Post-device Dimethylamine Treatment Enables Stable and Efficient Perovskite Solar Cells.

The incorporation of organic ligands via post-device treatment is an effective strategy to improve the stability of perovskite solar cells (PSCs). Although the active area is protected by metal electrode under post-treatment, the aggression of post-treatment ligands into active area cannot be avoided thoroughly. Unfortunately, the size of long-chain amines is too large, and the three-dimensional (3D) perovskite cannot maintain its 3D perovskite structure once the cation substitution occurs during the post-treatment. Despite that the low-dimensional (LD) perovskites are beneficial to stability, long-chain amines are harmful to carrier transport in PSCs. Here, we introduce dimethylamine (DMA), a slightly oversized cation that can be doped into 3D perovskite structure, for post-device treatment to improve the efficiency and stability of PSCs. After exposure to DMA gas, the inactive area of Cs/FA/MA mixed cation perovskite device that is not covered by metal electrode is converted into LD perovskite, passivating the defects of 3D perovskite in the active region, suppressing non-radiation recombination and ion migration. As a result, we achieved a power conversion efficiency (PCE) of 22.29 % with negligible hysteresis and better stability after DMA post-treatment, which is much higher than that (20.40 %) of the control device.

Risk Factors for Short-Term and Long-Term Low Back Pain After Transforaminal Endoscopic Lumbar Discectomy.

Introduction: Low back pain following transforaminal endoscopic lumbar discectomy (TELD) is prevalent (15-25% incidence). Modifying TELD techniques to avoid excessive disc removal has been suggested to reduce such pain. Facet injury, re-herniation, and disc space collapse might contribute. This retrospective study aimed to explore factors linked to post-TELD low back pain. Methods: A total of 351 patients with L3/4, L4/5, and L5/S1 intervertebral lumbar disc herniations, who underwent TELD at two spine centers, were included. Patients were followed for one year. Low back and leg pain visual analogue scale (VAS) scores, Oswestry Disability Index (ODI), Pfirrmann grade, and disc height were measured at 3 months and 1 year. Correlation analyses examined links between postoperative low back pain VAS scores, age, sex, disc/vertebrae height ratio (D/V H ratio), Pfirrmann grade, cannula position grade, re-herniation grade, high-intensity zone (HIZ), disc calcification, surgical grade, and other factors. Significant variables were identified using partial least square tests, with variable importance in projection (VIP) values quantifying their impact on low back pain. Results: Univariate analysis indicated that surgical grade correlated with long-term postoperative low back pain (P = 0.023), while re-herniation (P = 0.008, P = 0.000), disc height (P = 0.001, P = 0.034), and sex (P = 0.025, P = 0.003) correlated with both short- and long-term postoperative low back pain. Trephine/cannula position is correlated with short-term low back pain (P = 0.036). Worsening low back pain was associated with female sex, improper trephine/cannula position, re-herniation, and post-surgical disc space collapse. Intradiscal irrigation was linked to decreased low back pain. Discussion: This study highlights factors influencing low back pain after TELD. Loss of disc height, extent of re-herniation, quality of trephine/cannula position, and sex were associated with low back pain at both 3 months and 1-year post-TELD. Proper techniques, like minimizing disc height loss and re-herniation, may help mitigate postoperative low back pain.

Evaluating the Sorption Kinetics of Polychlorinated Biphenyls in Powdered and Granular Activated Carbon.

Activated carbon (AC) has been applied widely in water treatment as a strong sorbent for organic contaminants and, more recently, in-situ treatment and capping for remediating legacy contaminants. In some sediment environments, the sorption kinetics onto AC may significantly impact remedial performance, particularly for large, highly hydrophobic contaminants such as PCBs, but there is limited kinetic data on such compounds. In this study, batch experiments were conducted over 52 weeks to measure PCB adsorption kinetics on 2 ACs in granular (1.1 mm diameter) and powdered (0.02 mm) form using polydimethylsiloxane (PDMS) fibers to measure aqueous concentrations over time. The experiment was conducted in glass containers with water at known PCB concentration and containing 10 mg/L natural organic matter (NOM) and activated carbon. Blanks without activated carbon were used to estimate kinetics and equilibrium uptake to PDMS and NOM. The PDMS measured aqueous concentration in AC containing slurries was then used to estimate kinetics and equilibrium uptake of the various PCBs onto the AC. Achieving equilibration of PCBs onto the powdered activated carbon (PAC) was accomplished in days to weeks, but granular activated carbon (GAC) uptake was not complete for some high molecular weight congeners in a year. The data were used to fit linear driving force models with both linear and Freundlich models of equilibrium. The models were then used to predict uptake onto powdered and granular AC during in-situ capping and treatment using the CapSim model. Slow kinetics can significantly limit the performance of granular AC in high upwelling (> 1-10 cm/day) environments. This study demonstrates the usage of polymeric passive samplers to explore sorption kinetics and equilibrium for low solubility compounds as well as the differences in performance of granular and powdered forms of AC for remediation of PCB contaminated sediment.

Postoperative hematoma in cervical spondylosis patient complicated with Huntington's disease: Case report and literature review.

Hematoma is a life-threatening complication of anterior surgery in cervical spondylosis patients. Herein, we report a cervical spondylosis patient complicated with Huntington's disease, who developed unexpected neck hematoma after anterior cervical discectomy and fusion (ACDF) surgical treatment. During the debridement, we found no noticeable vessel lesions and concluded that the occurrence of postoperative hematoma might be due to the drainage displacement caused by excessive uncontrolled movements of the neck after the operation. The patient recovered well, and further literature review suggests that chorea secondary to Huntington's disease likely increases mechanical stress on the cervical spine, indicating an internal relationship between degenerative cervical spondylosis and Huntington's disease. Cervical spondylotic patients complicated with Huntington's disease can be treated with surgical intervention but need to be immobilized and under close observation.

Evaluation of Haplo-Paraspinal-Muscle-Preserving Technique to Prevent Postoperative Axial Pain in Cervical Laminoplasty.

BACKGROUND: The present study aimed to assess the efficacy of a new haplo-paraspinal-muscle-preserving (HMP) laminoplasty technique in the treatment of cervical myelopathy. METHODS: The medical records of 68 patients diagnosed with multisegmental cervical myelopathy were retrospectively reviewed. Of these, 22 patients who underwent HMP laminoplasty were defined as the muscle-preserved group (MP), and 46 patients who underwent traditional open-door laminoplasty were enrolled and defined as the traditional open-door laminoplasty group (LP). Patient demographic data and surgical parameters like clinical and radiological parameters, operation duration, blood loss, and spinal canal expansion distance were compared. RESULTS: Average surgical time and blood loss were significantly reduced in the MP group when compared with the LP group (P < 0.05). Both groups demonstrated significant improvements in neurological function and spinal canal expansion (P > 0.05). However, the visual analog scale score in the MP group was significantly lower compared with the LP group at the 6-month follow-up (P < 0.05), but no differences were found at the 1-year follow-up. The loss of lordosis was more prominent in the LP group when compared with the MP group at 1-year follow-up (P < 0.05). Lower events of persistent axial pain were found in the MP group but with no statistical significance. More hinge side laminae fractures could be found in the MP group, but more hinge side displacements were found in the LP group. CONCLUSIONS: The HMP laminoplasty technique is relatively safe, effective, easier to perform, and better for lordosis maintenance and complication control compared with the traditional open-door technique. CLINICAL RELEVANCE: Although traditional open-door laminoplasty is an efficient approach in treating multisegmental cervical myelopathy, the complications could significantly affect the clinical outcome. Our new HMP laminoplasty technique has a lower complication rate and a better lordosis maintenance ability; therefore, it could be a better choice in treating multisegmental cervical myelopathy.

Predictive Effect of Intervertebral Foramen Width on Pain Relief After ACDF for the Treatment of Cervical Radiculopathy.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To investigate the relationship between the preoperative width of the intervertebral foramen (WIVF) and the pain relief in patients who underwent anterior cervical discectomy and fusion (ACDF) for the treatment of cervical radiculopathy. METHODS: Patients were divided into 2 groups based on pain relief status at the 6-month follow-up (pain relief group: 430 patients; persistent pain group: 108 patients). Possible factors such as age, sex, body mass index (BMI), the symptom duration, the preoperative Japanese Orthopedic Association (JOA) scores, the canal stenosis status, and the graft material were obtained. The C2-C7 Cobb angle, disc space, and width and height of the intervertebral foramen were measured on X-ray and CT 3-dimension reconstruction. Multivariate logistic regression was performed to identify the factors that affected pain relief. A receiver operating characteristic (ROC) curve was drawn for the predictive factors to determine the optimal threshold for foreseeing persistent pain. RESULTS: There were significant differences in the preoperative WIVF, symptom duration and ratio of disc space distraction between the 2 groups (each P < 0.05). The regression model showed that pain relief was negatively affected by the symptom duration and ratio of disc space distraction. Besides, an increase in the preoperative width of the intervertebral foramen (WIVF) could significantly decrease the possibility of persistent pain. Based on the ROC curve, the optimal threshold of preoperative WIVF was 4.35 mm. CONCLUSION: When the preoperative WIVF is equal to or less than 4.35 mm, the possibility of the occurrence of postoperative persistent pain significantly increased.

Irisin reduces bone fracture by facilitating osteogenesis and antagonizing TGF-ß/Smad signaling in a growing mouse model of osteogenesis imperfecta.

Objective: Osteogenesis imperfecta (OI) is a congenital disorder characterized by muscle defect and skeletal fragility, and no cure is yet available. Crosstalk between bone and muscle has become a new coming focus of therapeutic strategy in OI. Irisin, a secreted myokine, was found to be involved in regulating bone metabolism, and may be beneficial for the treatment of OI. However, its effects in OI have yet to be determined. This study sought to determine whether Irisin therapy is capable of reducing fracture risk in OI and to investigate the potential mechanisms of action. Methods: Fibronectin type III domain containing 5 (FNDC5)/Irisin expression was assessed by enzyme-linked immunosorbent assay (ELISA) and immunohistochemical staining. In vivo, X-ray was used for fracture counting and micro-CT, dynamic histomorphometry analysis, immunohistochemistry, histomorphometry, and biomechanical test were used to evaluate the effects of Irisin on fracture frequency and bone quality in OI mouse model, oim/oim mouse. In vitro, osteogenesis-related gene expressions were determined by quantitative real-time PCR (qRT-PCR), western blot, and osteoblastogenesis assay were assessed by alkaline phosphatase (ALP) staining and alizarin red S (ARS) staining. Mechanistically, cell immunofluorescence staining, co-immunoprecipitation (co-IP) (Co-IP), molecular docking, western blot, luciferase reporter assay, and chromatin immunoprecipitation (ChIP) assay were used for elucidating the mechanisms of how Irisin antagonized transforming growth factor-ß (TGF-ß)/Smad signaling in oim/oim osteoblasts and further attenuated the inhibitory effect of TGF-ß1 on osteogenic differentiation. Results: Musculoskeletal system-related FNDC5/Irisin was decreased in the serum, muscle, and bone in oim/oim mice. Irisin administration reduced bone fracture and attenuated bone abnormalities by improving bone mass and strength and facilitating the expression of osteogenic differentiation markers. In vivo study and in vitro experiments showed that Irisin antagonized TGF-ß/Smad signaling by interfering with TGF-ß1-TGF-ß receptor II (TßRII) binding. In oim/oim osteoblasts, Irisin alleviated TGF-ß1-induced suppression of osteogenic differentiation through both integrin-dependent and integrin-independent mechanisms. Independent of integrin receptors, Irisin affected osteogenesis by activating ERK/p38 signaling and counteracting TGF-ß/Smad2/3 signaling. In particular, Irisin alleviated TGF-ß1-induced inhibition of Runx2 function at the osteocalcin promoter through decreasing Smad2/3 signaling and inducing HADC4/5 degeneration. Conclusions: Collectively, Irisin could effectively reduce bone fracture in oim/oim mice through promoting osteogenesis and counteracting TGF-ß/Smad signaling. Translational potential statement: Findings from this study provided evidence for using Irisin as a potential therapeutic reagent to prevent the progression of OI.

Preoperative Cervical Cobb Angle Is a Risk Factor for Postoperative Axial Neck Pain after Anterior Cervical Discectomy and Fusion with Zero-Profile Interbody.

OBJECTIVES: Anterior cervical discectomy and fusion (ACDF) with zero-profile interbody has a lower incidence of complications in treating cervical spondylotic myelopathy (CSM). However, postoperative axial neck pain is still commonly occurred, and the factors affecting which is not known. Here, we retrospectively analyze the risk factors for postoperative axial pain after performing ACDF with zero-profile implant in single-level CSM. METHODS: Patients who suffered from single-level CSM and who received ACDF with zero-profile implant between 2018 January to 2020 December were reviewed. Of 180 single-level CSM patients, 144 patients who passed the inclusion criteria were enrolled. Patients were divided into two groups according to the severity of postoperative axial pain as measured by postoperative neck visual analogue scale (nVAS). Clinical parameters including age, sex, smoking history, symptom duration, body mass index (BMI), the Japanese Orthopaedic Association (JOA) scores, as well as radiological parameters were obtained pre- and post-operatively, and the data were compared between two groups. Pearson's chi-square tests and Mann-Whitney U tests were implemented to identify statistically significant differences between subgroups for categorical and continuous data, respectively; otherwise, the data were tested with Student's t-test. Risk factors were identified using logistic regression. RESULTS: Of the patients (97.8%) achieved satisfied neurological recovery, and 88.2% of the patients achieved fusion at 1-year follow-up. 33% of the patients (48 patients out of 144) had sustained postoperative axial pain after the surgery. Comparison of different severity groups exhibited no significant differences in terms of the possible risk factors (P > 0.05) except for pre- and post-operative C2-C7 Cobb angles (6.33 ± 6.53 vs. 11.88 ± 7.41, P < 0.05; 13.49 ± 5.31 vs 16.64 ± 7.34, P < 0.05). Furthermore, correlation analysis showed that the preoperative C2-C7 Cobb angle is significantly correlated with the severity of the postoperative axial pain (R2  = 0.83, P < 0.01). In addition, logistic regression analysis demonstrated that the preoperative C2-C7 Cobb angle is an independent predictor of postoperative axial pain (P < 0.01, OR = 0.53). Further receiver operating characteristic (ROC) analysis displayed an area under the curve (AUC) of 0.78 (P < 0.01) for preoperative C2-C7 Cobb angle, and the optimal cutoff was 8.4° (sensitivity 0.77, specificity 0.65). CONCLUSION: The pre-operative C2-C7 Cobb angle is a risk factor for severe postoperative axial pain after anterior cervical discectomy and fusion with zero-profile interbody, and we should be cautious when poor preoperative C2-C7 Cobb angle is found in myelopathy patients planning to use zero-profile interbody to treat such patients.

A hydrophobic layer prepared by cyclic grafting of polydimethylsiloxane on magnesium: improved corrosion resistance and biocompatibility.

Magnesium and its alloys have been widely studied as absorbable coronary stent materials. However, the rapid corrosion rate in the intravascular environment inhibits the application of magnesium-based stents. In order to endow magnesium-based stent with appropriate degradation rate and biocompatibility, a hydrophobic layer was constructed by in situ cyclic grafting 4,4'-diphenylmethane diisocyanate and aminopropyl-terminated polydimethylsiloxane on pure magnesium. SEM-EDS, X-ray photoelectron spectroscopy and water contact angle were detected to analyze the chemical composition of the layer. The amino groups were confirmed to be introduced on the surface which provide a platform for subsequent modification. The contact angle value of the modified surface is 132.1°, indicating a hydrophilic surface. The electrochemical measurements and immersion tests demonstrated that the hydrophobic layer significantly improved the anti-corrosion ability of the substrate. Besides, the biocompatibility of the hydrophobic surface was examined by platelet adhesion, cytocompatibility in vitro and subcutaneous implantation in vivo. Immunological and histological results indicated that the hydrophobic layer had excellent biocompatibility. Therefore, the presented study might be a promising method for the surface modification of biomedical magnesium-based stent.

A Novel Posterior Compression Score System for Outcome Prediction in Laminoplasty Treated OPLL Patients: A Propensity-Matched Analysis.

STUDY DESIGN: A retrospective observational study. OBJECTIVE: To describe a novel outcome indication system, the posterior compression score (PCS), and investigate its clinical value in cervical ossification of the posterior longitudinal ligament (OPLL) patients treated with laminoplasty. METHODS: A total of 282 OPLL patients who underwent laminoplasty from January 2013 to December 2018 were reviewed. The patients were divided into high-score (HS) or low-score (LS) groups based on whether the PCS was over 8. Propensity score matching analysis with a caliper of .1 was used to attenuate the potential selection bias. Clinical measurements, including the Japanese Orthopedic Association (JOA) score, visual analog scale (VAS), neck disability index (NDI), and radiological measurements, including C2-C7 lordotic angle and range of motion (ROM), were compared between the groups. RESULTS: The mean follow-up period was 29.87 ± 9.17 months. There were no significant differences between the two groups regarding patients' baseline demographical and clinical characteristics after propensity score matching. No significant differences were found in the operative time, blood loss, postoperative VAS score for neck and arm pain, postoperative C2-C7 lordotic angle, or postoperative ROM (P > .05). However, the postoperative JOA score and recovery rate were significantly higher in the HS group than in the LS group, while the postoperative NDI was significantly lower in the HS group (P < .05). CONCLUSION: OPLL patients with higher PCS scores displayed better clinical outcomes. The novel PCS system is suggested to be a reliable scoring system for surgical outcome evaluation in patients with cervical OPLL.

Is Anterior Trans-Intervertebral Space Decompression Important in Treating Cervical Spondylosis with Severe Intervertebral Space Narrowing? A Retrospective Cohort Study.

OBJECTIVE: To evaluate the clinical efficacy and practicality of anterior trans-intervertebral space decompression and fusion (ATIDF) by comparing radiological and clinical outcomes between ATIDF and traditional anterior cervical corpectomy and fusion (ACCF) in cervical spondylosis patients with severe disc space narrowing. METHODS: Seventy-one cervical spondylosis patients with severe disc space narrowing underwent anterior cervical spine surgery were included in this retrospective study. Thirty-seven patients underwent ATIDF and 34 patients underwent ACCF. The neck disability index (NDI), Japan Orthopaedic Association (JOA) score and the Hirabayashi improvement rate were used to evaluate patient neurological status. Cervical sagittal alignment (C2-C7 Cobb angle), surgical segment sagittal alignment (Cobb angle of surgical segment) and disc space height were also compared between the two groups. RESULTS: There were 39 males and 32 females; mean age was 63.72 ± 6.36 years (range, 39-81 years). Mean follow-up was 22.4 months (range, 6-45 months). All patients achieved an adequate neurological improvement. There were no significant differences in NDI, JOA scores and Hirabayashi improvement rate between the two groups. The change of C2-7 Cobb angle and surgical segment Cobb angle were both greater in the ATIDF group. The average intervertebral height ratio of the patients in the ATIDF group increased significantly after surgery (0.38 ± 0.17 before surgery to 1.13 ± 0.32 after surgery, P < 0.01). The overall complication rate was lower in the ATIDF group than the ACCF group (35.14% and 44.12%). At 6 months follow-up, three patients in the ACCF group presented with subsidence of the titanium mesh cage. CONCLUSION: ATIDF is an effective technique for treating cervical spondylosis with severe disc space narrowing; it can achieve adequate decompression and improve sagittal alignment while avoiding and reducing the implant-related complications inherent to traditional ACCF.

Small extracellular vesicle-mediated miR-320e transmission promotes osteogenesis in OPLL by targeting TAK1.

Ossification of the posterior longitudinal ligament (OPLL) is an emerging spinal disease caused by heterotopic ossification of the posterior longitudinal ligament. The pathological mechanism is poorly understood, which hinders the development of nonsurgical treatments. Here, we set out to explore the function and mechanism of small extracellular vesicles (sEVs) in OPLL. Global miRNA sequencings are performed on sEVs derived from ligament cells of normal and OPLL patients, and we have showed that miR-320e is abundantly expressed in OPLL-derived sEVs compare to other sEVs. Treatment with either sEVs or miR-320e significantly promote the osteoblastic differentiation of normal longitudinal ligament cells and mesenchymal stem cells and inhibit the osteoclastic differentiation of monocytes. Through a mechanistic study, we find that TAK1 is a downstream target of miR-320e, and we further validate these findings in vivo using OPLL model mice. Together, our data demonstrate that OPLL ligament cells secrete ossification-promoting sEVs that contribute to the development of ossification through the miR-320e/TAK1 axis.

Ag-Incorporated Polydopamine/Tannic Acid Coating on Titanium With Enhanced Cytocompatible and Antibacterial Properties.

Titanium (Ti) and its alloys are the most commonly used materials for bone implants. However, implant failure often happens due to bacterial infection. Developing antibacterial coatings on Ti implants is an effective strategy. Dopamine and tannic acid were cross-linked to form coating on Ti through Michael addition and Schiff base reaction. In addition, the Ag ions were grafted on the coating by the redox reaction of phenolic hydroxyl groups. Thus, an Ag-incorporated polydopamine/tannic acid coating was prepared on Ti substrate. SEM, EDS, water contact angle, FTIR, and XRD results demonstrated that the coating was formed on Ti successfully. The antibacterial activity of the coating against Gram-negative E. coli was examined, and the cytotoxicity of the coating was investigated by mouse fibroblast cells. The improvement of hydrophilicity, good cytocompatibility, and antibacterial effectiveness indicates that the coating has potential to surface modification of Ti implants.

In Situ Passive Sampling to Monitor Long Term Cap Effectiveness at a Tidally Influenced Shoreline.

Polydimethylsiloxane solid-phase microextraction passive samplers were used to evaluate long-term performance of a sand/gravel cap placed in 2005 in a tidally influenced shoreline in Puget Sound to reduce polycyclic aromatic hydrocarbon (PAH) transport into overlying surface water. Sampling in both 2010 and 2018 measured porewater concentrations of <1 ng/L total PAHs in the cap layer. d-PAH performance reference compounds were used to evaluate the extent of equilibration of the contaminants onto the samplers and to estimate net upwelling velocities through a mass-transfer model. The upwelling velocities were used to predict long-term migration of selected PAHs through the cap, showing that the cap is expected to continue being effective at limiting exposure of contaminants at the cap−water interface.

Intervertebral-spreader-assisted anterior cervical discectomy and fusion prevents postoperative axial pain by alleviating facet joint pressure.

OBJECTIVE: To evaluate the relationship of postoperative cervical axial pain with different vertebral distraction methods used during ACDF procedures in cervical spondylosis patients. METHODS: Ninety-four single-level cervical spondylotic myelopathy patients with significantly loss of intervertebral disc height who underwent ACDF surgery in our institute between January 2018 and January 2020 were enrolled. Cervical spine lateral radiographs were taken preoperatively, 3 days, 1-month, 2-month and 6-month after the surgery. The intervertebral disc height (IDH), interfacet distance (IFD), JOA (Japanese Orthopaedic Association) score, NDI (Neck Disability Index) score, nVAS (Neck Visual Analogue Scale) score and aVAS (Arm Visual Analogue Scale) score were measured. The correlation of clinical parameters and intervertebral disc height was evaluated. Then the correlation of clinical outcomes and different distraction method was evaluated. The patients were randomly divided into two groups, one uses Casper pin distractor system alone for distraction (Caspar alone group) and the other uses spreader assisted distraction method (Casper + spreader group). In biomechanical study, four cervical spine cadavers were selected for facet pressure measurements under different vertebral distraction methods, and the facet joint pressure was measured using force sensors. RESULTS: Satisfactory cervical fusion and neurological recovery were achieved in all patients. No significant correlation of IDH, IFD, JOA, NDI or aVAS with nVAS score was found. No significant difference between the change in disc height and clinical outcomes was found. However, by comparing the clinical parameters of patients in different vertebral distraction groups, we found significant changes in the early nVAS and NDI scores (P = 0.11, P = 0.48) of the Casper + spreader group (3 days postoperation), and was associated with a better nVAS score at 2 months postoperation (P < 0.05). The biomechanical study in cervical cadavers also showed significantly and continuously decreased facet joint pressure in the spreader assisted vertebral distraction group (P < 0.01). CONCLUSIONS: Spreader-assisted vertebral distraction method effectively alleviates postoperative neck pain in degenerative cervical spondylosis patients treated with ACDF. The mechanism may be related to the transient relief of facet joint pressure during the vertebral distraction procedure in ACDF.

Application of a new integrated low-profile anterior plate and cage system in single-level cervical spondylosis: a preliminary retrospective study.

BACKGROUND: Although ACDF has been widely used in treating cervical spondylosis and related diseases, the complications along with this anterior surgical technique have hindered its application and affected the postoperative outcome of the patients. Here, we investigated the clinical and radiological outcomes of a new integrated low-profile anterior plate and cage system for anterior cervical discectomy and fusion (ACDF) in treating cervical spondylosis. METHODS: A total of 96 cervical spondylosis patients who underwent single-level ACDF between 2018 to 2020 in our institute were enrolled. There were 28 patients using the new implants and 68 patients using the zero-profile (Zero-P) implants. The Japanese Orthopedic Association (JOA) score and the visual analog scale (VAS) were used to evaluate the clinical outcomes. The cervical and segmental Cobb angle and range of motion (ROM) were used to assessed the radiological outcomes. Incidence of complications were also recorded. All data were recorded at pre-operation, 6-month and 12-month post-operation. RESULTS: All patients were followed-up for at least 1-year, the mean follow-up time was over one year. The fusion rate was similar in the two groups. There was no significant difference in the postoperative JOA score recovery rate, postoperative VAS score of neck and arm pain, postoperative ROM, and incidence of complications between two groups (P > 0.05). However, postoperative cervical and segmental Cobb angle were better maintained in the new low-profile implant group compared to Zero-P group. CONCLUSIONS: The clinical outcomes of the new low-profile implant were satisfactory and comparable to that of zero-profile system. It may have advantages in improving and maintaining the cervical lordosis, and can be an alternative device for single-level cervical spondylosis treated with ACDF.

Anterior cervical discectomy and fusion, open-door laminoplasty, or laminectomy with fusion: Which is the better treatment for four-level cervical spondylotic myelopathy?

Four-level cervical spondylotic myelopathy (CSM) is a common disease affecting a large number of people, with the optimal surgical strategy remaining controversial. This study compared the clinical outcomes, radiological parameters, and postoperative complications of primarily performed surgical procedures such as anterior cervical discectomy and fusion (ACDF), open-door laminoplasty (LAMP), and laminectomy with fusion (LF) in treating four-level CSM. A total of 116 patients who received ACDF (38 cases), LAMP (45 cases), and LF (33 cases) were followed up for a minimum of 24 months were enrolled in this study and retrospectively analyzed. Clinical outcomes were evaluated using the Japanese Orthopedic Association (JOA) scoring system, the Neck Disability Index (NDI), and the Visual Analogue Scale (VAS). Changes in the curvature of the cervical spine were determined using the cervical curvature index (CCI) and the C2-C7 Cobb angle. Cervical mobility was evaluated using the C2-C7 range of motion (ROM) and active cervical ROM (aROM). Complications were recorded and compared among the three groups. All patients achieved significant improvement in JOA, NDI, and VAS scores at the final follow-up (P < 0.05), whereas no remarkable difference was found among the groups (P > 0.05). In addition, both C2-7 ROM and aROM were significantly reduced in the three groups and LAMP showed the least reduction relatively. As for complications, LAMP showed the lowest overall incidence of postoperative complications, and patients in the ACDF group were more susceptible to dysphagia, pseudoarthrosis than LAMP and LF. Considering improvements in clinical symptoms and neurological function, no remarkable difference was found among the groups. Nevertheless, LAMP had advantages over the other two surgical procedures in terms of preserving cervical mobility and reducing postoperative complications.

Intervertebral Foramen Width Is an Important Factor in Deciding Additional Uncinate Process Resection in ACDF-a Retrospective Study.

Background: Anterior cervical discectomy and fusion (ACDF) has been established as a classic procedure for the management of cervical radiculopathy. However, it is unclear whether combined uncinate process resection (UPR) is necessary for treating cervical radiculopathy. Here, we investigated the clinical outcome of ACDF combined with UPR compared to ACDF alone to determine the necessity of UPR in treating cervical radiculopathy. Hypothesis: Uncinate process resection may be necessary in certain patients along with ACDF to achieve better clinical outcomes of cervical radiculopathy. Patients and Methods: Fifty-five patients underwent ACDF with UPR, and 126 patients without UPR were reviewed. The width and height of the intervertebral foramen were measured by 45° oblique X-rays. We also measured the Japanese Orthopedic Association (JOA) score and visual analog scale (VAS) score. C2-C7 Cobb angles were obtained from all patients pre- and post-operatively. Meanwhile, linear regression analysis was used to evaluate the relationship between the clinical outcomes and the intervertebral foramen width before surgery. Results: Linear regression analysis indicated that the improvement in the JOA and VAS scores was irrelevant to both the pre-operative width of the intervertebral foramen (wIVF) and the height of the intervertebral foramen (hIVF) in the ACDF+UPR group. However, pre-operative wIVF was associated with post-operative JOA and VAS scores in the ACDF alone group. Those with pre-operative wIVF <3 mm in the ACDF group had the least improvement in post-operative clinical symptoms due to the change in wIVF (P > 0.05). The ACDF group whose wIVF was over 3 mm showed similar clinical outcomes to the ACDF + UPR group, and wIVF significantly increased post-operatively (P < 0.05). The fusion rate and C2-C7 Cobb angles did not show significant differences between the two groups (P > 0.05). Discussion: Our current findings suggest that UPR should be considered when wIVF is <3 mm pre-operatively. However, there is no need to sacrifice the uncovertebral joint in ACDF when the pre-operative wIVF is over 3 mm. Level of Evidence: Level III.

Efficacy and Safety of Ultrasonic Bone Curette-assisted Dome-like Laminoplasty in the Treatment of Cervical Ossification of Longitudinal Ligament.

OBJECTIVE: To assess the efficacy and safety of ultrasonic bone curette-assisted dome-like laminoplasty in the treatment of ossification of longitudinal ligament (OPLL) involving C2 . METHODS: A total of 64 patients with OPLL involving C2 level were enrolled. Thirty-eight patients who underwent ultrasonic bone curette-assisted dome-like laminoplasty were defined as ultrasonic bone curette group (UBC), and 28 patients who underwent traditional high-speed drill-assisted dome-like laminoplasty were defined as high-speed drill group (HSD). Patient characteristics such as age, sex, body mass index (BMI), symptomatic duration, and other information like the type of OPLL, the time of surgery, blood loss, C2 -C7 Cobb angle change and complications were all recorded and compared. The Japanese Orthopaedic Association (JOA) score, the nerve root functional improvement rate (IR), and the visual analogue scale (VAS) were used to assess neurological recovery and pain relief. The change of the distance between the apex of ossification and a continuous line connecting the anterior edges of the lamina was measured to assess the spinal expansion extent. The measured data were statistically processed and analyzed using SPSS 21.0 software, and the measurement data were expressed as mean ± SD. RESULTS: In ultrasonic bone curette (UBC) group and high-speed drill group (HSD) group, the average time for laminoplasty was 52.3 ± 18.2 min and 76.0 ± 21.8 min and the mean bleeding loss volume was 155.5 ± 41.3 mL and 177.4 ± 54.7 mL, respectively, with a statistically significant difference between the groups. Both groups demonstrated a significant improvement in neurological function. However, the VAS score in UBC group was lower than in HSD group at the 6-month follow-up (P < 0.05), but there was no significant difference at 1-year follow-up. We found that the loss of lordosis was 1.5° ± 1.0° in UBC group, which is significantly lower than that of HSD group at 1-year follow-up (3.8° ± 1.2°, P < 0.05). According to the change of canal dimension, we found that the expansion extent of the spinal canal in UBC group was similar to that of HSD group (P > 0.05). Only one patient in the UBC group and five patients in the HSD group displayed cerebrospinal fluid (CSF) leakag. CONCLUSIONS: With the use of ultrasonic bone curette in OPLL dome-like decompression, the decompression surgery could be completed relatively safely and quickly. It effectively reduced the amount of intraoperative blood loss and complications, and had better initial recovery of neck pain.

Bioavailability assessment in activated carbon treated coastal sediment with in situ and ex situ porewater measurements.

Passive sampling and bioaccumulation assessments were used to evaluate the performance of activated carbon (AC) remediation of polychlorinated biphenyl (PCB) contaminated sediment offshore in Parcel F of the former Hunters Point Naval Shipyard (HPNS) (San Francisco, California). Two different composite AC materials, AquaGate+PAC™ (86 tons) and SediMite™ (24 tons) were placed on the sediment surface covering an area of 3200 m2. PCB tissue concentrations in the clam Macoma nasuta were reduced 75 to 80% in pilot amendment areas after 8 months and 84-87% in non-lipid normalized tissues after 14 months during in situ monitoring, confirming the effectiveness of the AC at reducing bioavailability of the PCBs. Polydimethylsiloxane (PDMS) passive samplers were applied to evaluate and monitor freely dissolved concentrations (Cfree) of PCBs in sediment porewater before AC placement (i.e., during baseline) and at 8 months, 14 months and 26 months following placement. Although AC composite materials were placed only at the surface, 80% reductions were observed to a depth of 16 cm after 8 months and up to 26 cm after 26 months in AquaGate+PAC treatment area. Total PCB porewater concentrations in surface sediments (1-6 cm) were reduced 89 and 91% in the AquaGate+PAC and SediMite areas during final sampling. Ex situ passive sampling showed porewater concentrations 2-5 times larger than in situ measurements due to the absence of hyporheic exchange in laboratory measurements and near equilibration between sediment and porewater. Estimated post placement ex situ porewater concentrations were more consistent with a model of bioaccumulation using the octanol-water partition coefficient (KOW) as a bioaccumulation factor leading to a hypothesis that the bioaccumulation factor in the deposit feeding clam is better estimated by equilibrium ex situ porewater measurements.