Biomedical subjects
Publications and source records attributed to B L Rydevik.
Endoneurial fluid pressure measurements were made in the interstitial space of rat L5 dorsal root ganglia and in the corresponding sciatic nerves. Endoneurial fluid pressure was always higher in the ganglia than in the paired distal nerve. This proximodistal gradient in endoneurial fluid pressure may be the driving force responsible for the proximodistal convection of endoneurial fluid.
The series of experimental studies reviewed in this article supports a classification of median nerve compression at the wrist into early, intermediate, advanced, and acute nerve compression. The findings correlate well with experimental studies on the pathophysiology of nerve compression. A patient-specific management approach is recommended based upon the clinical and electrophysiologic findings which can be correlated with previously demonstrated intraneural pathologic changes.
Three-dimensional computer reconstruction of magnetic resonance images (MRI) of ten cadaveric specimens was used to determine carpal tunnel volume and carpal arch width. Magnetic resonance images-acquired data were compared with direct measurement of cadaveric carpal canal volume by means of a silicone-injection technique. Mean MRI three-dimensional reconstruction volume was 5.84 ml +/- 1.24 ml. Mean silicone-mold volume was 4.73 +/- 1.01 ml. A correction factor of 0.8161 was used to accurately calculate carpal tunnel volume from MRI-acquired data. There was no significant difference between calculated carpal tunnel volumes and silicone-mold volumes (p = 0.623), and there was a linear relationship between MRI-acquired volumes and silicone-mold volumes (correlation coefficient r = 0.97). Differences in MRI-volume determinations between observers were not significant (0.25 greater than or equal to p greater than 0.1). MRI three-dimensional reconstruction, a valid and reproducible technique for measuring carpal tunnel volume and dimensions, has considerable research potential for the evaluation of the relationship between the carpal canal and its contents before and after carpal tunnel release.