Analysis of Factors Associated with Lumbar Degenerative Disease Complicated by Baastrup's Disease.

OBJECTIVE: To investigate the factors associated with the occurrence of Baastrup's disease (BA) in patients with lumbar degenerative diseases (LDDs). METHODS: A retrospective analysis was conducted on 168 patients with LDDs (including lumbar disc herniation, lumbar spinal stenosis, and lumbar spondylolisthesis) who were treated at our hospital from January 2020 to January 2023, comprising 95 males and 73 females, aged 48-84 years.Patients were divided into two groups based on the presence of Baastrup's disease: those with BA (Group A) and those without BA (Group B).Relevant patient factors were extracted, including age, gender, occupation, smoking history, alcohol consumption history, body mass index, bone density, presence of internal diseases (diabetes, hypertension), lumbar lordosis angle, endplate Modic changes, degree of intervertebral disc degeneration, and facet joint degeneration (Weishaupt grading).Statistical analysis was performed using, Statistical Package for the Social Sciences 26.0 software to compare the differences in these factors between the two groups, and statistically significant results were included in a multivariate logistic regression analysis. RESULTS: Univariate analysis indicated that there were no statistically significant differences between the two groups in terms of gender, smoking history, alcohol consumption history, bone density, presence of internal diseases (diabetes, hypertension), lumbar lordosis angle, and endplate Modic changes (P>0.05),whereas age, occupation, body mass index, degree of intervertebral disc degeneration, and degree of facet joint degeneration showed statistically significant differences (P < 0.05).Multivariate logistic regression analysis revealed that age, degree of intervertebral disc degeneration, and degree of facet joint degeneration were independent risk factors for the occurrence of BA in patients with LDDs (P < 0.05). CONCLUSIONS: BA is relatively common in patients with LDDs, and advanced age, severe intervertebral disc degeneration, and facet joint degeneration are its independent risk factors.

Levels of 91 circulating inflammatory proteins and risk of lumbar spine and pelvic fractures and peripheral ligament injuries: a two-sample mendelian randomization study.

OBJECTIVE: Lumbar spine and pelvic fractures(LPF) are combined with peripheral ligament injuries(PLI), frequently. It has been reported that the site of fracture injury is usually paralleled by the secretion of inflammatory proteins. This study aimed to investigate the causal relationship between 91 circulating inflammatory proteins and LPF and PLI by using a Two-sample Mendelian randomization (MR) analysis. METHODS: Single nucleotide polymorphisms (SNPs) associated with 91 circulating inflammatory proteins, as exposures were selected from a large genome-wide association study (GWAS). The genetic variant data for LPF and PLI as outcomes from the FinnGen consortium. The inverse-variance-weighted (IVW) method was utilized as the main analysis for exposures and outcomes. In addition, the final results were reinforced by the methods of MR Egger, weighted median, simple mode, and weighted mode. The sensitivity analyses were used to validate the robustness of results and ensure the absence of heterogeneity and horizontal pleiotropy. MR-Steiger was used to assess whether the causal direction was correct to avoid reverse causality. RESULTS: This study has shown that Beta-nerve growth factor(Beta-NGF) and Interferon gamma(IFN-gamma) are both involved in the occurrence of LPF and PLI, and they are reducing the risk of occurrence(OR:0.800, 95%CI: 0.650-0.983; OR:0.723, 95%CI:0.568-0.920 and OR:0.812, 95%CI:0.703-0.937; OR:0.828, 95%CI:0.700-0.980). Similarly, Axin-1 and Sulfotransferase 1A1 (SULT-1A1) were causally associated with LPF(OR:0.687, 95%CI:0.501-0.942 and OR:1.178,95%CI:1.010-1.373). Furthermore, Interleukin-4(IL-4), Macrophage inflammatory protein 1a(MIP-1a), and STAM binding protein(STAM-BP) were causally associated with PLI(OR:1.236, 95% CI: 1.058-1.443; OR:1.107, 95% CI: 1.008-1.214 and OR:0.759, 95% CI: 0.617-0.933). The influence of heterogeneity and horizontal pleiotropy were further excluded by sensitivity analysis. CONCLUSION: This study provides new insights into the relationship between circulating inflammatory proteins and LPF and PLI, and may provide new clues for predicting this risk.

[Effectiveness of unilateral biportal endoscopy combined with percutaneous pedicle screw fixation in treatment of lumbar burst fractures with neurological symptoms].

Objective: To evaluate the effectiveness of spinal canal decompression assisted by unilateral biportal endoscopy (UBE) and percutaneous uniplanar pedicle screw internal fixation in the treatment of lumbar burst fractures with neurological symptoms. Methods: Between June 2021 and December 2022, 10 patients with single level lumbar burst fracture with neurological symptoms were treated with spinal canal decompression assisted by UBE and percutaneous uniplanar pedicle screw internal fixation. There were 7 males and 3 females with an average age of 43.1 years (range, 21-57 years). The injured vertebrae located at L 1 in 2 cases, L 2 in 4 cases, L 3 in 3 cases, and L 4 in 1 case. There were 7 cases of AO type A3 fractures and 3 cases of AO type A4 fractures. The total operation time, the time of operation under endoscopy, and complications were recorded. Pre- and post-operative visual analogue scale (VAS) score and American Spinal Injury Association (ASIA) scale (grading A-E corresponding to assigning 1-5 points for statistical analysis) were used to evaluate effectiveness. X-ray film and CT were performed to observe the fracture healing, and the ratio of anterior vertebral body height, Cobb angle, and rate of spinal canal invasion were measured to evaluate the reduction of fracture. Results: All operations was successfully completed, and the spinal canal decompression and the bone fragment in spinal canal reduction completed under the endoscopy. Total operation time was 119 minutes on average (range, 95-150 minutes), and the time of operation under endoscopy was 46 minutes on average (range, 35-55 minutes). There was no complication such as dural sac, nerve root, or blood vessel injury during operation. All incisions healed by first intention. All patients were followed up 18.7 months on average (range, 10-28 months). The VAS score after operation significantly decreased when compared with that before operation ( P<0.05), and further improved at last follow-up ( P<0.05). The ASIA scale after operation significantly improved when compared with that before operation ( P<0.05), and there was no significant difference ( P>0.05) in the ASIA scale between at 1 week after operation and at last follow-up. The imaging examination showed that the screw position was good and the articular process joint was preserved. During follow-up, there was no loosening, fracture, or fixation failure of the internal fixation. The ratio of anterior vertebral body height and Cobb angle significantly improved, the rate of spinal canal invasion significantly decreased after operation ( P<0.05), and without significant loss of correction during the follow-up ( P>0.05). Conclusion: Spinal canal decompression assisted by UBE and percutaneous uniplanar pedicle screw fixation is a feasible minimally invasive treatment for lumbar burst fractures with neurological symptoms, which can effectively restore the vertebral body sequence, as well as relieve the compression of spinal canal, and improve the neurological function.

Predicting and analysing of the unfavourable outcomes of early applicated percutaneous endoscopic interlaminar discectomy for lumbar disc herniation: development and validation based nomogram.

OBJECTIVE: To predict and analyse the unfavourable outcomes of early applicated percutaneous endoscopic interlaminar discectomy for lumbar disc herniation. METHODS: Information of 426 patients treated by early applicated percutaneous endoscopic interlaminar discectomy (PEID) for lumbar disc herniation (LDH) at our hospital from June 2017 to October 2021 in addition to 17 other features was collected. The risk factors were selected by the least absolute shrinkage and selection operator method (LASSO) regression. Then, a prediction model (nomogram) was established to predict the unfavourable outcomes of using the risk factors selected from LASSO regression. Bootstrap (n = 1000) was used to perform the internal validation, and the performance of the model was assessed by the concordance index (C-index), receiver operating characteristic curve, and calibration curve. The decision curve analysis (DCA) and clinical impact curve (CIC) were used to assess the clinical utility of the model, respectively. RESULTS: Finally, 53 of 426 patients showed unfavourable outcomes. Five potential factors, Modic change, Calcification, Lumbar epidural steroid injection preoperative, Articular process hyperplasia and cohesion, and Laminoplasty technique, were selected according to the LASSO regression, that identified the predictors to establish nomogram model. Meanwhile, the C-index of the prediction nomogram was 0.847, the area under the receiver operating characteristic curve value was 0.847, and the interval bootstrapping (n = 1000) validation C-index was 0.809. The model has good practicability for clinics according to the DCA and CIC. CONCLUSION: This nomogram model has good predictive performance and clinical practicability, which could provide a certain basis for predicting unfavourable outcomes of early applicated PEID for LDH.

A new classification of lumbar Basstrup's disease based on radiographic and clinical symptoms.

OBJECTIVE: To propose a new classification method for lumbar Basstrup's disease based on radiographic and clinical symptoms, and to test its credibility and reproducibility. METHODS: A retrospective analysis of 116 patients with complete data of lumbar Basstrup's disease in our hospital from January 2019 to January 2022, radiological imaging including X-ray, CT and MRI, were divided into two main types according to the number of segments: type I (single segment) and type II (multiple segments), each type was divided into a total of eight subtypes according to the degree of degeneration: Ia, Ib, Ic, Id, IIa, IIb, IIc, IId; it was further divided into 16 subtypes according to the presence or absence of clinical symptoms (i.e. low back pain or/and lower limb neurological symptoms: no 0, yes 1): Ia0, Ia1, Ib0, Ib1, Ic0, Ic1, Id0, Id1; IIa0, IIa1, IIb0, IIb1, IIc0, IIc1, IId0, IId1.The 116 patients with Basstrup's disease were successively typed twice (1 month interval) by five physicians according to the new classification method, and the reliability and reproducibility of the new classification were assessed using the Kappa consistency test. RESULTS: Among 116 patients with lumbar Basstrup's disease: there were 60 cases of type I (single segment), accounting for 51.72%, including Ia 19 cases, Ib 16 cases, Ic 10 cases, and Id 15 cases; there were 56 cases of type II (multiple segments), accounting for 48.28%, including IIa 10 cases, IIb 20 cases, IIc 14 cases, and IId 12 cases. Of the 116 patients, 47 cases had no clinical symptoms (Ia0 16 cases, Ib0 3 cases, Ic0 6 cases, Id0 1 case, IIa0 8 cases, IIb0 2 cases, IIc0 10 cases, IId0 1 case), accounting for 40.52%; 69 cases were accompanied by low back pain or/and lower extremity nerve symptoms (Ia1 3 cases, Ib1 13 cases, Ic1 4 cases, Id1 14 cases, IIa1 2 cases, IIb1 18 cases, IIc1 4 cases, IId1 11 cases), accounting for 59.48%.Five physicians completed two rounds of a total of 1160 typings, with inter-assessor typing agreement of 82.47% (80.17-85.34%) and a mean Kappa value of 0.723 (0.771-0.831); intra-assessor typing agreement of 82.76% (77.59-86.21%) and a mean Kappa value of 0.801 (0.742-0.841). CONCLUSION: The new classification method for lumbar Basstrup's disease based on radiographic and clinical symptoms is simple, practical, with good credibility and reproducibility, and provides some guidance for clinical treatment.

The significance of the best puncture side bone cement/vertebral volume ratio to prevent paravertebral vein leakage of bone cement during vertebroplasty: a retrospective study.

OBJECTIVES: To verify the clinical significance of the best puncture-side bone cement/vertebral volume ratio (PSBCV/VV%) and bone cement leakage in paravertebral veins during vertebroplasty. METHODS: This was a retrospective analysis of a total of 210 patients from September 2021 to December 2022, who were divided into an observation group (110 patients) and a control group (100 patients). In the observation group, patients' preoperative computed tomography (CT) data were imported into Mimics software, and the VV was calculated using the three-dimensional (3D) reconstruction function. Then, based on the best PSBCV/VV% of 13.68% determined in a previous study, the optimal PSBCV to be injected during vertebroplasty was calculated. In the control group, vertebroplasty was performed directly using the conventional method. The incidence of cement leakage into paravertebral veins was observed postoperatively in both groups. RESULTS: There were no statistically significant differences (P > 0.05) in the evaluated indicators between the two groups pre- or postoperatively, including the anterior vertebral margin height, mid-vertebral height, injured vertebral Cobb angle, visual analogue scale (VAS) score, and Oswestry Disability Index (ODI). Intragroup comparisons showed improvements in the anterior vertebral height, mid-vertebral height, injured vertebral Cobb angle, VAS score, and ODI after surgery compared with before surgery (P < 0.05). In the observation group, there were 3 cases of cement leakage into the paravertebral veins, for a leakage rate of 2.7%. In the control group, there were 11 cases of cement leakage into the paravertebral veins, for a leakage rate of 11%. The difference in the leakage rate between the two groups was statistically significant (P = 0.016). CONCLUSION: In vertebroplasty, preoperative VV calculations using Mimics software, combined with calculation of the PSBCV according to the best PSBCV/VV% (13.68%), can effectively prevent leakage of bone cement into paravertebral veins and further prevent serious life-threatening complications such as pulmonary embolism.

Operative Effect Comparison of Flexible Drill Guiding vs. Traditional Drill Guiding Template for Lower Cervical Pedicle Screw Insertion: A Retrospective Analysis.

OBJECTIVE: Accurately inserting pedicle screws is the key point of posterior pedicle screw fixation for lower cervical spine (C3-C7) instability. 3D printing technology can improve the accuracy of screw placement. This study compared the safety of 3D-printed flexible drill guiding template vs. traditional rigid drill guiding template for lower cervical pedicle screw insertion. METHODS: This was a retrospective study. A total of 34 patients who underwent lower cervical pedicle screw fixation from March 2018 to May 2021 were enrolled in this study, and they were divided into the flexible drill flexible drill group and the traditional drill group. A total of 18 patients in the flexible drill flexible drill group underwent pedicle screw fixation assisted by 3D printed flexible drill guiding templates for the lower cervix, and 16 patients in the traditional drill group underwent pedicle screw fixation assisted by 3D printed regular drill guiding templates for the lower cervix. The length of the incision and intraoperative blood loss during surgery were recorded and compared for the two groups. The grade, deviation of the screw entry point, deviation of the screw medial angle and screw length were measured and compared after surgery for the two groups by independent-sample tests. RESULTS: There was a significant difference in the length of the incision and blood loss between the two groups (P < 0.05). There was a significant difference between the two groups for grade (P = 0.016). The deviation of the screw entry point was 0.65 ± 0.50 mm in the flexible drill group and 0.78 ± 0.83 mm in the traditional drill group. The deviation of the screw medial angle was 2.14 ± 1.78 in the flexible drill group and 4.23 ± 2.51 in the traditional drill group, with a significant difference between the two groups (P < 0.05). CONCLUSION: Compared with regular guiding techniques, lower cervical pedicle screw placement assisted by multistep navigation templates and flexible K-wires results in less trauma and better safety.

Thoracolumbar Osteoporotic Vertebral Compression Fracture Treatment by Unilateral Percutaneous Vertebroplasty Using Curved Diffusion Needle.

Objective: To investigate the clinical effect of unilateral puncture vertebroplasty with curved diffusion needle (CDN) in the treatment of thoracolumbar osteoporotic vertebral compression fracture (OVCFs). Methods: We used the method of a retrospective study. The clinical data of 38 patients with OVCFs treated by unilateral puncture vertebroplasty with curved diffusion needle from January 2021 to January 2022 were analyzed. The operation time and the amount of bone cement injected were recorded to observe the leakage and dispersion of bone cement during the operation and the incidence of vertebral re-fracture at the last follow-up. Visual analog scale (VAS) and Oswestry disability index (ODI) were used to evaluate the pain and functional improvement before and after surgery. Results: All patients successfully completed the operation. The operation time was 31.2 ± 5.1 min, and the bone cement injection volume was 4.8 ± 1.1 ml. During the operation, three patients had bone cement leakage, and the leakage rate was 7.8%. The bone cement dispersion was excellent in 31 cases, among which seven cases were good; the postoperative follow-up time was 3-10 months, with an average of 6.3 months; no vertebral body re-fracture occurred. VAS score and ODI at 1d after the operation and at the last follow-up were significantly improved compared with those before the operation, and the difference was statistically significant (P < 0.05). Also there was a significant difference between the postoperative 1d and the last follow-up (P < 0.05). Conclusions: Unilateral puncture vertebroplasty for the treatment of thoracolumbar OVCFs can obtain good bone cement distribution, safety and does not increase complications, and the clinical effect is satisfactory.

Finite Element Analysis and Transiliac-Transsacral Screw Fixation for Posterior Pelvic Ring with Sacrum Dysplasia.

OBJECTIVE: Posterior pelvic ring sacroiliac screws are preferred by clinicians for their good biomechanical performance. However, there are few studies on mechanical analysis and intraoperative screw insertion of the dysplastic sacrum and sacroiliac screw. This study investigated the biomechanical performance of oblique sacroiliac screws (OSS) in S1 combined with transiliac-transsacral screws (TTSs) in S2 for pelvic fracture or sacroiliac dislocation with dysplastic sacrum and evaluated the safety of screw placement assisted by the navigation template. METHODS: Six models were established, including one OSS fixation in the S2 segment, one transverse sacroiliac screw (TSS) fixation in the S2 segment, one TTS fixation in the S2 segment, one OSS fixation in the S1 and S2 segments, one OSS fixation in the S1 segment and one TSS fixation in the S2 segment, one OSS fixation in the S1 segment and one TTS fixation in the S2 segment. Then, finite element analysis (FEA) was performed. Twelve dysplastic sacrum patients with pelvis fracture or sacroiliac dislocation underwent OSS insertion in the S1 combined with TTS insertion in the S2 under the assistance of the patient-specific locked navigation template. Grading and Matta scores were evaluated after surgery. RESULTS: In the one-screw fixation group, the vertical displacements of the sacrum surface of S2 OSS, S2 TSS and S2 TTS were 1.23, 1.42, and 1.22 mm, respectively, and the maximum stress of screw were 139.45 MPa, 144.81 MPa, 126.14 MPa, respectively. In the two-screw fixation group, the vertical displacements of the sacrum surface of the S1 OSS + S2 OSS, S1 OSS + S2 TSS and S1 OSS + S2 TTS were 0.91, 1.06, and 0.75 mm, respectively, and the maximum stress of screw were 149.26 MPa, 167.13 Pa, 136.76 MPa, respectively. Clinically, a total of 12 TTS and OSS were inserted under the assistance of navigation templates, with a surgical time of 55 ± 7.69 min, bleeding of 57.5 ± 18.15 ml and radiation times of 14.5 ± 4.95. One of the TTS and one of the OSS were grade 1, and the other screws were grade 0. The Matta scores of nine patients were excellent, and three patents were good. CONCLUSION: OSS in the S1 combined with TTS in the S2 had the best mechanical stability in six models, and it is safe for screw insertion assisted by the patient-specific locked navigation template.

Biomechanical and osteointegration study of 3D-printed porous PEEK hydroxyapatite-coated scaffolds.

The objective of this study as to evaluate the biomechanical and osteointegration properties of 3D printed porous polyetheretherketone (PEEK) with hydroxyapatite (HA) coating by simulated body fluid (SBF) method. Cylindrical scaffolds were designed and fabricated by using PEEK material through fused deposition molding (FDM). The scaffolds were divided into solid group, porous group and porous-HA group (decorated by hydroxyapatite). The mechanical properties of each group of scaffolds were tested. Then, a total of 12 New Zealand rabbits were implemented for implantation of scaffolds at femoral condyle. Finally, the osteointegration ability of scaffolds were evaluated by Micro computed tomography (Micro-CT), histology and fluorescence staining. The HA was successfully decorated on the surface of the PEEK scaffold. The modulus of solid, porous and porous-HA group was 1289.43 ± 71.44 MPa, 196.36 ± 9.89 MPa and 183.29 ± 7.71 MPa, and the compressive strength was 107.24 ± 5.15 MPa, 33.12 ± 3.86 MPa and 29.99 ± 4.16 MPa, respectively. The micro-CT results showed that the bone volume/total volume ratio (BV/TV) in the porous-HA group was significantly greater than that in solid and porous group. Compared with porous group, the trabecular number (Tb. N) and trabecular thickness (Tb. Th) of porous-HA group was higher, and the trabecular spacing (Tb. Sp) was lower. The histology and fluorescence staining showed that more new bone tissue was formed in the porous-HA at different periods compared with the porous and solid groups. In addition, according to the results of the biomechanical test and osteointegration assessment, the biomechanical properties of 3D-printed porous PEEK scaffolds are close to human trabecular bone tissue, and the hydroxyapatite coating does not degrade its biomechanical performance. The porous structure can facilitate the integration of bone tissue, and the HA coating can markedly improve this process.

[The effect of axis pedicle and intra-axial vertebral artery on C 2 pedicle screw placement].

Objective: To investigate the influence of axis pedicle and intra-axial vertebral artery (IAVA) alignment on C 2 pedicle screw placement by measuring the data of head and neck CT angiography. Methods: The axis pedicle diameter (D), isthmus height (H), isthmus thickness (T), and IAVA alignment types were measured in 116 patients (232 sides) who underwent head and neck CT angiography examinations between January 2020 and June 2020. Defined the IAVA offset direction by referencing the vertical line through the center of C 3 transverse foramen on the coronal scan, it was divided into lateral (L), neutral (N), and medial (M). Defined the IAVA high-riding degree by referencing the horizontal line through the outlet of the C 2 transverse foramen, it was divided into below (B), within (W), and above (A). The rate of pedicle stenosis, high-riding vertebral artery, and different IAVA types were calculated, and their relationships were analysed. Simulative C 2 pedicle screws were implanted by Mimics 19.0 software, and the interrelation among the rates of pedicle stenosis, high-riding vertebral artery, IAVA types, and vertebral artery injury were analyzed. Results: The rate of C 2 pedicle stenosis was 33.6% (78/232), and the rate of high-riding vertebral artery was 35.3% (82/232). According to the offset direction and the degree of riding, IAVA was divided into 9 types, among which the N-W type (29.3%) was the most, followed by the L-W type (19.0%) and the L-B type (12.9%), accounting for 60.9%. The vertebral artery injury rate of simulative implanted C 2 pedicle screws was 35.3% (82/232). The vertebral artery injury rate in patients with pedicle stenosis and high-riding vertebral artery was significantly higher than that who were not ( P<0.001). The rate of pedicle stenosis, high-riding vertebral artery, and vertebral artery injury were significantly different among IAVA types ( P<0.001), and M-A type was the most common. Conclusion: Vertebral artery injury is more common in pedicle stenosis and/or high-riding vertebral artery and/or IAVA M-A type. Preoperative head and neck CT angiography examination has clinical guiding significance.

Percutaneous endoscopic interlaminar discectomy via inner border of inferior pedicle approach for downmigrated disc herniation: a retrospective study.

OBJECTIVE: To evaluate the efficacy and feasibility of percutaneous endoscopic interlaminar discectomy (PEID) via the inner border of the inferior pedicle approach for downmigrated disc herniation. METHODS: Seventeen patients who had downmigrated disc herniation were included in this study from May 2020 to February 2021. After PEID via the inner border of the inferior pedicle approach, a retrospective study was conducted on all patients. Radiologic findings were investigated, and based on the level of migration seen on preoperative magnetic resonance imaging (MRI), participants were divided into two types (high-grade and low-grade migrations). Preoperative, 1st post-operative day, 3rd post-operative month, and the final follow-up visual analogue scale (VAS) assessments for back and leg pain and preoperative, 3rd post-operative month, and the final follow-up Oswestry disability index (ODI) evaluations were performed. The clinical effects at the final follow-up were assessed by the modified MacNab criterion. RESULTS: All patients successfully completed surgery. There were 10 males and 7 females in the group. These patients were 42 years old on average (range, 25-68 years). Four and 13 patients had downmigrated disc herniation with high-grade and low-grade, respectively, on MRI. The mean follow-up duration was 10.47 ± 1.84 months (range, 8-14 months). The mean VAS score for back and leg improved from 5.18 ± 0.81 preoperatively to 1.35 ± 0.49 at the final follow-up (P < 0.05) and 6.94 ± 0.66 preoperatively to 1.47 ± 0.51 at the final follow-up (P < 0.05), respectively. The mean ODI score improved from 48.00 ± 3.64 preoperatively to 18.71 ± 1.31 at the final follow-up (P < 0.05). According to the modified MacNab criterion, 15 patients (88.2%) obtained excellent, while the rest 2 patients (11.8%) reported good outcomes. CONCLUSION: PEID via the inner border of the inferior pedicle approach could be a good alternative option for the treatment of downmigrated disc herniation.

Correlation analysis of the puncture-side bone cement/vertebral body volume ratio and bone cement leakage in the paravertebral vein in vertebroplasty.

OBJECTIVES: To explore the influencing factors of bone cement leakage in the paravertebral vein after vertebroplasty for the treatment of osteoporotic vertebral compression fractures (OVCFs) and to determine the correlation between the puncture-side bone cement/vertebral body volume ratio and bone cement leakage in the paravertebral vein. METHODS: This was a retrospective analysis of 495 patients (585 vertebral bodies) with OVCFs treated from August 2018 to May 2021 in our hospital. The patients' postoperative CT data were imported into Mimics software, and the three-dimensional(3D) reconstruction function was used to calculate the bone cement volume (BCV), puncture-side bone cement volume (PSBCV), and vertebral body volume (VBV); the bone cement/vertebral body volume ratio (BCV/VCV%) and puncture-side bone cement/vertebral body volume ratio (PSBCV/VCV%) were additionally calculated. Sex, Age, Body mass index(BMI), Bone density, BCV, PSBCV, VBV, BCV/VCV%, and PSBCV/VCV were compared between the leakage group and the non-leakage group. Logistic regression analysis was used to assess the correlations between the factors that statistically significantly differed between the two groups and the presence of leakage in the paravertebral veins. A receiver operating characteristic (ROC) curve was used to determine the diagnostic value of the PSBCV/VCV% and to obtain the optional cut-off value. RESULTS: A total of 102 males and 393 females with an average age of 72.89 (52 ~ 93) years were included in our study. There were 57 cases of cement leakage (59 vertebral bodies) in the paravertebral vein. There were 438 patients (526 vertebral bodies) without paravertebral cement leakage. Univariate analysis showed that the differences in sex, bone density, PSBCV, and PSBCV/VCV% between the two groups were statistically significant (P < 0.05). Logistic regression analysis showed that there were correlations between sex, bone density, and PSBCV/VCV% and the presence of paravertebral cement leakage (P < 0.05). The ROC curve showed that the area under the curve of the PSBCV/VCV% for the diagnosis of cement leakage in the paravertebral vein was greater than 0.65, and P < 0.05, indicating a diagnostic value. The best cut-off point for the diagnosis of paravertebral cement leakage with the PSBCV/VCV% was 13.68%, with a sensitivity of 84.7% and specificity of 37.8%. CONCLUSION: Sex, bone density, and PSBCV/VCV% are risk factors for cement leakage in the paravertebral veins after vertebroplasty for the treatment of OVCFs; the PSBCV/VCV% is strongly associated with paravertebral venous leakage, and the optimal PSBCV/VCV% is 13.68%. When the PSBCV/VCV% exceeds the optimal value, the risk of cement leakage in the paravertebral vein becomes significantly increased.

Feasibility of Atlas Pedicle Screw Fixation Perpendicular to the Coronal Plane-A 3D Anatomic Analysis.

STUDY DESIGN: An anatomic analysis. OBJECTIVE: To investigate the feasibility of the ideal atlas pedicle screw trajectory perpendicular to the coronal plane via atlas digital 3D reconstruction. METHODS: One hundred adult atlases were evaluated in this study. The projection of the corridor for atlas pedicle screw fixation perpendicular to the coronal plane was quickly obtained using the perspective model of 3D reconstruction, and the area, long axis, short axis and width of the pedicle corridor were measured. The inner trajectory was near the lateral wall of the pedicle, and the center of the corridor was point A. The lateral trajectory was near the lateral wall of the transverse foramen, and the center of the trajectory was point C. The midpoint of A and C was B. The length of the inner, middle and lateral trajectorys were measured. The distances from points A, B and C to the posterior tubercle of the atlas and safety swing angle were measured. RESULTS: From the dorsal view, the pedicle corridor was fitted into an ellipse with an average long axis of 13.6 mm, an average short axis of 5.2 mm, and an average area of 56.3 mm2. From the axial view, the pedicle corridor had an average width of 9.4 mm. The average lengths of the inner trajectory, middle trajectory and lateral trajectory were 31.7 mm, 28.7 mm and 25.1 mm, respectively; The average distances from the posterior tubercle to points A, B and C were 17.1 mm, 20.8 mm and 24.5 mm, respectively. The average swing angles from points A, B and C were 16.1°, 25.5°, and 28.1°, respectively. CONCLUSION: Atlas pedicle screw fixation perpendicular to the coronal plane is feasible for almost all the volunteers. Pedicle screws close to the pedicle lateral wall of the atlas posterior arch perpendicular to the coronal plane is an advanced technique that is easy to master.

[Application of Curved Diffusion Needle in unilateral percutaneous vertebroplasty].

OBJECTIVE: To evaluate the effectiveness of Curved Diffusion Needle in unilateral percutaneous vertebroplasty (PVP) by compared with bilateral PVP. METHODS: A clinical data of 93 patients with osteoporotic vertebral compression fracture (OVCF) treated with PVP between January 2020 and January 2021 was retrospectively analyzed, including 47 patients underwent unilateral PVP assisted with Curved Diffusion Needle (unilateral group) and 46 patients underwent bilateral PVP (bilateral group). There was no significant difference in gender, age, cause of injury, time from injury to operation, T value of bone mineral density, AO classification, distribution of injured vertebrae, and preoperative visual analogue scale (VAS) score, Oswestry disability index (ODI), relative height of injured vertebrae, and Cobb angle between the two groups ( P>0.05). The operation time, the amount of bone cement injection, the incidence of bone cement leakage, the bone cement diffusion distribution, VAS score, ODI, the relative height of injured vertebrae, and Cobb angle were recorded and compared between the two groups. RESULTS: All operations successfully completed. The operation time was significantly shorter in unilateral group than in bilateral group ( t=-13.936, P=0.000), and the amount of bone cement injection was significantly less in unilateral group than in bilateral group ( t=-13.237, P=0.000). The incidence of bone cement leakage in unilateral group was 19.14%, which was significantly lower than that in bilateral group (39.13%) ( χ 2=4.505, P=0.034). The score of bone cement distribution in unilateral group was 7.0±1.3, of which 41 cases were excellent and 6 cases were well. The score of bilateral group was 7.4±0.8, of which 43 cases were excellent and 3 cases were well. There was no significant difference in score and grading of bone cement distribution between the two groups ( t=-1.630, P=0.107; Z=-1.013, P=0.311). All patients were followed up and the follow-up time was 3-10 months (mean, 6.5 months) in unilateral group and 3-10 months (mean, 6.1 months) in bilateral group. The VAS score, ODI, the relative height of injured vertebrae, and Cobb angle at 24 hours after operation and last follow-up were significantly better than those before operation in the two groups ( P<0.05). There were significant differences in all indicators between 24 hours after operation and last follow-up ( P<0.05). There was no significant difference in all indexes between the two groups ( P>0.05) at the same time point after operation. During follow-up, there was no complication such as contralateral vertebral collapse, refracture, adjacent vertebral fracture, or local kyphosis in the two groups. CONCLUSION: Unilateral PVP assisted with Curved Diffusion Needle for OVCF is beneficial to the distribution of bone cement, which can not only achieve similar effectiveness to bilateral PVP, but also achieve shorter operation time, less bone cement injection, and lower risk of bone cement leakage.

3D-Printed Screw-Rod Auxiliary System for Unstable Atlas Fractures: A Retrospective Analysis.

OBJECTIVE: To develop and validate the efficacy of a 3D-printed screw-rod auxiliary system for unstable atlas fractures. METHODS: This research is a retrospective analysis, and a total of 14 patients, including 11 males and three females, were enrolled in our hospital from January 2017 to March 2019 who underwent occipitocervical fusion assisted by the 3D-printed screw-rod auxiliary system were reviewed, and with an average age of 53.21 ± 14.81 years, an average body mass index (BMI) of 23.61 ± 1.93 kg/m2 . The operation time, blood loss and radiation times during the operation were recorded. The maximum fracture displacement values of pre- and post-operation were measured based on CT imaging. All screw grades were evaluated after surgery. The occipital-cervical 2 (O-C2 ) angle and occipitocervical inclination (OCI) angle of pre-operation, post-operation and the last following-up were measured. The dysphagia scale 3 months after surgery and at the last follow-up, the Neck Disability Index (NDI) 3 months after surgery and at the last follow-up were assessed. RESULTS: All patients were completed the surgery successfully. There was no patient with severe dysphagia or aggravation of nerve injury. The follow-up was from 12 to 14 months, and with an average of 12.5 months. The average surgery time, average blood loss and average radiation times for the 14 patients were 112.14 min, 171.43 mL and 5.07 times, respectively. There was a significant difference in maximum fracture displacement between pre- and post-operation values (P < 0.05). A total of 56 screws were inserted in 14 patients, among them, three screws were classified as grade 1, and the other screws were classified as grade 0. There was a significant difference in the O-C2 between pre-operation and 3 days after operation (P = 0.002); There was a significant difference in OCI angles between pre-operation and 3 days after operation (P < 0.05); there was no significant difference in the O-C2 or OCI angle between 3 days after the operation and the last follow-up (P = 0.079; P = 0.201). The dysphagia scales of two patients were assessed as mild at 3 months after surgery, and the others were assessed as normal at 3 months after surgery. All patients' dysphagia scores returned to normal at the last follow-up. The average NDI and average neck Visual Analogue Scale (VAS) scores at the last follow-up were 2.53 and 8.41, respectively. CONCLUSION: It can objectively restore the OCI to normal with few post-operative complications under the assistance of a screw-rod auxiliary system to perform occipitocervical fusion for unstable atlas fractures and atlantooccipital joint instability.

[Effectiveness analysis of three-dimensional printing assisted surgery for unstable pelvic fracture].

OBJECTIVE: To evaluate the effectiveness of three-dimensional (3D) printing assisted internal fixation for unstable pelvic fractures. METHODS: The clinical data of 28 patients with unstable pelvic fractures admitted between March 2015 and December 2017 were retrospectively analyzed. The patients were divided into two groups according to different surgical methods. Eighteen cases in the control group were treated with traditional anterior and posterior open reduction and internal fixation with plate; 10 cases in the observation group were treated with 3D printing technology to make pelvic models and assist in shaping the subcutaneous steel plates of the anterior ring. Sacroiliac screw navigation template was designed and printed to assist posterior ring sacroiliac screw fixation. There was no significant difference between the two groups in gender composition, age, cause of injury, fracture type, and time interval from injury to surgery ( P>0.05). The operation time, intraoperative blood loss, intraoperative fluoroscopy times, incision length, waiting time for weight-bearing exercise, and fracture healing time were recorded and compared between the two groups. Majeed score was used to evaluate the function at last follow-up. At immediate after operation, the reduction was evaluated according to Matta imaging scoring criteria, and the success of sacroiliac joint screw implantation in the observation group was evaluated. The deviation of screw entry point and direction between postoperative screws and preoperative simulated screws were compared in the observation group. RESULTS: All the operation was successfully completed, and all patients were followed up 6-18 months (mean, 14.4 months). In the control group, 1 case had wound infection and 2 cases had deep vein thrombosis. No serious complication such as important blood vessels, and nerve injury and pulmonary embolism occurred in other patients in the two groups. No screw pulling out or steel plate breaking occurred. The operation time, intraoperative blood loss, fluoroscopy times, incision length, and waiting time for weight-bearing exercise of the control group were significantly more than those of the observation group ( P<0.05); there was no significant difference in fracture healing time between the two groups ( t=0.12, P=0.90). There was no significant difference in reduction quality between the two groups at immediate after operation ( Z=-1.05, P=0.30); Majeed score of the observation group was significantly better than that of the control group at last follow-up ( Z=-2.42, P=0.02). The success rate of sacroiliac joint screw implantation in the observation group reached category Ⅰ. In the observation group, the deviation angle of the direction of the screw path between the postoperative screw and the preoperative simulated screw implant was (0.09±0.22)°, and the deviation values of the entry points on the X, Y, and Z axes were (0.13±0.63), (0.14±0.58), (0.15±0.53) mm, respectively. There was no significant difference when compared with those before the operation (all values were 0) ( P>0.05). CONCLUSION: Computer design combined with 3D printing technology to make personalized pelvic model and navigation template applied to unstable pelvic fractures, is helpful to accurately place sacroiliac screw, reduce the operation time, intraoperative blood loss, and the fluoroscopy times, has good waiting time for weight-bearing exercise and function, and it is an optional surgical treatment for unstable fractures.

[Surgical treatment strategy for the "shell" phenomenon after thoracolumbar fracture].

Objective: To explore the surgical treatment strategy of the vertebral "shell" after thoracolumbar fracture, and provide clinical reference for the intervention and treatment of "shell". Methods: Between June 2015 and January 2017, 53 patients with high risk of vertebral "shell" after thoracolumbar fracture surgery were enrolled in a prospective study according to the selection criteria. All patients were randomly divided into two groups according to the order of treatment, 27 cases in the treatment group were treated with short-segment fixation combined with vertebral reconstruction, 26 cases in the control group were treated with short-segment fixation. There was no significant difference in gender, age, injury cause, Denis classification, fracture segment, the degree of injured vertebra compression, bone mineral density, and American Spinal Cord Injury Association (ASIA) classification between the two groups ( P>0.05). The degree of injured vertebra compression, visual analogue scale (VAS) score, and Oswestry disability index (ODI) score at preoperation, immediate after operation, and last follow-up were calculated and compared between the two groups. The "shell" phenomenon and surgery complications were observed at the same time. Results: All patients were followed up 12-18 months with an average of 14.4 months. There were 5 cases of "shell" phenomenon in the treatment group and 4 cases of nonunion at last follow-up, 23 cases of "shell" phenomenon in the control group and 19 cases of nonunion at last follow-up; there was a significant difference between the two groups ( P<0.05). In the treatment group, 1 case had incision fat liquefaction and 4 cases had bone cement leakage; in the control group, 2 cases had screw loosening and 1 case had unilateral connecting rod rupture; there was no significant difference in the incidence of complications between the two groups ( χ2=0.504, P=0.478). The degree of injured vertebra compression, VAS score, and ODI score were significantly improved in both groups at immediate after operation and last follow-up ( P<0.05). There was no significant difference in the degree of injured vertebra compression between the two groups at immediate after operation ( P>0.05), but which was significantly higher in the control group than that in the treatment group at last follow-up ( P<0.05). Except that the ODI score of the control group was significantly higher than that of the treatment group at last follow-up ( P<0.05), there was no significant difference in VAS score and ODI score between the two groups at the other time points ( P>0.05). Conclusion: The treatment of thoracolumbar fracture with short-segment fixation combined with injured vertebral reconstruction can effectively prevent the "shell" phenomenon, which is conducive to maintaining the height of injured vertebral and improving the long-term function. The effectiveness is satisfactory.

[Effectiveness comparison between minimally invasive surgery and traditional open reduction internal fixation in treatment of unstable distal radial fractures].

Objective: To compare the effectiveness of minimally invasive percutaneous internal fixation and traditional open reduction via Henry approach and internal fixation in the treatment of unstable distal radial fractures. Methods: Fifty-six patients with unstable distal radial fractures that met the selection criteria between October 2013 and December 2014 were randomly divided into minimally invasive group (26 cases) and traditional group (30 cases). They were treated with oblique T-shaped locking plate internal fixation via minimally invasive percutaneous approach or traditional Henry approach. There was no significant difference in gender, age, side, causes of injury, fracture classification, and time from injury to operation between 2 groups ( P>0.05). The length of incision, operation time, intraoperative blood loss, hospitalization time, and fracture healing time were recorded in 2 groups. The difference of the length of the radial styloid process, the volar tilting angle, and the ulnar inclining angle between at 3 months postoperatively and preoperation were compared between 2 groups. The visual analogue scale (VAS) score, the percentage of the lateral wrist flexion and extension range, forearm rotation, and the hand grip strength (recorded as FS%, FR%, and HG% , respectively) were compared between 2 groups at 4 weeks and 3 months postoperatively. The wrist function was evaluated through the disability of arm-shoulder-hand (DASH) scores at 3 months postoperatively. Results: The length of incision, operation time, intraoperative blood loss, and hospitalization time in minimally invasive group were significantly less than those in traditional group ( P<0.05). The incisions of 2 groups were all achieved primary healing. All patients were followed up 10-16 months (mean, 12.6 months). There was no radial artery injury, screw too long, or screw entering the joint space. In minimally invasive group, 1 patient had the symptoms of median nerve irritation after operation, and recovered completely at 1 month; in traditional group, there were 2 cases of tendon irritation after operation. There was no significant difference in the fracture healing time, the difference of the length of the radial styloid process, the volar tilting angle, and the ulnar inclining angle between at 3 months postoperatively and preoperation between 2 groups ( P>0.05). At 4 weeks after operation, the VAS score in minimally invasive group was significantly less than that in traditional group, and the FS%, FR%, and HG% were significantly higher than those in traditional group ( P<0.05). There was no significant difference in above indicators between 2 groups at 3 months after operation ( P>0.05). The DASH score in minimally invasive group was significantly less than that in traditional group at 3 months after operation ( t=-5.308, P=0.000). The patient's aesthetic evaluation of postoperative wound in minimally invasive group was better than in traditional group. Conclusion: For treatment of unstable distal radial fractures, the metacarpal minimally invasive internal fixation has the advantages of smaller wound, incisional concealment, and quicker recovery of wrist joint.

[Photoelectric guided navigation unilateral puncture of the percutaneous kyphoplasty in treatment of thoracolumbar osteoporotic vertebral compression fracture].

Objective: To evaluate the safety of photoelectric guided navigation unilateral puncture of the percutaneous kyphoplasty (PKP) in the treatment of thoracolumbar osteoporotic vertebral compression fracture (OVCF). Methods: A randomized controlled clinical research was performed between June 2015 and January 2017. Eighty-five cases of OVCF were treated with photoelectric guided navigation unilateral puncture of the PKP (trial group, 43 cases) or C arm fluoroscopy unilateral puncture of the PKP (control group, 42 cases) respectively. There was no significant difference in gender, age, disease duration, segmental fracture, AO classification, bone mineral density, and preoperative visual analogue scale (VAS) score between 2 groups ( P>0.05). The concordance rate of puncture path and design path, the incidence of pedicle wall breaking, the incidence of bone cement leakage, and the rate of bone cement distribution center were observed and calculated on postoperative CT images; the intraoperative X-ray exposure frequency, frequency of puncture, operation time, VAS scores before operation and at 2 days after operation, and postoperative blood vessel or nerve injury were recorded and compared. Results: The intraoperative X-ray exposure frequency and puncture frequency in trial group were significantly less than those in control group ( P<0.05), but there was no significant difference in operation time between 2 groups ( t=0.440, P=0.661). The VAS scores of 2 groups at 2 days after operation were significantly improved when compared with preoperative ones ( P<0.05), but there was no significant difference in VAS score at 2 days after operation between 2 groups ( t=0.406, P=0.685). All the patients were followed up 6-18 months (mean, 10 months). No blood vessel or nerve injury occurred in 2 groups. The incidence of pedicle wall breaking, the incidence of bone cement leakage, the concordance rate of puncture path and design path, and the rate of bone cement distribution center in trial group were 2.33% (1/43), 2.33% (1/43), 86.05% (37/43), and 88.37% (38/43) respectively, all showing significant differences when compared with those of control group [19.05% (8/42), 21.43% (9/42), 45.24% (19/42), and 50.00% (21/42) respectively] ( P<0.05). Conclusion: Intraoperative photoelectric guided navigation unilateral puncture of the PKP can improve the success rate of target puncture and reduce the incidence of pedicle wall breaking effectively, and achieve better bone cement distribution and better security.