Minimally invasive total knee replacement in tibia first technique with the INNEX® knee system

Abstract

Since excellent long term results have been reported [8, 12, 14, 20, 22, 31, 32, 35, 39, 40, 42] a growing number of younger patients are receiving total knee replacement. These active patients expect fast recovery with early mobilization and short rehabilitation to reassume work and sports as soon as possible. Additionally, decreasing financial resources in public health systems force surgeons to minimize surgical trauma to be able to shorten hospital stay and thereby costs. The main reason for prolonged rehabilitation still is extensive soft tissue trauma with eventual wound healing problems and extensor mechanism disturbance. Therefore, after minimally invasive unicompartimental knee replacement had been established [34], minimally invasive techniques for total knee replacement have been developed [5-7, 15, 17, 33, 43, 45-47]. Unfortunately, minimally invasive total knee replacement is not well defined yet. Various clinical parameters could be taken into consideration, such as skin incision length, extent of transection of the retinaculum, the tendons and muscles of the extensor apparatus and the joint capsule as well as the amount of bone resection and patella manipulation [7]. Although important for patient's satisfaction skin incision length should not be the only determinant [7] and it varies considerably with knee position. If the goal of minimally invasive total knee replacement is less pain and rapid recovery, trauma to the extensor mechanism is probably the decisive factor and should be minimized. Therefore, we have chosen the subvastus approach for minimally invasive total knee replacement as the integrity of the vastus medialis muscle and its tendon is preserved [37]. The patella is lateralized but not everted and patella surface resection is not mandatory for adequate exposure. At the same time, the approach allows direct anterior access to the knee and thereby soft-tissue balancing. In contrary to other existing procedures, in our operative technique the tibia is cut first and all subsequent bone cuts are soft-tissue tension referenced. In cooperation with the ZIMMER company we have developed a minimal invasive instrumentation for the modular INNEX® knee system. © 2007 Springer Medizin Verlag Heidelberg.