This article reviews the progress of biomechanical studies on anterior cervical fusion and non-fusion surgery in recent years. The similarities and differences between animal and human cervical spines as well as the major three biomechanical test methods are introduced. Major progresses of biomechanical evaluation in anterior cervical fusion and non-fusion devices, hybrid surgery, coupled motion and biomechanical parameters, such as the instant center of rotation, are classified and summarized. Future development of loading method, multilevel hybrid surgery and coupling character are also discussed.
Animals ; Biomechanical Phenomena ; Cervical Vertebrae ; surgery ; Humans ; Rotation ; Spinal Fusion ; methods

Objective To evaluate the effect of ureteroscopic treatment for upper urinary tract obstruction. Methods A total of 56 cases of upper urinary tract obstruction were treated under ureteroscope by using direct-vision dilatation, electrocauterization or balloon dilatation. Results A successful dilatation was achieved in 49 cases (87.5%, 49/56) whereas a failure was encountered in 7 cases. There were no complications such as ureteral perforation, rapture or heavy bleeding. A follow-up for 0.5~3 years (mean, 2.5 years) in 43 cases was carried out. The obstruction disappeared in 33 cases, remained in 6 cases, and relapsed in 4. The hydronephrosis disappeared in 30 cases, subsided in 5 cases, and had no changes in 8. Conclusions The treatment of the upper urinary tract obstruction under ureteroscope offers advantages of minimal trauma and satisfactory outcomes.

Hepatic perfusion parameters play an important role in detecting and diagnosing diffusion diseases of liver. Based on a hemodynamic model. In this study, we described a fast and accurate method to calculate the perfusion parameters. First, we used a dual-input one-compartment kinetics model to illustrate the distribution of the contrast agent concentration among the body. Then, we used the Gaussian function to fit the scatter concentration data of portal vein and aorta, to obtain a liver agent concentration on function of time. Finally, we solved the model parameters by using Levenberg-Marquardt algorithm, and calculated the perfusion parameters. The results showed that the method proposed in this study could calculate the parameters precisely, and had a prosperous future application possibility.
Algorithms ; Contrast Media ; Hemodynamics ; Humans ; Liver ; physiology ; Models, Biological ; Perfusion

10.3969/j.issn.2095-4344.2013.26.019

BACKGROUND:The basic idea of artificial disc replacement is the intension to minimize the impact on adjacent segments based on the premise of stabilizing index segment, then prevent and reduce the incidence of adjacent segment degeneration.
OBJECTIVE:To explore the indications and contraindications of artificial disc replacement, peri-operative
economics considerations, long-term complications, as wel as the effect of artificial lumbar disc replacement combined with fusion surgery.
METHODS:The PubMed database, CNKI database and SinoMed database over the past decade were searched for the related articles. The retrospective and prospective clinical trials of artificial lumbar disc replacement were included. Repetitive studies and stale perspectives were excluded. A total of 34 articles were summarized and analyzed in the end.
RESULTS AND CONCLUSION:Since the first artificial lumbar disc prosthesis designed to be commercial y
distributed in 1982, there have been a plenty of clinical trials on lumbar disc replacement. However, there is no
answer to many problems that encountered in clinical trials. The effect of the number of replaced segment on the clinical outcomes, the effect of facet joint degeneration on the clinical outcomes, selection of the patients with the history of lumbar disc surgery, age of the patients and the rest time before disc replacement should be taken into consideration in the researches on indications and contraindications of artificial disc replacement. The
intraoperative blood loss, operation time and hospital stay after replacement can be used to evaluate whether lumbar disc replacement is better than the traditional lumbar fusion surgery or not. The complications after lumbar disc
replacement include heterotopic ossification, implants mechanical failure, and facet joint and adjacent segment
degeneration. The combination of lumbar disc replacement and fusion surgery for the treatment of multi-segmental lumbar disc diseases can achieve complement and thus obtaining the efficacy that better than the application of one surgery alone.

BACKGROUND:Artificial Lumbar disc replacement as a new choice for the treatment of degenerative disc disease has aroused widespread concern by clinicians because of the preservation of lumbar vertebra’s biomechanical characteristics during pain eliminating. While the design of the prosthesis structure and material needs further study and validation.
OBJECTIVE:To review the structure and material types of several newly designed artificial lumbar discs, then to discuss the trends in the optimization design of prosthesis, in order to provide instruction for the design and assessment of new lumbar artificial disc prosthesis.
METHODS:The PubMed database, CNKI database and SinoMed database were searched for related articles. New articles related to artificial lumbar disc structure, material, in vivo and in vitro biomechanics were included. Repetitive studies and stale perspectives were excluded. A total of 46 articles were summarized and discussed in the end.
RESULTS AND CONCLUSION:Artificial lumbar disc has developed for nearly 30 years, the design of structure and biological material has been in continuous improvement. At first, we summarized the principle and current situation in the design of movement reservation, movement constraint, instant fixation, base material, weight-bearing material and coating material of artificial lumbar disc prosthesis, then combined with the exist newly in vivo and in vitro biomechanical results to evaluate different kinds of design with the recent research trend to prospect the development of biomimetic design, material improvement, the optimization design of prosthesis and assisted devices.

Objective To evaluate the impact of steatotic hepatic grafts on postoperative early liver function and prognosis.Methods Clinical data of 35 cases receiving steatotic liver grafts in our hospital were retrospectively analyzed.The donor liver grafts were divided into 3 groups based on the degree of fatty infiltration(＜20%group,20%～40%group,≥40%group).Results were compared with that from control normal grafts(41 cases).Liver function parameters including AST,ALT,TB,PT on the day of surgery and 1,2,3,7 days later were monitored among the 4 groups,as well as the incidence of delayed nonfunction (DNF),and 3 and 6 months patient survival rate.Analysis of the correlation between degree of donor steatosis and liver function after operation was carried out.Resuits There was significant difference in postoperative ALT、AST、TB、PT level between≥40%group and 20%～40%group,and between 20%～40%and group＜20%group.There was no significant difference among the groups in DNF occurrence rate and 3 month.6 month patient survival rate.Correlation analysis suggested that the degree of donor steatosis was positively correlated with the damage of liver function.Conclusions Grafts with≤20% steatosis was safe,whereas≥20% especially ≥40% steatosis carries a high risk of posttransplant liver dysfunction even delayed nonfunction.

Objective: To investigate the effect of allogeneic red blood cell transfusion on T lymphocyte subsets and natural killer (NK) cells in peripheral blood of patients with gastric cancer during perioperative period. Methods: 50 patients with gastric cancer in our hospital from January 2017 to December 2017 were randomly divided into control group (n=25) and observation group (n=25). Perioperative allogeneic erythrocyte transfusion was performed in the observation group, while no allogeneic erythrocyte transfusion was performed in the control group. Blood samples were taken from two groups before and after operation 3 d, and serum T lymphocyte subsets (CD3⁺, CD4⁺, CD8⁺, CD4⁺ /CD8⁺ ) and NK cell levels were measured. T cell subsets and NK cell levels of patients in observation group, control group and observation group at different clinical stages before and after operation were counted. According to blood transfusion volume, the patients in the observation group were divided into <4 U group and <4 U group. T cell subsets and NK cell levels before and after operation were compared between the two groups. Results: There was no significant difference in CD3⁺, CD4⁺, CD8⁺, CD4⁺ /CD8⁺, NK cells between the two groups before operation (P>0.05). The levels of CD3⁺, CD4⁺, CD4⁺ /CD8⁺, NK cells in the two groups after operation were lower than those before operation and CD8⁺ levels were higher than those before operation. The levels of CD3⁺, CD4⁺, CD4⁺ /CD8⁺, NK cells in the observation group were lower than those in the control group, and the levels of CD8⁺ in the observation group were higher than those in the control group (P<0.05). The levels of CD3⁺, CD4⁺, CD8⁺, CD4⁺ /CD8⁺, NK cells in patients with stage Ⅰ-Ⅱ and stage Ⅲ-Ⅳ had no significant difference before operation (P>0.05). After operation, the levels of CD3⁺, CD4⁺, CD4⁺ /CD8⁺, NK cells in the two groups were lower and CD8⁺ levels were higher than those before operation. The levels of CD3⁺, CD4⁺, CD4⁺ /CD8⁺, NK cells in stage Ⅰ-Ⅱ patients were higher than those in stage Ⅲ-Ⅳ patients, and CD8⁺ levels were lower than those in stage Ⅲ-Ⅳ patients (P< 0.05); There was no significant difference in the levels of CD3⁺, CD4⁺, CD8⁺, CD4⁺ /CD8⁺, NK cells between the <4 U group and <4 U group before operation (P>0.05). After operation, the levels of CD8⁺ in the two groups were higher than those before operation, while the levels of CD3⁺, CD4⁺, CD4⁺ /CD8⁺, NK cells were lower than those before operation; The levels of CD3⁺, CD4⁺, CD4⁺ /CD8⁺, NK cells in the <4 U group were higher than those in >4 U group, and CD8⁺ levels were lower than those in >4 U group (P<0.05). Conclusions Perioperative allogeneic red blood cell transfusion can affect T cell subsets and NK cell content in peripheral blood of patients with gastric cancer, and there are some differences in the effects of different clinical stages of gastric cancer patients, which can cause the suppression of cellular immune function.

In recent years, with the growth of social development, the incidence of lumbar vertebrae diseases has increased year by year, and many surgical methods have been developed. These treatment methods mark the accumulation of surgical experience and the development of medical technology. However, a new issue appears, i.e. how to evaluate the degree of lumbar disease and postoperative rehabilitation. There is an urgent need to establish a quantitative index of preoperative examination and postoperative rehabilitation criteria for lumbar disease from both doctors’ and patients’ perspectives. The current studies show that the measurement of the center of rotation (COR) for lumbar vertebrae and surface electromyography (sEMG) can reduce the error in the evaluation of clinical curative effect for treating lumbar disease and can be applied widely. This review summarizes the relationship between COR and lumbar disease, as well as the role of COR and sEMG joint evaluation in clinical operation and postoperative rehabilitation.

The mechanical properties of artificial intervertebral disc (AID) are related to long-term reliability of prosthesis. There are three testing methods involved in the mechanical performance evaluation of AID based on different tools: the testing method using mechanical simulator, specimen testing method and finite element analysis method. In this study, the testing standard, testing equipment and materials of AID were firstly introduced. Then, the present status of AID static mechanical properties test (static axial compression, static axial compression-shear), dynamic mechanical properties test (dynamic axial compression, dynamic axial compression-shear), creep and stress relaxation test, device pushout test, core pushout test, subsidence test, etc. were focused on. The experimental techniques using specimen testing method and testing results of available artificial discs were summarized. The experimental methods and research status of finite element analysis were also summarized. Finally, the research trends of AID mechanical performance evaluation were forecasted. The simulator, load, dynamic cycle, motion mode, specimen and test standard would be important research fields in the future.