Protek Ag

Mathys Medizinaltechnik Ag

Ulrich Wehrli

Instrument for adjustment osteotomy of a lower extremity

A reference system for the implantation of condylar total knee prostheses comprises a measuring rod (1) parallel to the longitudinal axis of the tibia (T) having at least two attachment arms (2) for lateral attachment to the outside of the tibia (T), a guide rail (9) connected to the measuring rod having a measuring scale (10) thereon and an adjustable measuring carriage (11) to which a cutting block (15) for performing the necessary osteotomies is affixed for movement in two directions so that cutting block can be displaced and fixed in such a way that by slots therein, the osteotomy can be carried out at the right place. For determining the position, there is attached to the measuring rod an alignment bar (20) which forms the continuation of the measuring rod toward the pelvis and has a length such that the end reaches to the pelvis. Disposed at the top of the alignment bar is a movable alignment element which can, for setting purposes, be moved along the alignment bar at right angles to the sagittal plane and fixed. By means of a specific point of reference on the pelvic bone, i.e., a screw in the spina iliaca anterior superior, the tibia can be brought into the correct position during the operation.

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Wabern, Switzerland

Ulrich Wehrli