Osteoporotic bone defect (OBD) is a serious bone defect resulting from the disruption of the bone structural integrity due to fractures in osteoporotic conditions. OBD not only leads to increased risk of fractures, delayed bone healing, functional loss, and chronic pain, but also reduces patients′ quality of life and even elevates the risk of death. Currently, OBD is primarily treated with systemic medications and local bone grafting. However, drug therapy is often associated with serious side effects, low bioavailability and poor bone targeting performance, while bone grafting is limited by high infection rate in donor areas, scarce bone source and severe immune rejection. Therefore, there is an urgent need for new bone repair materials to improve the bone microenvironment and stimulate bone regeneration. Bioactive molecules have shown great potential in modulating OBD treatment, but their application in organisms is hindered by their low bioavailability and short half-life. Hydrogels have emerged as an ideal vehicle to address these limitations by prolonging the retention time and half-life of bioactive molecules at the site of injury, reducing side effects and promoting cell adhesion under physiological conditions. All these advantages promote osteoblast proliferation and differentiation, providing a promising solution for OBD treatment. However, hydrogels still face challenges such as uncontrolled degradation rate, inadequate mechanical properties and poor osseointegration ability. To this end, the authors systematically elucidated the challenges of hydrogels in OBD treatment and proposed countermeasures, aiming to provide a reference for the research and clinical application of hydrogels.

Objective:To compare the efficacy of robot system-assisted versus freehand screw revision for ankylosing spondylitis (AS) with lower cervical fractures.Methods:A multicenter retrospective cohort study was conducted to analyze the clinical data of 57 patients with AS combined with lower cervical fractures admitted to Honghui Hospital Affiliated to Xi'an Jiaotong University School of Medicine, Henan Provincial People's Hospital, Zhengzhou Orthopedic Hospital, and Qilu Hospital of Shandong University, including 46 males and 11 females, aged 38-77 years [(65.4±9.5)years]. Injury segments involved C 3 in 7 patients, C 4 in 13, C 5 in 25, C 6 in 10, and C 7 in 2. All the patients underwent revision surgery, among whom, 22 patients were treated with robot system-assisted cervical pedicle screw placement (robot nailing group, with 190 screws), and 35 with freehand cervical pedicle screw placement (freehand nailing group, with 300 screws). The operative duration, intraoperative bleeding volume, frequency of intraoperative fluoroscopy, incision length, and length of hospital stay of the two groups were compared; the time of single nscrew insertion, the number of single nail revisions, the distance between screws and the anterior cortex, the accuracy of screw placement of grade 0 and grade 0+1 were recorded in the two groups. The visual analogue scale (VAS), Japanese Orthopedic Society (JOA) score, neck dysfunction index (NDI), American Spine Injury Association (ASIA) classification before operation, at 3 days, 3 months after operation and at the last follow-up were compared between the two groups. The complication rate was also noted. Results:All the patients were followed up for 12-16 months [(14.3±2.1)months]. The operative duration, intraoperative bleeding volume, and frequency of intraoperative fluoroscopy were (186.4±12.9)minutes, (486.1±68.6)ml, and (3.4±1.3)times in the robot nailing group, which were shorter or less than (206.7±14.4)minutes, (660.3±45.2)ml, and (13.5±3.6)times in the freehand nailing group ( P<0.01). The incision length was (9.4±2.4)cm in the robot nailing group, longer than (5.6±1.2)cm in the freehand nailing group ( P<0.01), and the length of hospital stay was (3.7±0.4)days, shorter than (4.4±1.4)days in the freehand nailing group ( P<0.01). The length of single nail insertion, the number of single nail revision, and the distance between the screws and the front cortex were (6.5±0.4)minutes, (1.1±0.1)times, and (3.5±1.3)mm in the robot nailing group, which were shorter or less than (11.6±0.2)minutes, (1.5±0.2)times, and (12.4±4.7)mm in the freehand nailing group ( P<0.01). The accuracy of the screw placement in the robot nailing group was 90.0% (171/190) and 95.8% (182/190) with level 0 and 0+1 screws, better than 80.0% (240/300) and 89.0% (267/300) in the freehand nailing group ( P<0.05). There was no significant difference in VAS, JOA score, NDI, or ASIA grading between the two groups before operation ( P>0.05). The VAS, JOA, and NDI scores at 3 days after operation were (3.1±0.6)points, (12.1±1.2)points, and (15.6±2.9)points, respectively in the robot nailing group, which were better than (5.0±1.4)points, (11.3±1.1)points and (22.5±3.7)points, respectively in the freehand nailing group ( P<0.05). No statistically significant difference was observed in the ASIA grade between the two groups at 3 days after operation ( P>0.05). There were no significant differences in VAS, JOA, NDI scores, or ASIA grading between the two groups at 3 months after operation and at the last follow-up ( P>0.05). Compared with those before operation, the VAS, JOA, NDI scores, and ASIA grading were significantly improved at 3 days, 3 months after operation and at the last follow-up in the two groups, which were further improved with the passage of time. Two patients in the robot nailing group had pneumonia, with a complication rate of 9% (2/22), while 2 patients in the freehand nailing group had dural sac rupture and cerebrospinal fluid leakage and 3 had lung infection after operation, with a complication rate of 14% (5/35) ( P<0.05). Conclusion:Compared with freehand nailing, the robot system-assisted nailing revision for AS with lower cervical fracture has more advantages in terms of the operative duration, length of hospital stay, intraoperative bleeding volume, frequency of intraoperative fluoroscopy nailing speed and accuracy, screw holding force, early pain relief, function restoration, and complication rate, despite longer surgical incision.

Objective:To compare the clinical efficacy of navigation system and orthopedic robot-assisted nail placement in the treatment of lower cervical fracture and dislocation.Methods:A retrospective cohort study was conducted to analyze the clinical data of 49 patients with fracture and dislocation of the lower cervical spine who were admitted to Honghui Hospital, Xi′an Jiaotong University School of Medicine from May 2021 to October 2022, including 38 males and 11 females, aged 29-61 years [(39.3±7.3)years]. Injury segments involved C 3 in 12 patients, C 4 in 11, C 5 in 8, C 6 in 9 and C 7 in 9. Twenty-one patients were treated with S8 navigation system (navigation group, 84 screws), and 28 with TINAVI orthopedic robot (robot group, 112 screws). The two groups were compared in terms of the total surgical duration, single screw placement time, total screw placement time, distance between the screw and the anterior cortex, incision length, intraoperative radiation dose, intraoperative blood loss and length of hospital stay. The height of intervertebral space, Cobb angle, sliding distance between vertebral bodies and American Spinal Injury Association (ASIA) grade were assessed before surgery and at 3 days after surgery. Visual analogue scale (VAS), Japanese Orthopedic Association (JOA) score and neck dysfunction index (NDI) before surgery, at 3 days, 3 months after surgery and at the last follow-up were compared. The accuracy of screw placement, intraoperative invasion rate of adjacent facet joints and rate of postoperative complications (infection, screw loosening, etc.) were evaluated. Results:All the patients were followed up for 12-16 months [(13.6±1.9)months]. In the navigation group, the total surgical duration, distance from the screw to the anterior cortex and the intraoperative radiation dose were (236.2±30.6)minutes, (2.0±0.2)mm and (374.3±90.3)mGy respectively, which were significantly shorter or less than those in the robot group [(278.4±20.7)minutes, (10.6±2.9)mm and (448.4±77.9)mGy] ( P<0.01). The single screw placement time, total screw placement time, incision length and intraoperative blood loss were (3.5±0.4)minutes, (23.9±0.5)minutes, (9.1±2.4)cm and (422.2±30.4)ml respectively, which were significantly longer or more than those in the robot group [(2.6±0.2)minutes, (17.9±0.7)minutes, (6.6±2.6)cm and (360.3±56.3)ml] ( P<0.01). There was no significant difference in the length of hospital stay between the two groups ( P>0.05). No significant differences were observed in the height of the intervertebral space, Cobb angle, sliding distance between the vertebral bodies and ASIA grade between the two groups ( P>0.05). At 3 days after surgery, the height of intervertebral space, Cobb angle, sliding distance between vertebral bodies and ASIA grade in both groups were significantly improved when compared with those before surgery ( P<0.05 or 0.01). There were no significant differences in VAS, JOA scores or NDI between the two groups before surgery, at 3 days, 3 months after surgery and at the last follow-up ( P>0.05). The VAS, JOA scores and NDI in both groups were gradually improved at 3 days, 3 months and at the last follow-up after surgery when compared with those before surgery ( P<0.05). There was no significant difference in the accuracy of screw placement of levels 0 and 0+1 between the two groups ( P>0.05). No significant difference in the intraoperative invasion rate of adjacent facet joints between the two groups was found ( P>0.05). There were no serious complications such as infection or screw loosening after surgery in both groups. Conclusions:For lower cervical fracture and dislocation, although there are more advantages in total surgical duration, screw holding force and radiation control regarding the navigation system, and more outstanding performance in screw placement efficiency, incision length and intraoperative blood loss regarding the orthopedic robot, both of them can effectively rebuild the cervical structure, improve neurological function, relieve postoperative pain, improve screw placement accuracy and reduce facet joint injury and serious complications. Selection of the best auxiliary screw placement system should comprehensively consider patients′ conditions and the experience of the surgical team.

Osteoporotic bone defect (OBD) is a serious bone defect resulting from the disruption of the bone structural integrity due to fractures in osteoporotic conditions. OBD not only leads to increased risk of fractures, delayed bone healing, functional loss, and chronic pain, but also reduces patients′ quality of life and even elevates the risk of death. Currently, OBD is primarily treated with systemic medications and local bone grafting. However, drug therapy is often associated with serious side effects, low bioavailability and poor bone targeting performance, while bone grafting is limited by high infection rate in donor areas, scarce bone source and severe immune rejection. Therefore, there is an urgent need for new bone repair materials to improve the bone microenvironment and stimulate bone regeneration. Bioactive molecules have shown great potential in modulating OBD treatment, but their application in organisms is hindered by their low bioavailability and short half-life. Hydrogels have emerged as an ideal vehicle to address these limitations by prolonging the retention time and half-life of bioactive molecules at the site of injury, reducing side effects and promoting cell adhesion under physiological conditions. All these advantages promote osteoblast proliferation and differentiation, providing a promising solution for OBD treatment. However, hydrogels still face challenges such as uncontrolled degradation rate, inadequate mechanical properties and poor osseointegration ability. To this end, the authors systematically elucidated the challenges of hydrogels in OBD treatment and proposed countermeasures, aiming to provide a reference for the research and clinical application of hydrogels.

Objective:To compare the efficacy of robot system-assisted versus freehand screw revision for ankylosing spondylitis (AS) with lower cervical fractures.Methods:A multicenter retrospective cohort study was conducted to analyze the clinical data of 57 patients with AS combined with lower cervical fractures admitted to Honghui Hospital Affiliated to Xi'an Jiaotong University School of Medicine, Henan Provincial People's Hospital, Zhengzhou Orthopedic Hospital, and Qilu Hospital of Shandong University, including 46 males and 11 females, aged 38-77 years [(65.4±9.5)years]. Injury segments involved C 3 in 7 patients, C 4 in 13, C 5 in 25, C 6 in 10, and C 7 in 2. All the patients underwent revision surgery, among whom, 22 patients were treated with robot system-assisted cervical pedicle screw placement (robot nailing group, with 190 screws), and 35 with freehand cervical pedicle screw placement (freehand nailing group, with 300 screws). The operative duration, intraoperative bleeding volume, frequency of intraoperative fluoroscopy, incision length, and length of hospital stay of the two groups were compared; the time of single nscrew insertion, the number of single nail revisions, the distance between screws and the anterior cortex, the accuracy of screw placement of grade 0 and grade 0+1 were recorded in the two groups. The visual analogue scale (VAS), Japanese Orthopedic Society (JOA) score, neck dysfunction index (NDI), American Spine Injury Association (ASIA) classification before operation, at 3 days, 3 months after operation and at the last follow-up were compared between the two groups. The complication rate was also noted. Results:All the patients were followed up for 12-16 months [(14.3±2.1)months]. The operative duration, intraoperative bleeding volume, and frequency of intraoperative fluoroscopy were (186.4±12.9)minutes, (486.1±68.6)ml, and (3.4±1.3)times in the robot nailing group, which were shorter or less than (206.7±14.4)minutes, (660.3±45.2)ml, and (13.5±3.6)times in the freehand nailing group ( P<0.01). The incision length was (9.4±2.4)cm in the robot nailing group, longer than (5.6±1.2)cm in the freehand nailing group ( P<0.01), and the length of hospital stay was (3.7±0.4)days, shorter than (4.4±1.4)days in the freehand nailing group ( P<0.01). The length of single nail insertion, the number of single nail revision, and the distance between the screws and the front cortex were (6.5±0.4)minutes, (1.1±0.1)times, and (3.5±1.3)mm in the robot nailing group, which were shorter or less than (11.6±0.2)minutes, (1.5±0.2)times, and (12.4±4.7)mm in the freehand nailing group ( P<0.01). The accuracy of the screw placement in the robot nailing group was 90.0% (171/190) and 95.8% (182/190) with level 0 and 0+1 screws, better than 80.0% (240/300) and 89.0% (267/300) in the freehand nailing group ( P<0.05). There was no significant difference in VAS, JOA score, NDI, or ASIA grading between the two groups before operation ( P>0.05). The VAS, JOA, and NDI scores at 3 days after operation were (3.1±0.6)points, (12.1±1.2)points, and (15.6±2.9)points, respectively in the robot nailing group, which were better than (5.0±1.4)points, (11.3±1.1)points and (22.5±3.7)points, respectively in the freehand nailing group ( P<0.05). No statistically significant difference was observed in the ASIA grade between the two groups at 3 days after operation ( P>0.05). There were no significant differences in VAS, JOA, NDI scores, or ASIA grading between the two groups at 3 months after operation and at the last follow-up ( P>0.05). Compared with those before operation, the VAS, JOA, NDI scores, and ASIA grading were significantly improved at 3 days, 3 months after operation and at the last follow-up in the two groups, which were further improved with the passage of time. Two patients in the robot nailing group had pneumonia, with a complication rate of 9% (2/22), while 2 patients in the freehand nailing group had dural sac rupture and cerebrospinal fluid leakage and 3 had lung infection after operation, with a complication rate of 14% (5/35) ( P<0.05). Conclusion:Compared with freehand nailing, the robot system-assisted nailing revision for AS with lower cervical fracture has more advantages in terms of the operative duration, length of hospital stay, intraoperative bleeding volume, frequency of intraoperative fluoroscopy nailing speed and accuracy, screw holding force, early pain relief, function restoration, and complication rate, despite longer surgical incision.

Objective:To compare the clinical efficacy of navigation system and orthopedic robot-assisted nail placement in the treatment of lower cervical fracture and dislocation.Methods:A retrospective cohort study was conducted to analyze the clinical data of 49 patients with fracture and dislocation of the lower cervical spine who were admitted to Honghui Hospital, Xi′an Jiaotong University School of Medicine from May 2021 to October 2022, including 38 males and 11 females, aged 29-61 years [(39.3±7.3)years]. Injury segments involved C 3 in 12 patients, C 4 in 11, C 5 in 8, C 6 in 9 and C 7 in 9. Twenty-one patients were treated with S8 navigation system (navigation group, 84 screws), and 28 with TINAVI orthopedic robot (robot group, 112 screws). The two groups were compared in terms of the total surgical duration, single screw placement time, total screw placement time, distance between the screw and the anterior cortex, incision length, intraoperative radiation dose, intraoperative blood loss and length of hospital stay. The height of intervertebral space, Cobb angle, sliding distance between vertebral bodies and American Spinal Injury Association (ASIA) grade were assessed before surgery and at 3 days after surgery. Visual analogue scale (VAS), Japanese Orthopedic Association (JOA) score and neck dysfunction index (NDI) before surgery, at 3 days, 3 months after surgery and at the last follow-up were compared. The accuracy of screw placement, intraoperative invasion rate of adjacent facet joints and rate of postoperative complications (infection, screw loosening, etc.) were evaluated. Results:All the patients were followed up for 12-16 months [(13.6±1.9)months]. In the navigation group, the total surgical duration, distance from the screw to the anterior cortex and the intraoperative radiation dose were (236.2±30.6)minutes, (2.0±0.2)mm and (374.3±90.3)mGy respectively, which were significantly shorter or less than those in the robot group [(278.4±20.7)minutes, (10.6±2.9)mm and (448.4±77.9)mGy] ( P<0.01). The single screw placement time, total screw placement time, incision length and intraoperative blood loss were (3.5±0.4)minutes, (23.9±0.5)minutes, (9.1±2.4)cm and (422.2±30.4)ml respectively, which were significantly longer or more than those in the robot group [(2.6±0.2)minutes, (17.9±0.7)minutes, (6.6±2.6)cm and (360.3±56.3)ml] ( P<0.01). There was no significant difference in the length of hospital stay between the two groups ( P>0.05). No significant differences were observed in the height of the intervertebral space, Cobb angle, sliding distance between the vertebral bodies and ASIA grade between the two groups ( P>0.05). At 3 days after surgery, the height of intervertebral space, Cobb angle, sliding distance between vertebral bodies and ASIA grade in both groups were significantly improved when compared with those before surgery ( P<0.05 or 0.01). There were no significant differences in VAS, JOA scores or NDI between the two groups before surgery, at 3 days, 3 months after surgery and at the last follow-up ( P>0.05). The VAS, JOA scores and NDI in both groups were gradually improved at 3 days, 3 months and at the last follow-up after surgery when compared with those before surgery ( P<0.05). There was no significant difference in the accuracy of screw placement of levels 0 and 0+1 between the two groups ( P>0.05). No significant difference in the intraoperative invasion rate of adjacent facet joints between the two groups was found ( P>0.05). There were no serious complications such as infection or screw loosening after surgery in both groups. Conclusions:For lower cervical fracture and dislocation, although there are more advantages in total surgical duration, screw holding force and radiation control regarding the navigation system, and more outstanding performance in screw placement efficiency, incision length and intraoperative blood loss regarding the orthopedic robot, both of them can effectively rebuild the cervical structure, improve neurological function, relieve postoperative pain, improve screw placement accuracy and reduce facet joint injury and serious complications. Selection of the best auxiliary screw placement system should comprehensively consider patients′ conditions and the experience of the surgical team.

Objective:To compare the efficacy of percutaneous vertebroplasty (PVP) under enhanced regional and conventional anesthesia for multisegmental acute symptomatic osteoporotic thoracolumbar fractures (m-ASOTLF).Methods:A retrospective cohort study was conducted to analyze the data of 91 patients with m-ASOTLF who were admitted to Honghui Hospital of Xi′an Jiaotong University from January 2021 to December 2022, including 36 males and 55 females, aged 55-80 years [(67.4±7.3)years]. According to American Society of Anesthesiologists (ASA) classification system, 18 patients were classified as grade I, 52 grade II, and 21 grade III. Injured segments included T 6-T 10 in 23 patients, T 11-L 2 in 47 and L 3-L 5 in 21. All the patients were treated with PVP, among whom 45 were given enhanced regional anesthesia (enhanced anesthesia group) and 46 regional conventional anesthesia (conventional anesthesia group). The following indicators were compared between the two groups: the operation time, intraoperative bleeding, intraoperative heart rate, intraoperative mean arterial pressure (MAP), number of intraoperative fluoroscopies, and total amount of bone cement injected; the visual analogue scale (VAS) and Oswestry dysfunction index (ODI) before surgery, at 1 day, 1 month after surgery and at the last follow-up; the mini-mental state examination (MMSE) before surgery, at 1, 6, and 12 hours after surgery; the anterior vertebrae height (AVH), middle vertebrae height (MVH), and vertebral kyphosis angle (VKA) before and at 1 day after surgery; the incidence of complications such as bone cement leakage. Results:All the patients were followed up for 12-20 months [(15.8±2.6)months]. There were no significant differences between the two groups in the operation time, intraoperative bleeding, intraoperative heart rate, intraoperative MAP, number of intraoperative fluoroscopies or total amount of bone cement injected ( P>0.05). No significant differences were found between the two groups in VAS or ODI before surgery and at the last follow-up ( P>0.05). The VAS scores in the enhanced anesthesia group were (2.5±0.4)points and (1.8±0.3)points at 1 day and 1 month postoperatively respectively, which were both lower than (3.5±0.4)points and (2.0±0.5)points in the conventional anesthesia group ( P<0.01). The ODI values in the enhanced anesthesia group were 39.8±3.3 and 26.5±5.0 at 1 day and 1 month postoperatively respectively, which were both lower than 43.8±7.5 and 30.3±6.4 in the conventional anesthesia group ( P<0.01). The VAS and ODI at all postoperative time points decreased in both groups compared with those before surgery, with significant differences among those at all postoperative time points ( P<0.05). There was no significant difference between the two groups in the MMSE scores before, at 1, 6, and 12 hours after surgery ( P>0.05). The MMSE scores at 1 and 6 hours postoperatively were lower than that preoperatively in both groups ( P<0.05), and it was increased at 6 hours compared with that at 1 hour postoperatively ( P<0.05). There was no significant difference between the MMSE scores at 12 hours postoperatively and preoperatively in both groups ( P>0.05). The differences between the two groups in AVH, MVH, or VKA preoperatively were not statistically significant ( P>0.05). The AVH and MVH at 1 day postoperatively in the enhanced anesthesia group were (22.4±4.2)mm and (22.7±3.7)mm respectively, which were both higher than those in the conventional anesthesia group [(19.3±3.7)mm and (20.1±6.3)mm] ( P<0.05 or 0.01); the VKA at 1 day postoperatively in the enhanced anesthesia group was (13.9±3.7)°, which was lower than that in the conventional anesthesia group (15.8±4.1)° ( P<0.05). The AVH, MVH, and VKA in both groups were all improved at 1 day postoperatively compared with those preoperatively ( P<0.05). The incidence of bone cement leakage in the enhanced anesthesia group was 6.7% (3/45), which was lower than 21.7% (10/46) in the conventional anesthesia group ( P<0.05). Conclusion:Compared with conventional regional anesthesia, PVP under enhanced regional anesthesia for m-ASOTLF has more advantages in early postoperative pain relief, improvement of spinal function, restoration of vertebral height and reduction of bone cement leakage.

Cervical spinal cord injury without fracture-dislocation (CSCIWFD) in adults is a condition in which the cervical spinal cord is injured by an external force to the cervical spine, but the cervical spine itself is not fractured or dislocated on X-ray films or CT. Since CSCIWFD is caused by a second-strike injury to the body, with a compression formed by spinal cord edema and ligamentous hematoma, signs of neurological function impairment that may not appear until several days after the injury which often cause incomplete or complete paralysis, thus resulting in chronic pain and loss of work. Inadequate treatment in the early stages of injury can exacerbate delayed neurological deficits, seriously offecting the patients' quality of life and life expectancy. Currently, there are problems related to the diagnosis and treatment of CSCIWFD, such as the of clinical manifestations varying severity, complex mechanism of injury, high rates of missed diagnosis and misdiagnosis, and controversial treatment methods. Besides, standardized diagnostic and treatment regimens, multimodal diagnostic approach, and individualized treatment plans should be adopted to improve the diagnostic accuracy and therapeutic effects and maximize the prognosis of patients. In this regard, the authors discussed the clinical characteristics and key issues requiring urgent attention in the diagnosis and treatment of CSCIWFD to provide a reference for clinical diagnosis and treatment.

In order to establish a stable in vitro culture platform for chicken small intestine three-dimensional (3D) organoids, in this study, crypt cells were collected from the small intestine of 18-day-old embryos of AA broilers. On the basis of the L-WRN conditioned medium, we optimized the culture conditions of chicken small intestinal organoids by adjusting the proportions of nicotinamide, N-acetylcysteine, LY2157299, CHIR99021, Jagged-1, FGF, and other cytokines to select the medium suitable for the long-term stable growth of the organoids. The optimization results showed that the addition of 1.5 µmol/L CHIR99021 significantly improved the organoid formation efficiency and organoid diameter. When 0.5 µmol/L Jagged-1 was added, a small amount of bud-like tissue appeared in organoids. After the addition of 50 ng/mL FGF-2, the rate of organoid germination was significantly increased. The 1.5 µmol/L CHIR99021, 0.5 µmol/L Jagged-1, and 50 ng/mL FGF-2 added in the medium can cooperate with each other to improve the formation and speed up the proliferation and differentiation of organoids, while improving the stemness maintenance of cells. The morphology, cell types, and culture characteristics of chicken small intestinal organoids were studied by HE staining, transmission electron microscopy, reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR), indirect immunofluorescence, and immunohistochemistry. The results showed that the 3D organoids of the chicken small intestine cultured in vitro were morphologically consistent with the chicken intestinal tissue and contained differentiated epithelial cells. In summary, we successfully established an in vitro culture system for chicken small intestinal organoids, providing a new method for the subsequent research on chicken intestinal physiology, pathology, and host-pathogen interaction mechanism and the development of relevant drugs.
Animals ; Organoids/metabolism* ; Intestine, Small/drug effects* ; Chickens ; Cell Culture Techniques/methods* ; Culture Media ; Chick Embryo ; Tissue Culture Techniques/methods*

Objectives:To analyze the risk factors for prolonged length of stay(LOS)after lesion removal and bone graft fusion internal fixation in patients with spinal tuberculosis,and to develop and validate a predictive model.Methods:The clinical data of 152 patients with spinal tuberculosis who underwent lesion removal and bone grafting and fusion internal fixation at Honghui Hospital affiliated to Xi'an Jiaotong Univer-sity from February 2016 to December 2020 were retrospectively analyzed.The patients were divided into the prolonged LOS(PLOS)group and normal LOS(NLOS)group according to whether their postoperative LOS ex-ceeded the postoperative LOS of the 75th percentile of the overall study cohort.Univariate analyses were per-formed for gender,age,hypertension,diabetes,paraplegia,anticoagulation history,tuberculosis resistance,pre-operative anti-tuberculosis time,blood transfusion,surgical site,surgical approach,number of fused vertebrae,operative time,intraoperative blood loss(IBL),postoperative complications,blood transfusion cost,hospital cost,C-reactive protein(CRP),erythrocyte sedimentation rate(ESR),albumin(ALB),blood routine,and coagulation function in both groups.Based on Lasso regression,the risk factors significantly associated with postoperative LOS prolongation in spinal tuberculosis were selected and incorporated into a multivariate logistic regression analysis,and thereby a prediction model was established based on the results of multivariate logistic regres-sion analysis.The model was visualized by plotting a nomogram as a means of predicting the probability of risk for prolongation of LOS after spinal tuberculosis surgery.Internal validation of the model was performed using extended Bootstrap,where receiver operating characteristic(ROC)curves,calibration curves and decision curve analysis(DCA)were plotted to verify the discrimination,accuracy and clinical applicability.Results:The 152 patients enrolled in the study had a median LOS of 10d,and the 75%LOS was 14d.There were 96 patients in the PLOS group and 56 in the NLOS group.Univariate analysis showed that the differences in age,hypertension,diabetes,anticoagulation history,tuberculosis resistance,preoperative anti-tuberculosis time,surgical site,surgical approach,surgical time,IBL,postoperative complications,CRP,ESR,preoperative ALB,blood routine,and coagulation function were not statistically significant between the two groups(P＞0.05),while the differences in gender,paraplegia,blood transfusion,number of fused vertebrae,blood transfusion cost,and hospitalization cost were statistically significant(P＜0.05).The operative time,IBL,preoperative Hb,and preop-erative ALB were divided according to the Yoden index of ROC as the dividing point,and the cut-off value of operative time was 198(min),the cut-off value of IBL was 1000(mL),the cut-off value of preoperative Hb was 118(g/L),and the cut-off value of preoperative ALB was 38.8(g/L).Through Lasso regression model,the risk factors closely related to the prolongation of LOS after spinal tuberculosis were female,blood transfusion,the number of fused vertebrae≥3,operative time≥198min and IBL≥1000mL,preoperative Hb＜118g/L and preoperative ALB＜38.8g/L.Multivariate logistic regression analysis showed that female,number of fused ver-tebrae≥3,operative time≥198min and IBL≥1000mL were the risk factors for postoperative LOS prolongation in patients with spinal tuberculosis(P＜0.05).A visual nomogram model for logistic regression was constructed,and the predictors included female,number of fused vertebrae,operative time,and IBL.A Bootstrap self-sampling of 1,000 times was performed to complete the internal validation of the model,with a C-index value of 0.882 and an area under the curve(AUC)of ROC of 0.884(95%CI:0.782 to 0.985).The calibration curve showed that the apparent curve of the model fitted well with the curve after deviation correction.The DCA curve showed that the threshold range of 0.2 to 0.9 had the greatest clinical benefit.Conclusions:Female,number of fused vertebrae≥3,operative time≥198min and IBL≥1000mL are the main risk factors for pro-longed LOS after lesion removal and bone graft fusion with internal fixation in patients with spinal tuberculo-sis,and the predictive model based on the above risk factors can help physicians to make clinical decisions and optimize the perioperative management.