Habitual Physical Activity After Total Knee Replacement:analysis in 830 patients and comparison with a sex-and age-matched normative population (vol 92, pg 1109, 2012)

Background. Previous studies on physical activity after total knee arthroplasty (TKA) concentrated mainly on a return to sports activities. Objective. The objectives of this study were to determine the habitual physical activity behavior of people who had undergone TKA (TKA group) 1 to 5 years after surgery and to examine to what extent they adhered to international guidelines for health-enhancing physical activity. Additional aims were to compare younger (= 65 years old) people as well as men and women in the TKA group and to compare the results for the TKA group with those for a sex- and age-matched normative population (normative group). Design. This investigation was a cohort study. Methods. All people who had a primary TKA at 1 of 2 participating hospitals between 2002 and 2006 were sent the Short Questionnaire to Assess Health-Enhancing Physical Activity at least 1 year after surgery. Results. The TKA group spent, on average, 1,347 minutes per week on physical activity, most of which was light-intensity activity (780 minutes per week). Participants younger than 65 years of age spent significantly more time on physical activity than participants 65 years of age or older. There was no significant difference between male and female participants. Compared with the sex- and age-matched normative group, the TKA group spent significantly less time on the total amount of physical activity per week and met the guidelines for health-enhancing physical activity less often (55% versus 64%). Limitations. A self-administered questionnaire was used to assess habitual physical activity, and presurgery data on physical activity were not available. Conclusions. Almost half of the TKA group did not meet the health-enhancing physical activity guidelines, and the TKA group was not as physically active as the normative group. People who have undergone TKA should be encouraged to be more physically active

Temporary Segmental Distraction in a Dog with Degenerative Lumbosacral Stenosis

Objectives Degenerative lumbosacral stenosis (DLSS) is characterized by intervertebral disc degeneration and causes lower back pain in dogs. Temporary distraction in rabbit models with induced intervertebral disc degeneration showed signs of intervertebral disc repair. In the present study, we assessed safety and efficacy of temporary segmental distraction in a dog with clinical signs of DLSS. Methods Distraction of the lumbosacral junction by pedicle screw-rod fixation was applied in a 5-year-old Greyhound with DLSS and evaluated by radiography, magnetic resonance imaging, and force plate analysis before and after distraction. Results Safe distraction of the lumbosacral junction was demonstrated, with improvement of clinical signs after removal of the distraction device. Signal intensity of the intervertebral disc showed no changes over time. T2 value was highest directly after removal of the distraction device but decreased by 10% of the preoperative value at 9 months of follow-up. Disc height decreased (8%) immediately after removal of the distraction device, but recovered to the initial value. A decrease in the pelvic/thoracic propulsive force during pedicle screw-rod fixation and distraction was demonstrated, which slowly increased by 4% compared with the initial value. Clinical significance Temporary pedicle screw-rod fixation in combination with distraction in a dog with DLSS was safe, improved clinical signs and retained disc height at 9 months of follow-up

Effect of Cellulose Crystallinity on Solid/Liquid Phase Reactions Responsible for the Formation of Carbonaceous Residues during Pyrolysis

This study reports changes in solid phase composition when samples of Avicel cellulose (crystallinity: 60.5%) and ball-milled microcrystalline cellulose (crystallinity: 6.5%) were subjected to pyrolysis in a spoon reactor. Solid state chemistry evolution was examined by hydrolysis-ion exchange chromatography, scanning electron miscroscopy (SEM), Fourier transforminfrared (FTIR), and 13C nuclear magnetic resonance (NMR). The liquid reaction intermediate was found to cause particle agglomeration at temperatures below 300 °C. At higher temperatures, the ball-milled cellulose melted completely but the more crystalline cellulose conserved its fibrous structure. The formation of C?O and C?C groups was accelerated by the presence ofliquid intermediates derived from the amorphous cellulose. The content of cross-linked cellulose was quantified by the combined use of acid hydrolysis and 13C NMR. A new reaction mechanism to describe the changes in the solid residue composition at different reaction conditions is proposed