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adiographs often underestimate the severity of osteolysis that is seen intra-operatively. Assuch, pre-operative radiographic evaluation requires a minimum of 3 views of the hip.Computerized tomography is more accurate than plain radiography at delineating the extent ofosteolysis.Intra-operatively, the complete acetabular rim must be exposed. The integrity of thelocking mechanism, the screws, and the fixation of the acetabular component must beevaluated; well-fixed components do not require removal. Component position should beassessed to ensure that the combined acetabular and femoral version is adequate to minimizepost-operative instability. A constrained liner should be considered if the abductor complex isfound to be deficient.Determination should also be made as to whether bone grafting of osteolytic lesions isnecessary. There are several techniques for bone-grafting retroacetabular lesions. Ischial andpubic rami lesions are more difficult to graft because it is not possible to contain the bone graftmaterial within these lesions and thus prevent the graft material from gaining access to thebearing surface. In general, removal of the wear generator is often adequate for treatment ofosteolysis around a well fixed acetabular component, and bone grafting is not required.Poster: 95In Vivo Post-Cam Kinematics of a High Flexion Posterior-Stabilized TotalKnee Arthroplasty*Norimasa Shimizu - Osaka University Graduate School of Medicine - Suita, JapanTetsuya Tomita - - ,Kunihiko Kawashima - Osaka University - Suita, JapanTakaharu Yamazaki - osaka - suita, japanYasuo Kunugiza - Osaka University - Suita City, JapanMasahiro Kurita - dept. of prthopaedic biomaterial science,osaka univ. - suita-city, japanKazuma Futai - - ,Kazuomi Sugamoto - Osaka University Graduate School of Medicine - Suita, Japan*Email: Norimasa-shimizu@umin.ac.jpBackground: In deep knee flexion of posterior stabilized (PS) TKA, the interaction betweenfemoral cam and tibial post substitutes for the posterior cruciate ligament by providing anteriorposteriorstability to the knee. The post-cam mechanism can induce femoral posterior translation(bicondyler rollback) with knee flexion. The objective of this study is to clarify the post-camkinematics pattern in deep knee flexion of a high flexion PS TKA under weight-bearingconditions.Patients and methods: We investigated the in vivo knee kinematics of 16 knees (13 patients)implanted with LPS-FLEX Fixed Bearing TKA (Zimmer). Under fluoroscopic surveillance,each patient did a deep knee flexion under weight-bearing condition. Femorotibial motionincluding tibial polyethylene insert were analyzed using 2D/3D registration technique, whichuses computer-assisted design (CAD) models to reproduce the spatial position of the femoral,file:///E|/ISTA2010-Abstracts.htm[12/7/2011 3:15:47 PM]