Comparison of Precision between Optical and Electromagnetic Navigation Systems in Total Knee Arthroplasty.

Purpose: The purpose of this study is to compare and analyze the precision of optical and electromagnetic navigation systems in total knee arthroplasty (TKA).

Materials And Methods: We retrospectively reviewed 60 patients who underwent TKA using an optical navigation system and 60 patients who underwent TKA using an electromagnetic navigation system from June 2010 to March 2012. The mechanical axis that was measured on preoperative radiographs and by the intraoperative navigation systems were compared between the groups.

Association between preoperative anxiety in spinal stenosis patients and abnormal cerebral glucose metabolism: voxel-based statistical analysis of F-18 FDG brain PET.

Although a possible association between preoperative anxiety and abnormal cerebral glucose metabolism may exist, the authors are not aware of any report describing preoperative anxiety and cerebral metabolism in patients with spinal stenosis in detail. Fluorine-18 fluorodeoxyglucose positron emission tomography with statistical parametric mapping analysis was used to compare regional brain glucose metabolism between 34 spinal stenosis patients and 34 healthy comparison subjects. Spinal stenosis patients with preoperative anxiety showed several voxel clusters of significantly decreased cerebral metabolism.