Topical hemostatic agents in spinal surgery.

Spinal surgery can be associated with significant intraoperative blood loss which may lead to various complications. As the number of patients undergoing spinal surgery increases over time, accurate and effective hemostasis becomes critically important. Despite various surgical hemostatic techniques, conventional interventions such as compression, suture, ligation, and heat-generating cautery, are not suitable for osseous and epidural venous plexus bleeding during spinal procedures. Therefore, a variety of hemostatic agents have been developed to promote hemostasis. As they differ in terms of mechanism, form, application and potential adverse reactions, it is important to understand the natural features of existing agents. Here we comprehensively review currently available topical hemostatic agents from different sources and summarize their mechanisms of action, applications, and current or potential utilization in spinal surgery. We found hemostatic agents from different sources exert hemostatic actions through different mechanisms. In addition, topical hemostatic agents play various roles in spinal surgery including as hemostatic agent, dura mater repair, drug-carrier, skin closure, and fibrosis prevention. Compressive neurological complications are the most common complications of these hemostatic agents. Therefore, optimal use in spinal environments should match their features, indications, and efficacy with clinical conditions.

Recent progress in carbon dots for anti-pathogen applications in oral cavity.

Background: Oral microbial infections are one of the most common diseases. Their progress not only results in the irreversible destruction of teeth and other oral tissues but also closely links to oral cancers and systemic diseases. However, traditional treatment against oral infections by antibiotics is not effective enough due to microbial resistance and drug blocking by oral biofilms, along with the passive dilution of the drug on the infection site in the oral environment. Aim of review: Besides the traditional antibiotic treatment, carbon dots (CDs) recently became an emerging antimicrobial and microbial imaging agent because of their excellent (bio)physicochemical performance. Their application in treating oral infections has received widespread attention, as witnessed by increasing publication in this field. However, to date, there is no comprehensive review available yet to analyze their effectiveness and mechanism. Herein, as a step toward addressing the present gap, this review aims to discuss the recent advances in CDs against diverse oral pathogens and thus propose novel strategies in the treatment of oral microbial infections. Key scientific concepts of review: In this manuscript, the recent progress of CDs against oral pathogens is summarized for the first time. We highlighted the antimicrobial abilities of CDs in terms of oral planktonic bacteria, intracellular bacteria, oral pathogenic biofilms, and fungi. Next, we introduced their microbial imaging and detection capabilities and proposed the prospects of CDs in early diagnosis of oral infection and pathogen microbiological examination. Lastly, we discussed the perspectives on clinical transformation and the current limitations of CDs in the treatment of oral microbial infections.

Development of ε-poly(L-lysine) carbon dots-modified magnetic nanoparticles and their applications as novel antibacterial agents.

Magnetic nanoparticles (MNPs) are widely applied in antibacterial therapy owing to their distinct nanoscale structure, intrinsic peroxidase-like activities, and magnetic behavior. However, some deficiencies, such as the tendency to aggregate in water, unsatisfactory biocompatibility, and limited antibacterial effect, hindered their further clinical applications. Surface modification of MNPs is one of the main strategies to improve their (bio)physicochemical properties and enhance biological functions. Herein, antibacterial ε-poly (L-lysine) carbon dots (PL-CDs) modified MNPs (CMNPs) were synthesized to investigate their performance in eliminating pathogenic bacteria. It was found that the PL-CDs were successfully loaded on the surface of MNPs by detecting their morphology, surface charges, functional groups, and other physicochemical properties. The positively charged CMNPs show superparamagnetic properties and are well dispersed in water. Furthermore, bacterial experiments indicate that the CMNPs exhibited highly effective antimicrobial properties against Staphylococcus aureus. Notably, the in vitro cellular assays show that CMNPs have favorable cytocompatibility. Thus, CMNPs acting as novel smart nanomaterials could offer great potential for the clinical treatment of bacterial infections.

A Review and Summary of Patients with Symptomatic Postoperative Discal Pseudocysts of the Lumbar Spine.

OBJECTIVE: Postoperative discal pseudocyst (PDP) is a rare complication after discectomy. This study aimed to summarize the characteristics, pathological mechanisms and management of PDPs. METHODS: Nine patients with PDP who received surgical treatment at our institution from January 2014 to December 2021 were retrospectively reviewed. A systematic review of the literature on PDP was performed. The demographic data, clinical and imaging features, surgical options and patient prognosis were analyzed. RESULTS: Among the nine patients treated at our center, seven were male and two were female. The mean patient age (± standard deviation) at the time of surgery was 28.3 ± 5.7 years (range 18-37 years). The first operation performed on seven patients was percutaneous endoscopic transforaminal discectomy (PETD) and two patients underwent microdiscectomy. The time to conservative treatment before surgical intervention was 20 ± 9.2 days. In three cases, the disc cysts were located in L4/5 and in six cases the lesions were located in L5/S1. Intervertebral disc cyst interventions included foraminal scope (three cases), open discectomy (three cases), conservative treatment with a quadrant channel (one case) and CT-guided puncture (one case). All patients fully recovered after surgery and the mean follow-up time was 3.5 ± 2.1 years. A literature review identified 14 relevant articles that reported 43 PDP cases of PDP. CONCLUSION: PDP occurs in Asian males with mild intervertebral disc degeneration and occurs 1 month after discectomy. Treatment should be based on specific patient scenarios. Conservative treatment is necessary and surgery should be performed with caution.

Transdural circumferential decompression for thoracic spinal stenosis caused by beak-type ossification of the posterior longitudinal ligament: a technical note.

PURPOSE: Thoracic myelopathy caused by ossification of the posterior longitudinal ligament (OPLL) in the thoracic spine is usually progressive and responds poorly to conservative therapy, making surgery the only effective treatment option. A variety of surgical procedures have been developed to treat thoracic OPLL. However, the optimal surgical approach for removal of thoracic OPLL remains unclear. In the present study, we described a newly modified posterior approach for the removal of OPLL: circular decompression via dural approach, and complete removal of OPLL can be achieved under direct vision and without neurological deficit. MATERIALS AND METHODS: Three patients with beak-type thoracic OPLL presented with progressive thoracic myelopathy and leg weakness. Magnetic resonance imaging showed the spinal cord severely compressed. The surgical management of the three patients involved the 'cave-in' circular decompression and transdural resection of OPLL. RESULTS: Transdural circumferential decompression was successfully performed in all three patients. Clinical outcome measures, including pre- and postoperative radiographic parameters, were assessed. All of the patients were followed up for an average of 12 months (ranging from 10 to 15 months), and no surgery-related complications occurred. Weakness relief and neural function recovery were satisfactorily achieved in all patients by the final follow-up. CONCLUSIONS: Transdural circumferential decompression was an effective method for thoracic spinal stenosis caused by concurrent beak-type OPLL, by which OPLL could be safely removed. It is especially useful when there is a severe adhesion between the dura OPLL.

Recent Progress in antibacterial hydrogel coatings for targeting biofilm to prevent orthopedic implant-associated infections.

The application of orthopedic implants for bone tissue reconstruction and functional restoration is crucial for patients with severe bone fractures and defects. However, the abiotic nature of orthopedic implants allows bacterial adhesion and colonization, leading to the formation of bacterial biofilms on the implant surface. This can result in implant failure and severe complications such as osteomyelitis and septic arthritis. The emergence of antibiotic-resistant bacteria and the limited efficacy of drugs against biofilms have increased the risk of orthopedic implant-associated infections (OIAI), necessitating the development of alternative therapeutics. In this regard, antibacterial hydrogels based on bacteria repelling, contact killing, drug delivery, or external assistance strategies have been extensively investigated for coating orthopedic implants through surface modification, offering a promising approach to target biofilm formation and prevent OIAI. This review provides an overview of recent advancements in the application of antibacterial hydrogel coatings for preventing OIAI by targeting biofilm formation. The topics covered include: (1) the mechanisms underlying OIAI occurrence and the role of biofilms in exacerbating OIAI development; (2) current strategies to impart anti-biofilm properties to hydrogel coatings and the mechanisms involved in treating OIAI. This article aims to summarize the progress in antibacterial hydrogel coatings for OIAI prevention, providing valuable insights and facilitating the development of prognostic markers for the design of effective antibacterial orthopedic implants.

Culture-negative versus culture-positive in pyogenic spondylitis and analysis of risk factors for relapse.

OBJECTIVES: This study aims to compare and analyze the clinical features, diagnosis, treatment and prognosis of culture-negative and culture-positive primary pyogenic spondylitis. METHODS: In a retrospective analysis, 202 cases of adult primary pyogenic spondylitis with complete clinical data in our hospital from January 2013 to January 2020 were divided into two groups according to bacterial culture results: culture negative (n = 126) and culture positive (n = 76). We compare the clinical characteristics, diagnosis, treatment and prognosis of patients with different culture results. RESULTS: The culture positive rate was 37.62% (76/202). There were no significant differences in age, gender, affected segment, spinal abscess, diabetes mellitus, course of disease, surgery, recurrence, and follow-up time between the two groups (p>.05). There were statistically significant differences in hospital admission erythrocyte sedimentation rate (ESR), admission C-reactive protein (CRP), admission white blood cell (WBC) count, discharge ESR, discharge CRP, ESR decline rate, CRP (p<.05). There were statistically significant differences in the rate of decline, hospitalization days, and body temperature ≥38 °C (p<.05). Higher CRP levels on admission, antibiotic treatment time <6 weeks, and body temperature ≥ 38 °C are independent risk factors for infection recurrence. CONCLUSIONS: The culture-negative group's admission WBC, admission ESR, admission CRP, discharge ESR, discharge CRP, ESR decline rate, CRP decline rate, and hospital stay were lower than the culture positive group, the difference was statistically significant (p<.05). The independent risk factors for infection recurrence are higher CRP levels in hospital admission, antibiotic treatment time <6 weeks, and body temperature ≥ 38 °C.

Application of open-door laminoplasty with ARCH plate fixation in cervical intraspinal tumors.

BACKGROUND: The open-door laminoplasty is an effective procedure for the treatment of cervical spondylotic myelopathy. However, little information is available about the surgical results of open-door laminoplasty in the treatment of intraspinal tumors. In the present study, we aimed to investigate the clinical effect of open-door laminoplasty with ARCH plate fixation in the treatment of cervical intraspinal tumors. METHODS: This was a retrospective study. From January 2013 to May 2018, 38 patients (13 males and 25 females, the average age of 44 ± 17 years) with cervical intraspinal tumors underwent open-door laminoplasty with ARCH plate fixation in our hospital. The operation time, blood loss, pre- and postoperative visual analog scale (VAS), and Japanese Orthopedic Association (JOA) scores were determined. To determine the radiographic outcomes, cervical X-ray film and magnetic resonance imaging (MRI) were performed before and after the operation, and cervical X-ray sagittal film was used to measure Cobb angle. The clinical data before and after the operation were compared by t-test. RESULTS: A total of 38 patients underwent a successful operation and demonstrated primary healing. The average operation time was 113 ± 12 min. The average blood loss was 120 ± 19 mL. All patients were followed up for 26.1 ± 2.8 months, and the final follow-up time was more than 24 months. VAS scores were much better at 24 months after operation compared with those before the operation, which were decreased from 6.1 ± 1.1 to 1.4 ± 0.7 (t = 32.63, P < 0.01). The JOA score was improved from 9.9 ± 1.5 to 15.5 ± 0.6 (t = - 18.36, P < 0.01), and the mean JOA recovery rate was 79% ± 11% at 24 months after the operation. There was no significant difference in Cobb angle between pre-operation and 24 months after the operation, which was 9.8 ± 2.6 and 10.3 ± 3.1 respectively (t = - 0.61, P > 0.05). Neither spinal malalignment on the coronal plane nor displacement of the laminoplasty flap was observed on postoperative cervical X-ray and MRI examinations at the final follow-up. CONCLUSIONS: Open-door laminoplasty with ARCH plate fixation was a safe and effective surgical approach for the treatment of cervical intraspinal tumors.

Studies on 11 Cases of Spinal Epidural Abscess and Literature Review.

OBJECTIVE: In the present study, we aimed to describe the clinical features, diagnosis, treatment, and prognosis of spinal epidural abscess (SEA). METHODS: The complete clinical data of 11 SEA patients who were treated in our hospital system from January 2015 to June 2018 were retrospectively analyzed. Moreover, the clinical features, diagnosis, treatment, and prognosis of 642 SEA cases collected from the foreign literature from 2010 to 2019 were also investigated. RESULTS: Among our 11 SEA patients, nine cases had purulent inflammation, two cases had tuberculosis, two cases had infection caused by Staphylococcus aureus, one case had infection caused by Streptococcus constellatus, one case had infection caused by Klebsiella pneumoniae, five cases showed negative bacterial culture, and two cases had Mycobacterium tuberculosis. All 11 cases showed focal spinal pain, eight cases exhibited neurological deficits, and six cases experienced fever. Nine of the 11 cases involved the lumbosacral spine, one case involved the thoracic spine, and one case involved the cervical spine. Eight patients had a longer course of disease (>2 weeks), all 11 patients had vertebral osteomyelitis, and nine patients had intervertebral discitis. One patient had motor dysfunction of arms and legs, one patient had lower limb motor dysfunction, one patient had limb numbness, one patient experienced relapse after the conservative treatment, and one patient experienced relapse after the surgical treatment. The follow-up time was 15-24 months. CONCLUSION: The classic diagnosis of triads (focal spine pain, neurological deficit, and fever) was less specific for SEA. MRI examination, blood culture, tissue culture, and biopsy could be used for the diagnosis for SEA. Suppuritis was a common cause of SEA. Early detection, early diagnosis and early treatment, as well as the selection of the most suitable treatment regimen based on comprehensive evaluation, played crucial roles in a better prognosis of SEA. There was no statistically significant difference in terms of the general condition, diagnosis, treatment and prognosis between the patients with negative and positive culture results (P>0.05). For SEA patient with negative culture, antibiotic treatment should be used empirically.

Aspergillus spondylitis: case series and literature review.

BACKGROUND: Spinal fungal infections, especially spinal Aspergillus infections, are rare in the clinic. Here, we introduce the clinical features, diagnosis, treatment, and prognoses of 6 cases of Aspergillus spondylitis. METHODS: We retrospectively analysed the complete clinical data of patients with Aspergillus spondylitis treated in our hospital from January 2013 to January 2020. RESULTS: Aspergillus fumigatus was isolated in 4 cases, and Aspergillus spp. and Aspergillus niger were isolated in 1 case each. All six patients reported varying degrees of focal spinal pain; one patient reported radiating pain, one patient experienced bowel dysfunction and numbness in both lower limbs, and three patients had fever symptoms. One case involved the thoracic spine, one case involved the thoracolumbar junction, and 4 cases involved the lumbar spine. Three patients were already in an immunosuppressed state, and three patients entered an immunosuppressed state after spinal surgery. All six patients were successfully cured, and five required surgery. Of the 5 patients who underwent surgical treatment, 2 had spinal cord compression symptoms, and 3 had spinal instability. At the end of follow-up, 1 patient reported left back pain and 1 patient reported left limb numbness. CONCLUSION: The clinical manifestations of Aspergillus spondylitis are non-specific, and the diagnosis depends on typical imaging findings and microbiological and histopathological examination results. When there is no spinal instability, spinal nerve compression symptoms, or progressive deterioration, antifungal therapy alone may be considered. If spinal instability, spinal nerve compression, or epidural abscess formation is present, surgery combined with antifungal therapy is recommended.

Application of Laminoplasty Combined with ARCH Plate in the Treatment of Lumbar Intraspinal Tumors.

OBJECTIVE: To investigate the bone fusion and clinical effect of laminoplasty combined with ARCH plate fixation in the treatment of lumbar intraspinal tumors. METHODS: This was a clinical study. From June 2017 to January 2019, 24 patients (seven males and 17 females, average age 40 ± 16 years) with lumbar intraspinal tumors underwent laminoplasty combined with ARCH plate fixation in our hospital. The bone fusion was evaluated by X-ray and computed tomography (CT) scans that were taken 15.2 ± 2.17 months postoperatively. Each segment showed a bone bridge on one side, which was classified as "segmental partial fusion." Each segment showed bilateral bone bridges, which were classified as "segmental complete fusion". When all segments of the patient showed bilateral bone bridging so that the replanted lamina and the host lamina became a unit on the CT scan, it was defined as "complete fusion". In addition, the operation time and blood loss were recorded. Fisher's exact test was used to analyze the potential influencing factors of bone healing, including age (≤40 years vs >40 years), gender, number of operated levels (single vs two). Paired t-test was used to analyze pre- and postoperative Oswestry Disability Index (ODI) scale and low back and leg pain visual analog scale (VAS). RESULTS: A total of 33 segments of laminoplasty were successfully performed in 24 patients. The average operation time was 128 ± 18 minutes. The average blood loss was 110 ± 19 mL. All patients were followed up at least 12 months after operation (average, 15.2 ± 2.17 months). At the final follow-up, according to the definition of this study, the proportion of "segmental partial fusion" and "segmental complete fusion" were 30.3% (10/33) and 69.7% (23/33), respectively. And the proportion of patients with "complete fusion" was 70.8% (17/24). Age, gender, and number of operated levels were not associated with the fusion (P = 1.0, 0.37, and 0.06, respectively). ODI and VAS were much better at 1 month after operation and the final follow-up than those before the operation (P < 0.01). At 6 months after operation, the results of magnetic resonance imaging (MRI) showed that the supraspinous ligament was repaired, and there were no complications, such as spinal epidural scar recompression. CONCLUSIONS: Laminoplasty combined with ARCH plate was a better surgical method, and 70.8% of the patients showed complete bone fusion and there was no case of bilateral nonunion.

Surgical Technique for Decompression of Severe Thoracic Myelopathy due to Tuberous Ossification of Ligamentum Flavum.

STUDY DESIGN: Retrospective review. OBJECTIVE: To describe a safe surgical procedure, en bloc resection of the posterior wall of the thoracic canal, for the decompression of severe thoracic myelopathy caused by tuberous ossification of the ligamentum flavum (OLF). SUMMARY OF BACKGROUND DATA: OLF has been widely recognized as a cause of thoracic myelopathy in East Asia. Surgical decompression of thoracic myelopathy caused by OLF is technically demanding. Although several surgical decompression procedures have been described, acute neurological deterioration is common. MATERIALS AND METHODS: Eighteen patients with severe thoracic myelopathy caused by tuberous OLF underwent posterior decompression via segmental en bloc resection of the posterior wall of the thoracic canal. The ossified ligamentum flavum, laminae, and partial facet joints of each segment were resected en bloc. Ossified dura mater was removed if present. Posterior fixation with pedicle screws was followed by lateral bone graft fusion. RESULTS: The mean preoperative modified Japanese Orthopaedic Association score (total score, 11) was 4.1 (range, 2-5). Postoperatively, no neurological deterioration occurred, and all patients improved clinically. With an average follow-up of 31.2 months (range, 24-42 mo), the average modified Japanese Orthopaedic Association score was 7.8 (range, 6-10), representing a 2- to 5-point improvement. The average improvement rate was 55.2% (range, 33.3%-83.3%). Most patients were functionally independent at the last follow-up. Forty ossified segments were resected. The average time required for the resection of 1 segment was 77 minutes. Intraoperatively, dural ossification was noted in 11 patients. Complete resection was performed in all patients. Cerebrospinal fluid leakage occurred in 5 patients. CONCLUSION: Segmental en bloc resection of the posterior wall of the thoracic canal is a safe and effective alternative for OLF-related severe thoracic myelopathy.

Evaluating a Posterior Approach for Surgical Treatment of Thoracolumbar Pseudarthrosis in Ankylosing Spondylitis.

STUDY DESIGN: Retrospective study of a posterior approach for surgical treatment of thoracolumbar pseudarthrosis in ankylosing spondylitis (AS). OBJECTIVE: The aim of the current study was to report the surgical results of symptomatic thoracolumbar pseudarthrosis in AS through a posterior approach. SUMMARY OF BACKGROUND DATA: Spinal pseudarthrosis is a well-known complication in AS. The condition may complicate with mechanical back pain, spinal deformity, and sometimes neurological deficits. Conservative treatment often fails in this situation and surgical treatment is required. However, the optimal surgical procedure for this condition is still controversial. METHODS: From January 2006 to December 2011, 12 AS patients with spinal pseudarthrosis at the thoracolumbar segment were treated surgically after failure of >3 months conservative treatment. The indications for surgery were persisting back pain in all patients, combined with neurological deficits in 4 patients and spinal deformities in 3 patients. Transforaminal or transpedicular debridement of the pseudarthrosis at the anterior column was performed from a posterior approach. After complete debridement, bone graft at the anterior open wedge defect of the pseudarthrosis was performed from a posterior approach. Posterior pedicle screws were placed for fixation. Clinical and radiographic outcomes were assessed with an average follow-up of 28 months (range, 24-36 mo). RESULTS: The persistent back pain obtained significant relief in all cases after surgery. Four patients with neurological deficits showed complete recovery of neurological function at follow-up. The spinal deformities in 3 cases obtained correction. Solid bony fusion was achieved in all cases, and there was no correction loss at follow-up. CONCLUSIONS: In AS with symptomatic thoracolumbar pseudarthrosis, a posterior transforaminal or transpedicular approach can provide circumferential stability, anterior bone graft, and neurological decompression simultaneously. A supplemental anterior approach may be avoided by this method.

Spinal Cord Kinking in Thoracic Myelopathy Caused by Ossification of the Ligamentum Flavum.

BACKGROUND: Ossification of the ligamentum flavum (OLF) is being increasingly recognized as a cause of thoracic myelopathy. This study was to describe a rare clinical entity of spinal cord kinking (SK) in thoracic myelopathy secondary to OLF. METHODS: The data of 95 patients with thoracic myelopathy secondary to OLF were analyzed retrospectively. The incidence and location of SK were determined using preoperative magnetic resonance imaging (MRI). The clinical presentation and radiological characteristics in patients with SK were analyzed. Posterior en bloc laminectomy with OLF was performed, and the surgical results were evaluated. RESULTS: SK was found in seven patients (7.4%) based on preoperative MRI. The patients included one male and six females with an average age of 55.6 years (range, 48-64 years). Five patients presented with radiculomyelopathy and two presented with typical thoracic myelopathy of spastic paraparesis. In all cases, the kinking was located just above the end of the spinal cord where the conus medullaris (CM) was compressed by the OLF. The degree of SK varied from mild to severe. The tip of the CM was located between the upper third of T11 to the lower third of L1, above the lower edge of L1. With an average follow-up of 30.4 months, the modified Japanese Orthopedic Association score significantly improved from 5.7 ± 1.8 preoperatively to 8.9 ± 1.4 postoperatively (t = 12.05; P < 0.0001) with an improvement rate of 63.1 ± 12.3%. CONCLUSIONS: SK is a rare radiological phenomenon. It is typically located at the thoracolumbar junction, where the CM is compressed by the OLF. Our findings indicate that these patients may benefit from a posterior decompressive procedure.