Objective:To compare the efficacy of robot-assisted percutaneous reduction and screw fixation versus open reduction and plate fixation via the sinus tarsi approach in the treatment of Sanders types II and III calcaneal fractures.Methods:A retrospective cohort study was conducted to analyze the clinical data of 82 patients (90 feet) with calcaneal fractures admitted to the Department of Orthopedic Trauma, Beijing Jishuitan Hospital, Capital Medical University from January 2020 to April 2024, including 74 males and 8 females, aged 24-87 years [(46.4±12.1)years]. According to Essex-Lopresti classification, the fractures were classified as tongue-type in 43 patients and joint-collapse-type in 47. According to Sanders classification, 69 feet were classified as type II and 21 as type III. Forty-seven patients (52 feet) were treated with robot-assisted percutaneous reduction and screw fixation (screw fixation group) and 35 (38 feet) with open reduction and plate fixation via the sinus tarsi approach (plate fixation group). The two groups were compared in terms of the operation duration, intraoperative blood loss, length of hospital stay and time to weight-bearing. The width, height, length, B?hler angle and Gissane angle of the calcaneus before surgery and at 1 day after surgery were compared. The Maryland foot and ankle function score, American Orthopedic Foot and Ankle Society (AOFAS) ankle and hindfoot function score, and visual analogue scale (VAS) score at 1, 3 months postoperatively, and at the last follow-up were compared. The incidence of postoperative complications and removal rate of internal fixation were also detected in the two groups.Results:All the patients were followed up for 9-60 months [(30.0±14.5)months]. There was no significant difference in the operation duration between the two groups ( P>0.05). The intraoperative blood loss, length of hospital stay and time to weight-bearing in the screw fixation group were 10.0(10.0, 20.0)ml, 7.0(5.0, 8.0)days and (5.0±0.8)weeks, which were significantly less or shorter than 30.0(20.0, 50.0)ml, 8.0(6.0, 11.0)days and (6.9±0.7)weeks in the plate fixation group ( P<0.05). The width, height, length, B?hler angle and Gissane angle of the calcaneus at 1 day after surgery were (43.4±4.2)mm, (46.2±4.0)mm, (81.6±5.1)mm, 27.1(20.4, 30.4)° and (113.4±10.1)° in the screw fixation group, which were all improved compared with those before surgery [(47.8±4.6)mm, (39.3±4.8)mm, (79.2±5.9)mm, 9.5(0.0,16.5)° and (119.3±13.4)°] ( P<0.01). The width, height, length and B?hler angle of the calcaneus at 1 day after surgery were (41.6±5.7)mm, (48.4±4.8)mm, (83.1±5.7)mm and 27.3(21.3, 31.6)° in the plate fixation group, which were all improved compared with those before surgery [(47.8±5.0)mm, (41.7±5.1)mm, (80.1±5.9)mm and 12.9(7.2,19.8)°] ( P<0.01), with no significant difference in the Gissane angle ( P>0.05). Before surgery and at 1 day postoperatively, no significant differences were found in the width, length, B?hler angle or Gissane angle of the calcaneus between the two groups ( P>0.05), while the height of the calcaneus in the screw fixation group was lower than that in the plate fixation group ( P<0.05). At 1 month after surgery and at the last follow-up, there were no significant differences in the Maryland foot and ankle function score, AOFAS ankle and hindfoot function score, and VAS score between the two groups ( P>0.05). At 3 months after surgery in the screw fixation group, the Maryland foot and ankle function score was (79.7±3.8)points, significantly higher than (74.7±2.8)points in the plate fixation group ( P<0.01); the AOFAS ankle and hindfoot function score was (77.1±5.0)points, significantly higher than (70.1±3.6)points in the plate fixation group ( P<0.01); the VAS score was 1.0(1.0, 2.0)points, significantly lower than 2.5(2.0, 3.0)points in the plate fixation group ( P<0.01). No significant difference was detected in the incidence of postoperative complications between the two groups ( P>0.05). The removal rate of internal fixation was 10% (5/52) in the screw fixation group, significantly lower than 29% (11/38) in the plate fixation group ( P<0.05). Conclusion:Compared with open reduction and plate fixation via the sinus tarsi approach, robot-assisted percutaneous reduction and screw fixation has the advantages of less intraoperative blood loss, shorter hospital stay, earlier weight-bearing exercises, better early functional recovery and pain relief, and lower internal fixation removal rate in the treatment of Sanders types II and III calcaneal fractures.

Objective:To compare the efficacy of robot-assisted percutaneous reduction and screw fixation versus open reduction and plate fixation via the sinus tarsi approach in the treatment of Sanders types II and III calcaneal fractures.Methods:A retrospective cohort study was conducted to analyze the clinical data of 82 patients (90 feet) with calcaneal fractures admitted to the Department of Orthopedic Trauma, Beijing Jishuitan Hospital, Capital Medical University from January 2020 to April 2024, including 74 males and 8 females, aged 24-87 years [(46.4±12.1)years]. According to Essex-Lopresti classification, the fractures were classified as tongue-type in 43 patients and joint-collapse-type in 47. According to Sanders classification, 69 feet were classified as type II and 21 as type III. Forty-seven patients (52 feet) were treated with robot-assisted percutaneous reduction and screw fixation (screw fixation group) and 35 (38 feet) with open reduction and plate fixation via the sinus tarsi approach (plate fixation group). The two groups were compared in terms of the operation duration, intraoperative blood loss, length of hospital stay and time to weight-bearing. The width, height, length, B?hler angle and Gissane angle of the calcaneus before surgery and at 1 day after surgery were compared. The Maryland foot and ankle function score, American Orthopedic Foot and Ankle Society (AOFAS) ankle and hindfoot function score, and visual analogue scale (VAS) score at 1, 3 months postoperatively, and at the last follow-up were compared. The incidence of postoperative complications and removal rate of internal fixation were also detected in the two groups.Results:All the patients were followed up for 9-60 months [(30.0±14.5)months]. There was no significant difference in the operation duration between the two groups ( P>0.05). The intraoperative blood loss, length of hospital stay and time to weight-bearing in the screw fixation group were 10.0(10.0, 20.0)ml, 7.0(5.0, 8.0)days and (5.0±0.8)weeks, which were significantly less or shorter than 30.0(20.0, 50.0)ml, 8.0(6.0, 11.0)days and (6.9±0.7)weeks in the plate fixation group ( P<0.05). The width, height, length, B?hler angle and Gissane angle of the calcaneus at 1 day after surgery were (43.4±4.2)mm, (46.2±4.0)mm, (81.6±5.1)mm, 27.1(20.4, 30.4)° and (113.4±10.1)° in the screw fixation group, which were all improved compared with those before surgery [(47.8±4.6)mm, (39.3±4.8)mm, (79.2±5.9)mm, 9.5(0.0,16.5)° and (119.3±13.4)°] ( P<0.01). The width, height, length and B?hler angle of the calcaneus at 1 day after surgery were (41.6±5.7)mm, (48.4±4.8)mm, (83.1±5.7)mm and 27.3(21.3, 31.6)° in the plate fixation group, which were all improved compared with those before surgery [(47.8±5.0)mm, (41.7±5.1)mm, (80.1±5.9)mm and 12.9(7.2,19.8)°] ( P<0.01), with no significant difference in the Gissane angle ( P>0.05). Before surgery and at 1 day postoperatively, no significant differences were found in the width, length, B?hler angle or Gissane angle of the calcaneus between the two groups ( P>0.05), while the height of the calcaneus in the screw fixation group was lower than that in the plate fixation group ( P<0.05). At 1 month after surgery and at the last follow-up, there were no significant differences in the Maryland foot and ankle function score, AOFAS ankle and hindfoot function score, and VAS score between the two groups ( P>0.05). At 3 months after surgery in the screw fixation group, the Maryland foot and ankle function score was (79.7±3.8)points, significantly higher than (74.7±2.8)points in the plate fixation group ( P<0.01); the AOFAS ankle and hindfoot function score was (77.1±5.0)points, significantly higher than (70.1±3.6)points in the plate fixation group ( P<0.01); the VAS score was 1.0(1.0, 2.0)points, significantly lower than 2.5(2.0, 3.0)points in the plate fixation group ( P<0.01). No significant difference was detected in the incidence of postoperative complications between the two groups ( P>0.05). The removal rate of internal fixation was 10% (5/52) in the screw fixation group, significantly lower than 29% (11/38) in the plate fixation group ( P<0.05). Conclusion:Compared with open reduction and plate fixation via the sinus tarsi approach, robot-assisted percutaneous reduction and screw fixation has the advantages of less intraoperative blood loss, shorter hospital stay, earlier weight-bearing exercises, better early functional recovery and pain relief, and lower internal fixation removal rate in the treatment of Sanders types II and III calcaneal fractures.

Objective To establish a fluoroscopic percutaneous vertebral augmentation model in dogs by measuring and analyzing canine spinal anatomy.We also assessed the effectiveness and safety of this modeling method by postoperative radiological analysis.Methods Morphological measurements were taken in six dogs,aged approximately 12～24 months,and the following parameters of the lumbar vertebrae were determined:height of the L1～L7 vertebrae,width of the vertebral base,distance from the upper edge of the intervertebral disc to the narrowest part of the vertebra,distance from the vertical line of the spinous process to the upper edge of the intervertebral disc,and vertical distance from the midpoint of the transverse process to the lower edge of the intervertebral disc.These measurements were obtained to clarify the anatomical characteristics of the canine vertebrae and determine the optimal location,direction,and depth for bone-cement injection.A percutaneous vertebral augmentation model was subsequently established in the L4,L5,and L6 vertebrae of six healthy Beagle dogs,weighing 20～25 kg.The dogs were euthanized 4 weeks post-surgery and examined radiologically.Primary observations included the surgical duration,postoperative distribution of the implanted bone cement,and integrity of the vertebral canal and anterior edge of the vertebrae.Results Anatomical observation of the canine vertebrae revealed that the vertebral height increased gradually from L1～L5 and then decreased from L5～L7.The width of the vertebral base increased consistently from L1～L7.The distance from the vertical line of the spinous process to the upper edge of the intervertebral disc showed an increasing trend from L1～L7(1.9～4.0 mm).The distance between the midpoint of the base of the transverse process and the lower edge of the intervertebral disc increased gradually from L1～L5(4.7～6.9 mm).There was no significant difference in the distance between the midpoint of the base of the transverse process and the lower edge of the intervertebral disc in the L4,L5,and L6 segments among the dogs(P=0.925).The midpoint of the root of the transverse process of the spine was taken as the puncture point,and the insertion direction and horizontal plane were at an angle of 20°～30°,with a head tilt of 5°～15° and a puncture depth of 1.2～1.5 cm.If the puncture was directed towards the caudal side of the vertebra,the angle of the needle tail was 30°～35°,with a penetration depth of 1.5～1.8 cm.This technique allowed the successful construction of a canine vertebral puncture surgical model.A total of 15 canine vertebral puncture surgical models were successfully created,with an average surgery time of 22.7±4.6 min(15～30 min)per vertebral segment.During surgery,one vertebral segment experienced spinal cord injury result ing in paralysis of the hind limbs and bowel and bladder incontinence.Two vertebral cortical bones fractured,but there were no deaths due to anesthesia or infection.Four weeks post-surgery,micro-computed tomography-based three-dimensional reconstructions consistently showed bone cement distributed within the trabecular bone of the canine vertebrae,with newly formed bone tissue enveloping the implanted material.There was no leakage,and no complications such as damage to the vertebral canal or the anterior wall of the vertebrae.Conclusions A safe and reliable canine vertebral augmentation puncture model can be successfully established based on the anatomy of the canine lumbar vertebrae(L4～L6)and using the midpoint of the base of the transverse process as a bony landmark.

BACKGROUND:Hydroxyapatite is the main inorganic component of bone tissue.The polymer has the structure and function of a biomimetic extracellular matrix.The composites of hydroxyapatite and polymer have been widely studied. OBJECTIVE:To summarize the research status of hydroxyapatite composite polymer materials for bone tissue repair. METHODS:The articles collected in PubMed,Web of Science,CNKI and WanFang databases were searched from January 2010 to April 2023.The Chinese and English search terms were"hydroxyapatite,polymer,composites,degradability,bone defect,bone repair".Finally,75 articles were included for review. RESULTS AND CONCLUSION:Polymers often used in composite with hydroxyapatite for bone tissue repair include natural polymers(collagen,chitosan,alginate,serine protein,cellulose,hyaluronic acid,and polyhydroxybutyrate)and synthetic polymers[polylactic acid,polylactic acid-hydroxyacetic acid copolymer,poly(has-lactide),poly(amino acid)and poly(vinyl alcohol)].The mechanical properties and osteoinductivity of hydroxyapatite/polymer composites were improved compared with pure hydroxyapatite.Hydroxyapatite composite with polymers can be made into porous scaffolds,hydrogels,and coatings for bone repair.Hydroxyapatite/polymer composites can accelerate bone reconstruction with a slow release of loaded drugs and cytokines due to their bionic extracellular matrix structure and function.Based on the diversity of causes of bone defects and the fact that bone repair is a complex continuous process involving multiple biological factors and proteins,repair materials with mechanical properties matching bone tissue,degradation processes synchronized with bone repair,and efficient osteogenesis and vascularization need to be further investigated.

Immunoscenescence plays a key role in the initiation and development of tumors. Furthermore, immunoscenescence also impacts drug delivery and cancer therapeutic efficacy. To reduce the impact of immunosenescence on anti-tumor therapy, this experimental plan aimed to use neutrophils with tumor tropism properties to deliver sialic acid (SA)-modified liposomes into the tumor, kill tumor cells via SA-mediated photochemotherapy, enhance infiltration of neutrophils into the tumor, induce immunogenic death of tumor cells with chemotherapy, enhance infiltration of CD8⁺ T cells into the tumor-draining lymph nodes and tumors of immunosenescent mice, and achieve SA-mediated photochemotherapy. We found that CD8⁺ T cell and neutrophil levels in 16-month-old mice were significantly lower than those in 2- and 8-month-old mice; 16-month-old mice exhibited immunosenescence. The anti-tumor efficacy of SA-mediated non-photochemotherapy declined in 16-month-old mice, and tumors recurred after scabbing. SA-mediated photochemotherapy enhanced tumor infiltration by CD8⁺ T cells and neutrophils, induced crusting and regression of tumors in 8-month-old mice, inhibited metastasis and recurrence of tumors and eliminated the immunosenescence-induced decline in antitumor therapeutic efficacy in 16-month-old mice via the light-heat-chemical-immunity conversion.

Objective: To analyze the clinical characteristics of cases of novel coronavirus pneumonia and a preliminary study to explore the relationship between different clinical classification and liver damage. Methods: Consecutively confirmed novel coronavirus infection cases admitted to seven designated hospitals during January 23, 2020 to February 8, 2020 were included. Clinical classification (mild, moderate, severe, and critical) was carried out according to the diagnosis and treatment program of novel coronavirus pneumonia (Trial Fifth Edition) issued by the National Health Commission. The research data were analyzed using SPSS19.0 statistical software. Quantitative data were expressed as median (interquartile range), and qualitative data were expressed as frequency and rate. Results: 32 confirmed cases that met the inclusion criteria were included. 28 cases were of mild or moderate type (87.50%), and four cases (12.50%) of severe or critical type. Four cases (12.5%) were combined with one underlying disease (bronchial asthma, coronary heart disease, malignant tumor, chronic kidney disease), and one case (3.13%) was simultaneously combined with high blood pressure and malignant tumor. The results of laboratory examination showed that the alanine aminotransferase (ALT), aspartate aminotransferase (AST), albumin (ALB), and total bilirubin (TBil) for entire cohort were 26.98 (16.88 ~ 46.09) U/L and 24.75 (18.71 ~ 31.79) U/L, 39.00 (36.20 ~ 44.20) g/L and 16.40 (11.34- ~ 21.15) mmol/L, respectively. ALT, AST, ALB and TBil of the mild or moderate subgroups were 22.75 (16.31- ~ 37.25) U/L, 23.63 (18.71 ~ 26.50) U/L, 39.70 (36.50 ~ 46.10) g/L, and 15.95 (11.34 ~ 20.83) mmol/L, respectively. ALT, AST, ALB and TBil of the severe or critical subgroups were 60.25 (40.88 ~ 68.90) U/L, 37.00 (20.88 ~ 64.45) U/L, 35.75 (28.68 ~ 42.00) g/L, and 20.50 (11.28 ~ 25.00) mmol/L, respectively. Conclusion The results of this multicenter retrospective study suggests that novel coronavirus pneumonia combined with liver damage is more likely to be caused by adverse drug reactions and systemic inflammation in severe patients receiving medical treatment. Therefore, liver function monitoring and evaluation should be strengthened during the treatment of such patients.

Objective To evaluate the effect of simulated training on in-service physicians electrocardiogram(ecg) theory and operational learning effect.Methods Sixty resident doctors were randomly divided into experiment group (n=30) and control group(n=30).The experimental group adopted teaching + simulation training mode to implement the theory and operation of ECG in continuing while the control group were taught only by lectures.Training effect of both groups was assessed by electrocardiogram theory and operation examination before and after training respectively,and by questionnaires at the end of the training as well.Data of the examination and questionnaires were analyzed by t test or x2 test.P＜0.05 was considered statistically significant.Results After training,the score of theory examination was (90.87 ± 6.67) points in experiment group and was (85.83 ± 5.5) points in control group,with statistical difference between these two groups(t=3.201,P=0.003).Score of operation examination was(93.40 ± 4.31) points in experiment group and was(77.03 ± 7.96)points in control group,with significant differences(t=10.204,P=0.000).The satisfaction degree of enhancing learning interest,theoretical knowledge and operation skill,and strengthening the concept of humauistic care were significantly better in the experiment group than in the control group (x2=34.737,6.405,42.088,41.713,P=0.000,0.011,0.000,0.000).Conclusions Application of simulated training in the study of electrocardiogram is obviously superior in effect to the traditional teaching model.It can improve the theoretical knowledge and operation skill,which is helpful in elevating the in-service physicians' comprehensive capability.

Objective To examine the application effect of intelligent simulator(SimMan) in comprehensive skill training among doctors and nurses.Methods Totally 168 doctors and nurses were chosen as the training object,6 people (4 doctors and 2 nurses) formed a work team.Comprehensive training course was in accordance with 2010 American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care science.Real clinical situation was designed by using the third generation SimMan of Norway laerdal company.Trainees were administered two tests before and after training,in which there were two parts containing specialized operation ability and non-technical ability.Overall qualification rate,average mark and treatment time of qualified teams were compared before and after the training.SPSS 16.0 software was used to analyze the data and P ＜0.05 signifies statistically significance.Results Overall qualification rate,average mark and treatment time of qualified teams were 71.43％,(84.70 ± 3.15),and (449.25 ± 77.0) s respectively before training while 100％,(93.55 ± 3.86) and (323.71 ± 42.26) s after training.There were significant differences in results of two groups before and after training (P =0.002,0.000,0.000).Conclusions Application of the third generation intelligent simulator (SimMan) in comprehensive training will obviously improve training effectiveness and cultivate the non-technical ability.

Objective To explore the feasibility and short-term efficacy of laparoscopic and thoracoscopic Ivor Lewis esophagectomy using a circular-stapled anastomosis with trans-oral anvil in treating esophageal carcinoma.Methods 30 consecutive patients with esophageal cancer received minimally invasive Ivor Lewis esophagectomy from January 2011 to December 2011.Operations of all the cases comprised of both abdominal and thoracic procedures which were performed with Iaparoscopic and thoracoscopic techniques respectively.The intrathoracic esophago-gastric anastomosis was created using a circular-stapled anastomosis with trans-oral anvil technique.Results There were 24 males and 6 female with median age of 62.5-year-old (from 47 to 82).The lesions located in middle and/or lower portion of the esophagus.25 patients with esophageal squamous cell cancer (n =25) and 5 patients with adenocarcinoma (n =5) underwent an Ivor Lewis esophagectomy.All the operations were successfully performed without intra-operative technical failures of the anastomosis or deaths.The mean operation time was 95 minutes in abdomen and 177 minutes in thorax.The mean blood loss was 310 ml.The mean number of harvested lymph nodes was 10.6 from thorax and 4.9 from abdomen.Postoperalively,there were thoracic wound infections in 4 patients.One patient had a left diaphragmatic hernia and was successfully treated by re-operation 6 days after first operation.One patient had chylothorax and recovered without surgery.There was no anastomotic leak and the patients were able to have spoon meat at 5.6 postoperative days.Conclusion Laparoscopic and thoracoscopic Ivor Lewis esophagectomy can be accomplished smoothly with acceptable occurrence of complications.The circular-stapled anastomosis with the trans-oral anvil is an efficient,safe and reproducible technique for intrathoracic esophago-gastric anastomosis.

Objective To compare the number of lymph node dissected by intraoperative lymphatic mapping guided D2 gastrectomy and that by standard D2 gastrectomy plus lymphadenectomy in patients of advanced gastric cancer. Methods In this study 20 advanced gastric cancer cases received intraoperative peritumor injection of carbon nanoparticles suspension ( group 1 ) and D2 lymphadenectomy was guided by the black-stained lymph nodes. 21 cases undergoing standard D2 lymphadenectomy served as controls (group 2). The number of lymph nodes removed and the condition of lymphatic metastasis in two groups, blackstained lymph nodes in group 1, and postoperative complications were compared. Results The average lymph nodes dissected in group 1 (35. 1 ± 13.4) were higher than in control group (26.2 ±7.8). The differences were statistically significant (t =2. 126, P =0. 034). The number of removed N2 and N3 lymph nodes in group 1 were more than that in control group. The total black-stained ration of lymph nodes was 52. 7% in group 1. The positive rate of lymph nodes was higher in black-stained lymph nodes (27.6%) than in unstained lymph nodes ( 10. 8% ) in group 1 and in control group ( 16. 9% ). The differences were also statistically significant ( x2 = 6. 034, P = 0. 016; x2 = 5. 142, P = 0. 023 ). Postoperative afferent loop obstruction developed in one case in group 1. Conclusions Lymphatic mapping guided D2 radical gastrectomy plus lymphadenectomy increases the number of lymph nodes dessected and improves the efficiency of positive lymph nodes excision for patients of advanced gastric cancer.