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Lalit Puri - Northwestern University-Ortho Dept. - Glenview, USAGregory Strohmeyer - Northwestern University - Chicago, USA*Email: ritesh-shah@md.northwestern.eduComputer assisted total knee arthroplasty has been demonstrated to provide reproducible limb mechanicalalignment within three degrees from the neutral mechanical axis. However, restoring proper implant and extremityalignment remains a significant challenge with proximal tibial deficiencies. In this prospective study, we describe theuse of computer navigation to quantify the amount of bone loss on the medial or lateral tibial plateau and the use ofthis data to assess the need for augmentation with metallic tibial wedges.In this study, we demonstrate that CAS TKR in patients with significant tibial deformities can accurately measuresevere tibial deformities, predict tibial augment thickness, and provide excellent mechanical alignment and restorethe joint line without excessive bony resection, repeated osteotomies, and repeated augment trialing.Thursday, October 7, 2010, 13:30-14:10Session B5: Computer Navigation in TKR 1CT and Cine Video X Ray Based Analysis of Alignment and Stability ofComputer Navigated and Conventional TKR*Rajeev Kumar Sharma - Indraprastha Apollo Hospital - New Delhi, India*Email: dr_rksharma@hotmail.comThere is still want of evidence in the current literature of any significant improvement inclinical outcome when comparing computer-assisted total knee arthroplasty (CA-TKA) withconventional implantation. Analysis of alignment and of component orientation have shownboth significant and non-significant differences between the two methods. Not much work hasbeen reported on clinical evidence of stability of the joint.We compared computer-assisted and conventional surgery for TKA at 5.4 years follow-up forpatients with varus osteoarthritic knees with deformity of more than 15*. Our goal was to assessclinical outcome, stability and restoration of normal limb alignment.We used CT and Cine video X ray techniques to analysize our results in Computer navigatedand conventional TKRs. A three dimentional CT scan of the whole extremity was performedand evaluation was done in three planes; saggital, coronal and transverse views. CT scan wasdone between 10 to 14 days postoperative. Mean deviations in the mechanical axis, femoral andtibial plateau angles, and in transverse view, the trans-epicondylar axis vs posterior condylaraxis were measured. The prospective randomized study comprised of 98 patients with surgerydone on knees, one side navigated and other side conventional. Mean deviation in themechanical axis was 2.2* in conventional knees and 1.8* in navigated knees. In 5 % of casesretinacular release was needed and CT analysis showed TEA in deviation of more than 2 * inthese cases. We analysed intraoperative data (surgical time and intraoperative complications),postoperative complications, lower limb alignment, radiographic complication on X-rayimaging, and clinical outcome through knee and function score, range of motion and jointstability.Our results showed that CAS had greater consistency and accuracy in implant placement andfile:///E|/ISTA2010-Abstracts.htm[12/7/2011 3:15:47 PM]