BACKGROUND:Upper lumbar spinal stenosis is a multifactorial degenerative disorder of the spine.For narrowing of the spinal canal in the upper lumbar region(L1-L4),surgical decision-making is particularly complex.Existing minimally invasive surgeries each have their own advantages and limitations.Currently,there are few reports on biomechanical comparison and finite element analysis of different surgical methods for the treatment of high lumbar spinal stenosis.OBJECTIVE:To analyze the biomechanical impact of endoscopic unilateral laminotomy for bilateral decompression,transforaminal endoscopic lumbar decompression,and cross-overtop decompression in the treatment of upper lumbar spinal stenosis using endoscopy,and to verify the reliability and effectiveness of these three surgical techniques in treating upper lumbar spinal stenosis,providing a biomechanical basis for clinical decision-making.METHODS:The CT images of the lumbar spine of a healthy volunteer were selected,and the finite element model M0 of the normal lumbar L1-L5 segments was established using Mimics,Geomagic,Solid works,and Ansys software.The L2-L3 segment,representing upper lumbar characteristics,was chosen.Based on this model,the surgical models for endoscopic unilateral laminotomy for bilateral decompression(M1),transforaminal endoscopic lumbar decompression(M2),and cross-overtop decompression(M3)were established.Using software,the changes in the range of motion of the entire lumbar segment and the maximum Von Mises stress of the intervertebral discs were simulated and evaluated for each group of models under six loading conditions:flexion,extension,left lateral bending,right lateral bending,left rotation,and right rotation.RESULTS AND CONCLUSION:(1)Compared with model MO,the range of motion in M1,M2,and M3 increased under all six conditions,with M1 showing a greater increase.(2)M1 and M2 demonstrated significant increases in range of motion under forward bending,extension,and right rotation,while the increase under other conditions remained below 7％.(3)Compared with model M3,model M1 exhibited slightly increased overall joint range of motion during extension and left bending,while no significant changes were observed in other aspects,and the L1-L5 lumbar segments did not reach an unstable state.(4)In model M1,the maximum Von Mises stress of the intervertebral discs increased most significantly under flexion and extension loading conditions.However,under left lateral bending,right lateral bending,left rotation,and right rotation loading conditions,the increase did not exceed 5％.(5)These findings suggest that due to the sagittal anatomical characteristics of the facet joints,the unilateral laminotomy for bilateral decompression technique,while decompressing,involves resection of more facet joints,which impacts overall segmental stability.The transforaminal endoscopic lumbar decompression technique is suitable for patients with foraminal stenosis but cannot achieve complete decompression for those with severe ventral central stenosis.The Cross-Overtop technique effectively enlarges the volume of the central canal and lateral recess,optimizing decompression,and shows unique advantages in treating upper lumbar spinal stenosis.

BACKGROUND:Upper lumbar spinal stenosis is a multifactorial degenerative disorder of the spine.For narrowing of the spinal canal in the upper lumbar region(L1-L4),surgical decision-making is particularly complex.Existing minimally invasive surgeries each have their own advantages and limitations.Currently,there are few reports on biomechanical comparison and finite element analysis of different surgical methods for the treatment of high lumbar spinal stenosis.OBJECTIVE:To analyze the biomechanical impact of endoscopic unilateral laminotomy for bilateral decompression,transforaminal endoscopic lumbar decompression,and cross-overtop decompression in the treatment of upper lumbar spinal stenosis using endoscopy,and to verify the reliability and effectiveness of these three surgical techniques in treating upper lumbar spinal stenosis,providing a biomechanical basis for clinical decision-making.METHODS:The CT images of the lumbar spine of a healthy volunteer were selected,and the finite element model M0 of the normal lumbar L1-L5 segments was established using Mimics,Geomagic,Solid works,and Ansys software.The L2-L3 segment,representing upper lumbar characteristics,was chosen.Based on this model,the surgical models for endoscopic unilateral laminotomy for bilateral decompression(M1),transforaminal endoscopic lumbar decompression(M2),and cross-overtop decompression(M3)were established.Using software,the changes in the range of motion of the entire lumbar segment and the maximum Von Mises stress of the intervertebral discs were simulated and evaluated for each group of models under six loading conditions:flexion,extension,left lateral bending,right lateral bending,left rotation,and right rotation.RESULTS AND CONCLUSION:(1)Compared with model MO,the range of motion in M1,M2,and M3 increased under all six conditions,with M1 showing a greater increase.(2)M1 and M2 demonstrated significant increases in range of motion under forward bending,extension,and right rotation,while the increase under other conditions remained below 7％.(3)Compared with model M3,model M1 exhibited slightly increased overall joint range of motion during extension and left bending,while no significant changes were observed in other aspects,and the L1-L5 lumbar segments did not reach an unstable state.(4)In model M1,the maximum Von Mises stress of the intervertebral discs increased most significantly under flexion and extension loading conditions.However,under left lateral bending,right lateral bending,left rotation,and right rotation loading conditions,the increase did not exceed 5％.(5)These findings suggest that due to the sagittal anatomical characteristics of the facet joints,the unilateral laminotomy for bilateral decompression technique,while decompressing,involves resection of more facet joints,which impacts overall segmental stability.The transforaminal endoscopic lumbar decompression technique is suitable for patients with foraminal stenosis but cannot achieve complete decompression for those with severe ventral central stenosis.The Cross-Overtop technique effectively enlarges the volume of the central canal and lateral recess,optimizing decompression,and shows unique advantages in treating upper lumbar spinal stenosis.

Photodynamic immunotherapy is a promising strategy for cancer treatment. However, the dysfunctional tumor vasculature results in tumor hypoxia and the low efficiency of drug delivery, which in turn restricts the anticancer effect of photodynamic immunotherapy. In this study, we designed photosensitive lipid nanoparticles. The synthesized PFBT@Rox Lip nanoparticles could produce type I/II reactive oxygen species (ROS) by electron or energy transfer through PFBT under light irradiation. Moreover, this nanosystem could alleviate tumor hypoxia and promote vascular normalization through Roxadustat. Upon irradiation with white light, the ROS produced by PFBT@Rox Lip nanoparticles in situ dysregulated calcium homeostasis and triggered endoplasmic reticulum stress, which further promoted the release of damage-associated molecular patterns, enhanced antigen presentation, and stimulated an effective adaptive immune response, ultimately priming the tumor microenvironment (TME) together with the hypoxia alleviation and vessel normalization by Roxadustat. Indeed, in vivo results indicated that PFBT@Rox Lip nanoparticles promoted M1 polarization of tumor-associated macrophages, recruited more natural killer cells, and augmented infiltration of T cells, thereby leading to efficient photodynamic immunotherapy and potentiating the anti-primary and metastatic tumor efficacy of PD-1 antibody. Collectively, photodynamic immunotherapy with PFBT@Rox Lip nanoparticles efficiently program TME through the induction of immunogenicity and oxygenation, and effectively suppress tumor growth through immunogenic cell death and enhanced anti-tumor immunity.

Objective:To compare the efficacy of closed reduction and internal fixation combined with percutaneous kyphoplasty (PKP) and non-operative treatment for intertrochanteric fracture combined with osteoporotic vertebral compression fracture (OVCF) in the elderly.Methods:A retrospective cohort study was conducted to analyze the clinical data of 59 patients with intertrochanteric fracture combined with OVCF admitted to Tianjin Hospital from June 2020 to June 2023, including 16 males and 43 females, aged 66-91 years [(80.2±6.8)years]. The injured vertebral segments included T 10 in 3 patients, T 11 in 9, T 12 in 18, L 1 in 17, L 2 in 8, and L 3 in 4. According to the Genant semi-quantitative classification of vertebral fracture, 42 patients were scaled into grade 1 and 17 into grade 2. Based on the AO classification of intertrochanteric fracture, 33 patients were classified as type A1, 21 type A2, and 5 type A3. All the patients underwent closed reduction and internal fixation for intertrochanteric fractures, among whom 26 patients received PKP after the internal fixation of OVCF (PKP group) and 33 patients received non-surgical treatment after the internal fixation of OVCF (non-surgical group). The healing of the hip incision at 2 weeks after internal fixation and the healing of intertrochanteric fractures at 6 months after surgery were observed in both groups. The visual analogue scale (VAS) for low back pain was compared between the two groups before PKP, immediately after PKP, at 3 months after PKP, and at the last follow-up. The Oswestry disability index (ODI), anterior vertebral height ratio, and Cobb angle of the injured vertebrae were compared between the two groups before PKP, at 3 months after PKP, and at the last follow-up. The Harris hip function score was compared between the two groups at 3 months after internal fixation and at the last follow-up. Cement leakage was observed. The incidence of deep vein thrombosis (DVT) in the lower extremities after internal fixation were compared between the two groups. Results:All the patients were followed up for 10-46 months [(25.5±9.9)months]. The hip incisions of both groups all healed by first intention at 2 weeks after internal fixation, and the intertrochanteric fracture in both groups had bony union at 6 months after surgery. There were no significant differences between the two groups in VAS or ODI before PKP ( P>0.05). Immediately after PKP, at 3 months after PKP, and at the last follow-up, the VAS scores for low back pain were (2.6±0.6)points, (2.4±0.9)points, and (1.5±0.5)points in the PKP group, which were lower than those in the non-surgical group [(8.2±0.8)points, (3.7±1.2)points, and (3.3±0.6)points] ( P<0.01). At 3 months after PKP and at the last follow-up, the ODI values were (21.4±6.9)% and (16.2±6.3)% in the PKP group, which were lower than (38.6±11.6)% and (32.7±12.0)% in the non-surgical group ( P<0.01). The VAS for low back pain and ODI in both groups were gradually improved at each time point after PKP compared with those before PKP ( P<0.05 or 0.01). There were no significant differences in the anterior vertebral height ratio or Cobb angle of the injured vertebrae in the two groups before PKP ( P>0.05). At 3 months after PKP and at the last follow-up, the anterior vertebral height ratio was (79.8±9.6)% and (79.3±9.4)% in the PKP group, which were higher than (73.4±9.3)% and (62.0±10.4)% in the non-surgical group ( P<0.05 or 0.01); the values of the Cobb angle of the injured vertebrae were (12.6±3.6)° and (12.0±3.3)°in the PKP group, which were lower than (15.5±2.6)° and (20.4±4.9)° in the non-surgical group ( P<0.01). There were no significant differences in the anterior vertebral height ratio and Cobb angle of the injured vertebrae in the PKP group before PKP and at each time point after PKP ( P>0.05) while in the non-surgical group, the anterior vertebral height ratio at each time point after PKP was lower than that before PKP and the Cobb angle of the injured vertebrae was increased compared with that before PKP ( P<0.01). At 3 months after internal fixation and at the last follow-up, the Harris hip function scores in the PKP group were (76.4±3.4)points and (87.7±4.5)points, which were higher than (57.0±6.8)points and (76.3±8.9)points in the non-surgical group ( P<0.01). The Harris hip function scores in both groups were improved at the last follow-up, compared with those at 3 months after internal fixation. Five patients had cement leakage in the PKP group, all of which were lateral leakage.There was no occurrence of radiating pain in the lower extremities. The incidence of DVT at 1 month after internal fixation was 19.2% (5/26) in the PKP group, which was lower than 57.6% (19/33) in the non-surgical group ( P<0.01). Conclusion:Compared with non-operative treatment after the closed reduction and internal fixation, PKP after internal fixation can significantly relieve low back pain in the early stage, improve the functional restoration of the vertebral column, maintain vertebral height, prevent kyphosis, promote the recovery of the hip joint function, and reduce the occurrence of DVT in the lower extremities in the treatment of intertrochanteric fracture combined with OVCF.

Objective:To evaluate the effects and underlying mechanisms of metabolites derived from the kidney-reinforcing, blood circulation-activating, and collateral dredging decoction on the proliferation of multiple myeloma (MM) KM3 cells.Methods:MM KM3 cells in the logarithmic growth phase were treated with 3%, 6%, 9%, or 12% metabolites of kidney-reinforcing, blood circulation-activating, and collateral dredging decoction. Cell viability was assessed using the CCK-8 assay. Apoptosis and necrosis were evaluated using flow cytometry and TUNEL staining. Mitochondrial and cellular ultrastructural changes were examined using transmission electron microscopy. mRNA and protein expression levels of dynamin-related protein 1 (Drp1), mitochondrial fission protein 1 (Fis1), mitochondrial fission factor (MFF), PTEN-induced kinase 1 (Pink1), and E3 ubiquitin ligase (Parkin) were determined through quantitative real-time PCR and western blotting. High-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) combined with network pharmacology, was utilized for reverse verification of the pharmacodynamic mechanisms and therapeutic targets underlying the anti-MM activity of this decoction.Results:The metabolites of the kidney-reinforcing, blood circulation-activating, and collateral dredging decoction inhibited KM3 cell proliferation and induced apoptosis in a dose-dependent manner. Transmission electron microscopy revealed increased mitochondrial fission and autophagic structures, with effects intensifying at higher metabolite concentrations. mRNA and protein expression of Drp1, Fis1, MFF, Pink1, and Parkin were significantly upregulated in treatment groups compared to controls ( P<0.05), with the most pronounced effects observed in the 12% metabolite group ( P<0.01). HPLC-MS/MS identified 121 bioactive compounds in BHTF, which shared 474 overlapping targets with MM. Enrichment analysis suggested that BHTF exerts antitumor effects primarily through apigenin, palmatine, and other key components by modulating TNF, NF-κB, and mitophagy pathways. Conclusion:The kidney-reinforcing and blood circulation-activating and collateral dredging decoction suppresses the proliferation of MM KM3 cells, potentially through mechanisms involving the regulation of mitochondrial dynamics and induction of autophagy.

Objective:To explore the value of deep learning models based on ultrafast dynamic contrast-enhanced MRI (UF-DCE MRI) in predicting malignant breast lesions.Methods:The study was a cross-sectional study. Clinical and imaging data of 347 patients with breast lesions who received treatment at Tianjin Medical University Cancer Institute and Hospital from March 2023 to January 2024 were analyzed retrospectively. A total of 347 lesions were observed in the 347 patients, including 75 benign and 272 malignant lesions. The random number method was used to divide into the training set with 243 cases and the validation set with 104 cases in a ratio of 7∶3. All patients underwent breast UF-DCE MRI and conventional dynamic-enhanced MRI (DCE-MRI). A 27-channel model (27-phase enhancement images of input UF-DCE MRI), a 3-channel model (3-phase enhancement images of input DCE-MRI), and a 1-channel model (1st-phase enhancement images of DCE-MRI) were built based on the pre-trained ResNet18 deep learning model on ImageNet. The efficacy of each model in predicting breast malignant lesions was analyzed using receiver operating characteristic curves and area under the curve (AUC). The differences of AUC were compared using DeLong test.Results:In the training and validation sets, the 27-channel model had the highest AUC for diagnosing malignant breast lesions, which were 0.848 (95% CI 0.818-0.877) and 0.784 (95% CI 0.752-0.817), respectively. DeLong test showed no statistically significant difference in the AUC values of the three models in the validation set for the diagnosis of malignant lesions of the breast in a two-by-two comparison ( P>0.05). UF-DCE MRI scans were 27 phases totaling 81 s with a temporal resolution of 3 s/phase; DCE-MRI scans were 3 phases totaling 270 s with a temporal resolution of 90 s/phase. Conclusions:The model combining UF-DCE MRI with deep learning demonstrates comparable efficacy to DCE-MRI deep learning model in diagnosing breast malignant lesions. However the UF-DCE MRI has the advantages of high temporal resolution and short scanning time, which makes this model valuable for precise diagnosis and treatment of breast cancer.

Objective:To compare the efficacy of closed reduction and internal fixation combined with percutaneous kyphoplasty (PKP) and non-operative treatment for intertrochanteric fracture combined with osteoporotic vertebral compression fracture (OVCF) in the elderly.Methods:A retrospective cohort study was conducted to analyze the clinical data of 59 patients with intertrochanteric fracture combined with OVCF admitted to Tianjin Hospital from June 2020 to June 2023, including 16 males and 43 females, aged 66-91 years [(80.2±6.8)years]. The injured vertebral segments included T 10 in 3 patients, T 11 in 9, T 12 in 18, L 1 in 17, L 2 in 8, and L 3 in 4. According to the Genant semi-quantitative classification of vertebral fracture, 42 patients were scaled into grade 1 and 17 into grade 2. Based on the AO classification of intertrochanteric fracture, 33 patients were classified as type A1, 21 type A2, and 5 type A3. All the patients underwent closed reduction and internal fixation for intertrochanteric fractures, among whom 26 patients received PKP after the internal fixation of OVCF (PKP group) and 33 patients received non-surgical treatment after the internal fixation of OVCF (non-surgical group). The healing of the hip incision at 2 weeks after internal fixation and the healing of intertrochanteric fractures at 6 months after surgery were observed in both groups. The visual analogue scale (VAS) for low back pain was compared between the two groups before PKP, immediately after PKP, at 3 months after PKP, and at the last follow-up. The Oswestry disability index (ODI), anterior vertebral height ratio, and Cobb angle of the injured vertebrae were compared between the two groups before PKP, at 3 months after PKP, and at the last follow-up. The Harris hip function score was compared between the two groups at 3 months after internal fixation and at the last follow-up. Cement leakage was observed. The incidence of deep vein thrombosis (DVT) in the lower extremities after internal fixation were compared between the two groups. Results:All the patients were followed up for 10-46 months [(25.5±9.9)months]. The hip incisions of both groups all healed by first intention at 2 weeks after internal fixation, and the intertrochanteric fracture in both groups had bony union at 6 months after surgery. There were no significant differences between the two groups in VAS or ODI before PKP ( P>0.05). Immediately after PKP, at 3 months after PKP, and at the last follow-up, the VAS scores for low back pain were (2.6±0.6)points, (2.4±0.9)points, and (1.5±0.5)points in the PKP group, which were lower than those in the non-surgical group [(8.2±0.8)points, (3.7±1.2)points, and (3.3±0.6)points] ( P<0.01). At 3 months after PKP and at the last follow-up, the ODI values were (21.4±6.9)% and (16.2±6.3)% in the PKP group, which were lower than (38.6±11.6)% and (32.7±12.0)% in the non-surgical group ( P<0.01). The VAS for low back pain and ODI in both groups were gradually improved at each time point after PKP compared with those before PKP ( P<0.05 or 0.01). There were no significant differences in the anterior vertebral height ratio or Cobb angle of the injured vertebrae in the two groups before PKP ( P>0.05). At 3 months after PKP and at the last follow-up, the anterior vertebral height ratio was (79.8±9.6)% and (79.3±9.4)% in the PKP group, which were higher than (73.4±9.3)% and (62.0±10.4)% in the non-surgical group ( P<0.05 or 0.01); the values of the Cobb angle of the injured vertebrae were (12.6±3.6)° and (12.0±3.3)°in the PKP group, which were lower than (15.5±2.6)° and (20.4±4.9)° in the non-surgical group ( P<0.01). There were no significant differences in the anterior vertebral height ratio and Cobb angle of the injured vertebrae in the PKP group before PKP and at each time point after PKP ( P>0.05) while in the non-surgical group, the anterior vertebral height ratio at each time point after PKP was lower than that before PKP and the Cobb angle of the injured vertebrae was increased compared with that before PKP ( P<0.01). At 3 months after internal fixation and at the last follow-up, the Harris hip function scores in the PKP group were (76.4±3.4)points and (87.7±4.5)points, which were higher than (57.0±6.8)points and (76.3±8.9)points in the non-surgical group ( P<0.01). The Harris hip function scores in both groups were improved at the last follow-up, compared with those at 3 months after internal fixation. Five patients had cement leakage in the PKP group, all of which were lateral leakage.There was no occurrence of radiating pain in the lower extremities. The incidence of DVT at 1 month after internal fixation was 19.2% (5/26) in the PKP group, which was lower than 57.6% (19/33) in the non-surgical group ( P<0.01). Conclusion:Compared with non-operative treatment after the closed reduction and internal fixation, PKP after internal fixation can significantly relieve low back pain in the early stage, improve the functional restoration of the vertebral column, maintain vertebral height, prevent kyphosis, promote the recovery of the hip joint function, and reduce the occurrence of DVT in the lower extremities in the treatment of intertrochanteric fracture combined with OVCF.

Objective:To evaluate the effects and underlying mechanisms of metabolites derived from the kidney-reinforcing, blood circulation-activating, and collateral dredging decoction on the proliferation of multiple myeloma (MM) KM3 cells.Methods:MM KM3 cells in the logarithmic growth phase were treated with 3%, 6%, 9%, or 12% metabolites of kidney-reinforcing, blood circulation-activating, and collateral dredging decoction. Cell viability was assessed using the CCK-8 assay. Apoptosis and necrosis were evaluated using flow cytometry and TUNEL staining. Mitochondrial and cellular ultrastructural changes were examined using transmission electron microscopy. mRNA and protein expression levels of dynamin-related protein 1 (Drp1), mitochondrial fission protein 1 (Fis1), mitochondrial fission factor (MFF), PTEN-induced kinase 1 (Pink1), and E3 ubiquitin ligase (Parkin) were determined through quantitative real-time PCR and western blotting. High-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) combined with network pharmacology, was utilized for reverse verification of the pharmacodynamic mechanisms and therapeutic targets underlying the anti-MM activity of this decoction.Results:The metabolites of the kidney-reinforcing, blood circulation-activating, and collateral dredging decoction inhibited KM3 cell proliferation and induced apoptosis in a dose-dependent manner. Transmission electron microscopy revealed increased mitochondrial fission and autophagic structures, with effects intensifying at higher metabolite concentrations. mRNA and protein expression of Drp1, Fis1, MFF, Pink1, and Parkin were significantly upregulated in treatment groups compared to controls ( P<0.05), with the most pronounced effects observed in the 12% metabolite group ( P<0.01). HPLC-MS/MS identified 121 bioactive compounds in BHTF, which shared 474 overlapping targets with MM. Enrichment analysis suggested that BHTF exerts antitumor effects primarily through apigenin, palmatine, and other key components by modulating TNF, NF-κB, and mitophagy pathways. Conclusion:The kidney-reinforcing and blood circulation-activating and collateral dredging decoction suppresses the proliferation of MM KM3 cells, potentially through mechanisms involving the regulation of mitochondrial dynamics and induction of autophagy.

Objective:To explore the value of deep learning models based on ultrafast dynamic contrast-enhanced MRI (UF-DCE MRI) in predicting malignant breast lesions.Methods:The study was a cross-sectional study. Clinical and imaging data of 347 patients with breast lesions who received treatment at Tianjin Medical University Cancer Institute and Hospital from March 2023 to January 2024 were analyzed retrospectively. A total of 347 lesions were observed in the 347 patients, including 75 benign and 272 malignant lesions. The random number method was used to divide into the training set with 243 cases and the validation set with 104 cases in a ratio of 7∶3. All patients underwent breast UF-DCE MRI and conventional dynamic-enhanced MRI (DCE-MRI). A 27-channel model (27-phase enhancement images of input UF-DCE MRI), a 3-channel model (3-phase enhancement images of input DCE-MRI), and a 1-channel model (1st-phase enhancement images of DCE-MRI) were built based on the pre-trained ResNet18 deep learning model on ImageNet. The efficacy of each model in predicting breast malignant lesions was analyzed using receiver operating characteristic curves and area under the curve (AUC). The differences of AUC were compared using DeLong test.Results:In the training and validation sets, the 27-channel model had the highest AUC for diagnosing malignant breast lesions, which were 0.848 (95% CI 0.818-0.877) and 0.784 (95% CI 0.752-0.817), respectively. DeLong test showed no statistically significant difference in the AUC values of the three models in the validation set for the diagnosis of malignant lesions of the breast in a two-by-two comparison ( P>0.05). UF-DCE MRI scans were 27 phases totaling 81 s with a temporal resolution of 3 s/phase; DCE-MRI scans were 3 phases totaling 270 s with a temporal resolution of 90 s/phase. Conclusions:The model combining UF-DCE MRI with deep learning demonstrates comparable efficacy to DCE-MRI deep learning model in diagnosing breast malignant lesions. However the UF-DCE MRI has the advantages of high temporal resolution and short scanning time, which makes this model valuable for precise diagnosis and treatment of breast cancer.

Objective To investigate the effect of facet joint resection at different ranges under endoscopy on the stability of the cervical spine and provide a biomechanical theoretical basis for clinical surgery.Methods A normal finite element model of the cervical spine C5-6 was established based on CT data,and unilateral facetectomy models with different ranges(0,25％,50％,75％,and 100％)of laminectomy were obtained(Models 1-5)by simulating cervical endoscopic surgery.The ranges of motion(ROMs)of C5-6 and the von Mises stresses of the discs for the models in each group were compared and analyzed.Results Except for flexion,Models 1 and 2 showed insignificant changes in ROMs and disc von Mises stresses in each direction compared with those of the normal model.Model 3 showed a noticeable increase in ROMs and disc von Mises stresses in each direction compared with those of the normal model:ROMs under flexion,extension,left lateral bending,right lateral bending,left rotation,and right rotation increased by 27％,4％,3％,13％,5％,and 16％,respectively,and von Mises stresses increased by 32％,4％,2％,5％,9％,and 5％,respectively.Models 4 and 5 exhibited a significant increase in the ROMs and disc von Mises stresses in each direction compared to the normal model.For Model 4,ROMs were increased by 27％,14％,6％,24％,7％,167％,and von Mises stresses were increased by 33％,13％,3％,32％,10％,130％.For Model 5,ROMs were increased by 27％,17％,6％,25％,7％,167％,and von Mises stresses were increased by 33％,29％,8％,33％,12％,138％.Conclusions As the range of unilateral facetectomy increased,cervical ROM and disc von Mises stress extremum gradually increased.The cervical spine shows a significant ROM increase and stress changes when facet joint resection on one side exceeds 1/2.More than 1/2 of the facet joint should be preserved during surgery to avoid medical instability.