BACKGROUND:The development of calcium phosphate bone cement is limited due to its poor mechanical properties and weak osteogenic ability.Silicate bioactive glass is highly favored due to its excellent biological activity and osteogenic ability.Simultaneously,fiber structures can enhance the mechanical strength of materials.OBJECTIVE:To investigate the mechanical properties,biocompatibility,and osteogenic effect of silicate bioactive glass fiber composite calcium phosphate bone cement.METHODS:Different mass percentages(0％,10％,and 20％)of silicate bioactive glass fiber were added to the solid phase of calcium phosphate bone cement,mixed with the liquid phase and cured for 48 hours to obtain silicate bioactive glass fiber composite calcium phosphate bone cement.The mechanical properties,setting time,and ion precipitation of the cement were characterized.The three groups of bone cement extracts were co-cultured with MC3T3-E1 cells.The cell compatibility of the materials was evaluated by CCK-8 assay,live/dead staining,and phalloidin staining.After osteogenic induction,the osteogenic induction ability of the materials was evaluated by alkaline phosphatase staining,alizarin red staining,RUNX2 immunofluorescence staining,and RT-PCR.RESULTS AND CONCLUSION:(1)With the increase of silicate bioactive glass fiber content,the compressive strength and flexural strength of bone cement increased,and the setting time was prolonged.When bone cement was immersed in simulated body fluid,the precipitation of silicon ions,calcium ions,and phosphorus ions could be detected.Moreover,with the increase of silicate bioactive glass fiber content,the mass concentration of silicon ions and phosphorus ions released by bone cement increased,and the mass concentration of calcium ions decreased.(2)Live/dead staining and phalloidin staining results exhibited that silicate bioactive glass fiber composite calcium phosphate bone cement had no toxic effect on MC3T3-E1 cells.CCK-8 assay results showed that silicate bioactive glass fiber composite calcium phosphate bone cement could promote the proliferation of MC3T3-E1 cells.(3)With the increase of silicate bioactive glass fiber content in bone cement,the alkaline phosphatase activity and extracellular calcium deposition of MC3T3-E1 cells increased,the expression of RUNX2 protein increased,and the expression of alkaline phosphatase,osteocalcin,osteopontin,and RUNX2 mRNA expression increased.(4)The results indicate that silicate bioactive glass fibers can enhance the mechanical properties and osteogenic induction ability of calcium phosphate bone cement,among which 20％silicate bioactive glass fibers have a more obvious effect.

Objective:To analyze the clinical efficacy and learning curve for robot-assisted cortical bone trajectory (CBT) screw fixation performed by surgeons with different seniority in the treatment of lumbar degenerative disease.Methods:The clinical data of 91 lumbar degenerative disease patients underwent robot-assisted CBT screw fixation from August 2020 to December 2022 in Beijing Shijitan Hospital, Capital Medical University were retrospectively analyzed. Among them, 48 patients underwent surgery performed by the same senior surgeon (senior group), with a total of 234 CBT screws were placed; while 43 patients underwent surgery performed by the same junior surgeon (junior group), with a total of 206 CBT screws were placed. The surgical related indexes, functional improvement score, lower back pain and lower limb radiation pain scores, acceptable nail insertion rate, non invasion rate of facet joints and incidence of postoperative complications were compared between two groups. The functional improvement score was evaluated using the Japanese Orthopaedic Association (JOA) score, the pain score was evaluated using visual analog score (VAS). The cumulative sum (CUSUM) method was used to depict the learning curve with "single screw placement time" as the observation index.Results:There were no statistical difference in incision length, operation time, intraoperative blood loss and postoperative hospital stay between two groups ( P>0.05). The least squares means of JOA scores 1, 3 and 6 months after surgery in both groups increased significantly compared to baseline, while the least squares means of lower back pain VAS and lower limb radiation pain VAS decreased significantly compared to baseline; there were no statistical differences between two groups ( P>0.05). There were no statistical difference in acceptable nail insertion rate, non invasion rate of facet joints and incidence of postoperative complications between two group ( P>0.05). The CUSUM learning curves were fitting well and the inflection point for senior surgeon corresponded to 18 cases, while it was reached after performing surgery on 21 cases for junior surgeon. Conclusions:Robot-assisted CBT screw fixation performed by surgeons with different seniority could achieve similar clinical outcomes for treating lumbar degenerative disease. The senior surgeons are able to complete the initial learning stage faster than the junior surgeons, but there is not much difference in the number of surgeries performed the learning curve.

Objective:To compare the effectiveness and safety between robot-assisted percutaneous kyphoplasty (PKP) and traditional fluoroscopy-assisted PKP in the treatment of dual-segment recurrent osteoporotic vertebral compression fracture (OVCF) including in situ vertebral fracture.Methods:The clinical data of 33 patients with dual-segment recurrent OVCF including in situ vertebral fracture from January 2016 to January 2023 in Beijing Shijitan Hospital Affiliated to Capital Medical University were retrospectively analyzed. All the patients were treated with PKP. Among them, 14 patients were treated with robot-assisted surgery (robot-assisted group), and 19 patients were treated with fluoroscopy-assisted surgery (fluoroscopy-assisted group). The total surgical time, preparation time and number of fluoroscopy were recorded. The in situ and other fracture vertebral operation time, number of punctures, amount of bone cement injection, bone cement filling effect, bone cement leakage, pedicle wall breakthrough and other special intraoperative situations were separately recorded. The visual analogue score (VAS) before surgery and 1 d, 3 months after surgery was recorded.Results:The preparation time in robot-assisted group was significantly longer than that in fluoroscopy-assisted group: (30.8 ± 6.9) min vs. (19.1 ± 4.5) min, the number of fluoroscopy was significantly lower than that in fluoroscopy-assisted group: (17.1 ± 4.1) times vs. (41.0 ± 6.3) times, and there were statistical differences ( P<0.01 and <0.05); there were no statistical differences in total surgical time and VAS at any time point between the two groups ( P>0.05). For the in situ fracture segment, the operation time and number of punctures in robot-assisted group were significantly lower than those in fluoroscopy-assisted group: (15.4 ± 2.8) min vs. (22.0 ± 5.5) min and (1.1 ± 0.4) times vs. (2.4 ± 1.2) times, the amount of bone cement injection was significantly higher than those in fluoroscopy-assisted group: (2.36 ± 0.75) ml vs. (1.79 ± 0.69) ml, the filling effect of bone cement was significantly better than that in fluoroscopy-assisted group, and there were statistical differences ( P<0.01 and <0.05); there were no statistical difference in bone cement leakage and pedicle wall breakthrough between the two groups ( P>0.05). For the other fracture segment, the operation time in robot-assisted group was significantly shorter than that in fluoroscopy-assisted group: (13.8 ± 3.8) min vs. (19.2 ± 6.4) min, and there was statistical difference ( P<0.01); there were no statistical difference in number of punctures, amount of bone cement injection, filling effect of bone cement, bone cement leakage and pedicle wall breakthrough between the two groups ( P>0.05). Conclusions:Robot-assisted PKP in the treatment of dual-segment OVCF including in situ vertebral fracture, could reduce operation time, minimize punctures and fluoroscopy numbers, and provide superior bone cement filling results.

BACKGROUND:The development of calcium phosphate bone cement is limited due to its poor mechanical properties and weak osteogenic ability.Silicate bioactive glass is highly favored due to its excellent biological activity and osteogenic ability.Simultaneously,fiber structures can enhance the mechanical strength of materials.OBJECTIVE:To investigate the mechanical properties,biocompatibility,and osteogenic effect of silicate bioactive glass fiber composite calcium phosphate bone cement.METHODS:Different mass percentages(0％,10％,and 20％)of silicate bioactive glass fiber were added to the solid phase of calcium phosphate bone cement,mixed with the liquid phase and cured for 48 hours to obtain silicate bioactive glass fiber composite calcium phosphate bone cement.The mechanical properties,setting time,and ion precipitation of the cement were characterized.The three groups of bone cement extracts were co-cultured with MC3T3-E1 cells.The cell compatibility of the materials was evaluated by CCK-8 assay,live/dead staining,and phalloidin staining.After osteogenic induction,the osteogenic induction ability of the materials was evaluated by alkaline phosphatase staining,alizarin red staining,RUNX2 immunofluorescence staining,and RT-PCR.RESULTS AND CONCLUSION:(1)With the increase of silicate bioactive glass fiber content,the compressive strength and flexural strength of bone cement increased,and the setting time was prolonged.When bone cement was immersed in simulated body fluid,the precipitation of silicon ions,calcium ions,and phosphorus ions could be detected.Moreover,with the increase of silicate bioactive glass fiber content,the mass concentration of silicon ions and phosphorus ions released by bone cement increased,and the mass concentration of calcium ions decreased.(2)Live/dead staining and phalloidin staining results exhibited that silicate bioactive glass fiber composite calcium phosphate bone cement had no toxic effect on MC3T3-E1 cells.CCK-8 assay results showed that silicate bioactive glass fiber composite calcium phosphate bone cement could promote the proliferation of MC3T3-E1 cells.(3)With the increase of silicate bioactive glass fiber content in bone cement,the alkaline phosphatase activity and extracellular calcium deposition of MC3T3-E1 cells increased,the expression of RUNX2 protein increased,and the expression of alkaline phosphatase,osteocalcin,osteopontin,and RUNX2 mRNA expression increased.(4)The results indicate that silicate bioactive glass fibers can enhance the mechanical properties and osteogenic induction ability of calcium phosphate bone cement,among which 20％silicate bioactive glass fibers have a more obvious effect.

Objective:To analyze the clinical efficacy and learning curve for robot-assisted cortical bone trajectory (CBT) screw fixation performed by surgeons with different seniority in the treatment of lumbar degenerative disease.Methods:The clinical data of 91 lumbar degenerative disease patients underwent robot-assisted CBT screw fixation from August 2020 to December 2022 in Beijing Shijitan Hospital, Capital Medical University were retrospectively analyzed. Among them, 48 patients underwent surgery performed by the same senior surgeon (senior group), with a total of 234 CBT screws were placed; while 43 patients underwent surgery performed by the same junior surgeon (junior group), with a total of 206 CBT screws were placed. The surgical related indexes, functional improvement score, lower back pain and lower limb radiation pain scores, acceptable nail insertion rate, non invasion rate of facet joints and incidence of postoperative complications were compared between two groups. The functional improvement score was evaluated using the Japanese Orthopaedic Association (JOA) score, the pain score was evaluated using visual analog score (VAS). The cumulative sum (CUSUM) method was used to depict the learning curve with "single screw placement time" as the observation index.Results:There were no statistical difference in incision length, operation time, intraoperative blood loss and postoperative hospital stay between two groups ( P>0.05). The least squares means of JOA scores 1, 3 and 6 months after surgery in both groups increased significantly compared to baseline, while the least squares means of lower back pain VAS and lower limb radiation pain VAS decreased significantly compared to baseline; there were no statistical differences between two groups ( P>0.05). There were no statistical difference in acceptable nail insertion rate, non invasion rate of facet joints and incidence of postoperative complications between two group ( P>0.05). The CUSUM learning curves were fitting well and the inflection point for senior surgeon corresponded to 18 cases, while it was reached after performing surgery on 21 cases for junior surgeon. Conclusions:Robot-assisted CBT screw fixation performed by surgeons with different seniority could achieve similar clinical outcomes for treating lumbar degenerative disease. The senior surgeons are able to complete the initial learning stage faster than the junior surgeons, but there is not much difference in the number of surgeries performed the learning curve.

Objective:To compare the effectiveness and safety between robot-assisted percutaneous kyphoplasty (PKP) and traditional fluoroscopy-assisted PKP in the treatment of dual-segment recurrent osteoporotic vertebral compression fracture (OVCF) including in situ vertebral fracture.Methods:The clinical data of 33 patients with dual-segment recurrent OVCF including in situ vertebral fracture from January 2016 to January 2023 in Beijing Shijitan Hospital Affiliated to Capital Medical University were retrospectively analyzed. All the patients were treated with PKP. Among them, 14 patients were treated with robot-assisted surgery (robot-assisted group), and 19 patients were treated with fluoroscopy-assisted surgery (fluoroscopy-assisted group). The total surgical time, preparation time and number of fluoroscopy were recorded. The in situ and other fracture vertebral operation time, number of punctures, amount of bone cement injection, bone cement filling effect, bone cement leakage, pedicle wall breakthrough and other special intraoperative situations were separately recorded. The visual analogue score (VAS) before surgery and 1 d, 3 months after surgery was recorded.Results:The preparation time in robot-assisted group was significantly longer than that in fluoroscopy-assisted group: (30.8 ± 6.9) min vs. (19.1 ± 4.5) min, the number of fluoroscopy was significantly lower than that in fluoroscopy-assisted group: (17.1 ± 4.1) times vs. (41.0 ± 6.3) times, and there were statistical differences ( P<0.01 and <0.05); there were no statistical differences in total surgical time and VAS at any time point between the two groups ( P>0.05). For the in situ fracture segment, the operation time and number of punctures in robot-assisted group were significantly lower than those in fluoroscopy-assisted group: (15.4 ± 2.8) min vs. (22.0 ± 5.5) min and (1.1 ± 0.4) times vs. (2.4 ± 1.2) times, the amount of bone cement injection was significantly higher than those in fluoroscopy-assisted group: (2.36 ± 0.75) ml vs. (1.79 ± 0.69) ml, the filling effect of bone cement was significantly better than that in fluoroscopy-assisted group, and there were statistical differences ( P<0.01 and <0.05); there were no statistical difference in bone cement leakage and pedicle wall breakthrough between the two groups ( P>0.05). For the other fracture segment, the operation time in robot-assisted group was significantly shorter than that in fluoroscopy-assisted group: (13.8 ± 3.8) min vs. (19.2 ± 6.4) min, and there was statistical difference ( P<0.01); there were no statistical difference in number of punctures, amount of bone cement injection, filling effect of bone cement, bone cement leakage and pedicle wall breakthrough between the two groups ( P>0.05). Conclusions:Robot-assisted PKP in the treatment of dual-segment OVCF including in situ vertebral fracture, could reduce operation time, minimize punctures and fluoroscopy numbers, and provide superior bone cement filling results.

Objectives:To investigate the characteristics of clinical and imaging outcomes and their differ-ences between transforaminal endoscopic decompression and limited decompression and fusion surgery in the treatment of adult degenerative scoliosis(ADS).Methods:From January 2018 to January 2021,53 patients suf-fering from ADS who underwent surgery in our department were retrospectively analyzed,and they were divid-ed into either minimally invasive surgery(MIS)group(31 patients,underwent transforaminal endoscopic decom-pression)or fusion group(22 patients,underwent limited decompression and fusion surgery).The following data were comparatively analyzed:the baseline characteristics,the preoperative Lenke-Silva level,the radiographical parameters(scoliotic Cobb angle,global spinal balance parameters,and spinopelvic parameters)that measured at preoperation,before discharge,at six months after surgery,and at the final follow-up,clinical outcomes that evaluated at preoperation,before discharge,three months after surgery,six months after surgery,and the final follow-up,the incidence of surgical complications,and the reoperation rate.Results:The mean follow-up period was 15.68±3.26 months.The mean age of the patients in the MIS group was significantly higher than that in the fusion group(78.64±5.19 years vs 64.95±4.31 years,P＜0.05).In the MIS group,the majority of the patients were classified as Lenke-Silva Ⅰ and Ⅱ,and all the patients suffered from unilateral lower limb radiculopathy;In the fusion group,more patients were of Lenke-Silva Ⅱ and Ⅲ levels,and 73％of the patients suffered from unilateral lower limb radiculopathy.The preoperative scoliotic Cobb angle in the MIS group was significantly smaller than that in the fusion group(23.92°±9.06° vs 39.58°±13.12°,P＜0.05).Postop-eratively,both groups of patients showed significantly improvement in back pain,leg pain,and functional dis-ability.At the final follow-up,the scores for back pain and functional disability showed preferably improve-ment in the MIS group than those in the fusion group(P＜0.05).During the postoperative follow-up,no coronal or sagittal imbalance was observed in both groups;At the final follow-up:the mean scoliotic Cobb angle pro-gressed 1.51° in the MIS group,while the correction of scoliosis reduced 1.82° in the fusion group.The op-erative time,intraoperative blood loss,incidence of complications,and the reoperation rate in the MIS group were significantly lower than those in the fusion group(P＜0.05).Conclusions:For ADS patients without rigid imbalance,both surgical interventions are able to significantly improve clinical symptoms.The short-term fol-low-up outcomes reveal that the endoscopic decompression superiors in less scoliosis progression after opera-tion and functional improvement than limited fusion surgery.

Objectives:To compare the clinical efficacy between robot-assisted cortical bone trajectory screw(RCBTS)and robot-assisted pedicle screw(RPS)for patients with lumbar spinal stenosis(LSS)undergoing sin-gle-level decompression and fusion.Methods:In this retrospective cohort study,LSS patients who underwent robot-assisted single-level decompression and fusion in Beijing Shijitan Hospital between June 2020 and June 2022 were reviewed.A total of 99 patients were included and divided into RCBTS group of 41 patients and RPS group of 58 patients.There were 59 males and 40 females,with an average age of 67.07±4.65 years old.The incision length,operative time,intraoperative blood loss,24h postoperative drainage,and postopera-tive hospital stay were compared between groups.The Japanese Orthopaedic Association(JOA)score and visual analogue scale(VAS)of low back pain were compared at 3d,3 months and 6 months after operation,and the fixed effects of JOA score and VAS score changes were tested.The screw positions were graded according to the Gertzbein-Robbins method.The accuracy of screw placement of the two surgical methods was evaluated by reviewing the postoperative imaging data.The perioperative and postoperative 3 months of complications were compared between the two groups.Results:There were no significant differences in baseline data be-tween the two groups(P＜0.05).Comparing with the RPS group,the RCBTS group was shorter in operative time(134.39±22.23min vs 152.93±19.10min,P＜0.001),smaller in incision length(64.93±3.71mm vs 78.84±3.82mm,P＜0.001),less in intraoperative blood loss(155.61±37.15mL vs 172.41±43.22mL,P=0.001)and postoperative drainage within 24h(83.66±21.54mL vs 101.21±29.80mL,P=0.002),and shorter in postoperative hospital stay(4.90±1.26d vs 6.26±1.66d,P＜0.001),with statistical significance.There was no significant difference in JOA score and VAS score changes between the two groups at each time point(P＞0.05).The fixed effect test showed that time was a fixed effect of JOA and VAS score changes(P＜0.001).The RCBTS group was no sig-nificantly different from the RPS group in the accuracy of screw placement(grade A:152/164 vs 211/232,P=0.538;grade B:9/164 vs 15/232,P=0.688;grade C:3/164 vs 6/232,P=0.619),the rate of clinically accept-able screw placement(161/164 vs 226/232,P=0.619),the rate of bad screw placement(3/164 vs 6/232,P=0.619),and the incidence of postoperative complications(only 1 patient in the RCBTS group developed delayed wound healing)(P＞0.05).Conclusions:Compared with RPS,RCBTS has significant advantages in operative time,incision length,intraoperative blood loss,volume of postoperative drainage,and postoperative hospital stay.However,there is no significant difference between the two groups in terms of postoperative functional recovery and alleviation in low back pain.

Objective To investigate the application prospect of the most extensive genome engineering pig internationally in preclinical xenotransplantation. Methods Porcine endogenous retrovirus (PERV) knockout combined with 3 major heterologous antigen gene knockouts and 9 humanized genes for inhibition of complement activation, regulation of coagulation disorders, anti-inflammatory and anti-phagocytosis were transferred into a pig (PERV-KO/3-KO/9-TG) as a donor, and the heart, liver and kidney were obtained and transplanted to 3 Rhesus macaque recipients respectively to establish a preclinical research model of pig-to-Rhesus macaque xenotransplantation. The functional status of xenografts after blood flow reconstruction was observed and the survival of recipients was summarized. The hemodynamics of xenografts were monitored. The change of hematological indexes of each recipient was compared. The histopathological manifestation of xenografts was observed. Results After the blood flow was reconstructed, all xenografts showed ruddy color, soft texture and good perfusion. The transplant heart, liver and kidney showed full arterial and venous blood flow and good perfusion at 1 d after operation. The postoperative survival time of heart, liver, and kidney transplant recipients was 7, 26, and 1 d, respectively. The levels of creatine kinase, creatine kinase isoenzyme, and lactate dehydrogenase increased in heart transplant recipient at 1 d after operation, and gradually recovered to near normal levels at 6 d after operation. All indexes increased sharply at 7 d after operation. The level of aspartate aminotransferase increased in liver transplant recipients at 2 d after operation, and the alanine aminotransferase basically returned to normal at 10 d after operation, but the total bilirubin continued to increase. Both aspartate aminotransferase and alanine aminotransferase increased at 12 d after operation, and reached a peak at 15 d after operation. The kidney transplant recipient developed mild proteinuria at 1 d after operation, and died of sudden severe arrhythmia. Histopathology showed that the tissue structure of cardiac and renal xenografts was close to normal, and liver xenografts presented with patchy necrosis, the liver tissue structure was disordered, accompanied by inflammatory damage, interstitial hemorrhage and thrombotic microangiopathy. Conclusions PERV-KO/3-KO/9-TG pig shows advantages in overcoming hyperacute rejection, mitigating humoral rejection and coagulation dysregulation. However, whether it can be used as potential donor for clinical xenotransplantation needs further evaluation.

【Objective】 To establish a microbial limit test method for diatomite and pearlite, and verify its applicability. 【Methods】 According to the requirements of general rule 1105, Microbial Limit Test for Non Sterile Products of Pharmacopoeia of the People′s Republic of China (2020 Edition), the applicability test of microbial counting methods for three batches of perlite and diatomite was conducted before the microbial limit test of samples. The microbial growth of filter aid was analyzed and the recovery rate of each test bacterium was calculated. 【Results】 The ratio of the colony number of the test group minus the colony number of the test sample control group to the bacterial liquid control group was in the range of 0.5~2.0. 【Conclusion】 The method is accurate, reliable and can be used for microbial limit test of diatomite and perlite.