RESUMEN
The traditional treatment of intervertebral disc degeneration (IVDD) mainly focuses on symptomatic treatment, and cannot restore the physiological structure and function of the intervertebral disc. Therefore, more and more scholars begin to pay attention to the application of regenerative medicine and its derived therapeutic methods in IVDD. From the histological perspective, the early stage of IVDD shows the imbalance between synthesis and catabolism, but the cell number and tissue structure are relatively complete, and the intervention of exogenous molecules or gene therapy can achieve ECM regeneration. With the progress of IVDD, the replenishment of healthy cells is the key to treatment. In the final stage, the cell number and tissue structure are disordered. Biological materials with certain mechanical strength and cell load can be used to supplement ECM and healthy cells to realize the repair and regeneration of IVDD. Molecular, cell and gene therapy, combined with the application of new biomaterials, the treatment of IVDD is more inclined to compensate for the shortcomings through a combination approach in the future, in order to achieve the purpose of repair and regeneration.
RESUMEN
Objective: To investigate the efficacy of one-stage anterior debridement and bone graft fusion for the treatment of cervical pyogenic spondylodiscitis. Methods: This is a retrospective case series study. Retrospective analysis of clinical data from 23 patients with cervical pyogenic spondylodiscitis treated with one-stage anterior approach debridement and bone graft fusion was performed in the Department of Spinal Surgery, the First Affiliated Hospital of Xinjiang Medical University from January 2015 to January 2020. There were 14 males and 9 females,aged (51.9±12.8) years (range:26 to 82 years). Preoperatively, 14 patients had neurological deficits, classified according to the American Spinal Injury Association (ASIA) impairment scale as follows: grade A in 1 case, grade B in 1 case, grade C in 5 cases, and grade D in 7 cases. All patients underwent the one-stage anterior debridement and fusion procedure. The surgical time, blood loss, hospital stay, fusion time, and surgical complications were documented. Clinical efficacy was assessed using the visual analogue scale (VAS), the neck disability index (NDI), and the ASIA impairment scale. Preoperative and postoperative data were compared using paired sample t tests, repeated measures analysis of variance, and generalized estimating equations. Results: All the 23 patients underwent the operative procedures successfully. The operation time was (102.8±19.8) minutes (range:60 to 140 minutes), blood loss was (84.4±40.2) ml (range:30 to 160 ml), and the length of hospital stay was (17.4±6.0) days (range:10 to 30 days). Blood cultures were positive for the causative pathogen in 14 cases (60.8% positivity rate), while 9 cases had negative results. Irrigation fluid cultures yielded the causative pathogen in 19 cases (82.6% positivity rate), with 4 cases negative. All patients were followed up for more than 12 months, with a follow-up duration of (19.0±5.9) months (range:12 to 36 months). At the final follow-up, VAS improved from (5.9±1.1) points preoperatively to (0.8±0.3) points; NDI improved from (38.3±6.0)% preoperatively to (9.3±3.0)%, with statistically significant differences (all P<0.01). All patients experienced improvement in neurological function, with the exception of one patient in grade C and two in grade D, all other patients recovered to grade E. The C2-7 Cobb angle and the affected segment Cobb angle were corrected. white blood cell, erythrocyte sedimentation rate and C-reactive protein levels returned to normal. All patients achieved bony fusion, with a fusion time of (8.9±1.9) months (range:6 to 12 months). Two diabetic patients developed postoperative incision infection; no other surgery-related complications occurred in the remaining patients. Conclusion: One-stage anterior debridement and bone graft fusion can correct kyphosis, restore normal alignment, and improve neurological function in the treatment of single and double segment cervical pyogenic spondylodiscitis, representing a viable treatment option for cervical pyogenic spondylodiscitis.
RESUMEN
To study the effect of internal particle size on the microstructure properties and thermal decomposition characteristics of site mixed emulsion explosive at different altitudes. Site mixed emulsion explosive was prepared with different shear rate. The particle size, viscosity, sensitized bubbles, detonation velocity and peak pressure of the emulsion explosive were tested after stored at different simulated altitudes. The thermal decomposition characteristics of emulsion matrix prepared at three different rotational speeds were measured by thermogravimetric analyzer and kinetic analysis was performed by non-isothermal model Kissinger-Akah-Sunose (KAS) method. The results show that with the increase in altitude, the internal phase size showed a trend of first increasing and then decreasing, and the number of sensitized bubbles within the emulsion explosive decreases. At an altitude of 0 m, the detonation velocity and peak overpressure of the emulsion explosive prepared by 1600 r min-1 increased 4.78% and 29.09%, respectively compared with 1200 r min-1, and at an altitude of 4500 m, the detonation velocity increased 11.87%, the peak overpressure increased 43.98%. The thermal decomposition activation energy of the emulsion matrix at 1600 r min-1 increased 13.14% compared to 1200 r min-1. It shows that in the production of site mixed emulsion explosive at high altitude, reducing the particle size of the internal phase of emulsion explosives in a certain range can effectively improve the performance of emulsion explosives.
