ObjectiveTo investigate the effectiveness of repair procedure using biological mesh with Onlay-Reinforce technique in patients with perineal hernia. MethodsBetween January 2005 and December 2012, 9 patients with perineal hernia after laparoscopic abdominoperineal resection for rectal cancer (Miles operation) were treated. There were 3males and 6 females with a mean age of 70 years (range, 61-78 years). The disease duration was 1-9 months (mean, 4.5 months). The most beginning symptom was distending pain in perineal region, and then reducible mass was found without bowel incarceration. All patients underwent hernia repair using biological mesh with Onlay-Reinforce technique through original perineal incision. ResultsThe hernial size was 9.8-20.5 cm2 (mean, 16.0 cm2); the size of biological mesh was 58-80 cm2 (mean, 70.2 cm2); and the intraoperative blood loss was 10-80 mL (mean, 50.5 mL). All of the patients underwent repair operation successfully. The operation time was 45-90 minutes (mean, 60.6 minutes); and the hospitalization time was 4-7 days (mean, 5.9 days). One patient had urine retention, which was relieved after 7 days indwelling catheter. All the wounds healed by first intention without infection. The patients were followed up 14.5-60.7 months (mean, 37.8months). No chronic pain, obvious foreign body sensation, or hernia recurrence developed. ConclusionUse of biological mesh with Onlay-Reinforce technique for the repair of perineal hernia after Miles operation is safe and effective.
This study explored the variation of bursting force of multi-chamber infusion bag with different geometry size, providing guidance for its optimal design. Models of single-chamber infusion bag with different size were established. The finite element based on fluid cavity method was adopted to calculate the fluid-solid coupling deformation process of infusion bag to obtain corresponding critical bursting force. As a result, we proposed an empirical formula predicting the critical bursting force of one chamber infusion bag with specified geometry size. Besides, a theoretical analysis, which determines the force condition of three chamber infusion bag when falling from high altitude, was conducted. The proportion of force loaded on different chamber was gained. The results indicated that critical bursting force is positively related to the length and width of the chamber, and negatively related to the height of the chamber. While the infusion bag falling, the impact force loaded on each chamber is proportional to the total liquid within it. To raise the critical bursting force of in fusion bag, a greater length and width corresponding to reduced height are recommended considering the volume of liquid needed to be filled in.
In sonoporation, the cell membrane is broken-up temporarily by ultrasound mediated microbubbles, which is promoting drug or gene into the cell. In current literatures, there are numerous studies of single microbubble dynamics in sonoporation. However till now, little studies have been focused on the sonoporation incidence caused by more than one microbubble. In this article, the dynamic model of two adjacent microbubbles in stable cavitation has been introduced. By the model, the forces including secondary Bjerknes force on cell membrane given by microbubbles and their effects on sonoporation have been numerically studied. According to the experimental parameters, we numerically studied (1) effects of the ultrasound and microbubble parameters on the secondary Bjerknes forces; (2) the forces exerted on cell membrane by microbubble, including the secondary Bjerknes force; (3) the sonoporation possibility caused by those forces produced by microbubble. In this article, the ultrasound and microbubbles’ parameters range were found to produce sonoporation by two adjacent microbubbles. Furthermore, it is the first time to found that the microbubbles’ parameters are more important than ultrasound parameters on sonoporation.
In order to investigate in greater detail the two methods based on Hertz model for analyzing force-distance curve obtained by atomic force microscopy, we acquired the force-distance curves of Hela and MCF-7 cells by atomic force microscopy (AFM) indentation in this study. After the determination of contact point, Young's modulus in different indentation depth were calculated with two analysis methods of "two point" and "slope fitting". The results showed that the Young's modulus of Hela cell was higher than that of MCF-7 cell,which is in accordance with the F-actin distribution of the two types of cell. We found that the Young's modulus of the cells was decreased with increasing indentation depth and the curve trends by "slope fitting". This indicated that the "slope fitting" method could reduce the error caused by the miscalculation of contact point. The purpose of this study was to provide a guidance for researcher to choose an appropriate method for analyzing AFM indentation force-distance curve.
The aim of this experimental study focused on the relationship between pull-out strength (POS) and interfragmentary compressive force (IFCF) of AO cancellous lag screw during tightening procedure. The 6.5 mm AO cancellous lag screw and synthetic cancellous bone were used for this research. The test contains rotation tests and the subsequent pull-out tests, to record the IFCF and POS under different tightening angle groups. The results of this study demonstrated the specific relationship between IFCF and POS and showed that they didn’t reach the peak at the very same time. This study revealed the change of mechanical environment surrounding AO lag screw during tightening procedure and found the effective method to determine the optimum terminating time of AO lag screw inserting.
ObjectiveTo investigate the effectiveness of arthroscopic reinforced reconstruction of anterior cruciate ligament (ACL) with autologous hamstring tendon combined with anchor suture band. MethodsBetween February 2016 and March 2018, 60 patients who were to be treated with arthroscopic ACL reconstruction and met the selection criteria were selected in the study. Among them, 30 cases were reconstructed with autologous hamstring tendon combined with anchor suture band (trial group), and 30 cases were reconstructed with simple autologous hamstring tendon (control group). There was no significant difference in gender, age, disease duration, cause of injury, injury side, and preoperative Lysholm score, Tegner score, and International Knee Documentation Committee (IKDC) score between the two groups (P>0.05). After reconstruction, the patients in the trial group were allowed to start knee flexion and extension activities early without wearing an adjustable brace, while the patients in the control group were required to wear an adjustable brace for 12 weeks. The knee joint function (Lysholm score, Tegner score, IKDC score) and stability (Lachman test and pivot shift test) were compared between the two groups after operation.ResultsThere was no significant difference in graft diameter between the two groups (t=1.061, P=0.115). Compared with the control group, the operation time of the trial group was significantly different (t=4.924, P=0.000). All incisions healed primarily. In the control group, the intramuscular venous thrombosis occurred in 2 cases after operation. Both groups were followed up 18 months. The Lysholm score, Tegner score, and IKDC score of the two groups at each time point after operation were significantly higher than those before operation (P<0.05); the above scores in the trial group were significantly higher than those in the control group at 3, 6, and 9 months after operation (P<0.05); there was no significant difference between the two groups at 18 months after operation (P>0.05). There was no significant difference in Lachman test results between the two groups at each time point after operation (P>0.05). There was a significant difference in pivot shift test results at 6 months after operation between the two groups (P<0.05); but there was no significant difference at other time points (P>0.05). ConclusionThe effectiveness of ACL reinforcedreconstruction with autologous hamstring tendon combined with anchor suture band is satisfactory. Compared with using autologous hamstring tendon alone, it has better initial strength and joint stability, and is more conducive to early postoperative functional exercise and functional recovery of knee joint.
The surgical installation accuracy of the components in unicompartmental knee arthroplasty (UKA) is an important factor affecting the joint function and the implant life. Taking the ratio of the medial-lateral position of the femoral component relative to the tibial insert (a/A) as a parameter, and considering nine installation conditions of the femoral component, this study established the musculoskeletal multibody dynamics models of UKA to simulate the patients’ walking gait, and investigated the influences of the medial-lateral installation positions of the femoral component in UKA on the contact force, joint motion and ligament force of the knee joint. The results showed that, with the increase of a/A ratio, the medial contact force of the UKA implant was decreased and the lateral contact force of the cartilage was increased; the varus rotation, external rotation and posterior translation of the knee joint were increased; and the anterior cruciate ligament force, posterior cruciate ligament force and medial collateral ligament force were decreased. The medial-lateral installation positions of the femoral component in UKA had little effect on knee flexion-extension movement and lateral collateral ligament force. When the a/A ratio was less than or equalled to 0.375, the femoral component collided with the tibia. In order to prevent the overload on the medial implant and lateral cartilage, the excessive ligament force, and the collision between the femoral component and the tibia, it is suggested that the a/A ratio should be controlled within the range of 0.427−0.688 when the femoral component is installed in UKA. This study provides a reference for the accurate installation of the femoral component in UKA.
Objective To evaluate the surgical procedure of reinforced acetabular cage with caudal flange in reconstruction of pelvic defect after acetabular tumor resection. Methods Between June 2003 and December 2009, 25 patients with Harrington class III pelvic defect underwent reconstruction with a reinforced acetabular cage with caudal flange and total hip arthroplasty (THA). There were 13 males and 12 females with an average age of 51.2 years (range，13-73 years). The main cl inical manifestations included hip pain and buttock pain, with a median disease duration of 6 months (range, 1-96 months). Pathological findings showed 18 cases of metastasis, 3 cases of multiple myeloma, 1 case of non-Hodgkin’s lymphoma, 1 case of grade I chondrosarcoma, 1 case of giant cell tumor, and 1 case of chondroblastoma. For the patient with chondroblastoma, THA with LINK RIBBED system was used. An artificial total hip system made in China was used in 6 patients and LINK SP II system was used in the other 18 patients. Results No patients died perioperatively. Deep infection and hip dislocations occurred in 1 and 2 patients, respectively. At last follow-up, 8 of 18 patients with metastasis died of cancer and the average survival time was 11 months. The other 10 who were al ive were followed up 15 months on average. One patient with multiple myeloma died of pulmonary infection at 21 months after operation and the other 2 with multiple myeloma and 1 with lymphoma were al ive with an average follow-up of 17 months. The patient with grade I chondrosarcoma and patient with chondroblastoma were followed up 58 and 12 months, respectively, without recurrence. Recurrence occurred in the patient with giant cell tumor at 19 months afteroperation. Loosening of implant occurred in 3 patients because of local tumor recurrence. For the 23 patients at 6 months after operation, the mean Musculoskeletal Tumor Society (MSTS) 93 score was 81% (range, 57%-93%). Conclusion Reinforced acetabular cage with caudal flange could be used together with THA for reconstruction of Harrington class III pelvic defects after acetabular tumor resection, and low incidence of postoperative compl ication and good functional outcome could be expected.
Objective To evaluate the effectiveness of acetabulum reinforcement ring (Cage) with allograft bone for reconstructing acetabular defects in hip revision. Methods Between February 2006 and August 2010, 14 patients (14 hips) with serious acetabular bone defects after total hip arthroplasty underwent acetabular reconstruction by using Cage with allograft bone. There were 6 males and 8 females with a mean age of 59.2 years (range, 45-76 years). The mean time between first replacement and revision was 7.2 years (range, 5-12 years). The revision causes included infection in 8 cases, osteolysis and aseptic loosening in 6 cases. The hip function Harris score was 37.7 ± 5.3. According to America Association of Orthopedic Surgeon (AAOS) standard, the acetabular defect was classified as type III in 8 cases and as type IV in 6 cases. Results All incisions healed by first intention, and no complication occurred. The patients were followed up 14-62 months (mean, 44 months). The pain was relieved or disappeared. At last follow-up, the Harris score was 89.7 ± 3.2, showing significant difference when compared with preoperative score (t= — 44.40, P=0.04). No loosening of the acetabular component or osteolysis was found in 14 hips. No absorption or collapse of the allograft was observed in all patients. Conclusion Cage with allograft bone is a useful method of reconstructing acetabular bone defects in hip revision. Further follow-up is needed to assess the long-term effectiveness.
Although attention plays an important role in cognitive and perception, there is no simple way to measure one's attention abilities. We identified that the strength of brain functional network in sustained attention task can be used as the physiological indicator to predict behavioral performance. Behavioral and electroencephalogram (EEG) data from 14 subjects during three force control tasks were collected in this paper. The reciprocal of the product of force tolerance and variance were used to calculate the score of behavioral performance. EEG data were used to construct brain network connectivity by wavelet coherence method and then correlation analysis between each edge in connectivity matrices and behavioral score was performed. The linear regression model combined those with significantly correlated network connections into physiological indicator to predict participant's performance on three force control tasks, all of which had correlation coefficients greater than 0.7. These results indicate that brain functional network strength can provide a widely applicable biomarker for sustained attention tasks.