Warrick Bruce has designed two new instruments to make the TTO procedure easier and to eliminate some of the practical difficulties encountered using the original instrumenation.

The new combined osteometer and saw guide interlock to become a single instrument which is much easier to manage than the original two separate instruments. The thumbscrew locks the osteometer onto the saw guide for secure accurate osteotomies. The osteometer still has holes for fixation to the tibia using 1.6 arthrodesis wires.

Alternatively Warrick’s second new instrument ‘the Clasper’ may be used to lock the osteometer onto the tibia prior to cutting. The ‘Clasper’ has an additional role in that it is used to replace the kern bone holders in the original technique. The ‘Clasper’ grasps the tibia crest prior to closure and incorporates location holes for the very large fragment forceps to lock into. The ‘wedgie’, used for manipulating the three osteotomies remains unchanged.

 The angular security of locking plate systems depends on a rigid interface between screw and plate. This is acheived either by the use of interlocking threads or by using the morse taper phenomenon as seen in the Fixin system.

The threads on the head of our screws are fine as required but have a twin start. The threads taper down the head as a double helix. The pitch (the distance between the tips of the threads) of each individual fine thread is the same as the threads on the bone screw but because of the double helix the number of threads per millimeter of locking thread is double that of the bone screw giving the fine threads required for metal on metal. The screw moves through the bone at the same rate as it moves through the plate maintaining the relative positions of both bone fragment and plate.

 For further information on our Locking Technology Click Here