The invention relates to a surgical instrument with a linear element and with an insert or attachment which is arranged slidably and releasably in or on the linear element, the insert or attachment, and a guide element assigned thereto, being guided relative to the linear element on at least one guide track, and a stop being movable behind the insert or attachment or the guide element into or out from the guide track.
The present invention is intended to relate to all possible types of surgical instruments, for example including tubular shaft instruments. However, it relates in particular to sliding shaft instruments. These are used to carry out cutting, shearing, clamping or similar operations, for example in the human body. In these operations, suitable handpieces are used to move the slide along a slide surface of the shaft, and a jaw is generally actuated at the end thereof.
Sliding shaft instruments of this kind are used in particular as bone punches, as ear forceps, and in gynecological biopsies. A general problem is that surgical instruments of this kind are products which have a very wide variety of hinges, guides or grooves and channels. Such instruments are therefore extremely difficult to clean and sterilize, but cleaning of surgical instruments is of course of the utmost importance. The hygiene requirements for such surgical instruments are greatly increased due to the risk of transmission of diseases, for example hepatitis or AIDS.
A sliding shaft instrument is known from DE 43 16 769 C1, for example. In this instrument, however, there is a danger of the slide inadvertently coming loose from the shaft.
EP 0 838 198 A discloses a surgical instrument in which a push/pull rod is guided in an outer tube in order to move jaw parts. This rod has two recesses, a screw engaging in one recess, and a locking lug of a forceps arm engaging in the other recess. To release the rod, the screw must be loosened by hand.
DE 197 13 067 A discloses an arthroscopy instrument in which a push/pull rod is likewise guided in an outer tube. This rod has a depression in the area of the handpiece. To secure the rod in the handpiece and to release the rod, use is made of a threaded pin with a half recess. For releasing or securing, the threaded pin has to be turned through 180°.
A surgical instrument of the abovementioned type is known from WO 95/05123. In this, a pin protruding from a slide is guided in a slit of a sliding shaft element. A press button engages in this slit, which press button can be moved counter to the force of a spring. In the slit, the press button has a stop which limits the movement of the pin and thus of the slide. By pressing on the press button, this stop is moved out from the clear width of the slit so that the slide can be moved farther toward the rear, with the result that a T-shaped rail disengages from a correspondingly shaped groove of the shaft element and the slide can be removed from the shaft element. When assembling the instrument, the press button again has to be activated so that the pin comes to a position behind the stop.
The object of the present invention is to develop an instrument of the above mentioned type in which inadvertent release of the insert or attachment from the linear element is effectively avoided, but which at the same time permits easy dismantling and assembly.