BACKGROUND:Platelet-rich fibrin(PRF)is a second generation platelet concentrate with the advantages of simple operation,no anticoagulant,and high bioactivity,which has been applied in the fields of trauma repair,bone defect repair,and tendon soft tissue repair,and has been proved to have a certain tissue repair-promoting effect. OBJECTIVE:To study the repair effect of PRF on articular cartilage tissue in rats with knee osteoarthritis. METHODS:Thirty-six Sprague-Dawley rats were randomly divided into normal group,model group,and PRF group,with 12 rats in each group.Rats in the normal group did not undergo any treatment.In the model group,animal models of knee osteoarthritis were prepared and rat models were then given physiological saline into the joint cavity once a week after surgery.Rat models of knee osteoarthritis were also prepared in the PRF group,and autologous PRF was injected into the joint cavity once a week after surgery.After 5 weeks of continuous treatment,tissue samples were taken.Hematoxylin-eosin staining was used to observe the morphology of cartilage tissue.Tunel staining was used to detect chondrocyte apoptosis,ELISA was used to detect inflammatory factor levels.Western blot and RT-PCR were used to detect Bcl-2,Bax,and Caspase-3 expression in protein and mRNA levels,respectively. RESULTS AND CONCLUSION:The model group had severe cartilage tissue damage,while the PRF group had significantly improved cartilage tissue morphology compared with the model group.The model group had more apoptotic chondrocytes.Compared with the model group,the mean absorbance of Tunel positive staining in the PRF group significantly decreased(P<0.01).The levels of interleukin-1β,interleukin-6 and tumor necrosis factor-α were significantly increased in the model group and PRF group compared with the normal group(P<0.01)and were significantly decreased in the PRF group compared with the model group(P<0.01).The relative expressions of Bax and Caspase-3 at protein and mRNA levels were significantly increased in the model group and PRF group compared with the normal group(P<0.01),while the relative expressions of Bcl-2 at protein and mRNA were significantly decreased(P<0.01).Compared with the model group,the relative expression of Bax and Caspase-3 at protein and mRNA levels were significantly decreased in the PRF group(P<0.01),while the relative expressions of Bcl-2 at protein and mRNA levels were significantly increased(P<0.01).To conclude,PRF can inhibit chondrocyte apoptosis by inhibiting the expression of pro-inflammatory factors,thereby promoting cartilage tissue repair in knee osteoarthritis rats.

Replantation of traumatic amputation in children has its own characteristics. This consensus primarily focuses on the issues related to the treatment of traumatically amputated limb injuries in children. Organised along a timeline, the consensus summarises domestic and international clinical experiences in emergency care and injury assessment of traumatic limb amputation limbs, indications and contraindications for replantation surgery, principles and procedures of replantation surgery, postoperative medication and management, as well as rehabilitation in children. The aim of this consensus is to propose standardise the treatment protocols for limb replantation for children therefore to serve as a reference for clinical practitioners in medical practices, and further improve the treatment and care for the traumatic limb amputations in children.

OBJECTIVE: The purpose of this study is to explore the biomechanical characteristics of the tibia after unicompartmental knee arthroplasty with different distributions of two-pin holes, and to optimize the two-pin holes scheme to reduce the risk of tibial fractures after unicompartmental knee arthroplasty. METHODS: Lower limbs model is segmented and reconstructed from computed tomography images. Four combinations of two pin holes created for tibial cutting guide placement are simulated with finite element analysis. RESULTS: In the third mode, the positioning hole at the proximal medial edge of the tibial plateau has the highest stress value, and the position of the positioning hole near the medial edge of the proximal tibial plateau appears stress concentration. CONCLUSIONS The present study revealed that placing tibial cutting guide holding pins centrally would lower the risks of periprosthetic fracture of the medial tibial plateau.
Arthroplasty, Replacement, Knee ; Tibia/surgery* ; Lower Extremity ; Finite Element Analysis ; Tomography, X-Ray Computed

Cervical spondylosis is due to degenerative cervical disc and its stimulation or oppression of the adjacent nerves, spinal cord, spinal artery and other tissue caused by clinical symptoms. The cervical spine is an anatomical structure with activity, while the pillow has a certain plastic fixation effect on the cervical spine anatomy. Therefore, the pillow not only plays a health role in the cervical spine, but also plays an important role in restoring the normal physiological curvature of the cervical spine. Based on this, a multi-functional cervical vertebra treatment pillow is designed, which not only has the functions of traction, maintaining different positions of the cervical spine, correcting the cervical curvature and equipment exercises, but also has the functions of voice broadcast and network data terminal.

In the research of artificial joint biomechanics, it is a common method in the world to evaluate the biomechanical properties of the implanted fixtures through experiments . The domestic research started late, and the corresponding testing software were lacking. There is still no special software. In this paper, an integrated software test system was designed and built based on the existing hardware system, including:hardware control, data collection, data save, data processing and display. It can directly show the 3D motion trajectory and the angle curve of joints. The system can accurately measure the relative motion angle value, external torque value, and inter pressure value of each joint. It has some reference significance for the development of the artificial joints' evaluation system.

In the research of artificial joint biomechanics, it is a common method in the world to evaluate the biomechanical properties of the implanted fixtures through experiments . The domestic research started late, and the corresponding testing methods were lacking. There is still no unified standard. In this paper, a complete hardware test system was designed and built around the existing mechanical testing machine, including:binocular vision catcher, torque bearing clamp, film pressure sensor and so on. The system can accurately measure the relative motion angle value, external torque value, and inter pressure value of each joint. It has some reference significance for the forming and standardization of the artificial joints' evaluation system.
Biomechanical Phenomena ; Joint Prosthesis ; Motion ; Pressure ; Torque

This paper constructs numerical models of bioprosthetic heart valve and blood. The fluid solid interaction is carried out using penalty function method. The mechanical property of the bioprosthetic heart valve during cardiac cycle is simulated with ANSYS software. Results show that the Von Mises stress concentrates at the junction of attachment edge and coaptation edge. The open time of bioprosthetic heart valve is consistent with that of actural measurement. The peak velocity of blood is in the range of physiology. This model provides more realistic mechanical property of bioprosthetic heart valve during cardiac cycle compared to pure solid model, and facilitates design and optimization of bioprosthetic heart valve.
Bioprosthesis ; Heart Valve Prosthesis ; Heart Valves ; Humans ; Models, Cardiovascular ; Prosthesis Design

BACKGROUNDDue to racial differences in the morphology of the knee joint and due to most prostheses available in the market being designed using measurements from Caucasians, the objective of this study was to provide the morphometric data of the patella for the southern Chinese population for total knee arthroplasty (TKA), patellar resurfacing, and prostheses design.

METHODSThe CT slices of the knee joint were obtained from both knees of 40 Chinese volunteers (20 females, 20 males, and age from 20-25 years) by performing a computer tomographic scan. A 3D model was reconstructed by Mimics software based on the computed tomography images. Six metrical characteristics were measured by digital ruler. Statistical analysis was performed with the SPSS statistical program.

RESULTSThe mean, standard deviation and P values of measurements and ratios were calculated using SPSS. All dimensions showed a significant gender difference with P < 0.05, but the six variables of the left and right knees had no statistical significance with P > 0.05. In addition, we studied the relationship between six couples (H-W, H-T, H-HAF, W-T, W-HAF, T-HAF) of the four variables (H: height, W: width, T: thickness and HAF: height of articulating facet) that were measured, which showed a significant correlation.

CONCLUSIONSExamination of the southern Chinese population revealed that males have larger patellae than women. In both genders, comparing data between left and right knees shows no statistically significant difference. Compared with Westerners in previous studies, the patella in our study was thin and small. There was a good linear regression correlation between measurements of the patella. The indirect measurement method on 3D models makes it easy to obtain anatomical data, and the results can provide a region and gender specific database for morphometric measurements of the patella, and can be helpful for designing implants suited for southern Chinese patients.

Adult ; Arthroplasty, Replacement, Knee ; China ; Female ; Humans ; Male ; Patella ; diagnostic imaging ; Tomography, X-Ray Computed ; Young Adult

BACKGROUND:Clinical practice verified that percutaneous vertebroplasty in the treatment of osteoporotic vertebral compression fractures obtained obvious curative effects.
OBJECTIVE:To compare the therapeutic effect of percutaneous vertebroplasty for treatment for osteoporotic vertebral compression fractures with or without intravertebral cleft, in order to evaluate the efficacy and safety of percutaneous vertebroplasty for treatment of osteoporotic vertebral compression fractures.
METHODS:A total of 76 patients with osteoporotic vertebral compression fractures were selected and divided into two groups. Experimental group consisted of 27 patients with intravertebral cleft. Control group comprised 49 patients without intravertebral cleft. After vertebroplasty, visual analogue scale and Oswestry disability index, changes of anterior vertebral height, and types and characteristics of bone cement leakage were compared between the two groups.
RESULTS AND CONCLUSION:Visual analogue scale and Oswestry disability index were significantly decreased after treatment in the two groups (P<0.05). No significant differences in visual analogue scale, Oswestry disability index and incidence of bone cement leakage were detected between the two groups after treatment (P>0.05). No significant difference in the height of injured vertebra was detectable between pretreatment and posttreatment in the two groups (P>0.05). These results suggested that vertebroplasty is an effective method for lessening the pain in osteoporotic vertebral compression fractures in patients with or without intravertebral cleft, improving spinal activity function and elevating social activities. However, percutaneous vertebroplasty cannot effectively recover the height of the vertebra.

BACKGROUND:Operation is an important measure to improve the function of spinal cord and to stop the pathological progress of multilevel cervical spondylotic myelopathy. There are controversies how to select the optimum operation mode, to reduce postoperative complications and to elevate clinical curative effects.
OBJECTIVE:To systematical y review patients’ profiles of multilevel cervical spondylotic myelopathy, and to evaluate the effects of simple anterior approach, simple posterior approach and one stage posterior anterior combined approach on cervical spinal curvature index and functional recovery in patients.
METHOD148 sample profiles of patients, who received multilevel cervical spondylotic myelopathy operation in The Affiliated Hospital of Qingdao University and Qingdao Municipal Hospital from February 2000 to February 2008, and met the inclusion and exclusion criteria, were selected. They were divided into simple anterior approach group, simple posterior approach group and one stage posterior anterior combined approach group. The differences in the functional recovery were assessed after treatment using different therapeutic methods.
RESULTS AND CONCLUSION:Cervical spinal curvature index was highest in the simple posterior approach group before treatment (P<0.01). Cervical spinal curvature index was highest in the one stage posterior anterior combined approach group after treatment (P<0.01). Changes in cervical spinal curvature index were most obvious in the simple anterior approach group before and after treatment (P<0.01). No significant difference in Japanese Orthopaedic Association Scores was detected among three groups after treatment (P>0.05).
Significant differences in improvement rate of Japanese Orthopaedic Association Scores were detectable after treatment between the one stage posterior anterior combined approach group and simple anterior approach and simple posterior approach groups (P<0.001). Significant differences in cervical dysfunction index and SF-36 scores were detectable among the three groups before and after treatment (P<0.05). Results indicated that compared with the simple anterior approach and simple posterior approach, decompression through one stage posterior anterior combined approach is a reliable and effective operative procedure for treatment of multilevel cervical spondylotic myelopathy.