The role of cerebrospinal fluid cross-section area ratio in the prediction of dural ossification and clinical outcomes in patients with thoracic ossification of ligamentum flavum.

BACKGROUND: It is imperative to preoperatively distinguish dural ossification (DO) and thus anticipate the risks and outcome of the surgery for patients with ossification of ligamentum flavum (OLF). However, studies have disagreed as to the efficacy of the radiographic signs or factors to predict DO and surgical outcome. In additon, the association between the cerebrospinal fluid cross-section area ratio (CCAR) and DO or clinical outcome had not been reported. The purpose of this study was to analyse CCAR and its role in prediction of DO and neurological function recovery rate in patients with OLF. METHODS: Fifty-two consecutive patients with OLF, who underwent posterior thoracic decompression and fusion between September 2012 and March 2019 at a single institution, were retrospectively reviewed. Demographic data, radiographic signs of DO, CCAR, pre- and postoperative modified Japanese Orthopedic Association (mJOA) score were recorded. RESULTS: There were 27 patients in the DO group and 25 patients in the non-DO group, with a mean age at surgery of 57.4 years and 53.9 years, respectively. No significant differences were found in sex, age, segment of maximum compression and preoperative mJOA score between the two groups. The receiver operating characteristic curve showed that the value of CCAR had a relatively high value for diagnosis of DO and prediction of neurological function recovery rate (P = .000). According to the value of CCAR, three zones were defined as DO zone (≤14.3%), non-DO zone (≥44.5%), and gray zone (14.3 to 44.5%). When the value of CCAR≤14.3%, the recovery rate was poor or fair, while it had good or excellent recovery when CCAR≥45.2%. CONCLUSION: The value of CCAR had a high diagnostic value for prediction of DO and neurological function recovery rate in patients with OLF.

Kyphoscoliosis with Klippel-Trenaunay syndrome: a case report and literature review.

BACKGROUND: Klippel-Trenaunay syndrome (KTS) is a rare congenital syndrome characterized by the triad of venous varicosities, capillary malformations and limb hypertrophy. However, KTS may rarely occur in combination with kyphoscoliosis. CASE PRESENTATION: We presented an 18-year-old female with KTS and kyphoscoliosis. Hypertrophy of bone and soft tissue affected her left face, trunk and lower limb. Moreover, the patient is associated with subacute thyroiditis, vitamin D deficiency and iron deficiency anemia, high level of D-dimer, swollen tonsil, kyphoscoliosis and Chiari-I-malformation without syringomyelia. A posterior correction and spinal fusion from T10 to L5 levels were performed for this patient. The lumbar curve was corrected from 105° to 60° and the kyphosis improved from 58° to 26°. The distance of trunk shift decreased from 10 cm to 1.4 cm. There were no thrombotic events occurred. At the 8th month follow-up, there was no significantly change of the curve in the coronal and sagittal radiographs. During the 31-month follow-up, the patient did not experience any discomfort. And her general appearance did not have any change until the last follow-up. However, she refused to take radiograph for worrying about radiation. CONCLUSIONS: KTS is a rare disease with classic clinical triad. However, it can also have other different features, including kyphoscoliosis, elevated D-Dimer, vitamin D deficiency and iron-deficiency anemia. These issues should be taken into consideration when planning treatment for kyphoscoliosis in KTS patients.

Comparison of intraoperative neurophysiologic monitoring outcomes between cervical and thoracic spine surgery.

PURPOSE: The objective is to compare the intraoperative monitoring (IOM) outcomes between degenerative cervical and thoracic spine decompression surgery. METHOD: A total of 97 patients with cervical compression myelopathy (CCM) and 75 patients with thoracic compression myelopathy (TCM) were prospectively collected between December 2012 and June 2015 in our spine center. Somatosensory-evoked potentials (SSEP) and motor-evoked potentials (MEP) were used for IOM. The postoperative neurologic status of each patient was assessed immediately after surgery. And the IOM and neurological outcomes were mainly analyzed in this study. RESULTS: Under the same alarm criteria, the IOM changes present significant difference between the cervical and thoracic surgery. During the patients with monitoring alerts, the MEPs usually manifest as sudden loss in TCM whereas the gradual loss in CCM. And there were three permanent neurologic injuries in the thoracic cases, but none in cervical cases. CONCLUSION: The IOM loss between CCM and TCM patients present obvious difference and the sudden MEPs loss associated with spinal decompression need to be taken seriously especially in TCM.

Does intraoperative cell salvage system effectively decrease the need for allogeneic transfusions in scoliotic patients undergoing posterior spinal fusion? A prospective randomized study.

PURPOSE: To determine the safety and efficacy of intraoperative cell salvage system in decreasing the need for allogeneic transfusions in a cohort of scoliosis patients undergoing primary posterior spinal fusion with segmental spinal instrumentation. METHODS: A total of 110 consecutive scoliosis patients undergoing posterior instrumented spinal fusion were randomized into two groups according to whether a cell saver machine for intraoperative blood salvage was used or not. Data included age, body mass index, perioperative hemoglobin levels, surgical time, levels fused, perioperative estimated blood loss, perioperative transfusions and incidence of transfusion-related complications. A Chi-square test and t tests were performed for intraoperative and perioperative allogeneic transfusion between groups. A regression analysis was performed between selected covariates to investigate the predictive factors of perioperative transfusion. RESULTS: Perioperative allogenic blood transfusion rate was lower in the cell saver group (14.5 versus 32.7%, p = 0.025). Mean intraoperative red blood cell transfusion requirement was also lower (0.21 U/pt versus 0.58 U/pt, p = 0.032). A multivariate analysis demonstrated that no. of fused segments (OR: 1.472; p = 0.005), preoperative hemoglobin level (OR: 0.901; p = 0.001), and the use of cell saver system (OR: 0.133; p = 0.003) had a trend toward significance in predicting likelihood of transfusion. CONCLUSIONS: Cell saver use significantly reduces the need for allogeneic blood in spine deformity surgery, particularly in patients with low preoperative hemoglobin or longer operation time. This study confirms the utility of routine cell saver use during PSF with segmental spinal instrumentation for scoliosis patients.

[Therapeutic effect and mechanism of the surgical treatment for cervical vertigo with cervical spondylosis].

OBJECTIVE: To investigate the therapeutic effect and mechanism of the surgical treatment for cervical vertigo with cervical spondylosis. METHODS: Thirty-five patients in Department of Orthopaedics, Peking Union Medical College Hospital, Peking Union Medical College, who received surgical treatment for cervical spondylosis concomitant with cervical vertigo from 2004 to 2013 were reviewed retrospectively. The preoperative cervical curvature index (CCI), slip distance and intervertebral angle, as well as the pre-and-postoperative Cobb angle were measured. The pre-and-postoperative degree of vertigo was reported according to the American Academy of Otolaryngology-Head and Neck Surgery Committee on Hearing and Equilibrium standard. The therapeutic effect and mechanism for patients with different imaging features and thus underwent various surgical approaches were analyzed. RESULTS: The mean follow-up was 40.6 months. Cervical instability was found in 33 patients. 29 of 35 (82.9%) patients had a satisfied recovery from cervical vertigo. The difference in Cobb angle in pre- and postoperative neutral cervical X-ray images was positively associated with the improvement for the vertigo (Pearson's test, P < 0.05). CONCLUSIONS: Cervical instability may be the major cause of cervical vertigo in the context of cervical spondylosis. Cervical sympathetic nerves may have played an important role in the cervical vertigo. Surgery may relieve the cervical vertigo accompanying the cervical spondylosis.

[Comparison of Clinical Influence of Intramedullary versus Extramedullary Alignment Guides on Total Knee Arthroplasty].

UNLABELLED: Objective: To compare the clinical influence of intramedullary versus extramedullary alignment guides on total knee arthroplasty (TKA) in terms of alignment of the lower limbs,intraoperative tourniquet time,and postoperative complications. METHODS: We retrospectively analyzed the clinical data of 105 patients(210 knees)undergoing bilateral TKA from February 2012 to November 2013. All patients were divided to two groups:40 [age:(66.65 ± 9.57)years] were implanted using intramedullary guides on the tibia and 65 [age:(65.29±9.27)years] were implanted using extramedullary guides on the tibia. Alignment of lower limb,tibial component angle in the sagittal plane,tourniquet time,and postoperative complications were compared. RESULTS: The gender ratio,age,height,weight,body mass index,and preoperative alignment of lower limbs were not significantly different between these two groups (all P>0.05). The average coronal alignment of lower extremity was (179.69 ± 2.91)° in the intramedullary guides group and (178.26 ± 3.38)° in the extramedullary guides group (P=0.002). The alignment of lower limbs on neutral and valgus position were found in 68 cases(85.00%)in the intramedullary group and in 94 cases (72.31%) in extramedullary group (P=0.033) ;the tourniquet time was (79.46 ± 12.06) min in the intramedullary group and (84.68 ± 8.02) min in the extramedullary group (P=0.001); the postoperative complication rate was 6.25% in intramedullary group and 3.07% in extramedullary group (P=0.279). CONCLUSION: Alignment and tourniquet time can be significantly improved by the intramedullary instrumentation,while the incidence of complications associated with intramedullary instrumentation is higher than extramedullary instrumentation.

[The microbiology and antimicrobial susceptibility of the infected knee arthroplasty].

OBJECTIVES: To describe the microbiology, antimicrobial susceptibility of patients proven prosthetic joint infection (PJI) after primary total knee arthroplasty (TKA)and to provide reference for the diagnosis and treatment of this complication. METHODS: The medical data of the patients with infected knee arthroplasty, who were managed with revision surgery between January 1995 to December 2011 were reviewed. Twenty-nine cases were identified and majority of the patients were female (23/29). Diagnosis of PJI after primary TKA was between 1 week and 10 years (average 24.3 months). The microbiology and antimicrobial susceptibility were analyzed. RESULT: The overall positive rate of cultures was 65.5% (19/29). The most common organisms identified were Coagulase-negative Staphylococcus (CNS) (7/19) and Staphylococcus Aureus (SA) (5/19). Rare pathogens of Mycobacterium (2/19) and fungi (1/19) were also identified. Vancomycin was the most effective antibiotics with overall sensitivity rates of 100%.Resistant and rare pathogens were all in type IV infection. CONCLUSIONS: Gram-positive bacterias are the main pathogen, resistant and rare pathogens should be payed attention to. Antibiotic treatment for infected TKA should be based on the results of drug susceptibility. Vancomycin allows infected knee arthroplasties before the result.

Treatment of cerebrospinal fluid leakage with prolonged use of subfascial epidural drain and antibiotics in patients of thoracic myelopathy after posterior decompression surgery.

Background: Cerebrospinal fluid leakage (CSFL) is a prevalent and vexing complication associated with spine surgery. No standard protocol is available guiding CSFL management, especially for thoracic CSFL. The aim of this study was to retrospectively evaluate the efficacy of prolonged use of subfascial epidural drain and antibiotics to treat CSFL after posterior thoracic decompression surgery. Methods: Fifty-six patients with an average age of 52.3 years (24-76 years), who underwent thoracic decompression with CSFL (group A) and 65 patients with an average age of 54.9 years (25-80 years) without CSFL (group B) were retrospectively reviewed. Patients in group A had prolonged use of subfascial drainage and antibiotics and patients in group B were treated with conventional methods. The surgical results and rate of wound related complications was compared between the two groups. Results: The average subfascial drainage time was 7.0 ± 2.7 days (2-16 days) and 3.8 ± 1.4 days (2-7 days) in group A and B, respectively. Higher occupation rate (>49%), presence of dural ossification and higher MRI grade (>2) were more likely to presented with CSFL. In group A, four patients (7.1%) presented with deep wound infection and were successfully managed with wound debridement or intravenous antibiotics. In group B, one patient (1.5%) had a superficial wound infection and was treated with antibiotics. No patients presented with wound dehiscence, wound exudation or CSF fistulation. Conclusion: The occupation rate of ossified mass and presence of dural ossification were the major risk factors of CSFL. No significant difference in infection rates was observed between the patients in group A and B.

Thoracic spondylotic myelopathy in diffuse idiopathic skeletal hyperostosis: a comparative study.

BACKGROUND: To explore the characteristics and clinical management of thoracic spinal stenosis with diffuse idiopathic skeletal hyperostosis (DISH). METHODS: The patients diagnosed with thoracic spondylotic myelopathy who underwent spinal decompression and fusion surgery in a single center between 2012 and 2020 were retrospectively analyzed. All the patients were followed up for at least 2 years. Patients were classified into DISH and non-DISH groups. Demographic, radiographic and clinical parameters were compared between the two groups. RESULTS: A total of 100 thoracic spondylotic myelopathy patients were included in the study. 22 patients were diagnosed with DISH. The proportion of male patients in the DISH group was higher, and the average BMI was larger. The incidence of upper thoracic vertebrae with ossification of posterior longitudinal ligament (OPLL) (P < 0.05) and lumbar spine with ossification of ligamentum flavum (OLF) was higher (P < 0.05) in DISH the group. The proportion of patients received staged surgery is higher in the DISH group (P < 0.1). There were no significant differences between the two groups in the amount of surgical bleeding, the ratio of cerebrospinal fluid leakage, the time duration of drainage tube placement and the JOA scores. CONCLUSION: Thoracic spinal stenosis with DISH occurred more in male patients with larger BMI. The posterior decompression and fusion surgery could achieve comparable satisfying clinical outcomes between DISH and non-DISH patients. More proportion of patients received staged surgery in the DISH group; the underline mechanism may be DISH caused more OPLL in the upper thoracic spine and more OLF in the lumbar spine because of mechanical stress.

A Retrospective, Long-term Follow-up of the Clinical Outcomes and Cost-effectiveness of Single-anesthetic Multiple Total Joint Procedures in Hemophilic Arthropathy.

OBJECTIVE: Although total joint replacement (TJR) procedures are efficacious, perioperative high-dose factors replacement therapy (FRT) to avoid catastrophic bleeding represents a significant hurdle, particularly for patients with multiple joint affection. Double simultaneous bilateral TJRs were reported as safe and cost-effective. However, little is known about multiple TJRs. The feasibility and effects remain debatable. Surgeons need to weigh the high cost of FRT against safety. Accordingly, we aimed to evaluate the clinical outcomes and cost-effectiveness of single-anesthetic multiple-joint procedures of lower limbs in end-stage hemophilic arthropathy. METHODS: Our retrospective cohort study retrieved data from an inpatient database of patients with hemophilia who underwent total knee arthroplasty (TKA), total hip arthroplasty (THA), and/or ankle arthrodesis from January 2000 to April 2016. Complications, hospital stays, transfusion, doses of clotting factor, medical costs, range of motion (ROM), Harris hip scores (HHSs) and Hospital for special surgery knee scores (HSSs) were recorded. A P value < 0.05 was considered significant. RESULTS: A total number of 81 patients were included in this study, among which 89 TKAs and 52 THAs were performed. Compared to the single TJR group, the simultaneous multiple TJR group showed a significantly higher rate of blood transfusions (P < 0.05). But no significant differences were found in the length of hospital stays, factor consumption, hospitalization costs excluding prosthesis expenses, and total complication rates. Finally, similar postoperative ROM, HHS, and HSS were witnessed in two groups (P value > 0.05). CONCLUSION: Our data indicated that simultaneous multiple TJRs are a safe and cost-effective choice for treating hemophilic patients with multiple HA-affected lower limb joints.

[Comparison of blood loss during total knee arthroplasty between haemophilic arthropathy and osteoarthritis].

OBJECTIVE: To evaluate the amount of blood loss and the efficacy of clotting factor in controlling blood loss during total knee arthroplasty. METHODS: The medical documents of 18 patients with haemophilic arthritis (HA) secondary to haemophilia A and 19 patients with osteoarthritis (OA) were retrospectively reviewed. Demographic data,functional and hematological test results,the amount of blood loss and transfusion,and complications were analyzed. RESULTS: The median amounts of total and external blood loss were 2240 ml(1892-3415 ml) and 1326 ml(934-2256 ml)in the HA group, which were significant higher than those in the OA group [1746 ml(1259-2246 ml)and 846 ml (504-1217 ml), respectively]. The median amounts of external blood loss in the two groups were 680 ml(370-1330 ml)and 730 ml(200-1190 ml)and there was no significant difference(p=0.620). Moreover, more patients in the HA group required blood transfusion (84.2% vs. 47.4%), and more red cells were transfused per patient in the HA group (2.3 U vs. 0 U). CONCLUSIONS: The total blood loss and hidden blood loss are higher in the HA patients than in OA patients during total knee arthroplasty, although the external blood loss is basically the same. Management with more clotting factor may decrease the blood loss in HA patients.

The roles and applications of neural stem cells in spinal cord injury repair.

Spinal cord injury (SCI), which has no current cure, places a severe burden on patients. Stem cell-based therapies are considered promising in attempts to repair injured spinal cords; such options include neural stem cells (NSCs). NSCs are multipotent stem cells that differentiate into neuronal and neuroglial lineages. This feature makes NSCs suitable candidates for regenerating injured spinal cords. Many studies have revealed the therapeutic potential of NSCs. In this review, we discuss from an integrated view how NSCs can help SCI repair. We will discuss the sources and therapeutic potential of NSCs, as well as representative pre-clinical studies and clinical trials of NSC-based therapies for SCI repair.

Progression of Spinal Ligament Ossification in Patients with Thoracic Myelopathy.

OBJECTIVE: To evaluate the rate of increase in thickness and cross-section area (CSA) of the ossification in thoracic myelopathy with or without cervical and lumbar spinal ligament ossification. METHODS: A total of 24 patients with 170 segments (47 ligamentum flavum [OLF] and 123 cases of ossification of the posterior longitudinal ligament [OPLL]) of spinal ligament ossification between January 2012 and March 2019 at a single institution were retrospectively reviewed. Demographic data, classification of OPLL, Sato classification of OLF, pre- and postoperative neurological function and complications were recorded. The thickness and CSA at the segment of maximum compression were measured with Image J software on the axial CT image. RESULTS: Twelve female and 12 male patients with thoracic myelopathy and spinal ligament ossification were enrolled in the study. The mean age of the patients was 54.0 ± 11.9 years with an average follow-up of 22.2 ± 23.5 months. Overall, the mean rate of progression in thickness and CSA was 1.2 ± 1.6 and 18.4 ± 50.6 mm2 /year, respectively. Being female, aging (≥45 years), and lower BMI (<28 kg/m2 ) predisposed patients to have faster ossification growth in thickness and CSA. The difference between the rate of OPLL and OLF progression in thickness and CSA was not significant. However, the rate of OPLL progression in the thoracic spine was significantly higher than that in the cervical spine regarding thickness (1.4 ± 1.9 vs. 0.6 ± 0.7 mm/year) and CSA (27.7 ± 72.0 vs. 7.3 ± 10.3 mm2 /year). CONCLUSION: This is the first study to investigate ligament ossification progression in patients with thoracic myelopathy. The difference between the rate of OPLL and OLF progression in thickness and CSA was not significant. However, the rate of thoracic OPLL progression in thickness and CSA was significantly higher than that in the cervical spine.

Tissue Recognition Based on Electrical Impedance Classified by Support Vector Machine in Spinal Operation Area.

OBJECTIVE: One of the major difficulties in spinal surgery is the injury of important tissues caused by tissue misclassification, which is the source of surgical complications. Accurate recognization of the tissues is the key to increase safety and effect as well as to reduce the complications of spinal surgery. The study aimed at tissue recognition in the spinal operation area based on electrical impedance and the boundaries of electrical impedance between cortical bone, cancellous bone, spinal cord, muscle, and nucleus pulposus. METHODS: Two female white swines with body weight of 40 kg were used to expose cortical bone, cancellous bone, spinal cord, muscle, and nucleus pulposus under general anesthesia and aseptic conditions. The electrical impedance of these tissues at 12 frequencies (in the range of 10-100 kHz) was measured by electrochemical analyzer with a specially designed probe, at 22.0-25.0°C and 50%-60% humidity. Two types of tissue recognition models - one combines principal component analysis (PCA) and support vector machine (SVM) and the other combines combines SVM and ensemble learning - were constructed, and the boundaries of electrical impedance of the five tissues at 12 frequencies of current were figured out. Linear correlation, two-way ANOVA, and paired T-test were conducted to analyze the relationship between the electrical impedance of different tissues at different frequencies. RESULTS: The results suggest that the differences of electrical impedance mainly came from tissue type (p < 0.0001), the electrical impedance of five kinds of tissue was statistically different from each other (p < 0.0001). The tissue recognition accuracy of the algorithm based on principal component analysis and support vector machine ranged from 83%-100%, and the overall accuracy was 95.83%. The classification accuracy of the algorithm based on support vector machine and ensemble learning was 100%, and the boundaries of electrical impedance of five tissues at various frequencies were calculated. CONCLUSION: The electrical impedance of cortical bone, cancellous bone, spinal cord, muscle, and nucleus pulposus had significant differences in 10-100 kHz frequency. The application of support vector machine realized the accurate tissue recognition in the spinal operation area based on electrical impedance, which is expected to be translated and applied to tissue recognition during spinal surgery.

Current understanding of tandem spinal stenosis: epidemiology, diagnosis, and surgical strategy.

Tandem spinal stenosis (TSS) is defined as the concomitant occurrence of stenosis in at least two or more distinct regions (cervical, thoracic, or lumbar) of the spine and may present with a constellation of signs and symptoms. It has four subtypes, including cervico-lumbar, cervico-thoracic, thoraco-lumbar, and cervico-thoraco-lumbar TSS. The prevalence of TSS varies depending on the different subtypes and cohorts. The main aetiologies of TSS are spinal degenerative changes and heterotopic ossification, and patients with developmental spinal stenosis, ligament ossification, and spinal stenosis at any region are at an increased risk of developing TSS. The diagnosis of TSS is challenging. The clinical presentation of TSS could be complex, concealed, or severe, and these features may be confusing to clinicians, resulting in an incomplete or delayed diagnosis. Additionally, a consolidated diagnostic criterion for TSS is urgently required to improve consistency across studies and form a basis for establishing treatment guidelines. The optimal treatment option for TSS is still under debate; areas of controversies include choice of the decompression range, choice between simultaneous or staged surgical patterns, and the order of the surgeries. The present study reviews publications on TSS, consolidates current awareness on prevalence, aetiologies, potential risk factors, diagnostic dilemmas and criteria, and surgical strategies based on TSS subtypes. This is the first review to include thoracic spinal stenosis as a candidate disorder in TSS and aims at providing the readers with a comprehensive overview of TSS.

Recent progresses in novel in vitro models of primary neurons: A biomaterial perspective.

Central nervous system (CNS) diseases have been a growing threat to the health of humanity, emphasizing the urgent need of exploring the pathogenesis and therapeutic approaches of various CNS diseases. Primary neurons are directly obtained from animals or humans, which have wide applications including disease modeling, mechanism exploration and drug development. However, traditional two-dimensional (2D) monoculture cannot resemble the native microenvironment of CNS. With the increasing understanding of the complexity of the CNS and the remarkable development of novel biomaterials, in vitro models have experienced great innovation from 2D monoculture toward three-dimensional (3D) multicellular culture. The scope of this review includes the progress of various in vitro models of primary neurons in recent years to provide a holistic view of the modalities and applications of primary neuron models and how they have been connected with the revolution of biofabrication techniques. Special attention has been paid to the interaction between primary neurons and biomaterials. First, a brief introduction on the history of CNS modeling and primary neuron culture was conducted. Next, detailed progress in novel in vitro models were discussed ranging from 2D culture, ex vivo model, spheroid, scaffold-based model, 3D bioprinting model, and microfluidic chip. Modalities, applications, advantages, and limitations of the aforementioned models were described separately. Finally, we explored future prospects, providing new insights into how basic science research methodologies have advanced our understanding of the CNS, and highlighted some future directions of primary neuron culture in the next few decades.

The impairment of intramural periarterial drainage in brain after subarachnoid hemorrhage.

Interstitial fluid (ISF) from brain drains along the basement membranes of capillaries and arteries as Intramural Periarterial Drainage (IPAD); failure of IPAD results in cerebral amyloid angiopathy (CAA). In this study, we test the hypothesis that IPAD fails after subarachnoid haemorrhage (SAH). The rat SAH model was established using endovascular perforation method. Fluorescence dyes with various molecular weights were injected into cisterna magna of rats, and the pattern of IPAD after SAH was detected using immunofluorescence staining, two-photon fluorescent microscope, transmission electron microscope and magnetic resonance imaging tracking techniques. Our results showed that fluorescence dyes entered the brain along a periarterial compartment and were cleared from brain along the basement membranes of the capillaries, with different patterns based on individual molecular weights. After SAH, there was significant impairment in the IPAD system: marked expansion of perivascular spaces, and ISF clearance rate was significantly decreased, associated with the apoptosis of endothelial cells, activation of astrocytes, over-expression of matrix metalloproteinase 9 and loss of collagen type IV. In conclusion, experimental SAH leads to a failure of IPAD, clinically significant for long term complications such as CAA, following SAH.

[Experimental study of three dimensional navigation assisted spinal surgery by multi-segment registration technology based on structured light scanning].

OBJECTIVE: To study the registration method based on structured light scanning for navigation assisted spinal surgery and assess its accuracy so as to construct a registration system for the navigation assisted spinal surgery using structured light scanning. METHODS: Both the computed tomographic (CT) dataset and the structured light scanning images of thoracic vertebra were obtained. The pre-registration and multi-segment iterative closest point (ICP) algorithm were used for the registration of CT images and structured light images. Four segmentations were selected from the surface of thoracic vertebra and placed into different combinations. The accuracy for each combination was studied. Noise and perturbation were exerted to structured light and registration accuracy was studied. And calf vertebra was used for further verification. RESULTS: A combination of pre-registration and multi-segment iterative closest point (ICP) algorithm was competent for the registration of CT scanning data and the structured light scanning data. The registration error was less than 1 mm when two and more segments were selected for registration combination. The registration error was less than 1 mm when noise was exerted. CONCLUSION: With a high accuracy and a perturbation resistance, a combination of pre-registration and multi-segment registration algorithm based on structured light scanning is competent for the registration of CT scanning data and structured light scanning data.

Biofunctionalization of electrospun fiber membranes by LbL-collagen/chondroitin sulfate nanocoating followed by mineralization for bone regeneration.

It is of great significance to develop osteoinductive artificial scaffold for bone repair and regeneration. We constructed a biomimetic apatite interface on electrospun polycaprolactone fibers by combining layer-by-layer (LbL) nanocoating with mineralization to fabricate an osteoinductive artificial scaffold. After polydopamine modification, cationic type-І collagen and anionic chondroitin sulfate were sequentially adsorbed on the fiber surface. The fibers coated with the multilayer components served as the precursor matrix to induce apatite deposition. By adjusting the number of the layers and duration of mineralization, the nanoscale morphology of composite fibers was optimized. When ten bilayers of the collagen and chondroitin sulfate were deposited onto the fibers followed by one day-mineralization, the obtained polycaprolactone-apatite composite scaffolds significantly promoted the adhesion, proliferation, and osteogenic differentiation of MC3T3-E1 cells. In a subcutaneous implantation in mice, this composite fiber membrane enhanced in vivo ectopic osteogenesis. Our nano-architectural scaffolds were able to mimic the composition and structure of the bone matrix to a certain extent, holding great potential for bone repair and regeneration.