Patent ID: 7275336

Claim:
A distance measuring instrument for pedicle screws, comprising first and second limbs which cross at an axis of rotation ( 13 ) and whose ends ( 25 , 26 ) can be positioned at two pedicle screws ( 3 ) screwed into adjacent spinal vertebrae ( 1 , 2 ), with the first limb ( 11 ) merging at the opposite side to its end ( 26 ) into a crossbar ( 25 ) which is provided with an arc-shaped scale part ( 18 ), with the second limb ( 12 ) having a projection ( 21 ) projecting over the crossbar ( 25 ) for adjustment and being formed as a first pointer to display a spacing between two pedicle screws with the first pointer ( 16 ) at a first scale ( 22 ) of the scale part, wherein the second limb ( 12 ) is divided into a second pointer ( 16 a ) and into a flexural spring ( 15 ) extending parallel to it to which a pronounced thumb grip ( 21 a ) is fastened; and wherein the crossbar is shaped as a handle ( 25 a ) to produce a spreading force at the ends ( 26 , 27 ) via the flexural spring ( 15 ) which can be read off relative to the second pointer ( 16 a ) via a second scale ( 24 ) connected to the thumb grip ( 21 a ).