Association of thrombelastogram with postoperative hemorrhage after total joint arthroplasty by structural equation modeling / 中国组织工程研究

BACKGROUND: Postoperative anticoagulant therapy after hip and knee arthroplasties has been included in the perioperative management guidelines. However, the application of anticoagulant drugs accompanies with the risk of bleeding. Routine coagulation tests provide limited information about the quality of clots because they identify only the first stage of clotting, while thrombelastography provides a comprehensive assessment of coagulation function. But its practicality remains controversial and the research for bleeding after joint replacement is little reported. OBJECTIVE: To explore the distribution of thrombelastography parameters (time to initial fibrin formation, clotting time, α angle, and maximum amplitude) and to analyze the correlation of the four parameters with postoperative blood loss, thereby providing guidance for improving the safety and effectiveness of anticoagulant therapy. METHODS: Totally 148 patients with detection of thrombelastogram after arthroplasty from August 2015 to March 2017 in Sun Yat-sen Memorial Hospital, Sun Yat-sen University were enrolled, including 76 cases of total hip arthroplasty and 72 cases of total knee arthroplasty. Thrombelastography data were collected on day 1 postoperatively, and the perioperative blood loss was calculated. Structural equation modeling of each group was constructed to investigate the relationship of four parameters and total blood loss. RESULTS AND CONCLUSION: (1) In the structural equation modeling of hip and knee arthroplasties, the root mean square error of approximation was less than 0.08, goodness-of-fit index, adjusted goodness-of-fit index, normed fit index and comparative fit index was all higher than 0.9, and Parsi-mony goodness-of-fit index was less than 2, so the theoretical model was matched with the data. (2) There was a correlation of postoperative hemorrhage with time to initial fibrin formation, clotting time, α angle, and maximum amplitude. (3) That is to say, thrombelastogram can be used as an efficient tool in predicting bleeding after hip and knee arthroplasties. Future study based on this research will further verify the correlation and provide more information for its clinical practice.

Effect of interleukin-6 on the chondrocytes in the cartilage endplate of rabbits in vitro / 南方医科大学学报

<p><b>OBJECTIVE</b>To evaluate the effect of interleukin-6 (IL-6) on the biological behaviors of the chondrocytes in the cartilage endplate of rabbits.</p><p><b>METHODS</b>Chondrocytes isolated from the cartilage endplate of New Zealand rabbits, verified for their biological characteristics by such means as toluidine blue staining for type II collagen, were treated with IL-6 at different concentrations. The proliferation of the chondrocytes was evaluated by MTT assay at different time points following the treatment, the cell cycle changes were determined by flow cytometry and the changes of aggrecan and type II collagen mRNAs detected by RT-PCR.</p><p><b>RESULTS</b>At the concentrations of 10, 50 and 100 ng/ml, IL-6 did not obviously affect the rate of chondrocyte proliferation. IL-6 at 50 ng/ml resulted in no obvious changes of the cell cycle of the chondrocytes, but significantly decreased the expression of collagen IIa mRNA.</p><p><b>CONCLUSION</b>IL-6 has no effect on the proliferation and cell cycle of the chondrocytes, but at higher concentrations, it inhibits matrix synthesis of the chondrocytes to promote intervertebral disc degeneration.</p>

The risk factors and preventive strategies of heterotopic ossification after artificial disc replacement in lumbar spine / 中华外科杂志

<p><b>OBJECTIVE</b>To analyze the risk factors of heterotopic (HO) ossification after total lumbar disc replacement and probe the preventive strategies for it.</p><p><b>METHODS</b>The radiographs and clinical data of 78 discs in 65 patients who received artificial lumbar disc replacement (ADR) from April 1998 to December 2003 were analyzed retrospectively by two radiologists and one orthopaedic surgeon and then postoperative HO were graded according to McAfee system. The bony formations in disc spaces, time of HO were found, and range of motion (ROM) of the operated levels were measured on radiographic films. In addition, the risk factors such as preoperative peri-annulus ossification, bony endplates injuries, and subsided or mal-position of the prostheses were also analyzed by Logistic regression analysis.</p><p><b>RESULTS</b>Postoperative HO was found in 10 spaces of 9 cases. Class I of HO were occurred in 7 patients at means 2.1 years postoperatively with normal range of motion preserved. Three of them turned into class II or III with 10 degrees of mean ROM in the following 2.5 years. Another 2 (2/9) cases with preoperative peri-annulus ossification had bridging trabecular bone (class III) between the endplates and 9 degrees of ROM 2 years after surgery, then turned into class IV at 6 years with 0 degrees and 4 degrees of motion in the operated levels. As the risk factors of HO, preoperative annulus ossification (2 cases), bony endplates injuries (5 cases), mal-positioned prostheses (2 cases) and subsided prostheses (2 cases) were found simultaneity with significant positive relation to HO occurred (P < 0.05).</p><p><b>CONCLUSIONS</b>Factors such as preoperative ossification of annulus, endplate injuries, prosthesis subsided and mal-position would have higher risks to have HO occurred after ADR, but ROM of most affected levels are preserved. Strict control indication and avoid all above risk factors can prevent HO occurring effectively.</p>

Design and experiment of the pedicle aiming device for the cervical spine / 中国医学科学院学报

<p><b>OBJECTIVE</b>To probe the accuracy and safety of using an aiming device in the transpedicular fixation of cervical spine.</p><p><b>METHODS</b>Eight cervical specimens were obtained. We used the computed tomography (CT) to scan C3 to C7, measured the medial angle of the pedicle, and determined the location of the pedicle projecting on the articular process. Then we took the oblique X-ray film, measured the cephalic/caudal angle of the pedicle, and determined the location of the pedicle projecting on the articular process. All the specimens were equally divided into two groups. Screws of 2.8 mm x 30 mm, were used. Specimens in one group were inserted with the transpedicular screw manually, while specimens in the other one inserted with the transpedicular screw using a self-designed aiming device that can be modulate at the three dimensions according to the angles of the pedicles.</p><p><b>RESULTS</b>The first group totally had 40 screws from C3 to C7. There were 13 screws in the pedicle, 9 violated the walls of the pedicle but not involved the adjunct structure, and 18 injured the important structure such as spinal cord, verteberal artery, or nerve root. In the other group, only 4 screws violated the walls of the pedicle but not involved the adjunct structure, and the others all in the pedicles. The difference was of statistical significance (P < 0.01).</p><p><b>CONCLUSION</b>In the cervical spine, transpedicular fixation using an aiming device can improve the accuracy and safety during operation.</p>

Analysis of complications after treatment of femoral intertrochanteric fractures with internal fixation / 中华创伤骨科杂志

Objective To analyze causes for postoperative fixation-related complications of femoral in- tertrochanteric fractures treated with dynamic hip screws(DHS)and dynamic condylar screws(DCS).Methods From January 1995 to December 2004,215 cases of intertrochanteric fracture were treated with DHS/DCS.Their postoperative fixation-related complications were analyzed to find out the causes.Results All cases were followed up for 13 to 72 months(mean,32 months).The rate of excellent and good functional recovery of hip was 94.0%. Postoperative internal-fixation-related complications occurred in 31 cases,including hip varus in 14 cases who had posterior intertrochanteric fragments,delayed union of fracture in 12 cases who had fractured calcar and lesser trochanter and massive dissection of soft tissues,and cutting-out of lag screws in five cases,three of whom had to receive prosthetic replacement.Conclusions Unsuitable implant selection is an important factor leading to postoperative fixation-related complications.Unstable fracture,serious osteoporosis and unsatisfactory reduction will increase the incidence of complications.