1.Yttrium-90 selective internal radiation therapy on liver cancer: the past, the present, and the future
Jingqin MA ; Linhong ZHANG ; Minjie YANG ; Jiabin CAI ; Ying FANG ; Rong LIU ; Xudong QU ; Lingxiao LIU ; Zhiping YAN
Chinese Journal of Clinical Medicine 2025;32(1):3-8
Yttrium-90 selective internal radiation therapy (90Y-SIRT) is a treatment technique that delivers radioactive microspheres precisely to the arterial vascular bed of neoplasms, utilizing beta radiation to administer a high local dose of radiation to the neoplasm tissues. This technology has demonstrated significant efficacy in patients with unresectable pirmary liver cancers and liver metastases. This article systematically reviews the development history and clinical application status of 90Y-SIRT in the treatment of liver cancer, and looks forward to future development directions.
2.Energy efficiency of contrast-enhanced ultrasound combined with TERT promoter mutation to construct a nomogram model for the prediction of concomitant cervical lymph node metastasis in PTMC
Chang-hui WU ; Zhiping HUANG ; Huiping DAI ; Huifang QIU ; Chun HE ; Fang TANG
The Journal of Practical Medicine 2025;41(5):756-765
Objective The study aimed to investigate the predictive efficacy of contrast-enhanced ultrasound combined with telomerase reverse transcriptase(TERT)promoter mutation in constructing nomogram model for the prediction of concomitant cervical lymph node metastasis(CLNM)in papillary thyroid microcarcinoma(pTMC).Methods A total of 202 patients with pTMC who underwent partial or total thyroidectomy+lymph node dissection at our hospital from January 2021 to March 2024 were selected.Then,they were divided into the CLNM group(97 patients)and the non-CLNM group(105 patients)according to whether they had concomitant CLNM on postoperative pathological examination.General data and ultrasound(conventional ultrasound and contrast-enhanced ultrasound)characteristics were collected from all patients with pTMC,and Sanger sequencing was used to detect TERT promoter mutations.The influencing factors of pTMC complicated by CLNM were analyzed by single-factor and multifactorial unconditional logistic regression;the nomogram model of pTMC complicating CLNM with contrast-enhanced ultra-sound combined with TERT promoter mutation was constructed by RStudio 4.4.1 software,and the consistency and net benefit of the nomogram model were evaluated by using calibration curves,decision curves,and C-indexes,and the Hosmer-Lemeshow test for goodness of fit of the nomogram model;The predictive efficiency of the nomogram model constructed by combining contrast-enhanced ultrasound and TERT promoter mutation for pTMC complicated by CLNM was evaluated by plotting receiver operating characteristic(ROC)curves using MedCalc22.023 software.Results After postoperative pathological examination,the incidence of CLNM in 202 patients with pTMC was 48.02%(97/202).Univariate analysis showed that thyroglobulin antibodies,number of lesions,aspect ratio,micro-calcifications,enhancement time,enhancement mode,enhancement intensity,capsular continuity,and TERT promoter mutations were associated with pTMC complicating CLNM(P<0.05).Multifactorial unconditional logistic regression showed that multifocal tumours(OR=3.487,95%CI:1.641~7.406,P=0.001),microcalcifications(OR=4.484,95%CI:2.113~9.516,P<0.001),equal or high enhancement(OR=3.187,95%CI:1.460~6.957,P=0.004),disruption of peritoneal continuity(OR=2.201,95%CI:1.051~4.608,P=0.036),and TERT promoter mutation positivity(OR=4.460,95%CI:2.132~10.103,P<0.001)were the independent risk factors for pTMC complicating CLNM.A contrast-enhanced ultrasound combined TERT promoter mutation nomogram model was constructed based on independent risk factors for pTMC complicating CLNM[Logit(p)=-4.486+1.350×number of foci+1.399×microcalcifications+2.124×intensity of enhancement+1.524×capsular continuity+2.175×TERT promoter mutations].The C-index of this nomogram model was 0.899(95%CI:0.893~0.905),the calibra-tion curve alignment was close to the ideal curve,the decision curve was higher than the two extreme curves,and the Hosmer-Lemeshow test showed a P>0.05.The ROC curve analysis showed that the nomogram model constructed with contrast-enhanced ultrasound combined with TERT promoter mutations predicted CLNM in pTMC with an area under the curve of 0.899.This was significantly higher than the area under the curves for contrast-enhanced ultra-sound alone(0.857)and TERT promoter mutations alone(0.697)(P<0.05).Conclusion The contrast-enhanced ultrasound combined with TERT promoter mutations to construct a nomogram model has high predictive efficiency for pTMC complicating CLNM.
3.Application of active screening on carbapenem-resistant Enterobacterales monitoring in intensive care units:a multi-center study
Yiyu LYU ; Shaoyun QI ; Shihua SHEN ; Lu LIU ; Zhen TIAN ; Zhiwei XU ; Tao FANG ; Cuiying GUO ; Zhiping LI ; Ren DING ; Fanxiang MENG ; Ruojie LI ; Xiaoqian HU ; Xueping WANG ; Dequan WU ; Yile WU
Chinese Journal of Infection Control 2025;24(7):906-911
Objective To evaluate the effectiveness of active screening in improving the detection rate of carbape-nem-resistant Enterobacterales(CRE)in the intensive care units(ICUs).Methods From July 2023 to June 2024,active screening of rectal swab CRE was conducted on ICU patients in 10 hospitals.ICU patients who underwent ac-tive screening from July 2023 to June 2024 were selected as the study group,while those who did not undergo active screening from July 2022 to June 2023 were selected as the control group.Difference in CRE detection rates between the two groups of patients was compared.Results A total of 7 803 ICU patients were included in the study group,744 CRE strains were detected,with a detection rate of 9.53%,out of which 304 CRE strains were detected through routine detection(detection rate 3.90%),3 707 patients underwent active screen,440 CRE strains were detected(detection rate 11.87%).7 561 ICU patients were included in the control group,out of which 250 CRE strains were detected through routine detection,with a detection rate of 3.31%.There was a statistically significant difference in the overall detection rate of CRE between two groups of patients(x2=246.18,P<0.001).In the study group,CRE detection rate of active screening(11.87%)was higher than that of routine detection(3.90%),with statistically significant difference(x2=264.26,P<0.001).A total of 17 CRE strains were detected from the study group.The proportions of Klebsiella pneumoniae(80.92%vs 73.41%)and Serratia marcescens(2.30%vs0.23%)in the routine detection group were both higher than in the active screening group,while the proportion of Escherichia coli in the routine detection group was lower(8.22%vs 19.55%),all with statistically significant differences(all P<0.05).Conclusion The prevalence of CRE in ICUs is relatively high,with a wide range of bac-terial species.Active screening can improve the detection rate of CRE.
4.Application of active screening on carbapenem-resistant Enterobacterales monitoring in intensive care units:a multi-center study
Yiyu LYU ; Shaoyun QI ; Shihua SHEN ; Lu LIU ; Zhen TIAN ; Zhiwei XU ; Tao FANG ; Cuiying GUO ; Zhiping LI ; Ren DING ; Fanxiang MENG ; Ruojie LI ; Xiaoqian HU ; Xueping WANG ; Dequan WU ; Yile WU
Chinese Journal of Infection Control 2025;24(7):906-911
Objective To evaluate the effectiveness of active screening in improving the detection rate of carbape-nem-resistant Enterobacterales(CRE)in the intensive care units(ICUs).Methods From July 2023 to June 2024,active screening of rectal swab CRE was conducted on ICU patients in 10 hospitals.ICU patients who underwent ac-tive screening from July 2023 to June 2024 were selected as the study group,while those who did not undergo active screening from July 2022 to June 2023 were selected as the control group.Difference in CRE detection rates between the two groups of patients was compared.Results A total of 7 803 ICU patients were included in the study group,744 CRE strains were detected,with a detection rate of 9.53%,out of which 304 CRE strains were detected through routine detection(detection rate 3.90%),3 707 patients underwent active screen,440 CRE strains were detected(detection rate 11.87%).7 561 ICU patients were included in the control group,out of which 250 CRE strains were detected through routine detection,with a detection rate of 3.31%.There was a statistically significant difference in the overall detection rate of CRE between two groups of patients(x2=246.18,P<0.001).In the study group,CRE detection rate of active screening(11.87%)was higher than that of routine detection(3.90%),with statistically significant difference(x2=264.26,P<0.001).A total of 17 CRE strains were detected from the study group.The proportions of Klebsiella pneumoniae(80.92%vs 73.41%)and Serratia marcescens(2.30%vs0.23%)in the routine detection group were both higher than in the active screening group,while the proportion of Escherichia coli in the routine detection group was lower(8.22%vs 19.55%),all with statistically significant differences(all P<0.05).Conclusion The prevalence of CRE in ICUs is relatively high,with a wide range of bac-terial species.Active screening can improve the detection rate of CRE.
5.Energy efficiency of contrast-enhanced ultrasound combined with TERT promoter mutation to construct a nomogram model for the prediction of concomitant cervical lymph node metastasis in PTMC
Chang-hui WU ; Zhiping HUANG ; Huiping DAI ; Huifang QIU ; Chun HE ; Fang TANG
The Journal of Practical Medicine 2025;41(5):756-765
Objective The study aimed to investigate the predictive efficacy of contrast-enhanced ultrasound combined with telomerase reverse transcriptase(TERT)promoter mutation in constructing nomogram model for the prediction of concomitant cervical lymph node metastasis(CLNM)in papillary thyroid microcarcinoma(pTMC).Methods A total of 202 patients with pTMC who underwent partial or total thyroidectomy+lymph node dissection at our hospital from January 2021 to March 2024 were selected.Then,they were divided into the CLNM group(97 patients)and the non-CLNM group(105 patients)according to whether they had concomitant CLNM on postoperative pathological examination.General data and ultrasound(conventional ultrasound and contrast-enhanced ultrasound)characteristics were collected from all patients with pTMC,and Sanger sequencing was used to detect TERT promoter mutations.The influencing factors of pTMC complicated by CLNM were analyzed by single-factor and multifactorial unconditional logistic regression;the nomogram model of pTMC complicating CLNM with contrast-enhanced ultra-sound combined with TERT promoter mutation was constructed by RStudio 4.4.1 software,and the consistency and net benefit of the nomogram model were evaluated by using calibration curves,decision curves,and C-indexes,and the Hosmer-Lemeshow test for goodness of fit of the nomogram model;The predictive efficiency of the nomogram model constructed by combining contrast-enhanced ultrasound and TERT promoter mutation for pTMC complicated by CLNM was evaluated by plotting receiver operating characteristic(ROC)curves using MedCalc22.023 software.Results After postoperative pathological examination,the incidence of CLNM in 202 patients with pTMC was 48.02%(97/202).Univariate analysis showed that thyroglobulin antibodies,number of lesions,aspect ratio,micro-calcifications,enhancement time,enhancement mode,enhancement intensity,capsular continuity,and TERT promoter mutations were associated with pTMC complicating CLNM(P<0.05).Multifactorial unconditional logistic regression showed that multifocal tumours(OR=3.487,95%CI:1.641~7.406,P=0.001),microcalcifications(OR=4.484,95%CI:2.113~9.516,P<0.001),equal or high enhancement(OR=3.187,95%CI:1.460~6.957,P=0.004),disruption of peritoneal continuity(OR=2.201,95%CI:1.051~4.608,P=0.036),and TERT promoter mutation positivity(OR=4.460,95%CI:2.132~10.103,P<0.001)were the independent risk factors for pTMC complicating CLNM.A contrast-enhanced ultrasound combined TERT promoter mutation nomogram model was constructed based on independent risk factors for pTMC complicating CLNM[Logit(p)=-4.486+1.350×number of foci+1.399×microcalcifications+2.124×intensity of enhancement+1.524×capsular continuity+2.175×TERT promoter mutations].The C-index of this nomogram model was 0.899(95%CI:0.893~0.905),the calibra-tion curve alignment was close to the ideal curve,the decision curve was higher than the two extreme curves,and the Hosmer-Lemeshow test showed a P>0.05.The ROC curve analysis showed that the nomogram model constructed with contrast-enhanced ultrasound combined with TERT promoter mutations predicted CLNM in pTMC with an area under the curve of 0.899.This was significantly higher than the area under the curves for contrast-enhanced ultra-sound alone(0.857)and TERT promoter mutations alone(0.697)(P<0.05).Conclusion The contrast-enhanced ultrasound combined with TERT promoter mutations to construct a nomogram model has high predictive efficiency for pTMC complicating CLNM.
6.Analysis of the therapeutic efficacy and factors influencing sequential combination of nucleos(t)ide analogues with pegylated interferon alpha for 48~96 weeks in the treatment of patients with chronic hepatitis B
Rui JIA ; Wenxin WANG ; Zhiping ZHOU ; Weimin NIE ; Yongqian CHENG ; Jun ZHAO ; Fang LIAN ; Junqing LUAN ; Fusheng WANG ; Junliang FU
Chinese Journal of Hepatology 2023;31(12):1290-1296
Objective:To explore the therapeutic efficacy and factors influencing the sequential combination of nucleos(t)ide analogues (NAs) with pegylated interferon alpha (Peg-IFN-α) in the treatment of patients with chronic hepatitis B (CHB).Methods:144 CHB cases with NAs treatment for more than 1 year, HBV DNA < 20 IU/ml, hepatitis B surface antigen (HBsAg) quantification < 3 000 IU/ml, treated with a sequential combination of Peg-IFN-α treatment for 48 to 96 weeks, and followed up were selected from the Fifth Medical Center of the PLA General Hospital between May 2018 and May 2020. Intention-to-treat analysis was used to measure the HBsAg clearance rate at 96 weeks. The Kaplan-Meier method was used to compute the cumulative HBsAg clearance rate at 96 weeks. Univariate and multivariate logistic regression were used to analyze the factors influencing HBsAg clearance at 48 weeks of sequential combination therapy. Univariate and multifactorial COX proportional hazard models were used to analyze the factors influencing HBsAg clearance following 96 weeks of prolonged PEG-IFN-α treatment. The receiver operating characteristic curve was used to assess the predictive value of factors influencing HBsAg clearance. A Mann-Whitney U test was used to compare the measurement data between groups. The count data was compared using the χ2 test between groups. Results:41 (28.47%) cases achieved HBsAg clearance at 48 weeks of sequential combination therapy. The HBsAg clearance rate at 96 weeks was 40.28% (58/144) by intention-to-treat analysis. The Kaplan-Meier method computed that the cumulative HBsAg clearance rate at 96 weeks was 68.90%. Multivariate logistic regression analysis showed that HBsAg quantification at baseline ( OR = 0.090, 95% CI: 0.034-0.240, P < 0.001) and a 24-week drop in HBsAg level ( OR = 7.788, 95% CI: 3.408-17.798, P < 0.001) were independent predictors of HBsAg clearance in CHB patients treated sequentially in combination with NAs and Peg-IFN-α for 48 weeks. Receiver operating characteristic curve analysis showed that the baseline HBsAg quantification [area under the receiver operating characteristic curve (AUC), 0.911, 95% CI: 0.852-0.952)] and 24-week drop in HBsAg level (AUC = 0.881, 95% CI: 0.814-0.930) had equally good predictive value for 48-week HBsAg clearance, but there was no statistically significant difference between the two ( Z = 0.638, P = 0.523). The value of the combination of baseline HBsAg quantification and 24-week drop in HBsAg level (AUC = 0.981, 95% CI: 0.941-0.997) was superior to that of single baseline HBsAg quantification ( Z = 3.017, P = 0.003) and 24-week drop in HBsAg level ( Z = 3.214, P = 0.001) in predicting HBsAg clearance rate at 48 weeks. Multivariate COX proportional hazards model analysis showed that HBsAg quantification at 48 weeks ( HR = 0.364, 95% CI: 0.176-0.752, P = 0.006) was an independent predictor of HBsAg clearance with a prolonged course to 96 weeks of Peg-IFN-α treatment. Conclusion:The HBsAg clearance rate can be accurately predicted with baseline HBsAg quantification combined with a 24-week drop in HBsAg level in patients with CHB who are treated with a sequential combination of NAs and Peg-IFN-α therapy for 48 weeks. Prolonging the course of Peg-IFN-α treatment can enhance the HBsAg clearance rate's capability. An independent predictor of HBsAg clearance is HBsAg quantification at 48 weeks of sequential combination therapy with a prolonged course of 96 weeks of Peg-IFN-α treatment.
7.Establishment of fingerprint ,chemometric analysis and multi-component content determination of Zhuang medi- cine Jinmu granules
Linjie LI ; Tanfang XIE ; Yuhan WANG ; Zhiping WANG ; Fang LI ; Xiaoxun WANG ; Qiao FENG
China Pharmacy 2022;33(4):439-451
OBJECTIVE To establish the fingerprint of Zhuang medicine Jinmu granules and carry out chemometric analysis , and determine the contents of three components . METHODS High performance liquid chromatography (HPLC) method was adopted. Using rutin as the reference ,HPLC fingerprints of 10 batches of Jinmu granules were drawn and similarity evaluation was performed by Similarity Evaluation of Chromatographic Fingerprint of Traditional Chinese Medicine (2012 edition);the common peak was determined by comparing with mixed control ;SPSS 21.0 software was used for cluster analysis ,and SIMCA 14.1 software was used for principal component analysis and orthogonal partial least squares-discriminant analysis. The differential components affecting the quality of Jinmu granules were screened by taking the variable importance in projection (VIP)value >1 as the standard ;the HPLC method was used to determine the contents of astilbin ,polydatin and berberine hydrochloride in Jinmu granules. RESULTS There were 22 common peaks in 10 batches of Jinmu granules ,and the similarities were 0.962-0.997;five common peaks were identified ,namely gallic acid (peak 2),polydatin(peak 9),rutin(peak 11),astilbin(peak 13)and kaempferol (peak 20). The results of cluster analysis showed that 10 batches of Jinmu granules could be clustered into 3 categories:S1 and S 3-S4 were grouped into one category ;S5-S6 and S 9 were grouped into one category ;S2,S7-S8 and S 10 were grouped into one category. The results of principal component analysis showed that the parameter of model interpretation was 0.951 and that of prediction ability was 0.723. The classification results were basically consistent with cluster analysis. The classifica tion results of orthogonal partial least squares- com discriminant analysis were also ba sically consistent with clus- ter analysis. The common peaks with VIP value >1 in the order were peak 7>peak 11(rutin)>peak 17>peak 13(astilbin)> peak 3>peak 8>peak 6>peak 16 respectively. The linear ranges of astilbin ,polydatin and berberine hydrochloride were 0.012 6- 1.225 0,0.010 8-1.052 5 and 0.020 0-1.562 5 mg/mL,respectively(all R 2=0.999 9). RSDs of precision ,stability(24 h)and repeatability tests were all less than 3%. The average recoveries were 99.48%(RSD=2.67%,n=9),98.57%(RSD=1.77%,n= 9)and 100.84%(RSD=2.49%,n=9). The contents were 1.221 0-7.011 6,2.251 1-4.462 9,1.252 4-3.328 7 mg/g,respectively. CONCLUSIONS Established fingerprint and the method of content determination are accurate ,stable and simple. Combined with chemometric analysis ,it can be used for the quality control and evaluation of Zhuang medicine Jinmu granules.
8.In vitro effect of a short hairpin RNA targeting epidermal growth factor receptor combined with sirolimus on proliferation and apoptosis of the human cutaneous squamous cell carcinoma cell line Colo-16
Hui WANG ; Dong LIU ; Fang TIAN ; Zhiping WEI
Chinese Journal of Dermatology 2022;55(2):135-141
Objective:To investigate the effect of a short hairpin RNA (shRNA) targeting epidermal growth factor receptor (EGFR) combined with sirolimus on proliferation and apoptosis of the human cutaneous squamous cell carcinoma cell line Colo-16, and to explore underlying mechanisms.Methods:Cultured Colo-16 cells were divided into 5 groups: normal cell group receiving conventional culture and treatment with phosphate-buffered saline (PBS) , negative control group transfected with a shRNA-NC-expressing plasmid and treated with PBS, sirolimus group receiving conventional culture and sirolimus treatment, EGFR shRNA group transfected with an EGFR shRNA-expressing plasmid and treated with PBS, and combined group transfected with an EGFR shRNA-expressing plasmid and treated with sirolimus. Methyl thiazol tetrazolium (MTT) assay was performed to evaluate cellular proliferative activity in the above groups from 24 to 96 hours, and flow cytometry to detect cell apoptosis after 48-hour treatment. Semiquantitative RT-PCR was conducted to determine the mRNA expression of Bcl-2 and Bax, and Western blot analysis to determine the expression of apoptosis-related proteins cleaved caspase-3, cleaved caspase-9, Bcl-2, Bax, cell proliferation-related proteins phosphorylated mammalian target of rapamycin (p-mTOR) , phosphorylated protein kinase B (p-AKT) , phosphorylated 70-kDa ribosomal protein S6 kinase (p-P70S6k) , and cyclin D1. Comparisons among groups were carried out by using one-way analysis of variance, and multiple comparisons between 2 groups by using Student-Newman-Keuls q test. Results:MTT assay showed that the proliferative activity of Colo-16 cells was significantly lower in the sirolimus group, EGFR shRNA group and combined group during 24 - 96 hours than in the normal cell group (all P < 0.05) , and higher in the combined group than in the sirolimus group and EGFR shRNA group at 24-96 hours (all P < 0.001) , and there was no significant difference in the cellular proliferative activity at any time points between the normal cell group and negative control group (all P > 0.05) . Flow cytometry showed that the apoptosis rate was significantly higher in the sirolimus group, EGFR shRNA group and combined group (9.52% ± 0.25%, 12.65% ± 0.23%, 19.81% ± 0.31%, respectively) than in the normal cell group (3.33% ± 0.18%, q = 60.07, 78.08, 122.81, respectively, all P < 0.001) and negative control group (3.42% ± 0.19%, q = 59.90, 77.91, 122.64, respectively, all P < 0.001) , and was highest in the combined group. As RT-PCR and Western blot analysis revealed, the sirolimus group, EGFR shRNA group and combined group showed significantly decreased mRNA expression of Bcl-2 and protein expression of cyclin D1, p-AKT, p-mTOR, p-P70S6K and Bcl-2, but significantly increased mRNA expression of Bax and protein expression of cleaved caspase-3, cleaved caspase-9 and Bax compared with the normal cell group (all P < 0.05) . Compared with the sirolimus group and EGFR shRNA group, the combined group showed significantly decreased mRNA expression of Bcl-2 and protein expression of cyclin D1, p-AKT, p-mTOR, p-P70S6K and Bcl-2 (all P < 0.05) , but significantly increased mRNA expression of Bax and protein expression of cleaved caspase-3, cleaved caspase-9 and Bax (all P < 0.01) . Conclusion:EGFR shRNA and sirolimus exerted a synergistic effect in inhibiting the proliferation and promoting the apoptosis of Colo-16 cells, which may be related to the inhibition of the phosphoinositide 3-kinase (PI3K) /AKT/mTOR pathway.
9.Effects of hospital discharge readiness plan based on deep integration of medical nursing and rehabilitation in children with cerebral palsy
Zhiping WANG ; Jihong FANG ; Guanglei TONG ; Sinan LI ; Hong LI ; Kun XUAN ; Nan XIA ; Yulin LI ; Man XING ; Yujie HU
Chinese Journal of Modern Nursing 2022;28(22):3010-3016
Objective:To explore the effect of the hospital discharge readiness plan based on deep integration of medical nursing and rehabilitation in children with cerebral palsy.Methods:From January 2020 to September 2021, 60 children with cerebral palsy and their 60 parents admitted to the Children's Rehabilitation Department of Anhui Children's Hospital were selected as the research object. The children and parents were divided into the observation group and the control group by random number table, with 30 children and 30 parents in each group. The control group was given routine nursing, and the observation group was given the hospital discharge readiness plan based on the deep integration of medical nursing and rehabilitation. On the first day of admission and the day before discharge, the effects were evaluated using the Chinese version of the Chinese version of the Readiness for Hospital Discharge Scale (RHDS) -Parent Form, the Chinese version of the Quality of Discharge Teaching Scale (QDTS) -Parent Form, the Activities of Daily Living (ADL) Rehabilitation Nursing Rating Scale for Children with Cerebral Palsy.Results:After the intervention, the scores of the observation group were higher than those of the control group in terms of readiness for hospital discharge, quality of discharge teaching, and the differences were statistically significant ( P<0.05) . Conclusions:The hospital discharge readiness plan based on deep integration of medical nursing and rehabilitation in children with cerebral palsy can effectively improve their discharge readiness, the quality of discharge teaching and the ADL of children with cerebral palsy.
10.Biomechanical Study of Posterior Dynamic Fixation at Atlantoaxial Joints
Jie TONG ; Wei JI ; Zhiping HUANG ; Ruozhou ZHOU ; Zuozhong FANG ; Qing’an ZHU
Journal of Medical Biomechanics 2021;36(2):E189-E194
Objective To evaluate the influence of dynamic fixation (rotating and sliding pedicle screws) on stability of the atlantoaxial joint. Methods A series of in vitro biomechanical tests were performed using six fresh adult cervical spines (occipital bone-C4 segment) to simulate different conditions in surgery, including the intact state, the injury state, rigid fixation, rotating pedicle screw fixation, sliding pedicle screw fixation. The repeated measurement design was employed, and under intact, injury and different fixation states, the pure moment of 1.5 N·m in flexion-extension, left-right lateral bending, left-right axial rotation directions were applied using the spinal testing machine. The movement of atlantoaxial spine was measured consecutively by three-dimensional (3D) measurement system in order to analyze the range of motion (ROM) and neutral zone (NZ) of atlantoaxial joints. Results Under injury state, ROM of atlantoaxial joints was significantly larger than that under intact state during flexion, extension, lateral bending and rotation, leading to the instability of atlantoaxial joints. ROM of fixation segments was significantly reduced during flexion, extension, lateral bending and rotation after rigid and dynamic fixation. Compared with rigid fixation, dynamic fixation showed a significant ROM increase during lateral bending. NZs of fixation segments after dynamic fixation were significantly reduced. There were no significant ROM differences between rigid fixation and dynamic fixation. Conclusions The stability of atlantoaxial joints by dynamic fixation during flexion, extension and rotation was comparable to that by rigid fixation, but weaker during lateral bending. Dynamic screw fixation can maintain the relative stability of atlantoaxial joints.

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