No abstract

Circadian rhythm (CR) imparts significant benefits in treating multiple diseases, such as heart diseases and arthritis. But the CR effect on intervertebral disc degeneration (IVDD) therapy remains unclear. Recent studies revealed that pulsed electromagnetic fields (PEMF) are capable of alleviating IVDD. In this study, we evaluated the CR-mediated regulation of PEMF therapeutic effect on IVDD induced by rat tail disc needle puncture. Our results demonstrated that the daytime PEMF stimulation (DPEMF) is more effective than the nighttime PEMF (NPEMF) in delaying IVDD. Moreover, the rats treated with DPEMF maintained better disc stability and histology after 8 weeks, relative to NPEMF. CR and PEMF cotherapies were also examined in cellular models, whereby serum shock was used to induce different levels of clock gene expression in the nucleus pulposus (NP), thus imitating CR in vitro. PEMF at ZT8 (higher level of clock gene expression) correlated with a higher extracellular matrix (ECM) component expression, compared to ZT20 (lower level of clock gene expression). Taken together, these data suggest a strong role of CR in regulating the beneficial effect of PEMF on IVDD. Our findings provide a potential clinical significance of CR in optimizing PEMF positive effects on IVDD.

No abstract

Background: The objective of this study was to investigate the clinical efficacy and therapeutic value of posterior decompression reduction, bone grafting fusion, and internal fixation for treatment of symptomatic old thoracolumbar fractures. Methods: Retrospective analysis was conducted for 14 patients (9 men, 5 women; average age 40.1 years) with old thoracolumbar fractures who underwent posterior operation. American Spinal Injury Association (ASIA) scores were used to evaluate neurologic recovery. Recovery of vertebral body height, Cobb angle in the sagittal plane, spinal canal volume ratio (%) and bone graft fusion were analyzed by radiography and computed tomography on different follow-up times. Results: Mean follow-up was 27.1 months (23–36 months). Of three patients with ASIA grade A, 2 had improved postoperative urination and defecation, although no classification change. Preoperative ASIA score for eight patients with incomplete injury was grade B; four patients recovered to grade C at final follow-up. Preoperative ASIA score was C in three patients, increased to D in two patients and returned to normal E in one patient. Preoperative results showed average injured vertebra height loss rate decreased from 50.4% to 8.9%; average Cobb angle on the sagittal plane recovered from 39.6° to 6.9°; and the average spinal canal volume ratio recovered from 33.8% to 5.9%. Bony fusion was achieved; local lumbago and leg pain were relieved to some extent. No patients exhibited loosening of the fracture treated by internal fixation, pseudoarthrosis, or other related serious complications.Conclusion: Treatment of old thoracolumbar fractures by posterior decompression reduction, bone grafting fusion, and internal fixation can relieve spinal cord compression, improve neurologic function of some patients (ASIA grades B–C), effectively relieve pain, correct deformity, restore biomechanical stability, and significantly improve quality of life.