Factors determining the success of radiofrequency denervation in lumbar facet joint pain: a prospective study

Background and aims Radiofrequency denervation (RF) of the lumbar facet joints has been shown to be effective in well-selected patients. However, long-term success varies between studies. We evaluated the influence of selected psychosocial and constitutional factors on the outcome of RF, expressed as the duration of pain relief. Methods This prospective observational study included 44 patients who received RF denervations at the University Hospital of Berne. Success was defined as at least 50% pain reduction 7–21 days, 6 months and 1 year after RF therapy. The Cox-regression analysis was performed to evaluate the influence of the following factors on the duration of success: age, sex, depression, work inability and previous surgery. Results Complete follow-up was available for 41 patients. The success rate 7–21 days after the denervation was 76%. It decreased to 32% at 6 months and to 22% at 1 year. The median success duration was 17 weeks (95% CI 10–26). The Cox-regression analysis showed a significant shorter duration of success for patients with depression (hazard ratio [HR] 2.97, 95% CI 1.32–6.65), previous surgery (HR 2.39, 95% CI 1.10–5.21) and number of treated joints (HR 1.95 for each increase in the number of joints, 95% CI 1.14–3.33). In bivariate analyses, only depression was kept to be significant. Conclusions Depression seems to be related with a short duration of success. Based on these findings, a comprehensive study is warranted to evaluate whether psychosocial factors have to be considered when recruiting patients for radiofrequency denervation.

Prediction of bone strength at the distal tibia by HR-pQCT and DXA

Areal bone mineral density (aBMD) at the distal tibia, measured at the epiphysis (T-EPI) and diaphysis (T-DIA), is predictive for fracture risk. Structural bone parameters evaluated at the distal tibia by high resolution peripheral quantitative computed tomography (HR-pQCT) displayed differences between healthy and fracture patients. With its simple geometry, T-DIA may allow investigating the correlation between bone structural parameter and bone strength.

Exploring High-resolution Magic Angle Spinning (HR-MAS) NMR Spectroscopy for Metabonomic Analysis of Apples

Classical liquid-state high-resolution (HR) NMR spectroscopy has proved a powerful tool in the metabonomic analysis of liquid food samples like fruit juices. In this paper the application of (1)H high-resolution magic angle spinning (HR-MAS) NMR spectroscopy to apple tissue is presented probing its potential for metabonomic studies. The (1)H HR-MAS NMR spectra are discussed in terms of the chemical composition of apple tissue and compared to liquid-state NMR spectra of apple juice. Differences indicate that specific metabolic changes are induced by juice preparation. The feasibility of HR-MAS NMR-based multivariate analysis is demonstrated by a study distinguishing three different apple cultivars by principal component analysis (PCA). Preliminary results are shown from subsequent studies comparing three different cultivation methods by means of PCA and partial least squares discriminant analysis (PLS-DA) of the HR-MAS NMR data. The compounds responsible for discriminating organically grown apples are discussed. Finally, an outlook of our ongoing work is given including a longitudinal study on apples.