Risk Factors for Thirty-Day Readmission Following Lumbar Surgery: A Meta-Analysis.

OBJECTIVE: Thirty-day readmission is one of the common complications after lumbar surgery. More 30-day readmission increases the total hospitalization, economic burden, and physical pain of patients, delays the progress of postoperative rehabilitation, and even lead to die. Therefore, it is necessary to analyze the risk factors of 30-day readmission following lumbar surgery. METHODS: We searched for all the clinical trials published from the establishment of the database to May 1, 2022 through the Cochrane Library, Web of Science, Embase, and PubMed. Data including age, American Society of Anesthesiology physical status class, preoperative hematocrit (Hct), diabetes mellitus (DM), current smoker, chronic obstructive pulmonary disease (COPD), length of hospital stay (LHS), operation time, and surgical site infection (SSI) were extracted. We used Review Manager 5.4 for data analysis. RESULTS: Six studies with 30,989 participants were eligible for this meta-analysis. The analysis revealed that there were statistically significant differences in the age (95% confidence interval [CI]: -3.35-2.90, P < 0.001), preoperative Hct (95% CI: 0.75-1.33, P < 0.001), DM (95% CI: 0.56-0.74, P < 0.001), COPD (95% CI: 0.38-0.58, P < 0.001), operation time (95% CI: -35.54-16.18, P < 0.001), LHS (95% CI: -0.54-0.50, P < 0.001), and SSI (95% CI: 0.02-0.03, P < 0.001) between no readmission and readmission groups. In terms of the American Society of Anesthesiology physical status class and current smoker, there was no significant effect on the 30-day readmission (P = 0.16 and P = 0.35 respectively). CONCLUSIONS: Age, preoperative Hct, DM, COPD, operation time, LHS, and SSI are the danger factors of 30-day readmission following lumbar surgery.

Numerical and Experimental Analyses on the Temperature Distribution in the Dental Implant Preparation Area when Using a Surgical Guide.

PURPOSE: During dental implantation, if the temperature within the bone tissue exceeds a critical value, the thermal necrosis of bone cells may take place, inhibiting osseointegration. In contrast to conventional dental implant surgery, a surgery guided by a surgical template is a safer and more efficient technique; however, the temperature within the implant field is more difficult to control, because the surgical guide blocks irrigation water. The purpose of this study was to investigate the temperature distribution in the drilling site when preparing for dental implant placement with a surgical guide, and to derive suggestions for clinical operation. MATERIALS AND METHODS: Initially, the sources of heat during drilling were investigated, and theoretical equations were listed. Subsequently, a measurement system using thermocouples was constructed, with which the temperature increments at specific points in the simulated bone samples were recorded during guided drilling with different cooling methods. Based on the equations and data assessed, a thermal simulation model with a finite element method (FEM) was created, and the temperature change of the whole surgical field was calculated on the basis of the numerical simulation results. Consequently, the point experiencing the highest temperature within the bone was determined. RESULTS: From the experimental measurements, the highest temperature increment was located at a depth of 6 mm without irrigation and at 8 mm with cooling, rather than at the deepest point of the prepared hole. Because the surgical guide blocks the cooling water from entering the drilling site, the biggest increment of temperature using conventional irrigation with the surgical guide was 1.95 times that recorded when using a surgical guide consisting of cooling channels, and 3.6 times that recorded using a drill with an internal cooling hole. And from numerical analysis, during drilling for implant placement site with conventional irrigation, the highest temperature (45.6°C) was close to the critical point at which bone necrosis occurs. CONCLUSIONS: Based on theoretical analysis, experimentation, and FEM simulation, the temperature distribution of the drilling area in the placement of dental implants under surgical guide was determined. For clinical operation, improved cooling methods, such as using a drill with an internal cooling channel, should be used, and the drill should be regularly withdrawn during drilling.

[The influence of drilling pulling ways and cooling systems on dental implant surgery].

PURPOSE: To study the effect of different ways of pulling the drilling burs and cooling systems on alveolar bone temperature of the surgical area, and explore the changes of temperature field in dental implants. METHODS: Forty-eight unified standard artificial (nylon) bone blocks were fabricated and divided into 6 groups according to different drilling pulling ways and cooling systems. The changes of bone temperature field were detected in 6 groups, and the highest temperature in temperature field was measured and recorded. The date was analyzed with SPSS 12.0 software package for ANOVA. RESULTS: The temperature in the surgical area using internal cooling systems under the same drilling pulling was lower than using external cooling systems. The temperature in the surgical area using secondary drilling pulling way was lower than using direct drilling methods under the same cooling systems. The temperature in the surgical area using secondary drilling pulling way was the lowest when internal cooling systems was adopted(P<0.05). CONCLUSIONS: Drilling pulling way and internal cooling systems can effectively reduce the temperature in the surgical area, lessen heat production and improve the success rate of dental implants.