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. The largest clusters were areas of left insula and left prefrontal cortex (Brodmann's areas 9 and 11). The second largest cluster area was left prefrontal cortex (Brodmann's area 10). The other clusters were right insula (Brodmann's area 13), right superior temporal gyrus (Brodmann's area 22), and right middle frontal gyrus (Brodmann's area 8).

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. The postoperative positions of the femoral and tibial components in the sagittal and coronal plane were assessed. RESULTS: The difference of the mechanical axis measured on the preoperative radiograph and by the intraoperative navigation systems was 0.6 degrees more varus in the electromagnetic navigation system group than in the optical navigation system group, but showed no statistically significant difference between the two groups (p>0.05). The positions of the femoral and tibial components in the sagittal and coronal planes on the postoperative radiographs also showed no statistically significant difference between the two groups (p>0.05). CONCLUSIONS: In TKA, both optical and electromagnetic navigation systems showed high accuracy and reproducibility, and the measurements from the postoperative radiographs showed no significant difference between the two groups.