| 摘要 |
<p>Precision depth guided instruments are provided for use in performing percutaneous implantation of hard tissue implant materials. A depth guided stylet includes a point adapted for piercing hard tissue, and preferably, self-tapping threads for self-tapping into hard tissue. The stylet may include an elongated rod having a first section having a first diameter, and a second section having a second diameter larger than the first diameter. A cannula for use with a depth guided stylet includes an elongated tube having first and second open ends adapted for a depth guided stylet to pass therethrough. The cannula may include a pawl passing through the elongated tube for ratcheting against a rack of gear teeth provided on the stylet. Alternatively, a camming mechanism may be pivotal arranged on the stylet. Upon pivoting the camming mechanism, the cam surface provides a driving force against the cannula to drive the cannula along the stylet. Another embodiment includes a stylet which is releasably fixed in a cannula so a threaded end of the stylet extends from the end of the cannula. The threaded end is used to draw the cannula into the desired implantation position, and a mechanism provides a sufficient mechanical advantage to retract the threaded end into the cannula. Methods of using the instruments are also described, as are kits which include the instruments and which are used to open a pathway into hard tissue.</p> |
