Background Degenerative cervical myelopathy (DCM) is the leading cause of chronic spinal cord dysfunction and can lead to severe neurological impairment if untreated. While decompressive surgery is the standard treatment, predicting postoperative recovery remains a challenge. This study evaluates whether preoperative cerebrospinal fluid (CSF)/serum albumin and immunoglobulin (immunoglobulin G and immunoglobulin A) ratios, as indicators of blood-spinal cord barrier (BSCB) disruption, are associated biomarkers with long-term neurological recovery following surgery. Methods We conducted a prospective, single-center cohort study involving 49 DCM patients (29 males, 20 females, mean age: 61 ± 17), with 38 completing a one-year follow-up. Preoperative BSCB integrity was assessed using Reiber diagnostics, which evaluates CSF/serum protein ratios. Neurological status was assessed using the modified Japanese Orthopaedic Association (mJOA) score. Results Our results show a significant correlation between preoperative albumin, immunoglobulin G and immunoglobulin A CSF/serum ratios, and the one-year postoperative mJOA score (all P = 0.048). Lower ratios, predominantly accompanying a less severe BSCB disruption, were associated with better neurological outcomes (mJOA). Conclusions These findings suggest that preoperative CSF/serum ratios have the potential to serve as biomarkers for postoperative recovery in DCM, supporting more personalized treatment planning. However, larger studies with more extensive cohorts are needed to validate these results and improve the statistical power of subgroup analyses. Future research should focus on refining BSCB-related diagnostics to enhance preoperative risk assessment.

Background:Unilateral monosegmental radiculopathy, caused by foraminal soft disc nerve root compression, can be treated with posterior cervical foraminotomy (PCF). Conventional fluoroscopy is widely used for level localization and verifying decompression extent intraoperatively. However, the failure rate increases, especially in obese patients and the lower cervical spine. Can intraoperative three-dimensional (3D) navigation improve outcomes in PCF compared with conventional fluoroscopy? Materials and Methods:In this retrospective study, we analyzed two groups: 42 patients (mean age: 54 ± 10 years) who underwent PCF using intraoperative 3D navigation (study group) and 63 patients (mean age: 51 ± 11 years) who underwent PCF with conventional fluoroscopy (control group). Each cohort was divided into upper (C3-C6) and lower cervical spine (C6-T1) subgroups. Differences were explored by Mann-Whitney U and Friedman tests. Results:Both groups experienced significant postoperative symptom improvement, with no significant neurological differences. Subgroup analyses revealed no significant differences between surgeries in the upper (C3-C6) and lower (C6-T1) cervical spine. Only blood loss in the C3-C6 group differed significantly between control and study groups. Conclusion:Intraoperative 3D navigation was successfully used for PCF, resulting in significant symptom relief. Outcomes after PCF with 3D navigation appeared comparable to those achieved with conventional fluoroscopy, without statistical evidence of a clear advantage. Thus, technical complexity should be considered when selecting the surgical method.

Degenerative cervical myelopathy (DCM) is a leading cause of spinal cord dysfunction, driven by mechanical compression, secondary inflammatory and vascular changes. This study examines CSF Angiopoietin-2 (Ang2) and Vascular-Endothelial-Growth-Factor-C (VEGF-C) levels in DCM patients before and after decompressive surgery and their potential correlation with clinical outcomes. CSF samples were collected from 50 preoperative (DCMpre) and 20 patients three months postoperatively (DCMpost). A control group comprises 52 individuals undergoing thoracoabdominal aortic aneurysm (TAAA) surgery. Ang2 and VEGF-C levels were measured using ELISA and magnetic bead assays. Clinical assessments included modified Japanese Orthopaedic Association (mJOA) score, Neck Disability Index (NDI), and Oswestry Disability Index (ODI). Statistical analyses included ANOVA, paired t-tests, and Spearman correlation. Ang2 levels were significantly lower in DCM patients than in controls (DCMpre: 276 ± 90 pg/mL, DCMpost: 277 ± 65 pg/mL, TAAA: 463 ± 240 pg/mL; p < 0.001), with a postoperative increase in patients symptomatic for > 6 months (p < 0.05). VEGF-C levels did not differ significantly between groups. Preoperative Ang2 levels correlated with disability indices (NDI: r = -0.46, ODI: r = -0.44, p < 0.001). Ang2 levels are reduced in DCM and increase postoperatively, particularly in chronic cases, indicating a response to surgical intervention. While Ang2 correlates with disability indices, neither Ang2 nor VEGF-C serve as definitive biomarkers for disease severity or recovery.

Introduction:Minimally invasive posterior cervical fixation remains technically challenging due to narrow pedicle dimensions and proximity to neurovascular structures. This multicenter study evaluates the accuracy and safety of a dedicated minimally invasive cervical pedicle screw-rod system with 3D navigation guidance. Research question:Can minimally invasive cervical pedicle screw placement achieve accuracy rates comparable to open techniques while maintaining patient safety? Material and methods:Retrospective multicenter analysis of 46 patients (60.7 ± 17.4 years) undergoing percutaneous cervical pedicle screw-rod instrumentation at three German university centers (01/2022-04/2024). Indications included degenerative disease (n = 21), tumors (n = 13), trauma (n = 8), and inflammation (n = 4). Primary outcome was neurological status (Frankel classification); secondary outcomes included screw accuracy (Bredow classification), surgical characteristics, and complications. All procedures utilized 3D navigation based on cone-beam CT or intraoperative CT. Results:In total, 232 pedicle screws were implanted from C2 to T2. Favorable screw position (Bredow grades 1-2) was achieved in 89.7% overall, with significantly lower accuracy at C3-C6 versus other levels (86.0% vs. 95.4%, p = 0.0297). No permanent neurological deficits occurred. Two screws required intraoperative repositioning; zero revision surgeries were needed. Mean surgical duration was 148 ± 66min with blood loss of 236 ± 183 ml. Discussion and conclusion:Minimally invasive cervical pedicle screw-rod instrumentation with 3D navigation achieves high accuracy and safety comparable to open techniques. In the majority of cases, the technique supplemented anterior fusion for additional stability, but it may also serve as posterior-only instrumentation for in tumor-related osteolysis or traumatic injuries. Mid-cervical levels remain particularly challenging and require heightened vigilance.

Despite extensive research on aneurysm treatment and neurocritical care, aneurysmal subarachnoid hemorrhage (SAH) is still a life-threatening disease, often leaving survivors with lasting neurological and cognitive impairments. Early brain injury (EBI) and delayed cerebral ischemia (DCI) are the main contributors to brain damage, with neuroinflammation being a critical shared pathophysiological process. While numerous inflammatory markers and their temporal profiles in cerebrospinal fluid (CSF) have already been identified, comparisons with age- and sex-matched controls are limited. This study analyzed CSF from 17 SAH patients requiring an external ventricular drain (EVD) due to symptomatic hydrocephalus, sampled on days 4 and 10 post-ictus. An age- and sex-matched control group included 17 cerebrovascularly healthy patients requiring lumbar drains during aortic surgery. Chemokines and cytokines were quantified using immunoassays. Significantly elevated markers in SAH patients across both time points included MCP-1, CXCL-13, Eotaxin-1, CXCL-10, IL-8, and MIF. MIP-1α and MIP-1β showed significant differences at particular time points, indicating a distinct temporal profile for each parameter. These findings highlight neuroinflammation’s key role in intracranial and systemic pathophysiology following SAH, emphasizing its complexity and individual variability. Knowing demographic factors impact the specific manifestations of pathophysiological processes, the comparison with an age- and sex-matched control group is meaningful.

Introduction IgG4-related disease is an immune-mediated condition characterized by tissue infiltration of IgG4-positive plasma cells. Involvement of the spinal meninges results in hypertrophic spinal pachymeningitis (HSP), causing spinal cord and nerve root compression. Research question and case description In this review, we present a case of IgG4-related hypertrophic spinal pachymeningitis. Furthermore, we provide an updated literature review on IgG4-related HSP. Materials and methods We describe the case of a 45-year-old male presenting with cervical myelopathy. MR-imaging showed a ventrodorsal thickening of the meninges resulting in spinal cord compression. The patient underwent surgical decompression through laminectomy and excision of the dural thickening. The pathological findings demonstrated hypertrophic pachymeningitis with further examination showing large-scale dural infiltration of IgG4-positive lymphocytes. Adjuvant therapy with methylprednisolone and rituximab resulted in full neurological recovery with no signs of recurrence on MRI or clinically 12 months postoperatively.An updated review of the literature regarding IgG4-related HSP was performed according to PRISMA-guidelines. Relevant articles were searched from the PubMed, Web of Science and Embase databases. Patient characteristics, MRI- and histopathological findings, treatment modality and outcome were reviewed. Results The literature review provided a summary of 52 available cases, which included the one cases from our centre. Progressive worsening of neurological impairment was observed in 28 patients (58%). The lesions involved the thoracic spine (n=33, 62.2%), cervical spine (n=35, 70%), lumbar spine (n=10, 20%), and sacral spine (n=1, 2.2%). The dural thickening typically appeared as striated, fusiform, or oval changes, with homogeneous and patterns being the most common. Surgical decompression followed by immunosuppressive treatment was the main choice of therapy. The disease proved fatal in one case. Discussion and Conclusion IgG4-related HSP usually affects the cervical and thoracic dura and therefore often presents with myelopathy. Surgical decompression in cases of neurological deficits may prevent permanent neurological impairment. Immunosuppressive therapy constitutes the cornerstone in the treatment IgG4-related HSP.

Background:Since its introduction, placement of cervical pedicle screws (CPS) has been considered a procedure with a very high-risk profile. Minimally invasive CPS placement was not even considered at all. However, as surgical techniques and image guided intra-operative navigation have been refined over the last decade, navigated CPS placement has become a standard procedure in well-established spine centers. Currently, the first off-the-shelf percutaneous CPS placement platforms are becoming available. The aim of this study is to assess feasibility and accuracy of an minimally invasive surgery (MIS) CPS fixation system in a pilot series. Methods:Between January and July 2023, we treated a cohort of ten patients using a new cervical MIS platform. Forty pedicle screws were inserted percutaneously in the c-spine using intra-operative computed tomography (CT) guided navigation and retrospectively analysed for accuracy using a modified Gertzbein & Robbins (G&R) classification. Adverse events and other patient-related data were also documented. Results:Ninety percent of all screws were placed accurately (80% on perfect trajectory, 10% showed minor perforations). Another 10% (four screws) caused pedicle wall breaches between 2 and 4 mm, but were not revised, since misplacement was not associated with neurological deficit or inferior biomechanics. One patient experienced neurological deterioration, but not associated with screw misplacement. The transverse foramen was breached twice, however not endangering the vertebral arteries. Conclusions:In this pilot series MIS CPS placement yielded accurate placement rates comparable to open surgical approaches reported in the literature. Hence, MIS CPS placement appears to be a feasible and safe procedure in selected cases.

OBJECTIVE This study evaluates the precision of a commercially available spine planning software in automatic spine labelling and screw-trajectory proposal. METHODS The software uses automatic segmentation and registration of the vertebra to generate screw proposals. 877 trajectories were compared. Four neurosurgeons assessed suggested trajectories, performed corrections, and manually planned pedicle screws. Additionally, automatic identification/labelling was evaluated. RESULTS Automatic labelling was correct in 89% of the cases. 92.9% of automatically planned trajectories were in accordance with G&R grade A + B. Automatic mode reduced the time spent planning screw trajectories by 7 s per screw to 20 s per vertebra. Manual mode yielded differences in screw-length between surgeons (largest distribution peak: 5 mm), automatic in contrast at 0 mm. The size of suggested pedicle screws was significantly smaller (largest peaks in difference between 0.5 and 3 mm) than the surgeon's choice. CONCLUSION Automatic identification of vertebrae works in most cases and suggested pedicle screw trajectories are acceptable. So far, it does not substitute for an experienced surgeon's assessment.

The pathophysiology of degenerative cervical myelopathy (DCM) is characterized by chronic compression-induced damage to the spinal cord leading to secondary harm such as disruption of the blood spinal cord barrier (BSCB). It is therefore the purpose of this study to analyze BSCB disruption in pre- and postoperative DCM patients and to correlate those with the clinical status and postoperative outcome. This prospectively controlled cohort included 50 DCM patients (21 female; 29 male; mean age: 62.9 ± 11.2 years). As neurological healthy controls, 52 (17 female; 35 male; mean age 61.8 ± 17.3 years) patients with thoracic abdominal aortic aneurysm (TAAA) and indication for open surgery were included. All patients underwent a neurological examination and DCM-associated scores (Neck Disability Index, modified Japanese Orthopaedic Association Score) were assessed. To evaluate the BSCB status, blood and cerebrospinal fluid (CSF) samples (lumbar puncture or CSF drainage) were taken preoperatively and in 15 DCM patients postoperatively (4 female; 11 male; mean age: 64.7 ± 11.1 years). Regarding BSCB disruption, CSF and blood serum were examined for albumin, immunoglobulin (Ig) G, IgA and IgM. Quotients for CSF/serum were standardized and calculated according to Reiber diagnostic criteria. Significantly increased preoperative CSF/serum quotients were found in DCM patients as compared to control patients: AlbuminQ (p < .001), IgAQ (p < .001) and IgGQ (p < .001). IgMQ showed no significant difference (T = − 1.15, p = .255). After surgical decompression, neurological symptoms improved in DCM patients, as shown by a significantly higher postoperative mJOA compared to the preoperative score (p = .001). This neurological improvement was accompanied by a significant change in postoperative CSF/serum quotients for Albumin (p = .005) and IgG (p = .004) with a trend of a weak correlation between CSF markers and neurological recovery. This study further substantiates the previous findings, that a BSCB disruption in DCM patients is evident. Interestingly, surgical decompression appears to be accompanied by neurological improvement and a reduction of CSF/serum quotients, implying a BSCB recovery. We found a weak association between BSCB recovery and neurological improvement. A BSCB disruption might be a key pathomechanism in DCM patients, which could be relevant to treatment and clinical recovery.

PURPOSE:Instrumentation in spinal revision surgery is considered challenging. Altered or missing anatomical landmarks hinder the surgeons' intraoperative orientation. In recent history, the importance of navigated approaches to spinal screw placement is constantly increasing. A growing number of medical centers have introduced intraoperative CT (iCT) navigation as a new clinical standard. In this study, we compare the accuracy of dorsal iCT-navigated instrumentation in revision surgery versus primary interventions.METHODS:Between September 2017 and January 2019, we prospectively analyzed a consecutive series of dorsal instrumentation using iCT. Patients with previous operative interventions in the relevant spinal segments were included in the revision group and compared with a previously assessed group of primary interventions (nonrevision group). Each screw was assessed individually by an independent observer, making use of a modified Gertzbein and Robbins classification.RESULTS:In this period, 39 patients were treated in the revision group with a total amount of 269 implanted screws. We achieved an overall accuracy of 95.91% compared with 95.12% in the nonrevision group (46 patients, 287 screws). We found no significant difference in accuracy between the two groups or any anatomical region of the spine.CONCLUSION:In summary, iCT-navigated screw placement yields a good accuracy in spinal revision surgery, without significant difference to primary interventions.

Healing of large bone defects remains a challenge in reconstructive surgery, especially with impaired healing potential due to severe trauma, infection or irradiation. In vivo studies are often performed in healthy animals, which might not accurately reflect the situation in clinical cases. In the present study, we successfully combined a critical-sized femoral defect model with an ionizing radiation protocol in rats. To support bone healing, tissue-engineered constructs were transferred into the defect after ectopic preossification and prevascularization. The combination of SiHA, MSCs and BMP-2 resulted in the significant ectopic formation of bone tissue, which can easily be transferred by means of our custom-made titanium chamber. Implanted osteogenic MSCs survived in vivo for a total of 18 weeks. The use of SiHA alone did not lead to bone formation after ectopic implantation. Analysis of gene expression showed early osteoblast differentiation and a hypoxic and inflammatory environment in implanted constructs. Irradiation led to impaired bone healing, decreased vascularization and lower short-term survival of implanted cells. We conclude that our model is highly valuable for the investigation of bone healing and tissue engineering in pre-damaged tissue and that healing of bone defects can be substantially supported by combining SiHA, MSCs and BMP-2.

BACKGROUND: Intraoperative computed tomography (iCT) navigated dorsal instrumentation has been successfully introduced as a new clinical standard. The proximity of vital anatomic structures makes cervical spine instrumentation an especially delicate task. Therefore, navigated approaches might prove to be beneficial. In this study, the accuracy of conventional instrumentation was compared with iCT navigated dorsal cervical spine instrumentation with focus on cervical pedicle screws (CPSs) versus lateral mass screws (LMSs) and pathologies. METHODS: We analyzed a prospective consecutive series of patients undergoing cervical dorsal instrumentation with iCT and spinal navigation and retrospectively analyzed a cohort that received conventional cervical instrumentation with C-arm fluoroscopy (control group). Accuracy was assessed with a modified Gertzbein-Robbins classification. Underlying pathologies were taken into account regarding accuracy in different entities. RESULTS: Fifty-nine patients were treated using iCT (357 screws: 238 CPSs, 119 LMSs), and 98 patients underwent conventional instrumentation (632 screws: 69 CPSs, 563 LMSs). We achieved an initial accuracy of 93.28% (n = 220 screws) in the iCT group and 80.9% (n = 511 screws) in the control group (P < 0.001). Significant differences were found regarding the accuracy of CPS placement in cases of degenerative disorders (iCT vs. control; 94% vs. 63%; P < 0.001) and trauma (iCT vs. control; 88% vs. 72%; P < 0.05). iCT yielded favorable precision rates in regard to LMS placement (iCT vs. control; 94.2% vs. 82%; P < 0.05). CONCLUSIONS: Accuracy of iCT navigated instrumentation was significantly higher than conventional instrumentation. An overall tendency toward the use of CPSs with iCT navigation is evident, increasing the mechanical properties of the construct. iCT appears to be especially beneficial in elective surgery cases of degenerative spinal disorders.

The engineering of vascular grafts is a growing field in regenerative medicine. Although numerous attempts have been made, the current vascular grafts made of polyurethane (PU), Dacron®, or Teflon® still display unsatisfying results. Electrospinning of biopolymers and native proteins has been in the focus of research to imitate the extracellular matrix (ECM) of vessels to produce a small caliber, off-the-shelf tissue engineered vascular graft (TEVG) as a substitute for poorly performing PU, Dacron, or Teflon prostheses. Blended poly-ε-caprolactone (PCL)/collagen grafts have shown promising results regarding biomechanical and cell supporting features. In order to find a suitable PCL/collagen blend, we fabricated plane electrospun PCL scaffolds using various collagen type I concentrations ranging from 5% to 75%. We analyzed biocompatibility and morphological aspectsin vitro. Our results show beneficial features of collagen I integration regarding cell viability and functionality, but also adverse effects like the loss of a confluent monolayer at high concentrations of collagen. Furthermore, electrospun PCL scaffolds containing 25% collagen I seem to be ideal for engineering vascular grafts.

Aim of the present study was the establishment of an efficient and reproducible model for irradiation of rat femora as a model for impaired osteogenesis and angiogenesis. Four different irradiation protocols were compared: single irradiation of the left femur with 20 Gy and explantation after 4 or 8 weeks (group A, B) and three irradiation fractions at 3-4 days intervals with 10 Gy and explantation after 4 or 8 weeks (group C, D). The contralateral, unirradiated femur served as control. Evaluation included histology, microcomputertomography (μCT), and real-time polymerase chain reaction. Histology showed a pronounced increase of vacuoles in bone marrow after irradiation, especially after 4 weeks (group A and C), demonstrating bone marrow edema and fatty degeneration. Irradiation provoked a decrease of total cell numbers in cortical bone and of hypoxia-inducible factor 1 alpha (HIF1α)-positive cells in bone marrow. The expression of several markers (osteocalcin [OCN], runt-related transcription factor 2 [RUNX2], transforming growth factor beta 1 [TGFβ1], tumor necrosis factor alpha [TNFα], vascular endothelial growth factor A [VEGFA], and HIF1α) was decreased in group A after irradiation. This might suggest a decreased metabolism after irradiation. A significant decrease in small-sized vessels was seen in μCT evaluation in group A and D. Single irradiation with 20 Gy had the most severe and reproducible impact on osteogenesis and angiogenesis after 4 weeks while being well tolerated by all animals, thus making it an excellent model for evaluation of bone healing and vascularization in irradiated tissue.