Operating instrument for a height-adjustable spinal implant
A height-adjustable implant for insertion between vertebrae, includes first and second sleeve parts which are rotationally fixed in coaxial alignment and interconnected in an axially displaceable manner. The first sleeve part has an internal thread. A nut is positioned coaxially in an inner space surrounded by the sleeve parts and is fixed to the second sleeve part so that it can rotate but is axially fixed. The nut has an external thread which engages in the internal thread of the first sleeve part. A toothed ring extends coaxially with the central longitudinal axis of the sleeve parts and is located on the nut. The second sleeve part has a radial access opening in the vicinity of the toothed ring. An operating instrument for activating the implant adjustment includes a handgrip and a shaft extending through the handgrip, a rotary grip carried on one end and another end carrying a toothed wheel for rotational actuation of the nut in the interior space of the implant.
1. An operating instrument for a height-adjustable implant for insertion between vertebral bodies, the implant having two sleeve parts that are axially displaceable relative to one another and that enclose an interior space, and a nut disposed in the interior space and configured to axially displace one of the sleeve parts relative to the other sleeve part and carrying a toothed ring, the operating instrument comprising:
a handgrip and a shaft extending through said handgrip, said shaft having one end carrying a rotary grip and another end carrying a toothed wheel for rotational actuation of the nut in the interior space of the implant;
a jacket tube having a distal end affixed to said handgrip and a proximal end in proximity of said toothed wheel, said proximal end of said jacket tube having an external thread formed thereon, said thread being configured for meshing with an inner thread of the access opening of the implant;
a segment of said shaft extending between said toothed wheel and said handgrip extends through said jacket tube;
said proximal end of said jacket tube being configured for fixation at an access opening of the implant; and
said toothed wheel having teeth projecting axially out of said proximal end of said jacket tube.
2. The operating instrument according to claim 1 , wherein said jacket tube is radially flared out at said proximal end and encloses said toothed wheel.
3. The operating instrument according to claim 1 , wherein said teeth of said toothed wheel are longitudinally oriented bolts.
4. The operating instrument according to claim 3 , wherein said toothed wheel includes a disk affixed to a forward end of said shaft, said bolts project from said disk.