Methods: From March 2020 to March 2023, 100 inpatients with DS were classified into groups A, B, C, and D based on the CARDS classification system. Preoperative radiological data were analyzed to measure the severity of central canal stenosis, facet joint arthropathy, intervertebral disc herniation, and spinal epidural lipomatosis, osteophyte formation, range of motion (ROM), and computed tomography value of the vertebral bodies. The radiological characteristics and clinical contraindications for OLIF were compared among the groups. Results: Of the 100 patients, 51% had clinical contraindications for OLIF, which included 85%, 25%, 62.5%, and 20% of patients in groups A, B, C, and D, respectively. Compared with group B, group A demonstrated greater severity of central canal stenosis, whereas group C showed a higher degree of facet joint arthropathy. More patients in groups A and C had severe central canal stenosis. Regarding the ROM results, group A had segmental stiffness, whereas group D presented relatively unstable slip segments. Conclusions Patients with different DS subtypes have varied radiological characteristics. Groups B and D are suitable candidates for OLIF. Most patients in group A are unsuitable for OLIF because of bony hyperplasia, severe spinal stenosis, and segmental stiffness.

Methods: Motor-evoked potentials (MEPs) and somatosensory-evoked potentials (SEPs) were recorded in 48 patients with TOLF (hybrid 20 vs. en bloc 28) during surgery. Patients were categorized based on MEP/SEP improvement, deterioration, or no change, and MEP/SEP improvement rates were measured in the improvement group. Furthermore, all patients were assessed using the Ashworth and modified Japanese Orthopedic Association scores. Results: The incidences of both MEP/SEP improvement (21.4% vs. 25.0%, p=0.772) and deterioration (21.4% vs. 20.0%, p=0.904) were similar between the en bloc and hybrid laminectomy groups, and no difference in preoperative and postoperative clinical assessments was observed between the two groups (p>0.05). In four patients (4/28, 14.3%) undergoing en bloc laminectomy, MEP amplitudes initially increased after OLF removal but gradually decreased. This delayed MEP reduction did not occur in the hybrid laminectomy group. Furthermore, more patients undergoing en bloc laminectomy had CFL than those undergoing hybrid laminectomy (46.4% vs. 15.0%, p=0.023). In the improvement group, the hybrid laminectomy group exhibited higher MEP improvement rates in the bilateral abductor hallucis than the en bloc laminectomy group (left side: 213.4%±35.9% vs. 152.5%±41.0%, p=0.028; right side: 201.2%±32.0% vs. 145.2%±46.3%, p=0.043). Conclusions Compared with en bloc laminectomy, hybrid laminectomy may be a safe and effective method for treating multilevel TOLF, potentially reducing intraoperative spinal cord irritation and CFL and causing relatively better functional recovery.

Methods: From March 2020 to March 2023, 100 inpatients with DS were classified into groups A, B, C, and D based on the CARDS classification system. Preoperative radiological data were analyzed to measure the severity of central canal stenosis, facet joint arthropathy, intervertebral disc herniation, and spinal epidural lipomatosis, osteophyte formation, range of motion (ROM), and computed tomography value of the vertebral bodies. The radiological characteristics and clinical contraindications for OLIF were compared among the groups. Results: Of the 100 patients, 51% had clinical contraindications for OLIF, which included 85%, 25%, 62.5%, and 20% of patients in groups A, B, C, and D, respectively. Compared with group B, group A demonstrated greater severity of central canal stenosis, whereas group C showed a higher degree of facet joint arthropathy. More patients in groups A and C had severe central canal stenosis. Regarding the ROM results, group A had segmental stiffness, whereas group D presented relatively unstable slip segments. Conclusions Patients with different DS subtypes have varied radiological characteristics. Groups B and D are suitable candidates for OLIF. Most patients in group A are unsuitable for OLIF because of bony hyperplasia, severe spinal stenosis, and segmental stiffness.

Methods: Motor-evoked potentials (MEPs) and somatosensory-evoked potentials (SEPs) were recorded in 48 patients with TOLF (hybrid 20 vs. en bloc 28) during surgery. Patients were categorized based on MEP/SEP improvement, deterioration, or no change, and MEP/SEP improvement rates were measured in the improvement group. Furthermore, all patients were assessed using the Ashworth and modified Japanese Orthopedic Association scores. Results: The incidences of both MEP/SEP improvement (21.4% vs. 25.0%, p=0.772) and deterioration (21.4% vs. 20.0%, p=0.904) were similar between the en bloc and hybrid laminectomy groups, and no difference in preoperative and postoperative clinical assessments was observed between the two groups (p>0.05). In four patients (4/28, 14.3%) undergoing en bloc laminectomy, MEP amplitudes initially increased after OLF removal but gradually decreased. This delayed MEP reduction did not occur in the hybrid laminectomy group. Furthermore, more patients undergoing en bloc laminectomy had CFL than those undergoing hybrid laminectomy (46.4% vs. 15.0%, p=0.023). In the improvement group, the hybrid laminectomy group exhibited higher MEP improvement rates in the bilateral abductor hallucis than the en bloc laminectomy group (left side: 213.4%±35.9% vs. 152.5%±41.0%, p=0.028; right side: 201.2%±32.0% vs. 145.2%±46.3%, p=0.043). Conclusions Compared with en bloc laminectomy, hybrid laminectomy may be a safe and effective method for treating multilevel TOLF, potentially reducing intraoperative spinal cord irritation and CFL and causing relatively better functional recovery.

Methods: From March 2020 to March 2023, 100 inpatients with DS were classified into groups A, B, C, and D based on the CARDS classification system. Preoperative radiological data were analyzed to measure the severity of central canal stenosis, facet joint arthropathy, intervertebral disc herniation, and spinal epidural lipomatosis, osteophyte formation, range of motion (ROM), and computed tomography value of the vertebral bodies. The radiological characteristics and clinical contraindications for OLIF were compared among the groups. Results: Of the 100 patients, 51% had clinical contraindications for OLIF, which included 85%, 25%, 62.5%, and 20% of patients in groups A, B, C, and D, respectively. Compared with group B, group A demonstrated greater severity of central canal stenosis, whereas group C showed a higher degree of facet joint arthropathy. More patients in groups A and C had severe central canal stenosis. Regarding the ROM results, group A had segmental stiffness, whereas group D presented relatively unstable slip segments. Conclusions Patients with different DS subtypes have varied radiological characteristics. Groups B and D are suitable candidates for OLIF. Most patients in group A are unsuitable for OLIF because of bony hyperplasia, severe spinal stenosis, and segmental stiffness.

Methods: Motor-evoked potentials (MEPs) and somatosensory-evoked potentials (SEPs) were recorded in 48 patients with TOLF (hybrid 20 vs. en bloc 28) during surgery. Patients were categorized based on MEP/SEP improvement, deterioration, or no change, and MEP/SEP improvement rates were measured in the improvement group. Furthermore, all patients were assessed using the Ashworth and modified Japanese Orthopedic Association scores. Results: The incidences of both MEP/SEP improvement (21.4% vs. 25.0%, p=0.772) and deterioration (21.4% vs. 20.0%, p=0.904) were similar between the en bloc and hybrid laminectomy groups, and no difference in preoperative and postoperative clinical assessments was observed between the two groups (p>0.05). In four patients (4/28, 14.3%) undergoing en bloc laminectomy, MEP amplitudes initially increased after OLF removal but gradually decreased. This delayed MEP reduction did not occur in the hybrid laminectomy group. Furthermore, more patients undergoing en bloc laminectomy had CFL than those undergoing hybrid laminectomy (46.4% vs. 15.0%, p=0.023). In the improvement group, the hybrid laminectomy group exhibited higher MEP improvement rates in the bilateral abductor hallucis than the en bloc laminectomy group (left side: 213.4%±35.9% vs. 152.5%±41.0%, p=0.028; right side: 201.2%±32.0% vs. 145.2%±46.3%, p=0.043). Conclusions Compared with en bloc laminectomy, hybrid laminectomy may be a safe and effective method for treating multilevel TOLF, potentially reducing intraoperative spinal cord irritation and CFL and causing relatively better functional recovery.

Methods: The median sagittal diameter and transverse diameter of the spinal canal from C2 to C7 were measured on CT images. The ratio of the median sagittal diameter to the transverse diameter was calculated. Accordingly, the spinal canal shape of each segment was classified into four, and the specific criteria of lunar phase classification were determined through linear discriminant analysis based on the ratio of the median sagittal diameter to the transverse diameter. The inter-rater reliability of the classification was explored using Kappa coefficients. Finally, the morphology of the different segments of the cervical spinal canal in healthy volunteers was revised and compared. Results: According to the ratio of the median sagittal diameter and the transverse diameter of the cervical spinal canal, the lunar phase classification of the cervical bony spinal canal was determined as follows: full-moon >0.65, 0.55< convex-moon ≤0.65, 0.46≤ quarter-moon ≤0.55, and residual-moon <0.46. The Kappa values of C2–C7 were 0.851, 0.958, 0.823, 0.927, 0.793, and 0.946, and the Kappa value of all C2–C7 segments was 0.854 that mainly presented two forms of full-moon (76.5%) and convex-moon (23.0%). A quarter-moon spinal canal was mainly distributed in C3, C4, C5, and C6; a residual-moon spinal canal was mainly distributed in C4 and C5; and the morphological distribution of C4 and C5 were similar (p>0.05). The frequency of the spinal canal of the residual-moon type was the highest, and the full-moon (6.5%) and residual-moon (7.5%) types of C7 were rare. Conclusions The morphological classification of the cervical spinal canal was established to present anatomical variations. The classification showed good inter-rater reliability.

Methods: Preoperatively, all 160 patients with OVCFs underwent pressure-pain threshold (PPT), temporal summation (TS), conditioned pain modulation (CPM), and imaging assessments. Pain intensity and pain-related disability were evaluated before and after PVP. Results: Preoperatively, patients with OVCFs had lower PPTs in both local pain and pain-free areas and lower CPM and higher TS in pain-free areas than healthy participants (p<0.05). Unlike patients with acute fractures, patients with subacute/chronic OVCFs showed higher TS with or without lower CPM in the pain-free area compared with healthy participants (p<0.05). Postoperatively, RBP occurred in 17 of 160 patients (10.6%). All preoperative covariates with significant differences between the RBP and non-RBP groups were subjected to multivariate logistic regression, showing that intravertebral vacuum cleft, posterior fascia edema, numeric rating pain scale scores for low back pain at rest, and TS were independently associated with RBP (p<0.05). Conclusions Augmented central pain processing may occur in patients with OVCFs, even in the subacute stage, and this preexisting CS may be associated with RBP. Preoperative assessment of TS in pain-free areas may provide additional information for identifying patients who may be at risk of RBP development, which may be beneficial for preventing this complication.

Objective:To investigate the diagnostic efficacy of MRI-based or CT-based measurements and the combined evaluation methods for preoperative bone quality assessment in patients with cervical degenerative diseases.Methods:Patients who underwent spine surgery for cervical degenerative diseases at the Department of Orthopedics, Huashan Hospital, Fudan University from September 2020 to March 2022 with available preoperative X-ray, CT, MRI and dule energy X-Ray absorptiometry (DEXA) data were included in this study. Vertebral bone quality score (VBQ) based on MRI T1-weightedimages and CT Hounsfiled unit (HU) values of the cervical spine were measured, and a combined diagnostic formula based on the binary logistic regression was constructed. The patients were divided into normal bone mass (T≥-1.0) and osteopenia/osteoporosis groups (T<-1.0). The student's t-test and Chi-square test were performed for comparisons between groups. The Pearson correlation coefficient was also used to investigate the correlation between DEXA-T scores, cervical VBQ and CT HU values. In addition, receiver operating characteristic curve (ROC) were plotted to explore the diagnostic efficacy of VBQ, CT HU and their combined diagnosis. Meanwhile, the corresponding sensitivity and specificity were obtained. Results:A total of 71 patients were included in this study (17 in the normal group and 54 in the osteopenia/osteoporosis group). The student's t-test showed that VBQ (2.90±0.70 vs. 3.83±0.83, t=4.23, P<0.001) and CT HU values (370.26±85.38 vs. 295.20±67.96, t=3.73, P=0.002) were significantly different between the two groups. The area under the ROC curve (AUC) for VBQ and CT values of the cervical spine were 0.81 and 0.75, respectively, and the AUC for the combined diagnostic value constructed on the basis of both was 0.85. Applying VBQ scores alone had a diagnostic sensitivity of 80% and a specificity of 70%, and the combined diagnosis with VBQ and CT HU had a sensitivity of 90% and a specificity of 75%. Person correlation analysis showed a significant correlation between DEXA T value, cervical VBQ value and CT HU value. The detailed formula was: DEXA T score=-0.63×cervical VBQ+0.64 ( r=-0.55, P<0.001), CT HU value=-40.20×cervical VBQ+458.40 ( r=-0.45, P<0.001), DEXA T score=0.006×CT HU-3.47 ( r=0.45, P<0.001). Conclusion:This study confirmed the feasibility of using cervical VBQ values, CT HU values and combined diagnostics for preoperative bone density screening in patients with degenerative cervical spine diseases. This method allows surgeons to perform an initial preoperative bone density screening based on the patient's existing imaging data, and thus could aid in confirming the indication and scheme of surgery. The method could be a powerful tool for preoperative bone density assessment screening in patients with cervical degenerative diseases.

Objective:To investigate the correlation between paraspinal muscle atrophy, morphological changes of facet joints and adjacent segment disease (ASDis) after lumbar fusion operation.Methods:A retrospective study was conducted among 195 patients who underwent posterior lumbar fusion again for ASDis at this institution from January 2014 to December 2020, including 29 patients with ASDis whose initial surgical fusion segment was L 4,5. According to Roussouly's staging, there were 5 cases of type I, 9 cases of type II, 10 cases of type III, and 5 cases of type IV. Another 29 cases were selected from patients without ASDis after lumbar fusion as a control group. The control group was paired 1∶1 with the ASDis group according to gender, fusion segment, and Roussouly typing of the lumbar spine. The cross-sectional area (CSA) and fat infiltration (FI) of paravertebral muscle, facet joint angle (F-J) and pedicle facet (P-F) angle before the first (second) operation were measured and compared between the two groups. Then logistic regression analysis was used to determine the predictors of ASDis after posterior lumbar fusion. Finally, the receiver operation characteristic (ROC) curve was described, and the area under the curve (AUC) and cut-off point were calculated. At the same time, the paraspinal muscle atrophy before the second operation in ASDis group was measured. Results:The average follow-up time of 98 patients was 59.25±6.38 months (range, 49-73 months). The average body mass index (BMI) of ASDis group was 24.76±3.64 kg/m 2, which was higher than that in control group (22.24±2.92 kg/m 2) ( t=2.481, P=0.041). The average CSA and relative cross-sectional area (rCSA) of paraspinal muscle in ASDis group were 3 214.32± 421.15 mm 2 and 1.69±0.36 respectively, which were less than 3 978.91±459.87 mm 2 and 2.26±0.29 in control group ( t=10.22, P=0.012; t=9.47, P=0.038). The FI degree of paraspinal muscle in ASDis group (21.95%±5.89%) was significantly higher than that in control group (14.64%±7.11%) ( t=7.32, P=0.002). The F-J angle in ASDis group was 35.06°±3.45°, which was less than 38.39°±4.67° in control group ( t=4.76, P=0.027). The P-F angle in ASDis group was 117.39°±8.13°, which was greater than 111.32°±4.78° in control group ( t=5.25, P=0.031). Multivariate logistic regression analysis showed that higher BMI ( OR=1.34, P=0.038), smaller rCSA of paraspinal muscle ( OR=0.02, P=0.017) and higher FI of paraspinal muscle ( OR=1.58, P=0.032) were the risk factors of postoperative ASDis. The ROC curve showed that the AUC of BMI was 0.680 and the cut-off point was 22.58 kg/m 2; The AUC of the FI of paraspinal muscle was 0.716 and the cut-off point was 15.69%; The AUC of rCSA of paraspinal muscle was 0.227 and the cut-off point was 1.92. For ASDis patients, the paraspinal muscle before the second operation had a higher degree of FI (25.47%±6.59% vs. 21.95%±5.89%, t=3.99, P=0.042) and a smaller rCSA (1.52±0.28 vs. 1.69±0.36, t=3.85, P=0.038) than that before the first operation. The difference between the FI degree of paraspinal muscle before the second operation and the first operation was negatively correlated with the occurrence time of ASDis ( r=-0.53, P=0.039) , and the difference of rCSA was positively correlated with the occurrence time of ASDis ( r=0.64, P=0.043) . Conclusion:When BMI >22.58 kg/m 2, FI of paraspinal muscle >15.69%, and rCSA of paraspinal muscle <1.92, it suggests that ASDis is more likely to occur after operation. And the more obvious paraspinal muscle atrophy after the first operation, the earlier ASDis may occur. Morphological changes of facet joints cannot be used as an index to predict the occurrence of ASDis.