Radiologic Evaluation of Uncinate Processes of the cervical spine and the Relationship Between UP and Vertebral Artery: Implication in Anterior Cervical Spine Surgery.

PURPOSE: The purpose of this study was to determine the relationship between the uncinate process and vertebral artery from a radiological view and to confirm the surgical safety margin in order to minimize the risk of vertebral artery injury during anterior cervical approaches. METHODS: We retrospectively reviewed computed tomography angiography of 205 patients by using a contrast-enhanced CTA protocol of the vertebral artery. Four kinds of images were simultaneously reconstructed to measure all the parameters associated with vertebral artery and uncinate process of cervical spine. RESULTS: The shortest distance from the UP's tip to the VA's medial border (p<0.001) was at the C-6 level (2.9±0.9mm on the left and 3.2±1.3 on the right), and the longest distance (p<0.001) was at the C-3 level on both sides. The distance between UP's tip and the medial border of the ipsilateral VA was statistically significantly different at each cervical level, and the right distance was larger than the left (p<0.05). We found the height of UP gradually increased from C-3 to C5-level and then decreased from C-5 to C-7 level for both sides. The mean distance between the medial borders of left UP and left VA was on average 7.5±1.4mm. The diameter of VA was on average 3.4±0.6mm on the left side and 3.2±0.7mm on the right. The diameter of the VA was statistically significantly different on both sides, and the left side was larger than the right (p<0.05). CONCLUSIONS: Detailed radiologic anatomy of vertebral artery and uncinate process was reviewed in this study. A deep understanding of the correlation between the uncinate process and vertebral artery is essential to perform anterior cervical spine surgery safely and ensure adequate spinal canal decompression.

Ultrasensitive and ultrastretchable metal crack strain sensor based on helical polydimethylsiloxane.

The majority of crack sensors do not offer simultaneously both a significant stretchability and an ultrahigh sensitivity. In this study, we present a straightforward and cost-effective approach to fabricate metal crack sensors that exhibit exceptional performance in terms of ultrahigh sensitivity and ultrahigh stretchability. This is achieved by incorporating a helical structure into the substrate through a modeling process and, subsequently, depositing a thin film of gold onto the polydimethylsiloxane substrate via sputter deposition. The metal thin film is then pre-stretched to generate microcracks. The sensor demonstrates a remarkable stretchability of 300%, an exceptional sensitivity with a maximum gauge factor reaching 107, a rapid response time of 158 ms, minimal hysteresis, and outstanding durability. These impressive attributes are attributed to the deliberate design of geometric structures and careful selection of connection types for the sensing materials, thereby presenting a novel approach to fabricating stretchable and highly sensitive crack-strain sensors. This work offers a universal platform for constructing strain sensors with both high sensitivity and stretchability, showing a far-reaching significance and influence for developing next-generation practically applicable soft electronics.

Metformin-grafted polycaprolactone nanoscaffold targeting sensory nerve controlled fibroblasts reprograming to alleviate epidural fibrosis.

Epidural fibrosis (EF), associated with various biological factors, is still a major troublesome clinical problem after laminectomy. In the present study, we initially demonstrate that sensory nerves can attenuate fibrogenic progression in EF animal models via the secretion of calcitonin gene-related peptide (CGRP), suggesting a new potential therapeutic target. Further studies showed that CGRP could inhibit the reprograming activation of fibroblasts through PI3K/AKT signal pathway. We subsequently identified metformin (MET), the most widely prescribed medication for obesity-associated type 2 diabetes, as a potent stimulator of sensory neurons to release more CGRP via activating CREB signal way. We copolymerized MET with innovative polycaprolactone (PCL) nanofibers to develop a metformin-grafted PCL nanoscaffold (METG-PCLN), which could ensure stable long-term drug release and serve as favorable physical barriers. In vivo results demonstrated that local implantation of METG-PCLN could penetrate into dorsal root ganglion cells (DRGs) to promote the CGRP synthesis, thus continuously inhibit the fibroblast activation and EF progress for 8 weeks after laminectomy, significantly better than conventional drug loading method. In conclusion, this study reveals the unprecedented potential of sensory neurons to counteract EF through CGRP signaling and introduces a novel strategy employing METG-PCLN to obstruct EF by fine-tuning sensory nerve-regulated fibrogenesis.

Comparison of clinical outcomes between sequestered cervical disk herniation and non-sequestered cervical disk herniation after anterior cervical decompression and fusion: a cohort study.

BACKGROUND: The advantages of anterior cervical decompression and fusion (ACDF) were well published, while research on postoperative results in different subtypes of cervical disk herniation (CDH) still remains blank. This study aimed to explore the surgical outcome between sequestration and other types in CDH. METHODS: This retrospective cohort study enrolled 108 patients treated with ACDF in our hospital. The participants were divided into two groups according to the existence of a sequestered disk. The Visual analog scale score, the Japanese Orthopedics Association (JOA) score and the Neck disability index score were used to evaluate postoperative outcome. RESULTS: Significant improvements were observed in both groups at every viewpoint (P < 0.001). The mean JOA was 15.04 ± 1.26 in the sequestered disk group and 14.45 ± 1.43 in the non-sequestered disk group two months after the operation (P = 0.026 < 0.05). The improvement in JOA at two months after ACDF showed a significant difference: 46.58% ± 39.17% in the sequestered disk group and 33.39% ± 28.82% in the non-sequestered disk group (P = 0.047 < 0.05). Thirty-two patients in the sequestered disk group (64%) and 19 patients in the non-sequestered disk group (32.76%) presented with high signal intensity of the spinal cord on preoperative cervical T2-weighted MRI (P < 0.001). CONCLUSIONS: Patients with sequestered cervical disks seemed to have a higher degree of symptom improvement two months after ACDF. CDH with a sequestered disk appears to be more likely to cause high signal intensity changes in the compressed cervical spine on T2-weighted MRI. We prefer early positive surgery in patients with sequestered cervical disks from the clinical point of view.

Predictive value of vertebral Hounsfiled Unit for titanium mesh cage subsidence following ACCF surgery.

OBJECTIVE: To investigate the predictive value of cervical Hounsfiled Unit (HU) values for postoperative titanium mesh cage (TMC) subsidence. METHODS: Clinical data of patients who underwent ACCF surgery for degenerative cervical myelopathy between January 2016 and August 2018 were analyzed. Among the 126 patients included, 74 were male and 52 were female, with a mean age of 61.0 ± 9.9 years. The mean follow-up was 37.1 ± 11.2 months. Preoperative vertebral HU values were measured and the degree of TMC subsidence during follow-up was assessed. Patients were divided into two groups according to the presence or absence of subsidence: the subsidence group and the control group. Vertebral HU values were compared between the two groups, and correlation analysis was performed between HU values and TMC subsidence values. In addition, the predictive value and threshold of HU were analyzed by using ROC. RESULTS: There were 22 patients (14 males and 8 females) who developed TMC subsidence (subsidence group), while 104 patients (60 males and 44 females) did not develop TMC subsidence (control group) during follow-up. Comparative analysis of demographic characteristics between the two groups showed no significant differences in gender, age, BMI, diagnosis, surgical levels, and follow-up duration (all P values > 0.05). There was a significant difference in mean HU between the subsidence group (287.6 ± 49.6) and the control group (342.4 ± 61.4) (t = -3.92, P < 0.01). In the subsidence group, there was a significant correlation between subsidence values and HU values (r = -0.52, P = 0.01), whereas no such correlation was observed in the control group (r = - 0.07, P = 0.51). ROC analysis indicated that vertebral HU values could potentially be used to predict subsidence after ACCF, with an area under the ROC curve of 0.77 (95% CI 0.66-0.87; P < 0.01). The optimal HU threshold was found to be 298, with a sensitivity of 76.9% and specificity of 68.2%. CONCLUSION: Preoperative vertebral HU values were associated with postoperative TMC subsidence. Vertebral HU may be a valuable predictor of postoperative subsidence.

A Pilot Study of a Finger Kinematic Parameter-Based Tool for Evaluating Degenerative Cervical Myelopathy.

STUDY DESIGN: This is a cross-sectional study. OBJECTIVE: To evaluate the effectiveness of a novel finger Kinematic Parameter-Based Tool in the grip and release (G&R) test for assessing degenerative cervical myelopathy (DCM). SUMMARY OF BACKGROUND DATA: The development and progression of DCM symptoms are gradual and obscure. Although previous studies have objectively evaluated hand movements specific to myelopathy using the G&R test, virtual reality, or wearable sensors, these methods have limitations, such as limited discrimination or inconvenience for simple screening. Consequently, there is a need to develop effective screening methods. MATERIALS AND METHODS: Totally, 297 asymptomatic volunteers and 258 DCM patients were enrolled. This system comprises a wearable acceleration/gyro sensor. The acceleration/gyro sensor was placed on the little finger of the participants to perform 40 cycles of full-range G&R as quickly as possible. The collected data were then transformed into kinematic parameters using sensor-based software and R studio software (version: RStudio 2022.07.2+576, Boston, USA). Gender, age, and body mass index (BMI) subgroups (classified as BMI<18.5-below normal weight; 18.5≤BMI<25-normal weight group; BMI≥25-overweight group) were matched as predictor variables, and 201 pairs were matched. Nonparametric analysis using the Mann-Whitney U test was used for diagnosing the differences between the two groups, and Kruskal-Wallis's test followed by the Mann-Whitney U test was used for analyzing the differences among three different age groups (<40, 41-60, and >60 yr group). The cut-off value of 10s G&R cycles and a combined parameter were determined using receiver operating characteristics curve analysis, area under the curve, and Youden index. RESULTS: The authors found that little finger kinematic parameters were significantly lower in DCM patients than in asymptomatic participants. The optimal diagnostic indicator appeared to be the average of the top 10 linear accelerations with an area under the curve of 0.923. CONCLUSION: The Finger Kinematic Test System is an objective, practical, and quantitative utility that appears to have the capacity to diagnose and evaluate the severity of DCM. LEVEL OF EVIDENCE: 3.

TE/TM mode electro-optic conversion based on a titanium diffusion lithium niobate waveguide with a polarization-maintained fiber structure.

For the development of photonic integrated circuits and lithium niobate (L i N b O 3, LN) optical waveguide technology, the implementation and application of polarization devices based on LN are also becoming more widespread, where titanium (Ti)-diffused LN waveguides form the basis of many important electro-optic (EO) integrated optical devices. Moreover, utilizing polarization conversion has the potential to enhance both the effectiveness and capacity of optical transmission. Thus, we have presented an EO polarization mode converter packaging with PANDA polarization-maintaining optical fibers (PMFs) in the broadband wavelength range (1440-1620 nm) to obtain the multiwavelength modulation, featuring the wavelength tunability. Additionally, the fabricated device is able to achieve transverse electric (TE) to transverse magnetic (TM) mode conversion efficiently with the applied voltage of  ±, which provides high conversion efficiency. Importantly, our device also features a high-frequency response of about 600 MHz with overall insertion loss below 5 dB. The rapid development of LN-based polarization devices holds great promise for chip-integrated systems in the field of polarization telecommunication.

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.

Interoceptive regulation of skeletal tissue homeostasis and repair.

Recent studies have determined that the nervous system can sense and respond to signals from skeletal tissue, a process known as skeletal interoception, which is crucial for maintaining bone homeostasis. The hypothalamus, located in the central nervous system (CNS), plays a key role in processing interoceptive signals and regulating bone homeostasis through the autonomic nervous system, neuropeptide release, and neuroendocrine mechanisms. These mechanisms control the differentiation of mesenchymal stem cells into osteoblasts (OBs), the activation of osteoclasts (OCs), and the functional activities of bone cells. Sensory nerves extensively innervate skeletal tissues, facilitating the transmission of interoceptive signals to the CNS. This review provides a comprehensive overview of current research on the generation and coordination of skeletal interoceptive signals by the CNS to maintain bone homeostasis and their potential role in pathological conditions. The findings expand our understanding of intersystem communication in bone biology and may have implications for developing novel therapeutic strategies for bone diseases.

Application of TVD-Net for sagittal alignment and instability measurements in cervical spine radiographs.

BACKGROUND: Cervical spinal malalignment and instability are frequently occurring pathological conditions involving neck pain, radiculopathy, and myelopathy, often requiring surgical intervention. Accurate assessment of cervical alignment and instability are essential in surgical planning and evaluating postoperative outcomes. PURPOSE: To automatically measure the sagittal alignment and instability of the cervical spine, we develop a novel deep-learning model by detecting landmarks on cervical radiographs. METHODS: We introduce the transformer-embedded residual network (ResNet) as the network's core to automatically identify vertebral landmarks on digital and film-transformed cervical radiographs, and simultaneously measure the segmental Cobb angle and horizontal displacement. A Transformer Module was embedded into the latent space to extract the relationship between different vertebrae. Then a Rotating Attention Module was integrated between the encoder-decoder pairs to highlight the key points and maintain more details. Finally, a Vector Loss Module was proposed to restrain the orientation of the adjacent vertebra to reduce misdetection. All images were obtained from local hospital. Digital images were split into training, validation, and test subsets (896, 225, and 353 images, respectively). Likewise, film-transformed images were split into 404, 115, and 150 images, respectively. The results of the model were compared with manual measurements. RESULTS: Our deep learning algorithm achieved mean absolute difference (MAD) at a level of 2.20° and 2.33°, symmetric mean absolute error(SMAPE)at 16.63% and 19.35%, respectively, when measuring Cobb angle on digital images and films. On evaluating cervical instability, the diagnostic accuracy, sensitivity, specificity, precision, and F1-score evaluation metrics were calculated. The corresponding values were 89.80%, 86.49%, 90.68%, 71.11%, and 78.05% on digital images, and 90.00%, 83.78%, 91.15%, 75.61%, and 79.49% on film-transformed images, which were comparable to experienced surgeons. Visualization results demonstrated robust effectiveness in subjects with severe osteophytes or artifacts. CONCLUSION: This study presents a novel and efficient deep-learning model to assist landmarks identification and angulation and displacement calculation on lateral cervical spine radiographs, and demonstrates excellent accuracy in measuring cervical alignment and sound sensitivity and specificity in cervical instability diagnosis. It should be helpful for future research and clinical applications.

Low-dose celecoxib-loaded PCL fibers reverse intervertebral disc degeneration by up-regulating CHSY3 expression.

Intervertebral disc degeneration (IDD) has been identified as one of the predominant factors leading to persistent low back pain and disability in middle-aged and elderly people. Dysregulation of Prostaglandin E2 (PGE2) can cause IDD, while low-dose celecoxib can maintain PGE2 at the physiological level and activate the skeletal interoception. Here, as nano fibers have been extensively used in the treatment of IDD, novel polycaprolactone (PCL) nano fibers loaded with low-dose celecoxib were fabricated for IDD treatment. In vitro studies demonstrated that the nano fibers had the ability of releasing low-dose celecoxib slowly and sustainably and maintain PGE2. Meanwhile, in a puncture-induced rabbit IDD model, the nano fibers reversed IDD. Furthermore, low-dose celecoxib released from the nano fibers was firstly proved to promote CHSY3 expression. In a lumbar spine instability-induced mouse IDD model, low-dose celecoxib inhibited IDD in CHSY3wt mice rather than CHSY3-/- mice. This model indicated that CHSY3 was indispensable for low-dose celecoxib to alleviate IDD. In conclusion, this study developed a novel low-dose celecoxib-loaded PCL nano fibers to reverse IDD by maintaining PGE2 at the physiological level and promoting CHSY3 expression.

Sustained Release of Dicumarol via Novel Grafted Polymer in Electrospun Nanofiber Membrane for Treatment of Peritendinous Adhesion.

The prevention and treatment of post-traumatic peritendinous adhesion (PA) have always been a great difficulty for orthopedic surgeons. Current treatments include resecting surgery, non-steroidal anti-inflammatory drugs (NSAIDs) usage and implantable membranes, often target single disease pathogenic processes, resulting in unfavorable therapeutic outcomes. Here a polylactic acid (PLA)-dicumarol conjugates-electrospun nanofiber membrane (ENM) (PCD) is generated, which can achieve spatial accuracy and temporal sustainability in drug release. It is further demonstrated that PCD possesses a significantly higher and more sustainable drug release profile than traditional drug-loading ENM. By providing a physical barrier and continuous releasing of dicumarol, PCD implantation significantly reduces tissue adhesion by 25%, decreases fibroblasts activity and inhibits key fibrogenic cytokine transforming growth factor beta (TGFß) production by 30%, and improves the biomechanical tendon property by 14.69%. Mechanistically, PCD potently inhibits the connexin43 (Cx43) and thereby tunes down the fibroblastic TGFß/Smad3 signaling pathway. Thus, this approach leverages the anti-adhesion effect of dicumarol and drug release properties of grafted copolymer ENM by esters to provide a promising therapeutic strategy for patients who suffer from PA.

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.

Comparison of clinical outcomes between cervical disc arthroplasty and anterior cervical discectomy and fusion for the treatment of single-level cervical spondylosis: a 10-year follow-up study.

BACKGROUND CONTEXT: The theoretical advantage of cervical disc arthroplasty includes preserved motion at the cervical level, which may reduce degeneration of the adjacent segments. The long-term follow-up results are still controversial. PURPOSE: The present study aimed to retrospectively study the long-term efficacy and complications of cervical disc arthroplasty using a single commercially-available device in a single center. STUDY DESIGN: This was a propensity-score matched cohort study. PATIENT SAMPLE: This study enrolled 148 single-level cervical degenerative disease patients from January 2009 to March 2012. After 1:1 propensity score matching, 39 patients remained in the ACDF or ACDR groups. OUTCOME MEASURES: The outcome measures were neurological functions (Neck Disability Index (NDI) and Japan Orthopedic Association (JOA) scores), radiographic evaluations (cervical curvature, operative segment range of motion, degenerative condition of adjacent segments, heterotopic ossification (HO) of the surgical segment), and complications. METHODS: NDI and JOA scores were used to evaluate patient neurological functions. Cervical curvature (C2-C7 Cobb angle) and operative segment range of motion (ROM) were compared between the two groups. Grading criteria for osteophyte formation were used to evaluate the degenerative condition of adjacent segments. HO after ACDR was graded according to the McAfee grading method. RESULTS: The average follow-up time was 119.3 ±17.2 months. Satisfactory improvements in neurological function were obtained for both the ACDR and ACDF groups. There were no significant differences in VAS or NDI scores between the two groups. In the ACDR group, the ROM of the operative segment increased from 6.7 ±4.3° before the operation to 8.9 ±3.5° on the second day after the operation (p<.001). The ROM of the operative segment was 8.1 ±4.0° at the 1-year follow-up, 7.2 ±3.6° at the 2-year follow-up, 5.7 ±4.5° at the 5-year follow-up and 4.3 ±3.9° at the last follow-up. ASD was more likely to develop in the caudal adjacent segments and progressed with the follow-up time. At the last follow-up, HO was present in 27 patients (69.23%), while high-grade HO (McAfee scores III and IV) was detected in 6 patients (15.38%). CONCLUSIONS: Through nearly 10 years of follow-up, ACDR was as effective as ACDF for treating single-level degenerative cervical disc disease. However, HO and the role of ACDR in the protection of ASD remains to be further observed and followed up.

Continuous release of mefloquine featured in electrospun fiber membranes alleviates epidural fibrosis and aids in sensory neurological function after lumbar laminectomy.

Recurrent low back pain after spinal surgeries, such as lumbar laminectomy, is a major complication of excessive epidural fibrosis. Although multiple preclinical and clinical methods have been aimed at ameliorating epidural fibrosis, their safety and efficacy remain largely unclear. Single implanted electrospun fibrous membranes provide physical barriers that can decrease tissue fibrosis after surgery; however, they also trigger local inflammation due to the implantation of a foreign body, thus subsequently attenuating their anti-fibrosis properties. Here, we designed a strategy that permits easy incorporation of mefloquine into polylactic acid membranes, and stable long-term mefloquine release, to potentially improve anti-fibrosis effects and relieve or prevent low back pain. The electrospun fibrous membranes grafted with mefloquine showed a well-controlled early temporary peak release, and secondary drug release occurred smoothly over several weeks. Histopathological and histomorphometric results indicated that the drug-loaded membranes had excellent anti-fibrosis effects after laminectomy in rats. Inflammation and neovascularization at the surgical site indicated that the mefloquine-grafted electrospun fibrous membranes provided sustained anti-inflammatory outcomes while effectively alleviating associated neuropathic pain hypersensitivity. In summary, our study indicated that polylactic acid-mefloquine grafted electrospun fibrous membranes may be a potential local agent to mitigate epidural fibrosis and support sensory neurological function after laminectomy, thereby potentially improving patients' postoperative outcomes.

Sensory Nerve Maintains Intervertebral Disc Extracellular Matrix Homeostasis Via CGRP/CHSY1 Axis.

Sensory nerves are long being recognized as collecting units of various outer stimuli; recent advances indicate that the sensory nerve also plays pivotal roles in maintaining organ homeostasis. Here, this study shows that sensory nerve orchestrates intervertebral disc (IVD) homeostasis by regulating its extracellular matrix (ECM) metabolism. Specifically, genetical sensory denervation of IVD results in loss of IVD water preserve molecule chondroitin sulfate (CS), the reduction of CS bio-synthesis gene chondroitin sulfate synthase 1 (CHSY1) expression, and dysregulated ECM homeostasis of IVD. Particularly, knockdown of sensory neuros calcitonin gene-related peptide (CGRP) expression induces similar ECM metabolic disorder compared to sensory nerve denervation model, and this effect is abolished in CHSY1 knockout mice. Furthermore, in vitro evidence shows that CGRP regulates nucleus pulposus cell CHSY1 expression and CS synthesis via CGRP receptor component receptor activity-modifying protein 1 (RAMP1) and cyclic AMP response element-binding protein (CREB) signaling. Therapeutically, local injection of forskolin significantly attenuates IVD degeneration progression in mouse annulus fibrosus puncture model. Overall, these results indicate that sensory nerve maintains IVD ECM homeostasis via CGRP/CHSY1 axis and promotes IVD repair, and this expands the understanding concerning how IVD links to sensory nerve system, thus shedding light on future development of novel therapeutical strategy to IVD degeneration.

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.

Analysis of time-space variations during dynamic cervical spine motion in cervical spondylosis myelopathy patients.

BACKGROUND CONTEXT: Decreased cervical range of motion (ROM) is a common symptom of myelopathy patients. Many previous studies have relied on a variety of experimental approaches for quantifying static cervical range of motion. However, the change rules of time-space variation during dynamic cervical spine motion remains unknown. PURPOSE: To develop and validate the effectiveness of a novel wearable robot-based sensor system, Analysis of Dynamic Cervical spine Motion (ADCM), in evaluating the dynamic cervical spine motion dysfunction of patients with cervical spondylotic myelopathy (CSM). STUDY DESIGN/SETTING: A cross-sectional study. PATIENT SAMPLE: One hundred forty consecutive healthy individuals (70 men and 70 women) and 120 CSM patients (60 men and 60 women) were enrolled in the present study. OUTCOME MEASURES: The cervical motion process parameters, including the flexion and extension ROM, the flexion and extension time, and the Japanese Orthopedic Association scores (JOA) for cervical spine were measured. METHODS: Two hundred and sixty consecutive participants were asked to wear ADCM system and then fully flex and extend their neck rapidly and evenly at tolerable maximum speed. The cervical motion process was recorded and converted into waveforms. Relevant waveform parameters were measured and analyzed. The number of complete flexion-extension motions in 10 seconds has been defined as 10s F-E cycles. The Japanese Orthopedics Association (JOA) scores of CSM patients were marked. RESULTS: CSM patients had a lower number of 10s F-E cycles than healthy subjects. There were significant differences in flexion and extension time and ROM between two groups. The waveforms of myelopathy patients were wider and lower than those in healthy individuals. The average ratio value (defined as F) of wave height to wave width (a+b/c+d) could quantitatively reflect such differences of waveforms. The average F value was correlated with the JOA scores of the cervical motion function (r=0.7538), and F value declined as JOA scores decreased. According to receiver operating characteristic curve analysis, the optimal threshold value of the normal average ratio was more than 34.7. CONCLUSIONS: ADCM appears to be an objective and quantitative severity assessment tool for confirmed CSM patients by evaluating dynamic cervical spine motion dysfunction.

Electro-optic high-speed optical beam shifting based on a lithium niobate tapered waveguide.

We propose an electro-optic on-chip beam shifting device based on gradient microstructured electrodes and an optical tapered waveguide fabricated using lithium niobate (LN). The distribution of refractive index variations of the optical waveguide can be electro-optically defined and tailored by the designed gradient microstructured electrodes, which directs the beam propagation and shifting. The length of the beam shifting device is 18 mm and the width of the waveguide is gradually increased from 8 µm to 80 µm. The functionality of the beam shifting device is experimentally demonstrated, and it is observed that it has an electro-optic tunability of 0.41 µm/V, and a high-speed response time of 19 ns (λ=1310 nm). This study can provide potential applications in optical switching and modulation, beam scanning and ranging, optical spatial communications, etc.

Bi-Needle PELD with Intra-Discal Irrigation Technique for the Management of Lumbar Disc Herniation.

BACKGROUND: Lumbar disc herniation (LDH) is the most common cause of sciatica. Percutaneous endoscopic discectomy (PELD) is indicated when conservative treatments fail, which has been proved effective. During conventional PELD, ruptured discs and loose fragments inside discs are removed as much as possible to guarantee a lower reherniation rate, but it inevitably would lead to deterioration of disc degeneration and loss of disc height after PELD. Ensuring sufficient decompression while alleviating the post-operation disc degeneration process is still a clinical problem. OBJECTIVE: To evaluate the imaging and clinical outcomes of bi-needle PELD with intradiscal irrigation technique for the treatment of lumbar disc herniation (LDH). STUDY DESIGN: Multicenter retrospective cohort study. SETTING: Shanghai Changzheng Hospital, Naval Medical University, Shanghai, China. METHODS: A total of 48 patients who underwent bi-needle PELD (B-PELD) or conventional-PELD (C-PELD) for LDH in our 2 spine centers were included in this study. There were 26 cases in the C-PELD group (male 12 cases, female 14 cases) with an average age of 34.6 ± 6.8 years. And there were 22 patients in the B-PELD group (male 10 cases, female 12 cases) with an average age of 35.1 ± 6.4 years. The difference in postoperative disc degeneration (Pfirrmann grades, disc-vertebra height ratios [D-V H ratios]), visual analog scale (VAS) of low back pain, and reoperation rates were compared between the 2 groups. RESULTS: There was no significant difference in gender, age, disease duration, and surgical level between the 2 groups (P > 0.05). The postoperative VAS of back pain was 2.31 ± 0.53 for the C-PELD group and 0.63 ± 0.74 for the B-PELD group; the difference was significant (P = 0.013). The difference between the preoperative and postoperative D-V H ratios in the C-PELD group was significant (P < 0.0001), while it was not significant in the B-PELD group (P = 0.6708). The difference between the loss of D-V H ratios after surgery was significant between the 2 groups (P = 0.0003). The loss of D-V H ratios was higher in the C-PELD group. The difference between the preoperative and postoperative Pfirrmann grades in the B-PELD group was not significant (P = 0.7261); however, it was significant in the C-PELD group (P = 0.0012). The reoperation rate in the C-PELD group was 7.7%, and the reoperation rate in the B-PELD group was 4.5%; the difference was not significant (P = 1). LIMITATIONS: This study employed a retrospective design, and its inherent selection bias and limited statistical power should be considered. CONCLUSIONS: Bi-needle technique with saline irrigation maneuver showed a significant advantage of restoration of disc height and amelioration of disc degeneration compared to conventional PELD surgery.