MEDICAL IMPACT INSTRUMENT

A medical impact instrument, in particular in the form of an impact hammer, includes a shaft defining a shaft longitudinal direction, a proximal end and a distal end. An impact body is arranged on the shaft and defines a longitudinal axis. The impact body is movable in an impact position on the shaft between a distal stop defining a distal stop position of the impact body and a proximal stop defining a proximal stop position of the impact body for transmitting an impact pulse to the distal end of the shaft in the distal or proximal direction. The impact instrument includes a fixing device for temporarily fixing the impact body to the shaft in at least one, in particular arbitrary, fixing position between the distal stop position and the proximal stop position.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present disclosure claims priority to German Patent Application No. 10 2022 118 986.4, filed Jul. 28, 2022, the content of which is incorporated by reference herein in its entirety and for all purposes.

FIELD

The present disclosure relates to medical impact instruments generally, and more specifically to a medical impact instrument, in particular in the form of an impact hammer, comprising a shaft defining a shaft longitudinal direction and a proximal and a distal end, and comprising an impact body arranged on the shaft and defining a longitudinal axis, wherein the impact body in an impact position on the shaft is movable, in particular displaceable, between a distal stop defining a distal stop position of the impact body and a proximal stop defining a proximal stop position for transmitting an impact pulse to the distal end of the shaft in the distal or proximal direction.

BACKGROUND

Medical impact instruments of the kind described at the outset are known, for example, in the form of impact hammers, also referred to as so-called “slap hammers”, in different variants. Distal ends of the impact instruments can be coupled, e.g., to implants in order to, for example, strike them into or out of a bone by transmitting impact pulses. Such an impact instrument may optionally also be coupled, in particular with its distal end, to a medical object. Due to the mobility of the impact body and the shaft relative to one another, it is necessary for achieving such a coupling to handle the impact instrument with two hands, namely holding the shaft and the impact body each with one hand. However, this is disadvantageous, in particular, in a medical operation in an operating room, because an operation time should always be kept as short as possible and also a simple handling of instruments used here is desirable.

SUMMARY

In a first aspect of the present disclosure, a medical impact instrument, in particular in the form of an impact hammer, comprises a shaft defining a shaft longitudinal direction as well as a proximal and a distal end, and comprising an impact body arranged on the shaft and defining a longitudinal axis. The impact body in an impact position on the shaft is movable, in particular displaceable, between a distal stop defining a distal stop position of the impact body and a proximal stop defining a proximal stop position of the impact body for transmitting an impact pulse to the distal end of the shaft in the distal or proximal direction. The impact instrument comprises a fixing device for temporarily fixing the impact body to the shaft in at least one, in particular an arbitrary, fixing position between the distal stop position and the proximal stop position.

DETAILED DESCRIPTION

Although the present disclosure is illustrated and described herein with reference to specific embodiments, the present disclosure is not intended to be limited to the details shown. Rather, various modifications may be made in the details within the scope and range of equivalents and without departing from the present disclosure.

The present disclosure relates to a medical impact instrument, in particular in the form of an impact hammer, comprising a shaft defining a shaft longitudinal direction as well as a proximal and a distal end, and comprising an impact body arranged on the shaft and defining a longitudinal axis, wherein the impact body in an impact position on the shaft is movable, in particular displaceable, between a distal stop defining a distal stop position of the impact body and a proximal stop defining a proximal stop position of the impact body for transmitting an impact pulse to the distal end of the shaft in the distal or proximal direction, wherein the impact instrument comprises a fixing device for temporarily fixing the impact body to the shaft in at least one, in particular an arbitrary, fixing position between the distal stop position and the proximal stop position.

A medical impact instrument with such a fixing device enables a user, in particular, to fix or lock the impact body to the shaft in one or more, in particular in a plurality, and also an arbitrary fixing position. Fixing in this sense is to be understood to mean that the impact body and the shaft are immovable relative to one another in the fixing position. One could also say that the shaft is immovably held to the impact body in the fixing position. This fixing of the impact body to the shaft simplifies the handling of the medical impact instrument. When the impact body is fixed to the shaft, a user can handle the impact instrument with only one hand without the help of a second hand and, for example, can couple it to a medical object, for example a fastening element in the form of a pin. In other words, the fixing device enables, in particular, a simple one-hand operation of the medical impact instrument.

The impact body is favorably configured in the form of a handle. This makes it possible, in particular, to grip the medical impact instrument at the impact body with one hand and to then handle it with one hand, in particular in order to couple it to a medical object. To this end, the medical impact instrument is preferably transferred with the fixing device into a fixing position.

For optimal handling, it is advantageous if the handle has an ergonomically formed outer contour for holding same with one hand.

It is favorable if the impact body in a basic position is fixed relative to the shaft and adopts the at least one fixing position. A user can thus grip the impact instrument, in particular, at the impact body with one hand, the impact body then remaining immovable relative to a distal end of the impact instrument. The impact instrument can thus be coupled to a medical object in a simple manner.

It is advantageous if the fixing device is configured to fix the impact body to the shaft in the proximal stop position and/or in the distal stop position. The fixing device is thus suited not only to fix the impact body to the shaft in at least one or an arbitrary number of fixing positions between the distal and the proximal stop position, but also in the extreme positions of the impact body, namely the proximal stop position and the distal stop position.

In accordance with a further preferred embodiment, provision may be made that the fixing device is transferable from a fixing position, in which the impact body is fixed to the shaft in any one of the fixing positions, into the impact position, in which the impact body and the shaft are movable relative to one another, and vice versa. This configuration enables a user, in particular, to transfer the impact body from the fixing position into the impact position, in order to exert impact pulses with the impact body of the impact instrument on the distal end thereof, namely optionally in the distal or in the proximal direction. In particular, the fixing device may be configured in such a way that an actuation by a user is actively necessary to not only transfer the fixing device from the fixing position into the impact position, but also to hold it in said impact position.

The fixing device favorably comprises a restoring device for automatically holding the fixing device in the fixing position. This configuration has the advantage, in particular, that the impact body is held on the shaft in one of the possible fixing positions without a user have to actuate the fixing device in any way. Thus, in particular, an unintentional and undesired movement of the impact body relative to the shaft can be prevented.

The fixing device can advantageously be brought from the locking position into the impact position against the action of the restoring device. A user therefore must exert a force in order to actuate the fixing device, in particular in such a way that it is transferred from the locking position into the impact position.

The restoring device can be formed in a simple manner if it comprises at least one restoring element.

The restoring device can be made in a simple and cost-effective manner if the at least one restoring element is configured in the form of a rubber-elastic or spring-elastic element.

The at least one restoring element is preferably configured in the form of a compression or tension spring. This makes it possible, in particular, to transfer the fixing device from the fixing position into the impact position by exerting a compressive or tensile force counter to the action of the at least one restoring element.

In accordance with a further preferred embodiment, provision may be made that the fixing device comprises at least one fixing element for being brought into force-locking and/or positive-locking engagement both with the shaft and with the impact body in the at least one fixing position. This configuration makes it possible, for example, to configure the fixing element to be movable, namely both relative to the shaft and relative to the impact body in the impact position. In the fixing position, the at least one fixing element can then, in particular, block a relative movement between the impact body and the shaft, for example by engaging both with the impact body and with the shaft in a force-locking and/or positive-locking manner.

The restoring device can be arranged and a compact impact instrument can be formed in a simple manner if the at least one restoring element is supported on a fixing element support face of the at least one fixing element on the one hand and on an impact body support face of the impact body on the other hand. Such a configuration makes it possible, in particular, to arrange the at least one restoring element inside the impact body in a protected manner. Inside in this sense means within an envelope surface that is defined by the impact body and preferably has a constant tangent. Furthermore, it is thus also possible, in particular, to move the fixing element relative to the impact body against the action of the at least one restoring element. For example, the impact body can be gripped with one hand and the at least one fixing element can be moved relative to the impact body, for example displaced in the distal direction, by actuating with one finger.

It is advantageous if the fixing element support face is configured pointing in the distal direction and if the impact body support face is configured pointing in the proximal direction. Both the fixing element support face and the impact body support face may be configured, e.g., as annular faces. This makes it possible, in particular, to use the stated support faces in cooperation with a restoring element in the form of a coil or helical spring.

It is favorable if the at least one fixing element is movable relative to the impact body for transferring the fixing device from the fixing position into the impact position. In particular, the at least one fixing element may be arranged or formed so as to be displaceable relative to the impact body. For example, the at least one fixing element may be movably, in particular displaceably, mounted on the impact body. This configuration enables, in particular, a simple one-hand operation by a user, who holds the impact body with their hand and displaces the at least one fixing element with a finger, for example their thumb, in order to transfer the fixing device from the locking position into the impact position.

The impact instrument can be configured in a simple and compact manner if the at least one fixing element is of sleeve-shaped configuration.

It is favorable if the at least one fixing element is movable relative to the impact body in the distal direction for transferring the fixing device from the locking position into the impact position. This configuration makes it possible, in particular, for a user to push the at least one fixing element in the distal direction with their thumb while they are holding the impact body with the same hand.

A proximal end of the at least one fixing element in the locking position preferably does not or substantially does not protrude beyond a proximal end of the impact body. This makes it possible, in particular, to use the impact instrument in the manner of a chisel and, for example, to act on the proximal end of the impact body with a hammer without thereby moving the fixing element in the distal direction, which would thereby transfer the impact body fixed relative to the shaft into the impact position.

In particular, in order to minimize a risk of injury, for example the risk of damage to a glove of a user, it is advantageous if the at least one fixing element is closed on the proximal side. In particular, the fixing element on the proximal side may be shaped to be concavely or convexly curved pointing in the proximal direction.

It is favorable if the impact body comprises a fixing element stop device with a distal and a proximal fixing element stop for delimiting a movement of the at least one fixing element in the distal and proximal direction. A configuration of that kind enables a simple handling of the impact instrument. A user can thus, for example, simply push the at least one fixing element against the distal fixing element stop for transferring the impact instrument from the fixing position into the impact position. The proximal fixing element stop delimits the movement of the at least one fixing element in the proximal direction. In particular, the restoring device can push the at least one fixing element against the proximal fixing element stop in the basic position.

It is advantageous if the at least one fixing element comprises a fixing element perforation, which extends transversely, in particular perpendicularly to the longitudinal axis and if the fixing element stop device passes through the fixing element perforation. This enables, in particular, a simple configuration of the impact instrument. The fixing element perforation may comprise, for example, rim or edge portions that point in the distal and in the proximal direction and that in cooperation with the fixing element stop device define the distal and proximal fixing element stops.

The distal fixing element stop is preferably arranged or formed on the proximal side relative to the proximal fixing element stop. This enables a particularly compact structure of the medical impact instrument.

It is favorable if the at least one fixing element is configured in the form of a clamping element and comprises at least one clamping arm extending in the longitudinal direction, and if a free end of the at least one clamping arm is configured to be movable, in particular pivotable, in the direction toward and away from the longitudinal axis of the shaft. Fixing elements of that kind make it possible, in particular in a simple manner, to achieve a clamping relative to the shaft. For example, this can be achieved by pushing the free end of the at least one clamping arm in the direction toward the longitudinal axis of the shaft.

The impact body preferably comprises a recess surrounding the shaft for accommodating the at least one clamping element. The recess makes it possible, in particular, for the free end of the at least one clamping element to be pivoted away from the shaft in order to release the shaft. In other words, a clamping between the at least one fixing element and the shaft can thus be released.

It is advantageous if the recess is delimited at least in sections by a clamping face pointing in the direction toward the longitudinal axis, which clamping face in the locking position cooperates with the at least one clamping element for preventing a movement of the free end of the at least one clamping element away from the longitudinal axis or for clampingly holding the at least one clamping element in the direction toward the longitudinal axis. For example, the free end of the at least one clamping element can slide on the clamping face for transferring the impact instrument from the impact position into the locking position.

The clamping face favorably expands conically in the distal direction and forms a sliding face. A relative movement between the free end of the at least one clamping element and the impact body can thus be enabled or prevented or blocked in a simple manner.

It is advantageous if formed on the free end of the clamping element is a sliding face, which points away from the longitudinal axis, is inclined relative to the longitudinal axis, and cooperates with the clamping face of the impact body. The sliding face on the free end of the clamping element, in particular in cooperation with the clamping face of the impact body, can help to prevent an unintentional jamming and thus blocking of the fixing device.

A first angle of inclination defined between the clamping face and the longitudinal axis is preferably greater than a second angle of inclination defined between the sliding face and the longitudinal axis. The different first and second angles of inclination make it possible, in particular, to prevent a self-locking between the fixing element and the impact body when using the impact instrument. Thus, they ensure, in particular, a reliable functioning of the impact instrument, in particular of its fixing device.

In accordance with a preferred embodiment, provision may be made that the impact body has a longitudinal perforation extending coaxially to the shaft longitudinal direction and that the shaft is accommodated at least partially in the longitudinal perforation. For example, the proximal shaft portion can be completely accommodated in the longitudinal perforation, independent of a relative position of the impact body and the shaft. The longitudinal perforation can also simplify an assembly of the impact instrument. It can thus optionally be easily and quickly disassembled for cleaning.

It is advantageous if the shaft comprises a distal shaft portion and a proximal shaft portion, if the proximal shaft portion is accommodated in the longitudinal perforation, and if the distal shaft portion projects out of the longitudinal perforation on the distal side. Such a configuration makes it possible, in particular, to design the impact instrument in such a way that the impact body, independently of a relative position to the shaft, also always defines the proximal end of the impact instrument with its proximal end.

It is advantageous if an inner face of the at least one fixing element pointing toward the longitudinal direction forms a guide face for the proximal shaft portion. This makes it possible, in particular, to move the at least one fixing element in a defined manner relative to the shaft, namely, for example, relative to the proximal shaft portion.

Furthermore, it may be advantageous if the longitudinal perforation of the impact body commencing from its proximal end forms a guide face pointing in the direction toward the longitudinal axis for the at least one fixing element. Due to this guide face, the at least one fixing element can be moved relative to the impact body in a defined manner. In particular, the guide face may be configured in such a way that a jamming of the fixing element relative to the impact body in the region of the guide face is not possible.

It is favorable if the proximal shaft portion comprises the distal stop with a first stop face that acts in the proximal direction, and if the impact body comprises a first impact body stop face that acts in the distal direction, which in the distal stop position interacts with the first stop face. For example, the impact instrument can be made in a simple manner by a proximal end face of the proximal shaft portion defining the first stop face.

The impact instrument can be formed in a simple and compact manner if the impact body comprises a stop element, which defines the first impact body stop face. In particular, the stop element can delimit not only a movement of the shaft relative to the impact body, but also a movement of the at least one fixing element relative to the impact body.

It is advantageous if the stop element defines a stop element longitudinal axis and if the stop element longitudinal axis extends transversely, in particular perpendicularly, to the shaft longitudinal direction. The stop element can thus be arranged or held, for example, transversely on the impact body.

The stop element can be easily configured in the form of a stop pin inserted into a transverse bore on the impact body.

A distance of the stop element from the proximal end of the impact body is preferably smaller than a distance from the distal end of the impact body. This enables a maximum stroke of the shaft, in particular of its proximal shaft portion, relative to the impact body, in particular in the longitudinal perforation formed on the impact body.

The fixing element stop device favorably comprises the stop element. It is thus possible, in particular, for the fixing element stop device to take on a plurality of functions. A compact structure of the impact instrument can be achieved in this way.

It is advantageous if the at least one restoring element is arranged or formed on the distal side of the stop element. It may thus be configured, e.g., in the form of a pressure element, which is compressed in the distal direction by moving the at least one fixing element.

Furthermore, it is favorable if the proximal shaft portion comprises the proximal stop with a second stop face acting in the distal direction and if the impact body comprises a second impact body stop face acting in the proximal direction, which in the proximal stop position cooperates with the second stop face. This configuration enables, in particular, a simple delimitation of a movement of the impact body relative to the shaft in the proximal direction.

A compact structure of the impact instrument can be achieved, in particular, if the distal delimiting wall comprises the second impact body stop face.

It is advantageous if a first distance between the first stop face and the second stop face is smaller than a second distance between the first impact body stop face and the second impact body stop face. In particular, a movement of the shaft relative to the impact body is made possible by this configuration. The difference between the two distances determines a maximum stroke of the impact body relative to the shaft.

The at least one restoring element is favorably arranged or formed surrounding the at least one fixing element. It is thus possible, in particular, to arrange the restoring element on the impact instrument in a protected manner, so that its functioning can be permanently ensured.

The impact body favorably comprises at least one flush opening. The flush opening can, in particular, establish a fluid connection between an environment of the impact body and the longitudinal perforation thereof. The impact instrument can thus be cleaned in a simple and secure manner, in particular without disassembling it.

The at least one flush opening is preferably formed in the region of a peripheral wall of the impact body surrounding the longitudinal axis or in the region of a distal delimiting wall of the impact body. It is therefore possible, in particular, to provide two or more flush openings, namely, for example, both in the region of the peripheral wall and in the region of the distal delimiting wall. Thus, in particular, a cleaning fluid is able to flow through the impact instrument for cleaning in order to securely remove contaminants.

It is advantageous if the longitudinal perforation passes through the distal delimiting wall and in the region of the distal delimiting wall forms a guide face for the distal shaft portion. In this way, in particular, a movement of the impact body relative to the shaft can be guided in a simple and defined manner. In particular, the guide face may be formed circumferentially. It may also be interrupted by at least one flush opening. In particular, the guide face may be of hollow-cylindrical configuration or comprise hollow-cylindrical surface portions.

In accordance with a further preferred embodiment, provision may be made that the impact instrument comprises a coupling device for temporarily coupling to a medical object. As explained at the outset, the impact instrument can thus be coupled, e.g., to a fastening element in order to strike it out of a bone in which it was anchored. For this purpose, impact pulses are transmitted from the impact body to the shaft in the impact position, namely when the impact body cooperates with the proximal stop that defines the proximal stop position.

It is advantageous if the medical object is configured in the form of a medical implant. For example, it may be configured in the form of a medical fastening element or in the form of an implant component of a joint implant. The medical impact instrument can thus be used, in particular, for anchoring or releasing the medical objects to or from a bone. Furthermore, a medical system comprising a medical impact instrument and at least one medical object can thus be defined.

It is favorable if the coupling device comprises a first coupling element, which is configured to be brought into force-locking and/or positive-locking engagement with a corresponding second coupling element comprised by the medical object in a coupling position. The coupling device enables, in particular, a simple and secure connection of the impact instrument to a medical object in the coupling position.

The coupling device can be formed in a simple manner if the first coupling element is configured in the form of a coupling projection or a coupling receptacle. The second coupling element can then be configured corresponding to the first coupling element in the form of a coupling receptacle or a coupling projection.

It is favorable if the coupling device comprises a securing device for securing a medical object to the medical impact instrument in the coupling position in a force-locking and/or positive-locking manner. The impact instrument can be coupled to the medical instrument by means of the coupling device. Independently thereof, the securing device serves to secure the medical object to the impact instrument in the coupling position, for example against unintentional release. Thus, in particular, a reliable handling of the impact instrument can be achieved. Thus, in particular, a risk of the medical object coupled to the impact instrument falling off the impact instrument in an undesirable manner can be significantly reduced.

It is favorable if the securing device is able to be brought from a release position, in which the medical impact instrument and the medical object are able to be brought into engagement in an engagement direction, into a securing position, in which a movement of the medical impact instrument and the medical object relative to one another in or opposite to the engagement direction is blocked. In other words, the securing device and the coupling device operate in linearly independent directions so that, in particular, an unintentional release of the medical object from the impact instrument is possible only after overcoming a release force for deactivating the securing device.

The impact instrument can be made in a simple manner if the engagement direction extends transversely, in particular perpendicularly, to the shaft longitudinal direction. Thus, as already indicated, linearly independent movements can be achieved in order to secure the medical object to the shaft in the coupling position in a defined manner.

It is advantageous if the securing device comprises a securing member, which is in force-locking and/or positive-locking engagement with a securing element of the medical object in the securing position. The securing member can thus secure the medical object to the shaft in the coupling position, in particular in a defined manner, namely when the securing member adopts not the release position, but rather the securing position.

The securing member is favorably movably, in particular displaceably, mounted on the shaft. A simple securing mechanism for the medical object on the impact instrument can thus be achieved.

It is advantageous if the securing device comprises a securing member stop against which the securing member strikes in the securing position. The securing member stop may serve the purpose, in particular, that the securing member is not able to fall off the shaft in the distal direction in an undesirable manner. The securing member stop therefore serves to delimit a movement of the securing member, in particular in the distal direction.

The securing device can be made in a simple manner if the securing member stop comprises a stop face pointing in the proximal direction. A movement of the securing member in the distal direction can thus be blocked when it cooperates with the stop face of the securing member stop.

It is favorable if the securing member comprises a securing member shaft and a securing member head arranged or formed thereon on the proximal side and if the securing member head is configured to cooperate with the securing member stop. In other words, the securing member head also forms a stop or a stop face, which cooperates with the securing member stop in order to, in particular, delimit a movement of the securing member in the distal direction.

It is advantageous if the securing member head comprises a securing member head stop face, which points in the distal direction and cooperates with the stop face of the securing member stop. In particular, a movement of the securing member in the distal direction can thus be delimited in a simple manner.

The movement of the securing member in the distal direction can be delimited in a simple manner if the stop face is configured in the form of an annular face. The securing member head stop face may also be configured in the form of an annular face.

Furthermore, provision may be made that the securing member comprises a distal securing member end that can be brought into engagement with the medical object, and that the distal securing member end is rounded pointing in the distal direction. Thus, in particular, a risk of injury when using the impact instrument can be avoided. In addition, the rounded securing member end can prevent jamming with a projection or a recess on the medical object, for example when coupling or decoupling same.

The securing device favorably comprises a biasing device for automatically transferring the securing device from the release position into the securing position. As a result of the biasing device, it is thus achieved, in particular, that the securing device always adopts the securing position, without additional external forces. For example, by means of the biasing device, the securing device can be configured in the form of a latching or snapping connecting device, which enables a simple, in particular toolless coupling of the impact instrument to the medical object.

It is advantageous if the biasing device is configured to hold the securing member under bias in the securing position. The medical object can thus, in particular, be secured to the impact instrument in the coupling position with the securing device in a simple and secure manner.

The biasing device can be configured in a simple manner if it comprises at least one biasing element.

The at least one biasing element is favorably configured in the form of a rubber-elastic or spring-elastic element. These can be produced in a simple and cost-effective manner, for example from materials that are sterilizable with hot steam.

Depending on the configuration of the securing device, it may be advantageous if the biasing element is configured in the form of a compression or tension spring.

The at least one biasing element is preferably supported on the securing member on the one hand and on a support face pointing in the distal direction on the other hand. Such a configuration is advantageous, in particular, when using a biasing element in the form of a pressure element, i.e. a compression spring, for example.

It is favorable if the securing device comprises a support element arranged on the shaft and if the support element comprises the support face. The support element together with the support face thus forms, in particular, a stop for the biasing element and thus, in particular, also a stop for a movement of the securing member in the proximal direction.

The support element can be configured in a simple manner if it defines a support element longitudinal axis and if the support element longitudinal axis extends transversely, in particular perpendicularly, to the shaft longitudinal direction.

The impact instrument can be formed in a simple and cost-effective manner if the support element is configured in the form of a pin inserted into a transverse bore on the shaft. The pin may, for example, be screwed into the transverse bore and/or be materially bonded to the shaft, for example by adhesion, soldering, or welding.

An embodiment of a medical system denoted as a whole with the reference numeral10is schematically depicted inFIG.1. The medical system10comprises a medical impact instrument12and a medical object14, which are described in detail in the following.

The embodiment of the medical impact instrument12depicted in the Figures is configured in the form of an impact hammer16. Said impact hammer16comprises a shaft18, which defines a shaft longitudinal direction20as well as a proximal end22and a distal end24. Arranged on the shaft18is an impact body26, which defines a longitudinal axis28.

The impact body26is moveable, namely displaceable, on the shaft18in an impact position, namely between a distal stop position, which is defined by a distal stop30, and a proximal stop position, which is defined by a proximal stop32. This arrangement enables the transmission of an impact pulse to the distal end24of the shaft18in the distal and in the proximal direction.

The impact instrument12comprises a fixing device, which is denoted as a whole with the reference numeral34. It serves to temporarily fix the impact body26to the shaft18in an arbitrary fixing position between the distal stop position and the proximal stop position.

The shaft18comprises a distal shaft portion36and a proximal shaft portion38.

The shaft18is passed through by a longitudinal channel40from the proximal end22to the distal end24.

An outer diameter of the proximal shaft portion38is greater than an outer diameter of the distal shaft portion36, such that an annular face42pointing in the distal direction is formed in the transition between the proximal shaft portion38and the distal shaft portion36.

The proximal shaft portion38comprises the distal stop30with a first stop face44, which acts in the proximal direction and forms a proximal end face46of the shaft18. The first stop face44is of annular configuration.

The proximal shaft portion38also comprises the proximal stop32with a second stop face48, which points in the distal direction and is formed by the annular face42.

Formed on the distal shaft portion36is a transverse bore50, into which a support element52in the form of a cylindrical pin54is inserted. The support element52defines a support element longitudinal axis56, which extends transversely, namely perpendicularly in the embodiment depicted in the Figures, to the shaft longitudinal direction20. A distance of the transverse bore from the distal end24corresponds to about a distance of the annular face42from the proximal end22of the shaft18.

On the impact instrument12, namely on its shaft18, a coupling device58is provided for temporarily coupling to the medical object14.

In the Figures, the medical object14as one possible embodiment is configured in the form of a medical implant60. Furthermore, the medical implant60is depicted as an example in the Figures in the form of a medical fastening element62. Alternatively, the medical object14may also be configured in the form of an implant component of a joint implant. Here, different kinds of shafts, that are insertable into bone cavities, or also joint cups of ball joints are conceivable.

The coupling device58comprises a first coupling element64, which is formed near the distal end24of the shaft18. The first coupling element64is configured to be brought into force-locking and/or positive-locking engagement with a corresponding second coupling element66in a coupling position. In the case of the medical system10depicted in the Figures, the medical object14comprises the second coupling element66.

The first coupling element64comprises a coupling receptacle68in the form of an annular groove70, which concentrically surrounds the longitudinal axis28and is open pointing toward said longitudinal axis28. The annular groove70is adjoined on the distal side by an annular flange that projects in the direction toward the longitudinal axis28.

The medical fastening element62is configured in the form of a bone pin74, which has on its distal end a tip78for driving into a bone76of a patient.

The medical fastening element62comprises a cylindrical shaft80, which extends from the tip78up to a proximal end of the medical fastening element62on which the second coupling element66in the form of a head82is formed. Formed on the head82is an annular groove84, which points away from the longitudinal axis28and into which the annular flange72engages in the coupling position, as is depicted as an example inFIG.7.

The distal shaft portion36is provided with a chamfer86on one side commencing from the distal end24, such that the coupling receptacle68is laterally open. This enables a lateral insertion of the head82into the coupling receptacle68.

Due to the configuration of the annular groove84, a second annular flange88is formed, which delimits the head82on the distal side.

The head82and the first coupling element64are configured in such a way that they are able to be brought into engagement with one another in an engagement direction90. The engagement direction90extends transversely, namely perpendicularly in the embodiment depicted in the Figures, to the shaft longitudinal direction20. For coupling the impact instrument12and the medical object14, a shaft axis92defined by the shaft80of the bone pin74and the longitudinal axis28must be oriented in parallel to one another.

FIG.1shows the coupling position of the impact instrument12and the medical object14. The bone pin74before being coupled to the first coupling element64of the coupling device58is schematically depicted inFIG.2.

The coupling device58comprises a securing device94for securing the medical object14to the medical impact instrument12in the coupling position in a force-locking and/or positive-locking manner.

The securing device94is configured in such a way that it is able to be brought from a release position, in which the medical impact instrument12and the medical object14are able to be brought into engagement in the engagement direction90, into a securing position, in which a movement of the medical impact instrument12and the medical object14relative to one another in or opposite to the engagement direction90is blocked.

The securing device94comprises a securing member96, which is in force-locking and/or positive-locking engagement with a securing element98of the medical object14in the securing position. The securing element98is configured in the form of a depression100on the head82. The depression100is open pointing in the proximal direction.

The securing member94comprises a cylindrical securing member shaft102with a securing member head104arranged or formed thereon on the proximal side. The securing member head104forms a proximal end of the securing member96.

The securing member head104defines an outer diameter, which is greater than the outer diameter of the securing member shaft102. A securing member head stop face106that points in the distal direction is thereby formed in the transition region between the securing member head104and the securing member shaft102.

A distal securing member end108of the securing member96is able to be brought into engagement with the medical object14, namely with the depression100. The distal securing member end108is rounded pointing in the distal direction. A contour of the distal securing member end18and the depression100correspond to one another, as is schematically depicted inFIG.7.FIG.7shows the securing position.

Between the distal end24of the shaft18and the transverse bore50, an inner diameter of the longitudinal channel40expands in one step, such that a securing member stop110is formed. The securing member stop110comprises a stop face112, which points in the proximal direction and is of annular configuration. An inner diameter of the longitudinal channel40on the distal side of the stop face112corresponds to an outer diameter of the securing member shaft102. The securing member96is thus held in the longitudinal channel of the shaft18in a displaceably guided manner.

The securing member stop110of the securing device94delimits a movement of the securing member96on the shaft18in the distal direction. The securing member96strikes with its securing member head104in the securing position against the securing member stop110. The securing member head104and the securing member stop110are thus configured to cooperate with one another. In the securing position, the securing member head stop face106abuts against the stop face112. The stop face112is configured in the form of an annular face114.

The securing device94comprises a biasing device116for automatically transferring the securing device94from the release position into the securing position. In the embodiment depicted in the Figures, the biasing device116holds the securing member96under bias in the securing position. For this purpose, the biasing device116comprises a biasing element118. The biasing element118is configured as a spring-elastic element120. In alternative embodiments, the biasing element may be configured in the form of a rubber-elastic element.

The biasing element118is configured in the form of a compression spring122.

Furthermore, the biasing element118is supported distally on the securing member96, namely on its conically tapering securing member head104pointing in the proximal direction on the one hand and on a support face124acting in the distal direction on the other hand. The securing device94also comprises the support element52arranged on the shaft18. The support element52, in turn, comprises the support face124. This is an outer face of the support element52pointing in the distal direction52.

The described securing device94is configured in such a way that the compression spring122holds the securing member96under bias in the distal direction.

When the head82of the bone pin74is introduced into the coupling receptacle68commencing from the separating position schematically depicted inFIG.2, in which the medical object14and the medical impact instrument12are completely out of engagement, in the engagement direction90, i.e. transversely to the longitudinal axis28, the rounded distal securing member end108slides on the head82and is moved by the latter against the action of the biasing element118in the proximal direction. When the head82is completely accommodated by the first coupling element64, the compression spring122can move the securing member96back in the distal direction, such that the distal securing member end108is able to dip into the depression100and thus secure the bone pin74against undesired decoupling from the medical impact instrument12. The described securing device94is thus configured in the manner of a latching or snapping connecting device.

The impact body26is configured in the form of a handle126, which enables an ergonomically shaped outer contour128for the handle126to be held by one hand130of a user. The ergonomic outer contour128comprises two annular projections132and134spaced at a distance from one another, between which an annular groove136is formed. On the proximal side of the annular projection132and on the distal side of the annular projection134, an outer diameter of the handle126decreases in the proximal and distal direction, respectively. The outer contour128is of completely rounded configuration without sharp corners and edges. It is schematically shown inFIGS.8to10as well as13and14how the medical impact instrument12can be held by a user with one hand.

The impact body26has a longitudinal perforation138extending coaxially to the shaft longitudinal direction20. The shaft18is accommodated at least partially in the longitudinal perforation138.

The impact body26comprises an annular proximal impact body end face140pointing in the proximal direction and a distal impact body end face142pointing in the distal direction.

The substantially sleeve-shaped impact body26comprises a peripheral wall144surrounding the longitudinal axis28and a distal delimiting wall146.

The longitudinal perforation138passes through the distal delimiting wall146. An inner diameter of the longitudinal perforation138in the region of the distal delimiting wall146corresponds to the outer diameter of the distal shaft portion36. In this way, a guide face148for the distal shaft portion36pointing in the direction toward the longitudinal axis is formed in the region of the delimiting wall146.

On the proximal side of the distal delimiting wall, an inner diameter of the longitudinal perforation138initially expands conically and then remains constant on about one third of the total length of the impact body26. Thus, a recess150is formed, which has an inner diameter that is greater both than an outer diameter of the distal shaft portion36and greater than an outer diameter of the proximal shaft portion38. An inner diameter of the recess150tapers conically on the proximal side and thus forms a conical clamping face152. The clamping face152delimits the recess150in sections with the clamping face152pointing in the direction toward the longitudinal axis28.

The clamping face152is adjoined by a hollow-cylindrical portion154of the longitudinal perforation138. An inner diameter of the portion154is slightly greater than an outer diameter of the proximal shaft portion38. The reason for this is explained in the following in more detail.

On the proximal side, an inner diameter of the longitudinal perforation138adjoining the portion154expands in one step, such that an impact body support face156pointing in the proximal direction is formed. The impact body support face156is configured in the form of an annular face158. An inner diameter of the longitudinal perforation138commencing from the annular face158up to the proximal impact body end face140corresponds to about an inner diameter of the recess150.

Furthermore, a stop element160is arranged on the impact body26. It defines a stop element longitudinal axis162, which extends transversely, namely perpendicularly in the embodiment depicted in the Figures, to the shaft longitudinal direction20. The stop element160is configured in the form of a stop pin166inserted into a transverse bore164on the impact body26.

The transverse bore164is formed on the proximal side of the annular face158, namely closer toward the proximal impact body end face140than to the annular face158. A distance of the stop element160from the proximal impact body end face140, which defines a proximal end168of the impact body26, is thus smaller than a distance of the stop element160of the distal impact body end face142, which defines a distal end170of the impact body26.

Now, in the following, the structure and functioning of the fixing device34will be defined in more detail. In the embodiment depicted in the Figures, it comprises a fixing element172for being brought into engagement in a force-locking and/or positive-locking manner both with the shaft18and with the impact body26in one of the arbitrary fixing positions described above between the distal stop position and the proximal stop position.

The fixing element172is of sleeve-shaped configuration. An inner diameter of the fixing element172is configured corresponding to the outer diameter of the proximal shaft portion38, such that the fixing element172and the proximal shaft portion38in the impact position are displaceable in parallel to the shaft longitudinal direction20. The fixing element172is thus also guided on the proximal shaft portion38.

The fixing element172is closed on the proximal side. A closure element174is screwed into the fixing element172commencing from a proximal end176of the fixing element172. The closure element174has a flat depression178in order to, for example, partially accommodate a thumb180of a user and prevent it from slipping off.

The fixing element172comprises a sleeve portion182. It extends in the distal direction commencing from the proximal end176. A sleeve-shaped clamping element portion186that is reduced in external diameter protrudes from an end face184of the sleeve portion pointing in the distal direction, such that part of the end face184forms a fixing element support face188. Said support face188is annular and surrounds the clamping element portion186.

An outer diameter of the clamping element portion186expands conically toward its distal end190and forms a sliding face192. The sliding face192is adjoined by a cylindrical end portion194of the clamping element portion186. The end portion194defines an outer diameter, which is greater than an outer diameter of the clamping element portion186on the proximal side of the sliding face192. The outer diameter of the end portion194, however, is smaller than an outer diameter of the sleeve portion182.

The fixing element172is configured in the form of a clamping element196. Formed commencing from the distal end190in parallel to the longitudinal axis28are a plurality of slits198, such that a corresponding number of clamping arms200are formed. In the embodiment depicted in the Figures, six slits198are provided. The slits198extend up to the sleeve portion182. Due to the configuration of the end portion194, the clamping arms200have a thickened portion at their free ends222. In addition, a remaining portion of the sliding face192is formed on each clamping arm200.

The clamping element portion186has an outer diameter, which corresponds to the inner diameter of the portion154of the impact body26. Thus, the fixing element172is guided on the impact body26in the region of the portion154with an outer face of the clamping element portion186.

Furthermore, a fixing element perforation202is formed on the fixing element172. Said perforation extends transversely, namely perpendicularly in the embodiment depicted in the Figures, to the longitudinal axis28. The fixing element perforation202is formed in the region of the sleeve portion182and is formed in the manner of an elongate hole in parallel to the longitudinal axis28. The stop element160passes through the fixing element perforation202, as can be seen, for example, inFIG.10. An outer diameter of the stop pin166is smaller than a longitudinal extent of the fixing element perforation202in parallel to the longitudinal axis28, such that the fixing element172is movable in parallel to the longitudinal axis28.

The impact body26further comprises a fixing element stop device204. The fixing element stop device204comprises a distal fixing element stop206and a proximal fixing element stop208for delimiting a movement of the fixing element172in the distal and proximal direction. In the embodiment depicted in the Figures, the distal fixing element stop206is arranged or formed on the fixing element172on the proximal side relative to the proximal fixing element stop208. The distal fixing element stop206is formed by an inner end face of the fixing element perforation202pointing in the distal direction. The proximal fixing element stop208is formed by an inner end face212of the fixing element perforation202pointing in the proximal direction.

The fixing device34further comprises a restoring device214. It serves the purpose of holding the fixing device34in a locking position.

In the locking position the impact body26is fixed to the shaft18in an arbitrary fixing position. The fixing device34is further configured in such a way that it is transferable from the locking position into the impact position, in which the impact body26and the shaft18are movable relative to one another, and vice versa. In the embodiment depicted in the Figures, the fixing device34is configured in such a way that it is able to be brought from the locking position into the impact position against the action of the restoring device214. Therefore, in the embodiment depicted in the Figures, the fixing element172can be moved against the action of the restoring device214in order to transfer the fixing device34from the locking position into the impact position.

The restoring device214comprises a restoring element216. In the embodiment depicted in the Figures, the restoring element216is configured in the form of a spring-elastic element218. In alternative embodiments, the restoring element is configured in the form of one or more rubber-elastic elements.

In the embodiment depicted in the Figures, restoring element216is configured in the form of a compression spring220.

The restoring element216is supported on the fixing element support face188of the fixing element172on the one hand and on the impact body support face156of the impact body26on the other hand. The fixing element support face188points in the distal direction and, as mentioned, is configured as an annular face. It forms part of the end face184.

The restoring element216is arranged or formed surrounding the fixing element172. The restoring element216surrounds the fixing element172in the region of the clamping portion186. As described, it is supported proximally on the sleeve portion182, namely the end face184thereof.

The fixing element172is movable, namely displaceable, for transferring the fixing device34from the locking position into the impact position. In the embodiment depicted in the Figures, the fixing element172is movable relative to the impact body26in the distal direction for transferring the fixing device34from the locking position into the impact position.

The functioning of the fixing device34is described in the following.

FIG.6shows the locking position. The restoring element216pushes the fixing element172with the distal end face212against the stop element, thereby delimiting a movement of the fixing element172in the proximal direction. In this position, the end portions194of the clamping arms200are drawn back into the region of the portion154and interact in a force-locking and/or positive-locking manner both with the shaft18and with the impact body26. The impact body26is clampingly held to the shaft18in this locking position.

In order to be able to move the impact body26relative to the shaft28, the fixing device34must be transferred from the locking position into the impact position. For this purpose, a user can press, for example with their thumb180, against the closure element174on the fixing element172and thus move the fixing element172in the distal direction against the action of the restoring device214until the proximal end face210of the fixing element perforation202strikes against the stop element160. During this movement of the fixing element172relative to the impact body26in the distal direction, the end portions194move into the region of the recess150. Due to the greater inner diameter of the recess150, it is now possible for the free ends222of the clamping arms200to be pivotable away from the longitudinal axis82of the shaft18. Or in other words, the clamping arms200displaced in the distal direction are no longer biased against the proximal shaft portion38by the clamping face152or the inner wall face of the portion154. In the impact position, as it is schematically depicted as an example inFIGS.8to10as well as13and14, the impact body26is displaceable relative to the shaft18in parallel to the longitudinal axis28.

In the locking position, the clamping face152or the inner wall face of the portion154prevent a movement of the free ends222of the clamping arms200or the clamping element196away from the longitudinal axis28, such that, as described, the clamping element196is held in the direction toward the longitudinal axis28in the locking position in order to fix, namely to clamp, the impact body26to the shaft18in an arbitrary fixing position.

It should also be noted that a first angle of inclination224defined between the clamping face152and the longitudinal axis28is greater than a second angle of inclination226defined between the sliding face192and the longitudinal axis28.

Due to the described configuration of the medical impact instrument12, an inner face228of the fixing element172pointing in the direction toward the longitudinal axis28forms a guide face230for the proximal shaft portion38.

Furthermore, the longitudinal perforation138of the impact body26from the proximal end thereof forms a guide face232pointing in the direction toward the longitudinal axis28for the fixing element172, namely an outer face of the sleeve portion182.

When the fixing device is transferred from the locking position into the impact position, the impact body26can be moved relative to the shaft18. The proximal shaft portion38hereby comprises, as already mentioned, the distal stop30with the first stop face44acting in the proximal direction.

The impact body26comprises a first impact body stop face234, which cooperates with the first stop face44and acts in the distal direction. In the embodiment depicted in the Figures, the stop element160defines the first impact body stop face234. This means that, in the impact position, the impact body26is able to be moved only so far in the distal direction until the stop element160strikes with the impact body stop face234against the first stop face44, thus against the proximal end face46of the shaft18. Commencing from this extreme position, the impact body26is able to be moved in the proximal direction relative to the shaft18in the impact position until a second impact body stop face236of the impact body26strikes against the second stop face48, thus against the annular face42, as is schematically depicted as an example inFIG.13.

The second impact body stop face236is also configured in the form of an annular face238, which points in the proximal direction. It forms a side face of the distal delimiting wall146. The distal delimiting wall146thus comprises the second impact body stop face236.

A first distance240between the first stop face44and the second stop face48is smaller than a second distance242between the first impact body stop face234and the second impact body stop face236. A difference of the distances240and242determines a maximum movement stroke of the impact body26relative to the shaft18.

In order to also be able to transmit impact pulses with the medical impact instrument12to its distal end24in the locking position, for example with a hammer, which acts on the proximal impact body end face140, the proximal end176of the fixing element172in the locking position does not or substantially does not project beyond the proximal end168of the impact body26. The medical impact instrument12can thus also be used in the manner of a chisel. Greater impact pulses can thus optionally be exerted on the distal end24than with the impact body26when the latter in the impact position is moved with the stop element160against the proximal end face46.

In the case of the medical impact instrument12depicted in the Figures, the impact body26in the basic position is fixed relative to the shaft18and adopts a fixing position. The fixing device34hereby adopts the locking position. Using the fixing device34, the impact body26can thus be fixed to the shaft18not only in a fixing position between the distal stop position and the proximal stop position, but also in the proximal stop position and in the distal stop position.

For an optimal cleaning of the medical impact instrument12, a plurality of flush openings244and246formed on the impact body26are provided. The flush openings244are formed in the region of the peripheral wall144of the impact body26, the flush openings246in the region of the distal delimiting wall146of the impact body26. The flush openings246are configured as expansions of the guide face148, such that only portions thereof remain on which the distal shaft portion36is guided when moving the impact body26in the impact position relative to the shaft18.

The flush openings244create an access to the longitudinal perforation138.

The use of the impact instrument12is explained briefly in the following in connection withFIGS.8to14.

In order to drive the bone pin74coupled, as described above, to the distal end24into the bone76of the patient, the fixing device34is transferred into the impact position by displacing the fixing element172in the distal direction as schematically depicted inFIG.8. Now the impact body26can be moved with the stop element160against the first stop face44in order to transmit an impact pulse to the bone pin74and drive same into the bone76. In the impact position the impact body26can be moved back in the proximal direction relative to the shaft18and then back again toward the first stop face44for transmitting an impact pulse.

The fixing device34enables an arbitrary fixing position or an arbitrary clamping of the impact body26between the extreme stop positions, namely the distal stop position and the proximal stop position. Such an intermediate position, i.e. a fixing position between the distal stop position and the proximal stop position, is depicted as an example inFIG.11. Here, the fixing device34adopts the locking position. The fixing device34is also depicted in the locking position inFIG.12as well. However, here the impact body26adopts its proximal stop position.

In order to release the bone pin74from the bone76, the fixing device34is transferred from the locking position into the impact position and the impact body26is moved with the second impact body stop face236against the first stop face48. An impact pulse can thus be exerted with the impact body26in the proximal direction on the shaft18in order to successively extract the bone pin74from the bone76by repeatedly exerting such an impact pulse. This is depicted schematically inFIGS.13and14.

The described medical impact instrument12enables a simple and uncomplicated coupling thereof with one hand, for example to a medical object14anchored in a bone76. By releasing the fixing element172so that the fixing device34adopts the locking position, the impact body26is able to be immovably secured to the shaft18in any one of the described arbitrary fixing positions. A user can now bring the distal end24of the impact instrument12up to the medical object14, for example to the head82of the bone pin74, and couple same to the coupling element64in the engagement direction90. This is possible with only one hand, i.e. without the assistance of a second hand, because the distal end24in the locking position is fixed relative to the impact body26, which the user holds and guides with their hand130.

The described medical system10with its medical impact instrument12thus enables an improved handling in comparison to known medical impact instruments.