BACKGROUND:The previous study of the research group confirmed that Bushen Zhuangjin Decoction can regulate bone metabolism and play an anti-osteoporosis role,and nanocrystalline collagen-based bone can assist in the repair of limb bone defects.OBJECTIVE:To explore the repair effect of nanocrystalline collagen-based bone combined with Bushen Zhuangjin Decoction on osteoporotic bone defects.METHODS:Totally 84 female SD rats were randomly divided into a sham operation group(n=6,no modeling)and a bilateral ovariectomy group(n=78).After 12 weeks of bilateral ovariectomy,the sham operation group(n=6)and the bilateral ovariectomy group(n=6)were selected for osteoporosis modeling verification.The remaining 72 rats in the bilateral ovariectomy group were randomly divided into 6 intervention groups,with 12 rats in each group:groups A-E had femoral defect models(diameter 3.5 mm,depth 4 mm)established 12 weeks after bilateral ovariectomy.Group A was given double distilled water by gavage(once a day)after surgery;group B was given Bushen Zhuangjin Decoction by gavage(once a day)after surgery;group C had nanocrystalline collagen-based bone filled in the bone defect and then given double distilled water by gavage(once a day);group D had nanocrystalline collagen-based bone filled in the bone defect and then given alendronate sodium by gavage(once a week);group E had nanocrystalline collagen-based bone filled in the bone defect and then given Bushen Zhuangjin Decoction by gavage(once a day);group F had femoral defect models established at the same time after bilateral ovariectomy,and bone defect sites were filled with nanocrystalline collagen-based bone and then given Bushen Zhuangjin Decoction by gavage(once a day).All drugs were given continuously for 12 weeks.12 hours after the last administration,serum levels of type Ⅰ procollagen amino-terminal propeptide,type Ⅰ collagen cross-linked C-terminal peptide,and estradiol were detected;bone volume in the bone defect area was detected by Micro-CT.The expression of type Ⅰ collagen and vascular endothelial growth factor in the bone defect area was detected by immunohistochemical staining.RESULTS AND CONCLUSION:(1)Compared with group A,the serum level of type Ⅰ procollagen amino-terminal propeptide in groups D and E was decreased(P＜0.05).Compared with groups A and C,the serum estradiol level in groups D,E,and F was increased(P＜0.05).There was no significant difference in the bone volume in the defect area between groups A-F(P＞0.05).(2)Immunohistochemical staining showed that compared with group A,the expression of typeⅠ collagen and vascular endothelial growth factor in groups B,D,and E increased(P＜0.05).Compared with group C,the expression of type Ⅰ collagen in groups B,D,E,and F increased(P＜0.05),and the expression of vascular endothelial growth factor in groups D,E,and F increased(P＜0.05).(3)The results show that nanocrystalline collagen-based bone combined with Bushen Zhuangjin Decoction may have the potential to repair bone defects in ovariectomized osteoporotic rats.

BACKGROUND:Clinical studies suggest that both bone quality and excessive crown-to-implant ratio are factors that affect the success rate of implant surgery,but there is no consensus on how large the crown-to-implant ratio under each bone quality will affect the prognosis of implant repair.OBJECTIVE:To analyze the stress and strain of bone tissue around implant restorations with different crown-to-implant ratios under different bone types after stress loading using three-dimensional finite element method.Combined with the Frost bone mechanics regulation system theory,the physiological limits of bone strain were observed for each bone type within a certain range of crown to implant ratios.METHODS:Cone beam CT data were selected from a patient to establish solid bone block models with four different bone types(class Ⅰ bone:cortical bone thickness 3 mm+dense cancellous bone,class Ⅱ bone:cortical bone thickness 2 mm+relatively dense cancellous bone,class Ⅲ bone:cortical bone thickness 1 mm+relatively low-density cancellous bone,class Ⅳ bone:cortical bone thickness 1 mm+low-density cancellous bone).Implant restorations with five different crown-to-implant ratios(1,1.5,2,2.5,and 3)were created on each bone block model,for a total of 20 models.Vertical and oblique forces were applied to the dental crown to observe the von Mises stress values,strains,and displacement of the cortical and cancellous bones,as well as the degree of implant displacement.RESULTS AND CONCLUSION:(1)In the class Ⅰ bone model,when the crown-to-implant ratio reached 3 under oblique loading,the cortical bone strain exceeded the physiological limit.In the class Ⅱ bone model,under oblique loading,when the crown-to-implant ratio reached 2.5,the cortical bone strain exceeded the physiological limit.In the class Ⅲ bone model,under oblique loading,cortical bone exceeded the physiological limit when the crown-to-implant ratio reached 2.5,while cancellous bone reached the critical physiological limit at 1.In the class Ⅳ bone model,under oblique loading,when the crown-to-implant ratio reached 1.5,2,2.5,and 3,the cortical bone strain exceeded the physiological limit.In the class Ⅳ bone model,all five crown-to-implant ratios of cancellous bone exceeded physiological limits.(2)Under vertical load,the cancellous bone strain exceeded the physiological limit when the crown-root ratio reached 1,2,2.5,and 3 in the class Ⅲ bone model,and when the cancellous bone strain of the five crown-root ratios in the class Ⅳ bone model exceeded the physiological limit.(3)Under oblique or vertical load,the implant displacement of the 20 groups of models did not exceed 100 μm.(4)From the perspective of biomechanics,when patients with insufficient bone height choose implant restoration,the crown-root ratio that class Ⅰ bone can tolerate is up to 2.5 times,the crown-root ratio that class Ⅱ bone can tolerate is up to 2 times,and the crown-root ratio that class Ⅲ and class Ⅳ bones can tolerate is up to 1 times due to excessive strain of cancellous bone;but the crown-root ratio that cortical bone in class Ⅲ bone can tolerate is up to 2 times.Whether class Ⅲ bone can tolerate implant restoration with a high crown-root ratio and whether cancellous bone can tolerate higher strains needs further study.

BACKGROUND:In 2019,the modified cortical bone trajectory technique was proposed by our team,significantly improving traditional methods.Previous studies have highlighted its superior biomechanical properties for segment fixation.However,a comprehensive systematic analysis of its specific biomechanical effects on adjacent segment degeneration is lacking,particularly regarding its influence on range of motion and intervertebral disc stress in posterior lumbar interbody fusion and transforaminal lumbar interbody fusion techniques.OBJECTIVE:To investigate the biomechanical effects of modified cortical bone trajectory screw techniques on adjacent segment degeneration in posterior lumbar interbody fusion and transforaminal lumbar interbody fusion.METHODS:CT scans were performed on three human cadaver specimens to establish and validate three-dimensional intact finite element models of the L1-S1 segment.For each of these,the posterior lumbar interbody fusion or transforaminal lumbar interbody fusion with three different fixation techniques was reconstructed at the L4-L5 segment.The L4-L5 segment was fixed using three different internal fixation techniques(modified cortical bone trajectory,cortical bone trajectory,and traditional pedicle screws).The range of motion and von Mises stress of the intervertebral disc of the L3-L4 and L5-S1 segments were recorded with a 400 N compressive load and 7.5 N moments in flexion,extension,left-right bending,and left-right rotation.The impacts of the three internal fixation techniques on adjacent segment degeneration in the two kinds of fusion were compared and analyzed.RESULTS AND CONCLUSION:(1)In the posterior lumbar interbody fusion model,the modified cortical bone trajectory screw group showed a reduced range of motion on adjacent segments(L3-L4,L5-S1)under six loading conditions compared to both the cortical bone trajectory screw group and traditional bone trajectory screw group.Specifically,the modified cortical bone trajectory screw group significantly reduced the maximum stress on the intervertebral disc in the superior adjacent segment(L3-L4)during extension compared to the traditional bone trajectory screw group(P=0.005),while the stress on the intervertebral disc in the inferior adjacent segment(L5-S1)exhibited greater dispersion.Similarly,the cortical bone trajectory screw group also significantly reduced the maximum stress on the intervertebral disc in the superior adjacent segment(L3-L4)during extension compared with the traditional bone trajectory screw group(P=0.03).(2)Compared with transforaminal lumbar interbody fusion,the three internal fixation techniques(modified cortical bone trajectory,cortical bone trajectory,and traditional pedicle screws)showed a trend of reduced range of motion in the inferior adjacent segment(L5-S1)under six loading conditions.In contrast,the maximum stress on the intervertebral discs in both the superior and inferior adjacent segments(L3-L4,L5-S1)exhibited an increasing trend in the posterior lumbar interbody fusion model.(3)It is concluded that in the posterior lumbar interbody fusion model,the modified cortical bone trajectory screw exhibited superior biomechanical properties in reducing the range of motion at adjacent segments,which may have a beneficial effect on reducing the risk of adjacent segment degeneration.

BACKGROUND:The previous study of the research group confirmed that Bushen Zhuangjin Decoction can regulate bone metabolism and play an anti-osteoporosis role,and nanocrystalline collagen-based bone can assist in the repair of limb bone defects.OBJECTIVE:To explore the repair effect of nanocrystalline collagen-based bone combined with Bushen Zhuangjin Decoction on osteoporotic bone defects.METHODS:Totally 84 female SD rats were randomly divided into a sham operation group(n=6,no modeling)and a bilateral ovariectomy group(n=78).After 12 weeks of bilateral ovariectomy,the sham operation group(n=6)and the bilateral ovariectomy group(n=6)were selected for osteoporosis modeling verification.The remaining 72 rats in the bilateral ovariectomy group were randomly divided into 6 intervention groups,with 12 rats in each group:groups A-E had femoral defect models(diameter 3.5 mm,depth 4 mm)established 12 weeks after bilateral ovariectomy.Group A was given double distilled water by gavage(once a day)after surgery;group B was given Bushen Zhuangjin Decoction by gavage(once a day)after surgery;group C had nanocrystalline collagen-based bone filled in the bone defect and then given double distilled water by gavage(once a day);group D had nanocrystalline collagen-based bone filled in the bone defect and then given alendronate sodium by gavage(once a week);group E had nanocrystalline collagen-based bone filled in the bone defect and then given Bushen Zhuangjin Decoction by gavage(once a day);group F had femoral defect models established at the same time after bilateral ovariectomy,and bone defect sites were filled with nanocrystalline collagen-based bone and then given Bushen Zhuangjin Decoction by gavage(once a day).All drugs were given continuously for 12 weeks.12 hours after the last administration,serum levels of type Ⅰ procollagen amino-terminal propeptide,type Ⅰ collagen cross-linked C-terminal peptide,and estradiol were detected;bone volume in the bone defect area was detected by Micro-CT.The expression of type Ⅰ collagen and vascular endothelial growth factor in the bone defect area was detected by immunohistochemical staining.RESULTS AND CONCLUSION:(1)Compared with group A,the serum level of type Ⅰ procollagen amino-terminal propeptide in groups D and E was decreased(P＜0.05).Compared with groups A and C,the serum estradiol level in groups D,E,and F was increased(P＜0.05).There was no significant difference in the bone volume in the defect area between groups A-F(P＞0.05).(2)Immunohistochemical staining showed that compared with group A,the expression of typeⅠ collagen and vascular endothelial growth factor in groups B,D,and E increased(P＜0.05).Compared with group C,the expression of type Ⅰ collagen in groups B,D,E,and F increased(P＜0.05),and the expression of vascular endothelial growth factor in groups D,E,and F increased(P＜0.05).(3)The results show that nanocrystalline collagen-based bone combined with Bushen Zhuangjin Decoction may have the potential to repair bone defects in ovariectomized osteoporotic rats.

BACKGROUND:Clinical studies suggest that both bone quality and excessive crown-to-implant ratio are factors that affect the success rate of implant surgery,but there is no consensus on how large the crown-to-implant ratio under each bone quality will affect the prognosis of implant repair.OBJECTIVE:To analyze the stress and strain of bone tissue around implant restorations with different crown-to-implant ratios under different bone types after stress loading using three-dimensional finite element method.Combined with the Frost bone mechanics regulation system theory,the physiological limits of bone strain were observed for each bone type within a certain range of crown to implant ratios.METHODS:Cone beam CT data were selected from a patient to establish solid bone block models with four different bone types(class Ⅰ bone:cortical bone thickness 3 mm+dense cancellous bone,class Ⅱ bone:cortical bone thickness 2 mm+relatively dense cancellous bone,class Ⅲ bone:cortical bone thickness 1 mm+relatively low-density cancellous bone,class Ⅳ bone:cortical bone thickness 1 mm+low-density cancellous bone).Implant restorations with five different crown-to-implant ratios(1,1.5,2,2.5,and 3)were created on each bone block model,for a total of 20 models.Vertical and oblique forces were applied to the dental crown to observe the von Mises stress values,strains,and displacement of the cortical and cancellous bones,as well as the degree of implant displacement.RESULTS AND CONCLUSION:(1)In the class Ⅰ bone model,when the crown-to-implant ratio reached 3 under oblique loading,the cortical bone strain exceeded the physiological limit.In the class Ⅱ bone model,under oblique loading,when the crown-to-implant ratio reached 2.5,the cortical bone strain exceeded the physiological limit.In the class Ⅲ bone model,under oblique loading,cortical bone exceeded the physiological limit when the crown-to-implant ratio reached 2.5,while cancellous bone reached the critical physiological limit at 1.In the class Ⅳ bone model,under oblique loading,when the crown-to-implant ratio reached 1.5,2,2.5,and 3,the cortical bone strain exceeded the physiological limit.In the class Ⅳ bone model,all five crown-to-implant ratios of cancellous bone exceeded physiological limits.(2)Under vertical load,the cancellous bone strain exceeded the physiological limit when the crown-root ratio reached 1,2,2.5,and 3 in the class Ⅲ bone model,and when the cancellous bone strain of the five crown-root ratios in the class Ⅳ bone model exceeded the physiological limit.(3)Under oblique or vertical load,the implant displacement of the 20 groups of models did not exceed 100 μm.(4)From the perspective of biomechanics,when patients with insufficient bone height choose implant restoration,the crown-root ratio that class Ⅰ bone can tolerate is up to 2.5 times,the crown-root ratio that class Ⅱ bone can tolerate is up to 2 times,and the crown-root ratio that class Ⅲ and class Ⅳ bones can tolerate is up to 1 times due to excessive strain of cancellous bone;but the crown-root ratio that cortical bone in class Ⅲ bone can tolerate is up to 2 times.Whether class Ⅲ bone can tolerate implant restoration with a high crown-root ratio and whether cancellous bone can tolerate higher strains needs further study.

BACKGROUND:In 2019,the modified cortical bone trajectory technique was proposed by our team,significantly improving traditional methods.Previous studies have highlighted its superior biomechanical properties for segment fixation.However,a comprehensive systematic analysis of its specific biomechanical effects on adjacent segment degeneration is lacking,particularly regarding its influence on range of motion and intervertebral disc stress in posterior lumbar interbody fusion and transforaminal lumbar interbody fusion techniques.OBJECTIVE:To investigate the biomechanical effects of modified cortical bone trajectory screw techniques on adjacent segment degeneration in posterior lumbar interbody fusion and transforaminal lumbar interbody fusion.METHODS:CT scans were performed on three human cadaver specimens to establish and validate three-dimensional intact finite element models of the L1-S1 segment.For each of these,the posterior lumbar interbody fusion or transforaminal lumbar interbody fusion with three different fixation techniques was reconstructed at the L4-L5 segment.The L4-L5 segment was fixed using three different internal fixation techniques(modified cortical bone trajectory,cortical bone trajectory,and traditional pedicle screws).The range of motion and von Mises stress of the intervertebral disc of the L3-L4 and L5-S1 segments were recorded with a 400 N compressive load and 7.5 N moments in flexion,extension,left-right bending,and left-right rotation.The impacts of the three internal fixation techniques on adjacent segment degeneration in the two kinds of fusion were compared and analyzed.RESULTS AND CONCLUSION:(1)In the posterior lumbar interbody fusion model,the modified cortical bone trajectory screw group showed a reduced range of motion on adjacent segments(L3-L4,L5-S1)under six loading conditions compared to both the cortical bone trajectory screw group and traditional bone trajectory screw group.Specifically,the modified cortical bone trajectory screw group significantly reduced the maximum stress on the intervertebral disc in the superior adjacent segment(L3-L4)during extension compared to the traditional bone trajectory screw group(P=0.005),while the stress on the intervertebral disc in the inferior adjacent segment(L5-S1)exhibited greater dispersion.Similarly,the cortical bone trajectory screw group also significantly reduced the maximum stress on the intervertebral disc in the superior adjacent segment(L3-L4)during extension compared with the traditional bone trajectory screw group(P=0.03).(2)Compared with transforaminal lumbar interbody fusion,the three internal fixation techniques(modified cortical bone trajectory,cortical bone trajectory,and traditional pedicle screws)showed a trend of reduced range of motion in the inferior adjacent segment(L5-S1)under six loading conditions.In contrast,the maximum stress on the intervertebral discs in both the superior and inferior adjacent segments(L3-L4,L5-S1)exhibited an increasing trend in the posterior lumbar interbody fusion model.(3)It is concluded that in the posterior lumbar interbody fusion model,the modified cortical bone trajectory screw exhibited superior biomechanical properties in reducing the range of motion at adjacent segments,which may have a beneficial effect on reducing the risk of adjacent segment degeneration.

ObjectiveTo measure the distance from the surface of Fengfu （GV 16） to the deep important bony structures in children aged 4 to 8 years based on CT three-dimensional reconstruction technology， thereby providing imaging reference data for clinical acupuncture safe operations in terms of different age groups and needle insertion angles. MethodsCervical CT image data were collected from healthy children aged 4 to 8 years with five age groups （4-， 5-， 6-， 7-， 8-year-old groups）， 20 cases in each group. The images were imported into Mimics 21.0 software for three-dimensional reconstruction. The straight-line distances from the skin model surface of the Fengfu （GV 16） to the first underlying bony barrier （such as the lower edge of the occipital bone， the posterior arch of the atlas vertebra） were measured at intervals of 5° on both the transverse section （0° ± 35°） and the sagittal section （40° upward to 40° downward on the diagonal）. The correlation between the measured distance， age， and angle was analyzed. ResultsIn the transverse and sagittal sections， the measured distance from the skin surface to the underlying bone of Fengfu （GV 16） at each angle increased with age. In the transverse section， the increase was relatively small within the 0° to 20° angle range， whereas a more pronounced increase was observed when the angle exceeded 20°； at measurement angles of 30° to 35°， the distance of the skin surface to the bone at Fengfu （GV 16） in the 7- and 8-year-old groups was significantly greater than that in the 4-year-old group （P＜0.05）. In the sagittal section， the measured distance from the skin surface to the bone at Fengfu （GV 16） was shortest and changed greatly at oblique upward angles of 15° to 40° within each age group， and increased markedly at near-vertical angles of 0° to 10°； it was longest at oblique downward angles of -40° to -5° and showed relatively gradual changes. ConclusionThis study obtained the imaging distance data from Fengfu （GV 16） to the surrounding bony structures in children aged 4 to 8 years through three-dimensional modeling， finding that this distance has clear age and angle dependence， which can provide quantitative evidence for developing individualized and precise safe acupuncture schemes at Fengfu （GV 16） in pediatric clinical practice.

ObjectiveTo measure the distance from the surface of Fengfu （GV 16） to the deep important bony structures in children aged 4 to 8 years based on CT three-dimensional reconstruction technology， thereby providing imaging reference data for clinical acupuncture safe operations in terms of different age groups and needle insertion angles. MethodsCervical CT image data were collected from healthy children aged 4 to 8 years with five age groups （4-， 5-， 6-， 7-， 8-year-old groups）， 20 cases in each group. The images were imported into Mimics 21.0 software for three-dimensional reconstruction. The straight-line distances from the skin model surface of the Fengfu （GV 16） to the first underlying bony barrier （such as the lower edge of the occipital bone， the posterior arch of the atlas vertebra） were measured at intervals of 5° on both the transverse section （0° ± 35°） and the sagittal section （40° upward to 40° downward on the diagonal）. The correlation between the measured distance， age， and angle was analyzed. ResultsIn the transverse and sagittal sections， the measured distance from the skin surface to the underlying bone of Fengfu （GV 16） at each angle increased with age. In the transverse section， the increase was relatively small within the 0° to 20° angle range， whereas a more pronounced increase was observed when the angle exceeded 20°； at measurement angles of 30° to 35°， the distance of the skin surface to the bone at Fengfu （GV 16） in the 7- and 8-year-old groups was significantly greater than that in the 4-year-old group （P＜0.05）. In the sagittal section， the measured distance from the skin surface to the bone at Fengfu （GV 16） was shortest and changed greatly at oblique upward angles of 15° to 40° within each age group， and increased markedly at near-vertical angles of 0° to 10°； it was longest at oblique downward angles of -40° to -5° and showed relatively gradual changes. ConclusionThis study obtained the imaging distance data from Fengfu （GV 16） to the surrounding bony structures in children aged 4 to 8 years through three-dimensional modeling， finding that this distance has clear age and angle dependence， which can provide quantitative evidence for developing individualized and precise safe acupuncture schemes at Fengfu （GV 16） in pediatric clinical practice.

Objective To establish the method of thin layer chromatography （TLC） for identification and content quantitative determination of Shugantongluo capsules, and provide methodological reference for the quality control of Shugantongluo capsules. Methods Bupleuriradix, polygala tenuifolia yuanzhi, and acorus tatarinowii rhizoma were identified by TLC qualitatively. The content of Saikosaponin-a was determined by HPLC method. The chromatography was performed on Venusil XBP C₁₈（L） （4.6 mm×150 mm, 5 μm） with a stable temperature of 30℃. The mobile phase in isocratic elution consisted of acetonitrile-water （40∶60, V/V） at the flow rate of 1.0 ml/min with an injection volume of 20 μl. The detection wavelength was set at 210 nm. Results Clear spots were obtained with good separation in TLC identification which was highly specific. The Saikosaponin-a at the range of 25.00-500.0 μg/ml was linear with peak area （r=0.999 9）, the average recovery rate was 97.00%, and RSD was 2.60%. Conclusion These methods was easy to operate with accurate results, with good specificity and reproducibility, which could be uesd for the quality control for Shugantongluo capsules.

Background and Aims:Complete situs inversus(SIT)is a rare congenital abnormality of organ mirror-image arrangement,presenting certain challenges for abdominal surgical procedures.The Da Vinci robotic system,with its high-definition 3D vision and flexible operation,holds potential for application in patients with anatomical variations.This report presents the diagnosis and treatment process of a patient with rectal mass and SIT who underwent robotic-assisted surgery.Additionally,relevant literature is reviewed to provide insights for individualized surgical strategies in patients with complex anatomical variations and to promote the further clinical application of robotic-assisted surgery systems.Methods:A case from the First Affiliated Hospital of Zhengzhou University is reported,in which a patient with rectal mass and SIT successfully underwent lesion resection using the Da Vinci robotic system with an unconventional"five-port"technique.A systematic literature review was also conducted(including 35 case reports),to summarize the surgical characteristics of colorectal procedures in SIT patients and the advantages of robotic system application.Results:The patient was a 74-year-old male who presented with rectal bleeding.Imaging confirmed the diagnosis of SIT,and colonoscopy revealed a large polypoid mass with ulceration at the apex,located 13-18 cm from the anal verge.The patient subsequently underwent Da Vinci robotic-assisted resection of the rectal lesion.The robotic system effectively overcame the challenges posed by mirror-image anatomy,enabling complete excision of the lesion.The operation lasted 183 minutes,with intraoperative blood loss of less than 20 mL.Postoperative pathology confirmed a villous tubular adenoma with high-grade intraepithelial neoplasia.The patient had an uneventful recovery,and no recurrence was observed during the 9-month follow-up.Literature analysis demonstrated that the robotic system,through magnified 3D visualization,flexible instrument articulation,and tremor filtration,significantly improves surgical precision in patients with anatomical anomalies.Conclusion:The Da Vinci robotic system effectively addresses the challenges of anatomical variations related to SIT in low rectal surgery.Its stability and precision offer a new technical option for tumor resection under complex anatomical conditions,demonstrating clinical value for widespread application.