Introduction

By all developments of new technologies on the improvement of the Total Knee implantation, the discussion about the optimum Alignment is in full way. Besides, is to be considered, that Alignment contains not only static, but also dynamic factors and beside the frontal plan also the sagittal plan as well as in particular the rotation in femur and tibia have a great importance for the outcome after TKR. However, beside the bone alignment, the kapsulo-igamentous structures also play an important role for the results after TKR. If a Varus-Malalignment was valid, in the past the „older” literature described it as a big risk factor for pain, less function and durability. However, in the present literature, we discuss more and more about the optimum Alignment during TKR. In particular, newer publications show no interference of the durability with coronar Alignment also outside from 3 °, also the score results and patient's satisfaction seem to deliver no worse results with slight untercorrection of the varus alignment. Some publications described even better score results and Patient satisfaction with slight untercorrection. Condition for it is probably an exact balancing of the extension and flexion gap.

Total knee arthroplasty belongs today to one of the standard operation in orthopaedic surgery. During the last years the number of the total knee arthroplasty has dramatically increased. The prognosis for the future have shown also an increasing tendence. The Swedish Regiter Study and others showed that the results after total knee replacement not almost dependant on the design of the prothesis. More important are patient selection, operation technique and the postoperative therapy.

The goals of modern knee replacement surgery are restoring mechanical alignment, preserving of the joint line, balancing ligament with a well balanced extension and flexion gap to reach maximum stability and movement. Bone resection is the simple part of a total knee operation. Ligament balancing with equal extention and flextion gap represents a major chalange for the surgeon which may consequantly affect the stability both in extention and flextion. Stability of total knee arthroplasty is dependant on correct and percise rotation of the femoral component. Femoral component malrotation has been associated with numerous adverse sequelae, including patellofemoral and tibiofemoral instability, knee pain, arthrofibrosis, and abnormal knee kinematics. A great number of early revision today are due to malrotation of the femoral component.

Multiple differing surgical techniques are currently utilized to perform TKA.

femur first (measured resection)

In the classic femur first technique the excision of the bone done indepentaly after one another followed by ligament balancing in flextion and extension. There are 4 bony landmarks deciding the rotational position of the femur. The epicondylar line, whiteside line, the dorsal condyles and anetroir-posterior axis. All these landmarks are associated with problems and failure to define exactly these bony landmarks intraoperatively. This may lead not seldom to malrotation of the femural component, consequently instability, limitation of function and increased wear.

In the tibia first technique excision of the femur especially for flexion done dependant on the excision of the tibia. This carried out using a tensor. With using this technique the rotation of the femur will be oriented mainly at the ligament balancing espcialy in flexion. Flexion instability and patellae maltacking will be avoided.

We present our preferrd tibia first technique using a new tensor system. With this system it is possible to reach a well balanced extension and flextion gap. A 3° release is only needed in special cases. The rotation position of the femur depend primerly on the released soft tissue in extension. Also an exact reconstruction of the dorsal offset as well as an exact anterior or posterior referencing can be guaranteed with the instruments by infinitely variable ap movement. The use of bony landmarks also possible.

we think our new tensor present a step forwards in understanding the biomechanics of the knee and offer a new development of the instruments used in knee replacement. This could be useful especialy in cases of revision.

Today TKA belongs to a standard care in orthopaedics and traumatology. The number of the annual implantations has clearly increased during the last years and also in the future an increasing rate to be expected.

Also the number of Revision TKA and the treatment of complicated pathologies in the primary care will increase in the same way.

Therefore the requirements of the surgeon rised as well as a suitable and accurate systems will be needed. Beside revision cases, traumatic-, post-traumatic- and RA-patients demonstrate partly distinctive bone and ligamentous pathologies.

Beside the primary implant components and instrumentation-systems, modern knee systems must include also modular revision systems compatible with the primary systems to be able to carry out complicated primary as well as light to moderately severe recision cases. Besides, also the possibility should be able to change within the system (with constant bone-cuttings) on higher degrees of the constrain.

With the TC-Primary and TC-Revision system fulfils the above mentioned criteria so that nearly every situation can be handled.

We present our experience using this system in cases of revisions, traumatic, post-traumatic and RA-cases The handling of bone and ligamentous defects will be demonstrated. In particular the possibility the use of the TC-Revision also in primary TKA as P a so named “extension primary system” will be emphasized.

By the Modulary and compatibility of the TC-Primary and TC-Revision systems, the use of Wedges and Stems as well as the possibility of the different degrees of the constrain a knee family permits us to treat complicated primary as well as mild to moderate revision cases.