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Deformities were corrected at the level of the knee joint during TKA without prior osteotomies.For conventional techniques, surgeons used a combination of both intramedullary andextramedullary guides. Postoperative long leg radiographs were used to assess coronalalignment. Second, we used the same navigational technique clinically to perform TKA inpatients with extra-articular deformities.ResultsUsing both navigational and conventional techniques, it was possible to indirectly correct shaftdeformities by adjusting the inclination of bone cuts at the level of the knee joint. The amountof bone cutting at distal femur and proximal tibia were variable depending on the location anddirection of the deformity. There was no compromise of collateral ligaments or patellar tendonsin both techniques. However, the accuracy of restoring normal alignment was better innavigational techniques. The results of the clinical cases are still in progress waiting analysis ofa longer term follow up.DiscussionNavigational techniques eliminated the use of both intramedullary and extramedullary guides.The improved accuracy with navigational techniques led to better alignment that can improvefunctional and survival outcome of similar cases of TKA in real patients.References1. Hafez MA, et al. Computer assisted surgery for correction of skeletal deformities. InNavigation and MIS in orthopaedics. Stiehl JB, et al (eds). Springer 2006. pp 535-5412. Hafez MA, et al. Computer Assisted Surgery of the Knee: An overview. In Surgery of theKnee (4th Ed.), Install JN, Scott N (Eds). Churchill Livingston. 2006, 1655-16743. Hafez MA, et al. Computer-assisted Total Knee Arthroplasty Using Patient-SpecificTemplating. CORR. 2006;444:184-1924. Wang JW, et al. Total knee arthroplasty for arthritis of the knee with extra-articulardeformity. J Bone Joint Surg Am. 2002 Oct;84-A(10):1769-74.Friday, October 8, 2010, 11:00-11:50Session B11: Knee MechanicsShould a Mobile Bearing Wear Less Than a Fixed-Bearing TKR? theAnswer From in Vitro Wear Testing.*Hani Haider - University of Nebraska Medical Center - Omaha, USAChristian Kaddick - EndoLab GmbH - Thansau/Rosenheim, Germany*Email: hhaider@unmc.eduSome mobile bearing knee replacement designs have shown truly excellent long-term clinicalresults. The higher laxity of a mobile bearing helps reduce the shear forces and torquestransmitted to the prosthesis-bone interface, and this could only help reduce the risk ofloosening. Some argue that self-alignment of a mobile bearing rotationally can produce morecentral patellar tracking. However, the most commonly assumed benefit of mobile bearings isthe reduction in contact stress, which is typically expected to reduce fatigue and wear. In arotating platform TKR for example, wear is also expected to be less because the rolling/slidingfile:///E|/ISTA2010-Abstracts.htm[12/7/2011 3:15:47 PM]