In order to observe the effects of different facing directions of the germinal layer of periosteum on the cartilage regeneration, the human fibrin adhesive agent was used to adhere autogenous periosteum to repair the articular cartilage defect of rabbits. Twentyfour rabbits with 48 knee joints were divided randomly into two groups. A 0.6cm×1.2cm articular cartilage defect was created on the femoral trochlea until there was bleeding from the subchondral bone. A piece of periosteum, sized 0.75cm×1.5cm, was removed from the medial aspect of upper tibia. The periosteum was adhered to the defect by human fibrin adhesive agent. In Group 1 the germinal layer faced the subchondral bone and in Group 2 the germinal layer faced the joint cavity. The cartilage regeneration in both groups was observed by naked eyes and light microscope in 2nd and 6th weeks and by electron microscope after Safronin Ostained in 12th and 20th weeks. The results showed that before the 6th week, the cartilage regeneration was faster in Group 2 than that in Group 1. After that there was no significant difference in regeneration between the two groups. This suggested that the facing direction of the germinal layer was not a critical factor on cartilage regeneration. It was also found that the strength of the adhesive agent was not enough. The regenerated cartilage was proved to be hyaline cartilage.
Objective To investigate the appl ication of anti-rotation screw after dynamic hi p screw (DHS) in treatment of intertrochanteric fracture. Methods Between April 2006 and January 2010, 22 cases of intertrochanteric fractures underwent DHS fixation operation with an anti-rotation screw, including 15 males and 7 females with an average ageof 66.3 years (range, 54-83 years). Fractures were caused by sl ipping in 16 cases, traffic accident in 5 cases, and fall ing from height in 1 case. All cases showed closed fractures, including 13 cases in the left and 9 cases in the right. Eighteen cases were simple intertrochanteric fracture, 4 cases were intertrochanteric fractures compl icated with Colles fractures. According to Evans classification standard, there were 14 cases of type I, 6 cases of type II, 1 case of type III, and 1 case of type IV. The time from wound to operation was 3-7 days (mean, 4.5 days). Results The operation time ranged from 51-95 minutes (mean, 72 minutes). The intraoperative blood loss was 150-350 mL (mean, 270 mL). The hospital ization days were 12-35 days (mean, 16.8 days). Primary heal ing was observed in all cases. All cases were followed up 6-17 months (mean, 14 months). Union of fracture was observed at 12-16 weeks (mean, 13.6 weeks); no fracture or internal fixation loosening occurred. According to HUANG Gongyi’s standard of efficacy assessment, the results were excellent in 19 cases and good in 3 cases. Conclusion Appl ication of an anti-rotation screw can help to improve the strength of the DHS for the internal fixation of intertrochanteric fracture, especially the anti-rotation abil ity, which does not increase the operation time obviously.
Patients with amyotrophic lateral sclerosis ( ALS ) often have difficulty in expressing their intentions through language and behavior, which prevents them from communicating properly with the outside world and seriously affects their quality of life. The brain-computer interface (BCI) has received much attention as an aid for ALS patients to communicate with the outside world, but the heavy device causes inconvenience to patients in the application process. To improve the portability of the BCI system, this paper proposed a wearable P300-speller brain-computer interface system based on the augmented reality (MR-BCI). This system used Hololens2 augmented reality device to present the paradigm, an OpenBCI device to capture EEG signals, and Jetson Nano embedded computer to process the data. Meanwhile, to optimize the system’s performance for character recognition, this paper proposed a convolutional neural network classification method with low computational complexity applied to the embedded system for real-time classification. The results showed that compared with the P300-speller brain-computer interface system based on the computer screen (CS-BCI), MR-BCI induced an increase in the amplitude of the P300 component, an increase in accuracy of 1.7% and 1.4% in offline and online experiments, respectively, and an increase in the information transfer rate of 0.7 bit/min. The MR-BCI proposed in this paper achieves a wearable BCI system based on guaranteed system performance. It has a positive effect on the realization of the clinical application of BCI.