Surgical outcomes of robotic-assisted percutaneous fixation for thoracolumbar fractures in patients with ankylosing spondylitis.

BACKGROUND: Spinal fractures in patients with ankylosing spondylitis (AS) mainly present as instability, involving all three columns of the spine, and surgical intervention is often considered necessary. However, in AS patients, the significant alterations in bony structure and anatomy result in a lack of identifiable landmarks, which increases the difficulty of pedicle screw implantation. Therefore, we present the clinical outcomes of robotic-assisted percutaneous fixation for thoracolumbar fractures in patients with AS. METHODS: A retrospective review was conducted on a series of 12 patients diagnosed with AS. All patients sustained thoracolumbar fractures between October 2018 and October 2022 and underwent posterior robotic-assisted percutaneous fixation procedures. Outcomes of interest included operative time, intra-operative blood loss, complications, duration of hospital stay and fracture union. The clinical outcomes were assessed using the visual analogue scale (VAS) and Oswestry Disability Index (ODI). To investigate the achieved operative correction, pre- and postoperative radiographs in the lateral plane were analyzed by measuring the Cobb angle. RESULTS: The 12 patients had a mean age of 62.8 ± 13.0 years and a mean follow-up duration of 32.7 ± 18.9 months. Mean hospital stay duration was 15 ± 8.0 days. The mean operative time was 119.6 ± 32.2 min, and the median blood loss was 50 (50, 250) ml. The VAS value improved from 6.8 ± 0.9 preoperatively to 1.3 ± 1.0 at the final follow-up (P < 0.05). The ODI value improved from 83.6 ± 6.1% preoperatively to 11.8 ± 6.6% at the latest follow-up (P < 0.05). The average Cobb angle changed from 15.2 ± 11.0 pre-operatively to 8.3 ± 7.1 at final follow-up (P < 0.05). Bone healing was consistently achieved, with an average healing time of 6 (5.3, 7.0) months. Of the 108 screws implanted, 2 (1.9%) were improperly positioned. One patient experienced delayed nerve injury after the operation, but the nerve function returned to normal upon discharge. CONCLUSION: Posterior robotic-assisted percutaneous internal fixation can be used as an ideal surgical treatment for thoracolumbar fractures in AS patients. However, while robot-assisted pedicle screw placement can enhance the accuracy of pedicle screw insertion, it should not be relied upon solely.

Initial experience of 3-dimensional exoscope in decompression of massive lumbar disc herniation.

OBJECTIVES: To investigate the effect of a three-dimensional (3D) exoscope for decompression of single-segment massive lumbar disc herniation (LDH). METHODS: The study included 56 consecutive patients with single segment massive LDH who underwent decompression assisted by a 3D exoscope from October 2019 to October 2022 at a university hospital. The analysis was based on comparison of perioperative metrics including decompression time, estimated blood loss (EBL) during decompression and postoperative length of stay (PLS); clinical outcomes including assessment using the visual analogue scale (VAS) and the Oswestry disability index (ODI); and incidence of reoperation and complications. RESULTS: The mean decompression time was 28.35 ± 8.93 min (lumbar interbody fusion (LIF)) and 15.50 ± 5.84 min (fenestration discectomy (LOVE surgery)), the mean EBL during decompression was 42.65 ± 12.42 ml (LIF) and 24.32 ± 8.61 ml (LOVE surgery), and the mean PLS was 4.56 ± 0.82 days (LIF) and 2.00 ± 0.65 days (LOVE surgery). There were no complications such as cerebrospinal fluid leakage, nerve root injury and epidural hematoma. All patients who underwent decompression assisted by a 3D exoscope were followed up for 6 months. At the last follow-up, the VAS and ODI scores were significantly improved from the preoperative period to the last follow-up (P < 0.05). CONCLUSIONS: A 3D exoscope provides a visually detailed, deep and clear surgical field, which makes decompression safer and more effective and reduces short-term complications. A 3D exoscope may be a good assistance tool during decompression for single-segment massive LDH.

Clinical Observation of Posterior Approach for Surgical Treatment of Thoracolumbar Pseudarthrosis in Ankylosing Spinal Disorders.

OBJECTIVE: The objective of this study was to evaluate the surgical effectiveness of posterior procedure with long segment stabilization for treating thoracolumbar pseudarthrosis associated with ankylosing spinal disorders (ASDs) without anterior fusion or osteotomy. METHODS: Twelve patients with thoracolumbar pseudarthrosis in ASD were enrolled. All patients underwent posterior long-segment stabilization procedures. In some patients, the percutaneous technique or the aid of a robot or O-arm navigation was utilized for pedicle screw implantation. The clinical results were evaluated by means of the visual analog scale and Oswestry Disability Index. Radiological outcomes were evaluated for bone fusion, anterior column defect, local kyphotic correction, and position of the pedicle screws. RESULTS: All patients experienced effective bone fusion at the sites of pseudarthrosis. The mean operative time was 161.7 ± 57.1 minutes, and the average amount of blood loss was 305.8 ± 293.2 mL. For 6 patients who underwent surgery with the assistance of a robot or O-arm navigation, there was no statistically significant difference observed in terms of operative time and mean blood loss compared to those who used the freehand technique (P > 0.05). The visual analog scale score, Oswestry Disability Index value, and mean local kyphotic angle showed significant improvements at the final follow-up (P < 0.05). The accuracy of pedicle screw placement was 96%. CONCLUSIONS: Posterior surgery with long-segment fixation, without anterior fusion or osteotomy, can achieve satisfactory outcomes in ASD patients with thoracolumbar pseudarthrosis. The application of percutaneous techniques, as well as the assistance of robots or navigation technique may be a good choice for the treatment of pseudarthrosis in ASD patients.

Macrophage Membrane-Reversibly Cloaked Nanotherapeutics for the Anti-Inflammatory and Antioxidant Treatment of Rheumatoid Arthritis.

During rheumatoid arthritis (RA) development, over-produced proinflammatory cytokines represented by tumor necrosis factor-α (TNF-α) and reactive oxygen species (ROS) represented by H2 O2 form a self-promoted cycle to exacerbate the synovial inflammation and tissue damage. Herein, biomimetic nanocomplexes (NCs) reversibly cloaked with macrophage membrane (RM) are developed for effective RA management via dual scavenging of TNF-α and ROS. To construct the NCs, membrane-penetrating, helical polypeptide first condenses TNF-α siRNA (siTNF-α) and forms the cationic inner core, which further adsorbs catalase (CAT) via electrostatic interaction followed by surface coating with RM. The membrane-coated NCs enable prolonged blood circulation and active joint accumulation after systemic administration in Zymosan A-induced arthritis mice. In the oxidative microenvironment of joints, CAT degrades H2 O2 to produce O2 bubbles, which shed off the outer membrane layer to expose the positively charged inner core, thus facilitating effective intracellular delivery into macrophages. siRNA-mediated TNF-α silencing and CAT-mediated H2 O2 scavenging then cooperate to inhibit inflammation and alleviate oxidative stress, remodeling the osteomicroenvironment and fostering tissue repair. This study provides an enlightened strategy to resolve the blood circulation/cell internalization dilemma of cell membrane-coated nanosystems, and it renders a promising modality for RA treatment.

One-pot synthesis of dynamically cross-linked polymers for serum-resistant nucleic acid delivery.

Cationic polymers used for nucleic acid delivery often suffer from complicated syntheses, undesired intracellular cargo release and low serum stability. Herein, a series of ternary polymers were synthesized via facile green chemistry to achieve efficient plasmid DNA and mRNA delivery in serum. During the one-pot synthesis of the ternary polymer, acetylphenylboric acid (APBA), polyphenol and low-molecular weight polyethyleneimine (PEI 1.8k) were dynamically cross-linked with each other due to formation of an imine between PEI 1.8k and APBA and formation of a boronate ester between APBA and polyphenol. Series of polyphenols, including ellagic acid (EA), epigallocatechin gallate (EGCG), nordihydroguaiaretic acid (NDGA), rutin (RT) and rosmarinic acid (RA), and APBA molecules, including 2-acetylphenylboric acid (2-APBA), 3-acetylphenylboric acid (3-APBA) and 4-acetylphenylboric acid (4-APBA), were screened and the best-performing ternary polymer, 2-PEI-RT, constructed from RT and 2-APBA, was identified. The ternary polymer featured efficient DNA condensation to favor cellular internalization, and the acidic environment in endolysosomes triggered effective degradation of the polymer to promote cargo release. Thus, 2-PEI-RT showed robust plasmid DNA transfection efficiencies in various tumor cells in serum, outperforming the commercial reagent PEI 25k by 1-3 orders of magnitude. Moreover, 2-PEI-RT mediated efficient cytosolic delivery of Cas9-mRNA/sgRNA to enable pronounced CRISPR-Cas9 genome editing in vitro. Such a facile and robust platform holds great potential for non-viral nucleic acid delivery and gene therapy.

Integrin αVß3 Signaling in the Progression of Osteoarthritis Induced by Excessive Mechanical Stress.

Osteoarthritis (OA) is believed to be linked with cartilage degeneration, subchondral bone sclerosis, and synovial inflammation that lead to joint failure, and yet treatment that can effectively reverse the pathological process of the disease still not exists. Recent evidence suggests excessive mechanical stress (eMS) as an essential role in the pathogenesis of OA. Increased levels of integrin αVß3 have been detected in osteoarthritic cartilage and were previously implicated in OA pathogenesis. However, the role of integrin αVß3 in the process of eMS-induced OA remains unclear. Here, histologic and proteomic analyses of osteoarthritic cartilage in a rat destabilization of the medial meniscus model demonstrated elevated expression of integrin αVß3 as well as more serious cartilage degeneration in the medial weight-bearing area. Furthermore, results of in vitro study demonstrated that eMS led to a significant increase of integrin αVß3 expression and phosphorylation of downstream signaling molecules such as FAK and ERK, as well as upregulated expressions of inflammatory and degradative mediators. In addition, we found that inhibition of integrin αVß3 could alleviate chondrocyte inflammation triggered by eMS both in vivo and in vitro. Our findings suggest a central role for upregulation of integrin αVß3 signaling in OA pathogenesis and demonstrate that activation of integrin αVß3 signaling in cartilage contributes to inflammation and joint destruction in eMS-induced OA. Taken together, our data presented here provide a possibility for targeting integrin αVß3 signaling pathway as a disease-modifying therapy.

Size selection and placement of pedicle screws using robot-assisted versus fluoroscopy-guided techniques for thoracolumbar fractures: possible implications for the screw loosening rate.

BACKGROUND: There has been increased development of robotic technologies for the accuracy of percutaneous pedicle screw placement. However, it remains unclear whether the robot really optimize the selection of screw sizes and enhance screw stability. The purpose of this study is to compare the sizes (diameter and length), placement accuracy and the loosening rate of pedicle screws using robotic-assisted versus conventional fluoroscopy approaches for thoracolumbar fractures. METHODS: A retrospective cohort study was conducted to evaluate 70 consecutive patients [34 cases of robot-assisted percutaneous pedicle screw fixation (RAF) and 36 of conventional fluoroscopy-guided percutaneous pedicle screw fixation (FGF)]. Demographics, clinical characteristics, and radiological features were recorded. Pedicle screw length, diameter, and pedicle screw placement accuracy were assessed. The patients' sagittal kyphosis Cobb angles (KCA), anterior vertebral height ratios (VHA), and screw loosening rate were evaluated by radiographic data 1 year after surgery. RESULTS: There was no significant difference in the mean computed tomography (CT) Hounsfield unit (HU) values, operation duration, or length of hospital stay between the groups. Compared with the FGF group, the RAF group had a lower fluoroscopy frequency [14 (12-18) vs. 21 (16-25), P < 0.001] and a higher "grade A + B" pedicle screw placement rate (96.5% vs. 89.4%, P < 0.05). The mean screw diameter was 6.04 ± 0.55 mm in the RAF group and 5.78 ± 0.50 mm in the FGF group (P < 0.001). The mean screw length was 50.45 ± 4.37 mm in the RAF group and 48.63 ± 3.86 mm in the FGF group (P < 0.001). The correction loss of the KCA and VHR of the RAF group was less than that of the FGT group at the 1-year follow-up [(3.8 ± 1.8° vs. 4.9 ± 4.2°) and (5.5 ± 4.9% vs. 6.4 ± 5.7%)], and screw loosening occurred in 2 out of 34 patients (5.9%) in the RAF group, and 6 out of 36 patients (16.7%) in the FGF group, but there were no significant differences (P > 0.05). CONCLUSION: Compared with the fluoroscopy-guided technique, robotic-assisted spine surgery decreased radiation exposure and optimizes screw trajectories and dimensions intraoperatively. Although not statistically significant, the loosening rate of the RAF group was lower that of than the FGT group.

Utility of Flexion-Extension Radiographs with Brackets and Magnetic Resonance Facet Fluid for the Assessment of Lumbar Instability in Degenerative Lumbar Spondylolisthesis.

OBJECTIVE: To propose a new standardized technique for evaluating lumbar stability in degenerative lumbar spondylolisthesis using lumbar lateral flexion-extension radiographs with brackets and magnetic resonance facet fluid. METHODS: A retrospective analysis of 57 patients diagnosed with lumbar (L4-5) spondylolisthesis was performed. We analyzed lateral flexion-extension radiographs obtained with a bracket (LFEB) and without a bracket (LFE). Sagittal translation, segmental angulation, posterior opening, lumbar instability, and changes in lumbar lordosis were compared using functional radiographs. The mean width and maximum width of the facet fluid, mean facet joint length, and facet fluid index (FFI) of the 2 groups were compared using sagittal translation. RESULTS: The average value of sagittal translation was 1.68 ± 0.96 mm in LFE and 3.07 ± 1.29 mm in LFEB, and the difference was significant (P < 0.05). Segmental angulation, posterior opening, and changes in lumbar lordosis were significantly greater in LFEB than in LFE. The instability detection rate was 14.0% in LFE and 35.1% in LFEB. The FFI, maximum width, and mean width were significantly increased in the unstable lumbar spondylolisthesis group compared with the stable group in LFEB. The FFI and maximum width of the facet fluid were significantly increased in the unstable lumbar spondylolisthesis group compared with the stable group in LFE. CONCLUSIONS: Lumbar lateral flexion-extension radiographs with brackets can standardize the operation process and provide sufficient hyperflexion and hyperextension images. The width of the facet fluid and FFI are significant factors in the evaluation of lumbar stability in patients with lumbar spondylolisthesis.

Utility of a fulcrum for positioning support during flexion-extension radiographs for assessment of lumbar instability in patients with degenerative lumbar spondylolisthesis.

OBJECTIVE: The authors investigated a new standardized technique for evaluating lumbar stability in lumbar lateral flexion-extension (LFE) radiographs. For patients with lumbar spondylolisthesis, a three-part fulcrum with a support platform that included a semiarc leaning tool with armrests, a lifting platform for height adjustment, and a base for stability were used. Standard functional radiographs were used for comparison to determine whether adequate flexion-extension was acquired through use of the fulcrum method. METHODS: A total of 67 consecutive patients diagnosed with L4-5 degenerative lumbar spondylolisthesis were enrolled in the study. The authors analyzed LFE radiographs taken with the patient supported by a fulcrum (LFEF) and without a fulcrum. Sagittal translation (ST), segmental angulation (SA), posterior opening (PO), change in lumbar lordosis (CLL), and lumbar instability (LI) were measured for comparison using functional radiographs. RESULTS: The average value of SA was 5.76° ± 3.72° in LFE and 9.96° ± 4.00° in LFEF radiographs, with a significant difference between them (p < 0.05). ST and PO were also significantly greater in LFEF than in LFE. The detection rate of instability was 10.4% in LFE and 31.3% in LFEF, and the difference was significant. The CLL was 27.31° ± 11.96° in LFE and 37.07° ± 12.963.16° in LFEF, with a significant difference between these values (p < 0.05). CONCLUSIONS: Compared with traditional LFE radiographs, the LFEF radiographs significantly improved the detection rate of LI. In addition, this method may reduce patient discomfort during the process of obtaining radiographs.

Gold nanorods modified by endogenous protein with light-irradiation enhance bone repair via multiple osteogenic signal pathways.

Fracture is one of the most common clinical diseases that reduce the quality of patients' lives significantly. In this study, we prepared gold nanorods modified by endogenous proteins which collected from the autologous blood of individual mice for enhanced photothermal therapy (PTT) to treat fracture. Due to the outermost layer being endogenous proteins, we find that GNRs neither activate the immune cells in vitro nor cause any rejection immune responses after entering the body as compared with PEG modification. In addition, the internal bleeding and edema of the fracture site result in a rapid enrichment of GNRs after intravenous injection. Under near infrared (NIR) light irradiation, the mild photothermal effect of the accumulated GNRs can effectively promote healing of fracture in mice. The molecular mechanism of osteogenic capability is revealed by transcriptome sequencing and subsequent confirmatory experiments, indicating enhanced two key osteogenic signal transduction (MAPK, PI3K-Akt) and multiple key osteogenesis related factors expression following the treatment. Our strategy offers an alternative way to promote bone regeneration following a fracture.

Correlation Between Dural Sac Size in Dynamic Magnetic Resonance Imaging and Clinical Symptoms in Patients with Lumbar Spinal Stenosis.

OBJECTIVE: To assess the dynamic change of the dural sac size in patients with lumbar spinal stenosis (LSS) from supine to standing position and their correlation with clinical symptoms. METHODS: A total of 110 patients with LSS were prospectively enrolled to undergo both supine (0°) and standing (78°) magnetic resonance imaging (MRI). Dural sac cross-sectional area (DCSA) and dural sac anteroposterior diameter (DAPD) at the most constricted spinal level in supine and standing MRI were measured and compared. Clinical symptoms were assessed by duration of disease, claudication distance, visual analog scale (VAS) score of leg pain, and Chinese Oswestry Disability Index score of low back pain. The correlation between the parameters and clinical symptoms was analyzed by Pearson correlation coefficient (r). RESULTS: Mean minimum DCSA and DAPD in the standing position were significantly smaller (both P < 0.01) than in the supine position. DCSA and DAPD in standing MRI and their changes had better correlation with the intermittent claudication distance and VAS score of leg pain than in the supine position. A more than 15 mm2 reduction of DSCA was observed in patients with shorter claudication distance and more severe VAS score of leg pain (both P < 0.01). CONCLUSIONS: Dural sac size on MRI was reduced significantly from supine to standing position. Standing MRI and the changes of DCSA significantly correlated with claudication distance and VAS score of leg pain in patients with LSS. Therefore, standing MRI provides more radiologic information correlating with clinical symptoms in patients with LSS than supine MRI.

Electromagnetic Navigation in Distal Locking of Long Diaphyseal Interlocking Intramedullary Nailing.

OBJECTIVE: To describe the applications and effects of electromagnetic navigation (EN) technology in distal locking for the treatment of long diaphyseal fracture (LDF) with interlocking intramedullary nailing (IIN). STUDY DESIGN: An interventional study. PLACE AND DURATION OF STUDY: The Second Affiliated Hospital of Soochow University, China, from March 2013 to July 2014. METHODOLOGY: Patients who underwent IIN-LDF were selected. Twenty-four (50%) of whom were operated under EN guidance (group A) and the other 24 (50%) under conventional targeting guidance (group B). The distal locking time and X-ray irradiation time of the two groups were compared. RESULTS: Each group included 16 (33.3%) cases of femoral fracture and 8 (16.7%) cases of tibial fracture. The success rate of distal locking in group A was higher than that in group B (95.8% vs. 83.3%, p=0.045). There were statistically significant differences in the distal locking time and X-ray irradiation time of femoral intramedullary nailing between the two groups (p=0.027 and p=0.001, respectively). There were no statistically significant differences in the distal locking time and X-ray irradiation time of tibial intramedullary nailing between the two groups (p=0.347 and p=0.056, respectively). CONCLUSION: EN-IN was advantageous as it enabled easy targeting, significantly reduced intraoperative fluoroscopy and operation time and small trauma and had other advantages when used for treating LDFs, especially femoral diaphyseal fractures.