially aligned, reducing the risk of off-axis loading, bone fracture, or loss of positional control associated with improvised reverse malleting.

[0058] Third Embodiment — Multiple Magnet Pair Configuration (FIG.14)Referring to FIG. 14, a third embodiment of the device employs a plurality of rotating cylindrical permanent magnets and a corresponding plurality of sliding cylindrical permanent magnets arranged in series along the longitudinal axis. In this configuration, two or more rotating magnets, each mounted in or on a respective rotating magnet case fixed to the rotary input member, are spaced apart along the axis. Between adjacent rotating magnets, one or more sliding impacting magnets are each housed in a respective IM bracket constrained to translate axially but not rotate. All rotating and sliding magnets are magnetized diametrically, and multiple rotating magnets may be mounted either in the same rotational orientation or in opposite (reverse) rotational orientations on the same shaft, depending on the desired impact timing relationship between adjacent magnet pairs.

[0059] When adjacent rotating magnets are mounted in the same orientation, the alternating attractionrepulsion cycles of all magnet pairs are in phase, meaning all sliding magnets reach the same axial displacement simultaneously, and their forces add constructively at the output. When adjacent rotating magnets are mounted in opposite orientations, the cycles are offset by 180 degrees, resulting in the sliding magnets reaching peak distal displacement at different times, which produces a smoother, more continuous output force profile at the impactor plate. The designer can therefore choose between a high-peak, pulsed impact characteristic (same orientation) or a more continuous, lower-peak impact characteristic (opposite orientations) by adjusting the relative mounting angles of the rotating magnets.

[0060] The sliding magnets may be positioned independently, such as, in one embodiment, to individually support impaction and extraction forces. In other embodiments, multiple sliding magnets are coupled via their respective IM brackets to a shared transfer structure, for example, a common rigid frame, yoke, or set of transfer rods connecting all brackets to a single impactor plate. In this way, the axial displacements of all sliding magnets are combined at the output, multiplying the delivered impact energy compared to a single magnet pair of the same individual magnet size. This design allows the overall impact-generating capability of the adapter to be scaled to the requirements of a particular surgical procedure, patient, or implant system by selecting the appropriate number of magnet pairs, without exceeding a housing diameter compatible with standard surgical drill interfaces.

[0061] In one embodiment of the multiple magnet pair configuration, the output member is coupled to all of the plurality of sliding cylindrical permanent magnets such that the combined reciprocating motion of all sliding magnets is transmitted as a single coordinated output to the orthopedicinstrument. This may be achieved by mechanically connecting the impacting magnet bracket of each sliding magnet to a common rigid transfer frame or to a shared set of transfer rods, all of which terminate at a single impactor plate. In this arrangement, the axial displacements of all sliding magnets are summed at the impactor plate, and the resulting impaction force delivered to the orthopedic instrument equals the aggregate of the forces generated by all individual magnet pairs acting simultaneously, thereby maximizing the impact energy available from a given housing size and driver speed.

[0062] Alternative Technical Solutions for Converting Rotary Motion to Impaction Force

[0063] The present invention is not limited to the directly coupled diametric magnet configurations described above. Several alternative mechanisms for converting rotary motion to reciprocating impaction force are contemplated and may be used alone or in combination.

[0064] In a spring-loaded mechanism, rotary motion of the drive shaft drives a cam, eccentric, or lead screw that progressively compresses one or more coil or disc springs. When the cam or eccentric passes a release point in its rotational cycle, the compressed spring is suddenly freed to drive a movable impact mass distally against the impactor plate. The spring rapidly extends, delivering a sharp impulse to the output member, before the cam re-engages and begins compressing the spring for the next cycle. The stiffness and preload of the spring, the mass of the impact element, and the geometry of the cam profile can be adjusted to control the magnitude, duration, and repetition rate of the impact. This mechanism may be preferred in some applications because the spring stores energy over a portion of the rotational cycle and then releases it rapidly, potentially delivering a higher peak force than a continuously coupled magnetic mechanism of similar size.

[0065] In an attraction magnetic force mechanism, rotary motion positions a magnet or magnetic circuit element to generate a high attractive force between a stationary magnetically permeable or permanently magnetic target and a movable impact mass. A mechanical latch or cam-controlled stop holds the impact mass in a cocked position while the magnetic attractive force continues to build, and when the latch is released by continued rotation, the impact mass is pulled rapidly by magnetic attraction and strikes the impactor plate. This approach can be used to generate well-controlled, high-energy impulses whose magnitude is primarily determined by the strength of the magnetic coupling at the moment of release, and can be combined with guide structures that ensure precise axial alignment of the impact mass travel.

[0066] In a repulsive magnetic force mechanism, rotary motion progressively drives two like-polaritymagnetic faces toward each other, building up repulsive potential energy against a mechanical stop or spring while a cam or Geneva mechanism holds the assembly in the charged configuration. At a defined point in the rotation cycle, the cam releases the constrained component, and the stored repulsive magnetic energy drives the impact mass distally with a rapid, well-defined impulse. Compared to attraction-based designs, repulsion mechanisms may offer the advantage of not requiring physical contact between moving magnetic parts, potentially reducing wear and facilitating sterilization.

[0067] In a magnet-switch mechanism, a mechanically actuated magnetic shunt or permeable shield is rotated by the drive shaft into and out of a position that either channels magnetic flux to actively attract an impact mass ("ON" position) or diverts flux away from the impact mass, reducing the effective magnetic coupling ("OFF" position). The cycle of engagement and disengagement drives the impact mass in a reciprocating axial motion synchronized with the rotation. In some implementations, a magnet-switch mechanism is combined with a spring-loaded mechanism so that the magnetic attraction in the "ON" position compresses a spring against a stop, and the "OFF" position releases the spring to deliver an impact, while the magnet switch then resets for the next cycle.

[0068] Mechanisms for Adjusting Impaction Force

[0069] The impaction force delivered by the adapter can be adjusted through a variety of design and intraoperative mechanisms. In terms of magnet selection, the grade, size, and pole orientation of the permanent magnets can be varied to increase or decrease the peak magnetic force available to drive the sliding magnet. For example, replacing standard N42 neodymium magnets with N52 grade magnets of the same size increases the residual flux density and coercivity, resulting in stronger attraction and repulsion forces and greater peak impact. Conversely, using smaller magnets or magnets with lower energy products reduces the delivered force, which may be appropriate for delicate bone preparation or osteoporotic bone where fracture risk must be minimized.

[0070] The axial spacing between the rotating and impacting magnets can also be adjusted. Closer magnet spacing increases the peak attractive and repulsive forces and reduces the stroke length available for acceleration, while greater spacing reduces peak force but allows more time and distance for the impacting magnet to accelerate before impact. Adjustable spacing can be provided via a threaded adjustment collar or set of interchangeable spacer rings within the magnet bracketassemblies, allowing the surgeon or biomedical technician to set the desired force characteristic before the procedure.

[0071] The mass of the moving components, particularly the impacting magnet, IM bracket, transfer rods, and impactor plate, together determines the kinetic energy delivered at each impact for a given magnet displacement and velocity profile. Heavier moving components store more kinetic energy at a given velocity, delivering larger impulses, but may also result in greater rebound and reduced impact frequency. Interchangeable IM brackets with different masses, or add-on mass elements that can be attached to the bracket, can be used to tune the kinetic energy without changing the magnets. In spring-loaded embodiments, the spring constant and preload can be selected from a range of options to achieve different peak forces and impulse profiles.

[0072] In some embodiments, an internal adjustable limiter or travel stop is incorporated into the IM bracket guide structure. By limiting the maximum axial displacement of the IM bracket, the adjustable limiter restricts the stroke length and the kinetic energy that can be imparted to the impactor plate per cycle, thereby reducing the peak impact. Moving the limiter to a less restrictive position allows greater stroke and higher impact energy. In one implementation, the travel stop is a threaded collar accessible from the exterior of the body through a slot or aperture, so that the surgeon can adjust the impact force setting intraoperatively with a simple tool or by hand. In another implementation, the travel stop is adjusted by rotating a ring or dial on the exterior of the body that translates an internal cam to change the available stroke.

[0073] Damping elements, such as elastomeric pads, hydraulic dashpots, or pneumatic resistors, can be incorporated between the IM bracket and the impactor plate, or between the impactor plate and the end cap, to absorb a portion of the impact energy and modify the effective impulse delivered to the orthopedic instrament. By adjusting the stiffness and thickness of these damping elements, the peak impact force and its duration can be shaped to suit different clinical needs, for example providing a softer, longer-duration impulse for soft bone and a sharper, higher-peak impulse for hard cortical bone.

[0074] System of Adapters with Selected Impaction Force Profiles

[0075] In another aspect, the invention encompasses a system or family of adapters, each characterized by a selected impaction force profile suited to a specific clinical application, bone quality category, or instrument type. Within the family, all adapters share common proximal and distal attachment interfaces, so that any adapter in the family can be connected to the same powered surgical rotarydriver and to the same set of orthopedic instrument connectors without modification. Internally, however, the adapters differ in one or more parameters that determine the impaction force, such as magnet grade, magnet size, magnet axial spacing, moving mass, spring configuration, or travel stop position.

[0076] For example, a low -force adapter may be configured with lower-grade magnets, a reduced moving mass, and a shorter stroke, delivering impact forces appropriate for osteoporotic bone, pediatric patients, or delicate revision procedures where the risk of fracture is high and controlled, gentle impaction is required. A medium-force adapter may be configured with intermediate parameters suitable for the majority of primary hip and knee arthroplasty cases in patients with normal bone mineral density. A high-force adapter may incorporate high-grade neodymium magnets, a larger moving mass, and a full stroke, delivering maximum impact energy appropriate for dense cortical bone, large implants, or cases where additional seating force is needed.

[0077] In some embodiments, each adapter in the family is color-coded, labeled, or otherwise marked to indicate its nominal impact force range or intended clinical application, allowing the surgeon and the sterile processing team to identify the appropriate adapter quickly and reliably. The adapters may be provided in sterile single-use packaging, or as reusable devices supplied in a sterilization tray or case that includes all adapters in the family and the associated orthopedic instrument connectors. In still other embodiments, the adapters are partially reusable, with a reusable outer housing and proximal and distal connector assemblies, combined with single-use internal magnet or spring modules that are replaced after each case to maintain consistent impact performance and simplify sterilization. The system of adapters with graded impaction force profiles provides the orthopedic surgical team with a practical, flexible solution for adapting the impaction force to the specific needs of each patient and procedure while leveraging a single powered surgical rotary driver platform.

[0078] Surgical Use

[0079] When the device is attached proximally to the powered surgical driver and distally to an orthopedic instrument such as a broach, the surgeon activates the driver to initiate rotary motion of the drive shaft and rotating magnet. The resulting alternating magnetic attraction and repulsion between the rotating and impacting magnets produces reciprocating motion of the IM bracket, transfer rods, and impactor plate, which delivers a continuous series of axial impacts to the orthopedic instrument. The frequency of impacts scales with the rotational speed of the driver,and the magnitude of each impact is determined by the internal configuration of the adapter as described above. The surgeon directs the instrument in the desired direction, and the device provides controlled, consistent impaction force in the axial direction of the tool without requiring manual hammering. When broach insertion is complete, and extraction is required, the surgeon simply pulls the device with the attached instrament or reverses the direction of the powered driver, engaging the proximal rotating magnet and reversing the impact direction to withdraw the broach from bone in a controlled manner. Upon completion of the procedure, the device is removed from the driver and the instrument, cleaned, and sterilized for subsequent use in accordance with applicable guidelines.

[0080] Powered Orthopedic Surgical System

[0081] The invention also encompasses a powered orthopedic surgical system comprising a powered surgical rotary driver 300 having a motor and a rotary output shaft defining an axis of rotation, and an adapter of any embodiment described herein operatively coupled to the rotary output shaft. In use, the rotary input member of the adapter is coupled to and rotated by the rotary output shaft of the driver, and the output member of the adapter delivers reciprocating motion along the axis to an orthopedic instrument connected to the distal end of the housing. In one embodiment, the powered surgical rotary driver 300 is a battery-powered surgical drill of the type commonly used in orthopedic surgery, including a rechargeable battery pack 310 that provides electrical power to the motor, and a trigger or control interface that allows the surgeon to control the direction and speed of rotation of the output shaft. In other embodiments, a dual-trigger design is provided, which may be advantageous for the three-magnet configuration of the device. Such battery-powered surgical drills are widely available from orthopedic device manufacturers and are familiar to orthopedic surgeons. The system further comprises an orthopedic instrument connected to the distal end of the housing of the adapter. The orthopedic instrument may be selected from the group consisting of an osteotome, a broach, a chisel, and an implant inserter, each of which is coupled to the distal end of the housing via the instrament-specific connector and impactor bolt interface described herein. An osteotome connected to the distal end of the housing receives periodic axial impacts from the impactor plate and impactor bolts and uses these impacts to cut or shape bone. A broach connected to the distal end receives periodic axial impacts for advancing into the medullary canal during preparation for joint replacement, and, in embodiments with bidirectional impact capability, can receive axial extraction impacts when the driver rotation is reversed. A chisel connected to the distal end receives periodic axial impacts for bone resectionor tissue division. An implant inserter connected to the distal end receives periodic axial impacts to seat trial or definitive prosthetic implant components.

[0082] Methods of Use

[0083] The invention also provides a method of converting rotary motion from a powered surgical rotary driver into a reciprocating impaction force for orthopedic surgery. The method comprises first coupling an adapter as described herein to a powered surgical rotary driver, for example by engaging the proximal attachment mechanism of the adapter with the rotary output shaft of the driver, and coupling an orthopedic instrument to the distal end of the housing. The method further comprises rotating the rotary input member of the adapter about the longitudinal axis by activating the powered surgical driver. This rotation causes at least one rotating cylindrical permanent magnet, which is fixedly coupled to the rotary input member, to rotate about the axis, each rotating cylindrical permanent magnet having opposite magnetic polarities in respective halves separated by a diametric magnetization plane. Concurrently, at least one sliding cylindrical permanent magnet of the adapter is constrained by the guide structure to translate along the axis while being prevented from rotating, each sliding cylindrical permanent magnet being axially aligned with at least one of the rotating cylindrical permanent magnets and being diametrically magnetized in the same fashion. As the rotating magnet turns, the method further comprises alternately aligning like polarities and unlike polarities of the rotating and sliding cylindrical permanent magnets, thereby alternately magnetically repelling and magnetically attracting the sliding magnet to produce reciprocating motion along the axis. This reciprocating motion is transmitted through the output member to the orthopedic instrument, providing periodic axial impacts to generate impaction force for orthopedic surgery.

[0084] In embodiments employing dual rotating magnets with rotation limiter mechanisms, the method further comprises rotating the rotary input member in a first rotational direction to engage only the distal rotating cylindrical permanent magnet, thereby generating a series of axial impact forces in a first axial direction that drive the orthopedic instrument, for example, a broach, distally into bone. When extraction of the instrument is required, the method comprises rotating the rotary input member in an opposite second rotational direction to engage only the proximal rotating cylindrical permanent magnet, thereby generating a series of axial impact forces in an opposite second axial direction that extract the broach proximally from the bone. This directional switching is achieved without changing instruments or adapters, simply by reversing the rotation direction of the powered surgical driver.It is contemplated that any embodiment discussed in this specification can be implemented with respect to any method of the invention, and vice versa. It will be also understood that particular embodiments described herein are shown by way of illustration and not as limitations of the invention. The principal features of this invention can be employed in various embodiments without departing from the scope of the invention. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, numerous equivalents to the specific procedures described herein. Such equivalents are considered to be within the scope of this invention and are covered by the claims.

[0085] All publications and patent applications mentioned in the specification are indicative of the level of skill of those skilled in the art to which this invention pertains. All publications and patent applications are herein incorporated by reference to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference. Incorporation by reference is limited such that no subject matter is incorporated that is contrary to the explicit disclosure herein, no claims included in the documents are incorporated by reference herein, and any definitions provided in the documents are not incorporated by reference herein unless expressly included herein.

[0086] The use of the word “a” or “an” when used in conjunction with the term “comprising” in the claims and / or the specification may mean “one,” but it is also consistent with the meaning of “one or more,” “at least one,” and “one or more than one.” The use of the tern “or” in the claims is used to mean “and / or” unless explicitly indicated to refer to alternatives only or the alternatives are mutually exclusive, although the disclosure supports a definition that refers to only alternatives and “and / or.” Throughout this application, the term “about” is used to indicate that a value includes the inherent variation of error for the device, the method being employed to determine the value, or the variation that exists among the study subjects.

[0087] As used in this specification and claim(s), the words “comprising” (and any form of comprising, such as “comprise” and “comprises”), “having” (and any form of having, such as “have” and “has”), “including” (and any form of including, such as “includes” and “include”) or “containing” (and any form of containing, such as “contains” and “contain”) arc inclusive or open-ended and do not exclude additional, unrecited elements or method steps. In embodiments of any of the compositions and methods provided herein, “comprising” may be replaced with “consisting essentially of’ or “consisting of’. As used herein, the phrase “consisting essentially of’ requires the specified integer(s) or steps as well as those that do not materially affect the character orfunction of the claimed invention. As used herein, the term “consisting” is used to indicate the presence of the recited integer (e.g., a feature, an element, a characteristic, a property, a method / process step or a limitation) or group of integers (e.g., feature(s), element(s), characteristic(s), propertie(s), method / process steps or limitation(s)) only.

[0088] The term “or combinations thereof’ as used herein refers to all permutations and combinations of the listed items preceding the term. For example, “A, B, C, or combinations thereof’ is intended to include at least one of: A, B, C, AB, AC, BC, or ABC, and if order is important in a particular context, also BA, CA, CB, CBA, BCA, ACB, BAC, or CAB. Continuing with this example, expressly included are combinations that contain repeats of one or more item or term, such as BB, AAA, AB, BBC, AAABCCCC, CBBAAA, CABABB, and so forth. The skilled artisan will understand that typically there is no limit on the number of items or terms in any combination, unless otherwise apparent from the context.

[0089] As used herein, words of approximation such as, without limitation, “about”, "substantial" or "substantially" refers to a condition that when so modified is understood to not necessarily be absolute or perfect but would be considered close enough to those of ordinary skill in the art to warrant designating the condition as being present. The extent to which the description may vary will depend on how great a change can be instituted and still have one of ordinary skilled in the art recognize the modified feature as still having the required characteristics and capabilities of the unmodified feature. In general, but subject to the preceding discussion, a numerical value herein that is modified by a word of approximation such as “about” may vary from the stated value by at least ±1, 2, 3, 4, 5, 6, 7, 10, 12, 15, 20 or 25%.

[0090] All of the devices and / or methods disclosed and claimed herein can be made and executed without undue experimentation in light of the present disclosure. While the devices and methods of this invention have been described in terms of preferred embodiments, it will be apparent to those of skill in the art that variations may be applied to the devices and / or methods and in the steps or in the sequence of steps of the method described herein without departing from the concept, spirit, and scope of the invention. All such similar substitutes and modifications apparent to those skilled in the art arc deemed to be within the spirit, scope, and concept of the invention as defined by the appended claims.

Claims

WHAT IS CLAIMED IS:

1. An adapter (100) for converting rotary motion from a powered surgical rotary driver (300) into reciprocating motion of an orthopedic instrument, the adapter (100) comprising a housing having a proximal end configured for connection to a powered surgical rotary driver (300) and a distal end configured for connection to an orthopedic instrument, a rotary input member (215) disposed at the proximal end of the housing and configured to be rotated about an axis by the powered surgical rotary driver (300), and an output member (216, 217) configured to transmit reciprocating motion to the orthopedic instrument, characterized in that the adapter (100) further comprises:(a) a first cylindrical permanent magnet (210) fixedly coupled to the rotary input member (215) for rotation about the axis, the first cylindrical permanent magnet (210) having a first longitudinal axis substantially coincident with the axis and being magnetized such that:i. a first half of a volume of the first cylindrical permanent magnet (210) on a first side of a first plane intersecting the first longitudinal axis exhibits a first magnetic polarity, andii. a second half of the volume of the first cylindrical permanent magnet (210) on an opposite side of the first plane exhibits an opposite magnetic polarity; (b) a second cylindrical permanent magnet (213) disposed in the housing adjacent the first cylindrical permanent magnet (210) and axially aligned with the first cylindrical permanent magnet (210) along the axis, the second cylindrical permanent magnet (213) having a second longitudinal axis substantially coincident with the axis and being magnetized such that:i. a first half of a volume of the second cylindrical permanent magnet (213) on a first side of a second plane intersecting the second longitudinal axis exhibits the first magnetic polarity, andii. a second half of the volume of the second cylindrical permanent magnet (213) on an opposite side of the second plane exhibits the opposite magnetic polarity; (c) a guide structure (214) constraining the second cylindrical permanent magnet (213)against rotation about the axis while permitting translation of the second cylindrical permanent magnet (213) along the axis relative to the housing; and(d) the output member (216, 217) being coupled to the second cylindrical permanent magnet (213) and configured to transmit translation of the second cylindrical permanent magnet (213) along the axis to the orthopedic instrument as reciprocating motion, the reciprocating motion comprising periodic axial impacts applied to the orthopedic instrument so as to provide a periodic impact-generating effect on the orthopedic instrument for use in orthopedic surgery;wherein rotation of the first cylindrical permanent magnet (210) about the axis causes the first and second planes to alternate between angular orientations in which like magnetic polarities of the first (210) and second (213) cylindrical permanent magnets face each other to magnetically repel the second cylindrical permanent magnet (213) away from the first cylindrical permanent magnet (210) and angular orientations in which opposite magnetic polarities of the first (210) and second (213) cylindrical permanent magnets face each other to magnetically attract the second cylindrical permanent magnet (213) toward the first cylindrical permanent magnet (210), thereby driving the second cylindrical permanent magnet (213) and the output member (216, 217) in reciprocation along the axis.

2. The adapter (100) of claim 1, wherein the first cylindrical permanent magnet (210) and the second cylindrical permanent magnet (213) are diametric permanent magnets.

3. The adapter (100) of claim 1 or 2, wherein the first cylindrical permanent magnet (210) and the second cylindrical permanent magnet (213) comprise neodymium magnets.

4. The adapter (100) of any one of claims 1 to 3, wherein the first cylindrical permanent magnet (210) is housed within a rotating magnet case (211) fixedly coupled to the rotary input member (215).

5. 1’he adapter (100) of claim 4, wherein the rotating magnet case (211) is connected to a drive shaft (215) of the rotary input member.

6. The adapter (100) of any one of claims 1 to 5, wherein the second cylindrical permanent magnet (213) is housed within an impacting magnet bracket (214) forming part of the guidestructure.

7. The adapter (100) of any one of claims 1 to 6, further comprising a rotating magnet bracket (212) fixed to the housing and providing a platform within which the first cylindrical permanent magnet (210) rotates.

8. The adapter (100) of any one of claims 1 to 7, wherein the output member comprises:(a) at least one transfer rod (216) coupled to the second cylindrical permanent magnet (213); and(b) an impactor plate (217) coupled to the at least one transfer rod (216) and configured to transmit reciprocating motion to the orthopedic instrument.

9. The adapter (100) of claim 8, wherein the at least one transfer rod (216) is connected to an impacting magnet bracket (214) housing the second cylindrical permanent magnet (213) at a proximal end of the at least one transfer rod (216) and to the impactor plate (217) at a distal end of the at least one transfer rod (216).

10. The adapter (100) of claim 8 or 9, further comprising at least one impactor bolt (218) attached to the impactor plate (217) and configured to transfer impaction force to a connector for the orthopedic instrument.

11. The adapter (100) of claim 8 or 9, further comprising at least one distal extractor bolt (223) having a distal end attached to a connector structure of the orthopedic instrument at the distal end of the housing and a proximal end extending into the interior of the housing in axial alignment with a proximal face of the impactor plate (217), wherein during distal translation of the impactor plate (217), the proximal face of the impactor plate (217) moves away from the proximal end of the at least one distal extractor bolt (223) without engagement, and wherein during proximal translation of the impactor plate (217), the proximal face of the impactor plate (217) engages the proximal end of the at least one distal extractor bolt (223) to apply a proximally directed axial extraction force to the orthopedic instrument.

12. The adapter (100) of claim 11, wherein a plurality of distal extractor bolts (223) are arranged symmetrically around the axis to distribute extraction forces evenly across the connector structure of the orthopedic instrument, and wherein the at least one distal extractorbolt (223) provides a dedicated load path for extraction forces that is structurally independent from a load path for impaction forces provided by the at least one impactor bolt (218), such that impaction forces and extraction forces are each transmitted to the orthopedic instrument through respective separate force transmission paths via the common output member (216, 217).

13. The adapter (100) of any one of claims 1 to 12, wherein the housing is configured as a surgical adapter body sized and shaped to be attached to a standard powered surgical drill (300) for orthopedic surgery and to drive, in reciprocation, an orthopedic tool selected from the group consisting of an osteotome, a broach, a chisel, and an implant inserter.

14. The adapter (100) of any one of claims 1 to 13, further comprising a stabilizer mechanism (130) coupled to the housing and configured to provide rotational stability during operation.

15. The adapter (100) of any one of claims 1 to 14, wherein each of the first cylindrical permanent magnet (210) and the second cylindrical permanent magnet (213) includes a central axial passage through which a drive shaft (215) passes.

16. An adapter (100) for converting rotary motion from a powered surgical rotary driver (300) into reciprocating motion of an orthopedic instrument, the adapter (100) comprising a housing having a proximal end configured for connection to a powered surgical rotary driver (300) and a distal end configured for connection to an orthopedic instrument, a rotary input member (215) disposed at the proximal end of the housing and configured to be rotated about an axis by the powered surgical rotary driver (300), and an output member (216, 217) configured to transmit reciprocating motion to the orthopedic instrument, characterized in that the adapter (100) further comprises:(a) a distal cylindrical permanent magnet (210) fixedly coupled to the rotary input member (215) for rotation about the axis at a distal location, the distal cylindrical permanent magnet (210) having a first longitudinal axis substantially coincident with the axis and being magnetized such that a first half of a volume thereof on a first side of a first plane intersecting the first longitudinal axis exhibits a first magnetic polarity and a second half of the volume thereof on an opposite side of the first plane exhibits an opposite magnetic polarity;(b) a proximal cylindrical permanent magnet (222) fixedly coupled to the rotary inputmember (215) for rotation about the axis at a proximal location spaced apart from the distal cylindrical permanent magnet (210), the proximal cylindrical permanent magnet (222) having a second longitudinal axis substantially coincident with the axis and being magnetized such that a first half of a volume thereof on a first side of a second plane intersecting the second longitudinal axis exhibits the first magnetic polarity and a second half of the volume thereof on an opposite side of the second plane exhibits the opposite magnetic polarity;(c) an impacting cylindrical permanent magnet (213) disposed in the housing between the distal cylindrical permanent magnet (210) and the proximal cylindrical permanent magnet (222) and axially aligned therewith along the axis, the impacting cylindrical permanent magnet (213) having a third longitudinal axis substantially coincident with the axis and being magnetized such that a first half of a volume thereof on a first side of a third plane intersecting the third longitudinal axis exhibits the first magnetic polarity and a second half of the volume thereof on an opposite side of the third plane exhibits the opposite magnetic polarity:(d) a guide structure (214) constraining the impacting cylindrical permanent magnet (213) against rotation about the axis while permitting translation of the impacting cylindrical permanent magnet (213) along the axis relative to the housing; and (e) the output member (216, 217) being coupled to the impacting cylindrical permanent magnet (213) and configured to transmit translation of the impacting cylindrical permanent magnet (213) along the axis to the orthopedic instrument as reciprocating motion, the reciprocating motion comprising successive axial impacts imparted to the orthopedic instrument to generate an impact-generating effect during orthopedic procedures;wherein rotation of the distal cylindrical permanent magnet (210) and the proximal cylindrical permanent magnet (222) about the axis causes alternating attractive and repulsive magnetic interactions with the impacting cylindrical permanent magnet (213) to drive the impacting cylindrical permanent magnet (213) and the output member (216, 217) in reciprocation along the axis.

17. The adapter (100) of claim 16, wherein the distal cylindrical permanent magnet (210) andthe proximal cylindrical permanent magnet (222) are mounted in reverse orientation relative to each other such that their respective magnetization planes are oriented oppositely.

18. The adapter (100) of claim 16 or 17, further comprising:(a) a first rotation limiter mechanism (225) coupled to the distal cylindrical permanent magnet (210) and configured to permit rotation of the distal cylindrical permanent magnet (210) in a first rotational direction while preventing rotation in an opposite second rotational direction, and(b) a second rotation limiter mechanism (225) coupled to the proximal cylindrical permanent magnet (222) and configured to permit rotation of the proximal cylindrical permanent magnet (222) in the second rotational direction while preventing rotation in the first rotational direction;wherein rotation of the rotary input member (215) in the first rotational direction causes only the distal cylindrical permanent magnet (210) to rotate and, through interaction with the impacting cylindrical permanent magnet (213), generates a series of axial impact forces in a first axial direction for driving an orthopedic instrument distally, and rotation of the rotary input member (215) in the second rotational direction causes only the proximal cylindrical permanent magnet (222) to rotate and, through interaction with the impacting cylindrical permanent magnet (213), generates a series of axial impact forces in an opposite second axial direction for extracting the orthopedic instrument proximally.

19. The adapter (100) of claim 18, wherein each rotation limiter mechanism (225) is configured to permit up to 180 degrees of rotation in the permitted rotational direction before stopping.

20. The adapter (100) of claim 18, wherein the orthopedic instrument comprises a broach configured for insertion into a bone, and the axial impact forces in the first axial direction are used to drive the broach into the bone, while the axial impact forces in the opposite second axial direction are used to extract the broach from the bone.

21. The adapter (100) of any one of claims 16 to 19, further comprising at least one proximal extractor bolt (219) positioned at the proximal end of the housing and configured to receiveextraction force from the impacting cylindrical permanent magnet (213) during proximal translation thereof.

22. The adapter (100) of any one of claims 16 to 21 , wherein the output member comprises:(a) at least one transfer rod (216) coupled to an impacting magnet bracket (214) housing the impacting cylindrical permanent magnet (213); and(b) an impactor plate (217) coupled to the at least one transfer rod (216) and configured to transmit impaction force to the orthopedic instrument.

23. An adapter (100) for converting rotary motion from a powered surgical rotary driver (300) into reciprocating motion of an orthopedic instrument, the adapter (100) comprising a housing having a proximal end configured for connection to a powered surgical rotary driver (300) and a distal end configured for connection to an orthopedic instrument, a rotary input member (215) disposed at the proximal end of the housing and configured to be rotated about an axis by the powered surgical rotary driver (300), and an output member (216, 217) configured to transmit reciprocating motion to the orthopedic instrument, characterized in that the adapter (100) further comprises:(a) a plurality of rotating cylindrical permanent magnets (210, 222) spaced apart along the axis and fixedly coupled to the rotary input member (215) for rotation about the axis, each rotating cylindrical permanent magnet (210, 222) having a longitudinal axis substantially coincident with the axis and being magnetized such that a first half of a volume thereof on a first side of a plane intersecting the longitudinal axis exhibits a first magnetic polarity and a second half of the volume thereof on an opposite side of the plane exhibits an opposite magnetic polarity;(b) a plurality of sliding cylindrical permanent magnets (213) disposed in the housing, each sliding cylindrical permanent magnet (213) being positioned between adjacent ones of the plurality of rotating cylindrical permanent magnets (210, 222) and axially aligned therewith along the axis, each sliding cylindrical permanent magnet (213) having a longitudinal axis substantially coincident with the axis and being magnetized such that a first half of a volume thereof on a first side of a plane intersecting the longitudinal axis exhibits the first magnetic polarity and a second half of the volume thereof on an opposite side of the plane exhibits the opposite magnetic polarity;(c) a guide structure (214) constraining each of the plurality of sliding cylindrical permanent magnets (213) against rotation about the axis while permitting translation along the axis relative to the housing; and(d) the output member (216, 217) being coupled to at least one of the plurality of sliding cylindrical permanent magnets (213) and configured to transmit translation thereof along the axis to the orthopedic instrument as reciprocating motion, the reciprocating motion comprising periodic axial impacts applied to the orthopedic instrument to provide an impact-generating effect for orthopedic instruments such as osteotomes, broaches, chisels, or implant inserters;wherein rotation of the plurality of rotating cylindrical permanent magnets (210, 222) about the axis causes alternating attractive and repulsive magnetic interactions with the plurality of sliding cylindrical permanent magnets (213) to drive the plurality of sliding cylindrical permanent magnets (213) and the output member (216, 217) in reciprocation along the axis.

24. The adapter (100) of claim 23, wherein the plurality of rotating cylindrical permanent magnets (210, 222) comprises at least two rotating cylindrical permanent magnets and the plurality of sliding cylindrical permanent magnets (213) comprises at least one sliding cylindrical permanent magnet.

25. The adapter (100) of claim 23 or 25, wherein the output member (216, 217) is coupled to all of the plurality of sliding cylindrical permanent magnets (213) such that combined reciprocating motion from all sliding cylindrical permanent magnets (213) is transmitted to the orthopedic instrument.

26. The adapter (100) of any one of claims 23 to 25, wherein adjacent rotating cylindrical permanent magnets (210, 222) of the plurality of rotating cylindrical permanent magnets are mounted in the same rotational orientation.

27. The adapter (100) of any one of claims 23 to 25, wherein adjacent rotating cylindrical permanent magnets (210, 222) of the plurality of rotating cylindrical permanent magnets are mounted in opposite rotational orientations.

28. A powered orthopedic surgical system comprising a powered surgical rotary driver (300)having a motor and a rotary output shaft defining an axis of rotation, and an adapter (100) operatively coupled to the rotary output shaft for converting rotary motion into reciprocating motion of an orthopedic instrument, characterized in that the adapter (100) is the adapter of any one of claims 1 to 25, wherein the rotary input member (215) is rotated about the axis of rotation and the output member (216, 217) delivers reciprocating motion along the axis of rotation to an orthopedic instrument connected to the distal end of the housing.

29. The system of claim 28, wherein the powered surgical rotary driver (300) comprises a battery-powered surgical drill.

30. The system of claim 28 or 29, further comprising an orthopedic instrument selected from the group consisting of an osteotome, a broach, a chisel, and an implant inserter, the orthopedic instrument being coupled to the distal end of the housing.

31. A method of converting rotary motion from a powered surgical rotary driver (300) into reciprocating motion for orthopedic surgery, the method comprising coupling an adapter (100) to a powered surgical rotary driver (300) and rotating a rotary input member (215) of the adapter (100) about an axis, characterized in that the method further comprises:(a) rotating at least one rotating cylindrical permanent magnet (210) fixedly coupled to the rotary input member (215) about the axis, each rotating cylindrical permanent magnet (210) having opposite magnetic polarities in respective halves separated by a plane intersecting a longitudinal axis thereof;(b) constraining at least one sliding cylindrical permanent magnet (213) of the adapter (100) to translate along the axis while preventing rotation thereof about the axis, each sliding cylindrical permanent magnet (213) being axially aligned with at least one of the at least one rotating cylindrical permanent magnet (210) and having opposite magnetic polarities in respective halves separated by a plane intersecting a longitudinal axis thereof; and(c) alternately aligning like polarities and unlike polarities of the at least one rotating cylindrical permanent magnet (210) and the at least one sliding cylindrical permanent magnet (213) by said rotation, thereby alternately magnetically repelling and magnetically attracting the at least one sliding cylindrical permanent magnet (213) to produce reciprocating motion along the axis and transmitting the reciprocating motionto an orthopedic instrument coupled to the adapter (100), the reciprocating motion providing periodic axial impacts to the orthopedic instrument to generate impaction force for orthopedic surgery.

32. The method of claim 31 , further comprising rotating the rotary input member (215) in a first rotational direction to generate axial impacts in a first axial direction that drive a broach into a bone, and rotating the rotary input member (215) in an opposite second rotational direction to generate axial impacts in an opposite second axial direction that extract the broach from the bone.

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