Navigated bedside implantation of external ventricular drains with mobile health guidance: technical note and case series.

PURPOSE: External ventricular drain (EVD) implantation is one of the fundamental procedures of emergency neurosurgery usually performed freehand at bedside or in the operating room using anatomical landmarks. However, this technique is frequently associated with malpositioning leading to complications or dysfunction. Here, we describe a novel navigated bedside EVD insertion technique, which is evaluated in a clinical case series with the aim of safety, accuracy, and efficiency in neurosurgical emergency settings. METHODS: From 2021 to 2022, a mobile health-assisted navigation instrument (Thomale Guide, Christoph Miethke, Potsdam, Germany) was used alongside a battery-powered single-use drill (Phasor Health, Houston, USA) for bedside EVD placement in representative neurosurgical pathologies in emergency situations requiring ventricular cerebrospinal fluid (CSF) relief and intracranial pressure (ICP) monitoring. RESULTS: In all 12 patients (8 female and 4 male), navigated bedside EVDs were placed around the foramen of Monro at the first ventriculostomy attempt. The most frequent indication was aneurysmal subarachnoid hemorrhage. Mean operating time was 25.8 ± 15.0 min. None of the EVDs had to be revised due to malpositioning or dysfunction. Two EVDs were converted into a ventriculoperitoneal shunt. Drainage volume was 41.3 ± 37.1 ml per day in mean. Mean length of stay of an EVD was 6.25 ± 2.8 days. Complications included one postoperative subdural hematoma and cerebrospinal fluid infection, respectively. CONCLUSION: Combining a mobile health-assisted navigation instrument with a battery-powered drill and an appropriate ventricular catheter may enable and enhance safety, accuracy, and efficiency in bedside EVD implantation in various pathologies of emergency neurosurgery without adding relevant efforts.

High Frequency of Low-Virulent Microorganisms Detected by Sonication of Implanted Pulse Generators: So What?

INTRODUCTION: Deep brain stimulation (DBS) has become a well-established treatment modality for a variety of conditions over the last decades. Multiple surgeries are an essential part in the postoperative course of DBS patients if nonrechargeable implanted pulse generators (IPGs) are applied. So far, the rate of subclinical infections in this field is unknown. In this prospective cohort study, we used sonication to evaluate possible microbial colonization of IPGs from replacement surgery. METHODS: All consecutive patients undergoing IPG replacement between May 1, 2019 and November 15, 2020 were evaluated. The removed hardware was investigated using sonication to detect biofilm-associated bacteria. Demographic and clinical data were analyzed. RESULTS: A total of 71 patients with a mean (±SD) of 64.5 ± 15.3 years were evaluated. In 23 of these (i.e., 32.4%) patients, a positive sonication culture was found. In total, 25 microorganisms were detected. The most common isolated microorganisms were Cutibacterium acnes (formerly known as Propionibacterium acnes) (68%) and coagulase-negative Staphylococci (28%). Within the follow-up period (5.2 ± 4.3 months), none of the patients developed a clinical manifest infection. DISCUSSIONS/CONCLUSIONS: Bacterial colonization of IPGs without clinical signs of infection is common but does not lead to manifest infection. Further larger studies are warranted to clarify the impact of low-virulent pathogens in clinically asymptomatic patients.

Decompression with or without fusion in degenerative adjacent segment stenosis after lumbar fusions.

Adjacent segment stenosis can occur after lumbar fusion surgery, leading to significant discomfort and pain. If further surgeries are required, the choice of the operative technique is an individual decision. In patients without over instability, it is still uncertain whether patients with adjacent spinal stenosis should be treated like primary lumbar spinal stenosis via decompressive surgery alone or with decompression and fusion. This is a retrospective analysis with prospective collected data. We included patients with adjacent segment stenosis after lumbar fusion. Patients with spinal deformity and/or obvious instability and/or significant neuroforaminal stenosis were excluded. All patients were divided into two groups according to the surgical technique that has been used: (a) treated via microsurgical decompression (MDG), (b) decompression and fusion of the adjacent segment (FG). Treatment decision was at discretion of the surgeon. Primary outcome was the need for further lumbar surgery after 1 year. In addition, patient reported outcome was measured via numerical rating scale (NRS), SF-36, Oswestry disability Index (ODI), Pittsburgh Sleep Quality Index (PSQI), and General Depression Scale before and after 1 year after surgery. In a further follow-up, need for additional lumbar surgery was redetermined. Total study population was 37 patients with a median age of 72 years. A total of 86.1% of patients suffered from a proximal adjacent segment stenosis and most common level was L3/4 (51.4%). A total of 61.1% of included patients developed adjacent segment stenosis after fusion of one single lumbar segment. Eighteen patients were included in MDG and 19 patients in FG. Both groups benefited from surgical interventions and there was no significant difference concerning pain, pain associated disability, sleeping, life quality, and mood after 1 year or the need of follow-up surgeries 1 year after primary fusion (5 in MDG vs. 5 in FG, p = 0.92) and at the second follow-up with a median time after surgery of 30 months (6 in MDG vs. 7 in FG, p = 0.823). Duration of surgery and hospital stay was significant shorter in MDG. There was no difference concerning operative complications rate. Both groups improved significantly in pain associated disability index, pain in motion, and concerning the sleeping quality. The present study indicates that decompression may not be inferior to decompression and fusion in patients suffering from degenerative adjacent segment stenosis without obvious signs of instability, deformation, and neuroforaminal stenosis after lumbar fusion in short-term follow-up. Due to significant shorter time of surgery, a pure microsurgical decompression may be a sufficient alternative to a decompression and fusion, particular regarding old age of this patient cohort.

Clinical implementation of a 3D4K-exoscope (Orbeye) in microneurosurgery.

Exoscopic surgery promises alleviation of physical strain, improved intraoperative visualization and facilitation of the clinical workflow. In this prospective observational study, we investigate the clinical usability of a novel 3D4K-exoscope in routine neurosurgical interventions. Questionnaires on the use of the exoscope were carried out. Exemplary cases were additionally video-documented. All participating neurosurgeons (n = 10) received initial device training. Changing to a conventional microscope was possible at all times. A linear mixed model was used to analyse the impact of time on the switchover rate. For further analysis, we dichotomized the surgeons in a frequent (n = 1) and an infrequent (n = 9) user group. A one-sample Wilcoxon signed rank test was used to evaluate, if the number of surgeries differed between the two groups. Thirty-nine operations were included. No intraoperative complications occurred. In 69.2% of the procedures, the surgeon switched to the conventional microscope. While during the first half of the study the conversion rate was 90%, it decreased to 52.6% in the second half (p = 0.003). The number of interventions between the frequent and the infrequent user group differed significantly (p = 0.007). Main reasons for switching to ocular-based surgery were impaired hand-eye coordination and poor depth perception. The exoscope investigated in this study can be easily integrated in established neurosurgical workflows. Surgical ergonomics improved compared to standard microsurgical setups. Excellent image quality and precise control of the camera added to overall user satisfaction. For experienced surgeons, the incentive to switch from ocular-based to exoscopic surgery greatly varies.

Intraoperative imaging and navigated spinopelvic instrumentation: S2-alar-iliac screws combined with tricortical S1 pedicle screw fixation.

PURPOSE: The present study aimed to assess the feasibility, safety and accuracy of navigated spinopelvic fixation with focus on S2-alar-iliac screws (S2AIS) and tricortical S1 pedicle screw implantation with the use of high-resolution three-dimensional intraoperative imaging and real-time spinal navigation. METHODS: Patients undergoing navigated intraoperative CT-based spinopelvic stabilization between January 2016 and September 2019 were included. Pelvic fixation was achieved by implantation of S2AIS or iliac screws (IS). S1 screws were implanted with the goal of achieving tricortical purchase. In all cases, instrumentation was performed with real-time spinal navigation and intraoperative screw positioning was assessed using intraoperative computed tomography (iCT), cone-beam CT (CBCT) and robotic cone-beam CT (rCBCT). Screw accuracy was evaluated based on radiographic criteria. To identify predictors of complications, univariate analysis was performed. RESULTS: Overall, 52 patients (85%) received S2AIS and nine patients (15%) received IS instrumentation. Intraoperative imaging and spinal navigation were performed with iCT in 34 patients, CBCT in 21 patients and rCBCT in six patients. A total number of 10/128 (7.8%) iliac screws underwent successful intraoperative correction due to misalignment. Tricortical purchase was successfully accomplished in 58/110 (53%) of the S1 screws with a clear learning curve in the course of time. S2AIS implantation was associated with significantly fewer surgical side infection-associated surgeries. CONCLUSIONS: Real-time navigation facilitated spinopelvic instrumentation with increasing accuracy of S2AIS and tricortical S1 screws. Intraoperative imaging by iCT, CBCT or rCBCT permitted screw assessment with the chance of direct navigated revision of misplaced iliac screws to avoid secondary screw revision surgery.

Workflow and performance of intraoperative CT, cone-beam CT, and robotic cone-beam CT for spinal navigation in 503 consecutive patients.

OBJECTIVE: A direct comparison of intraoperative CT (iCT), cone-beam CT (CBCT), and robotic cone-beam CT (rCBCT) has been necessary to identify the ideal imaging solution for each individual user's need. Herein, the authors sought to analyze workflow, handling, and performance of iCT, CBCT, and rCBCT imaging for navigated pedicle screw instrumentation across the entire spine performed within the same surgical environment by the same group of surgeons. METHODS: Between 2014 and 2018, 503 consecutive patients received 2673 navigated pedicle screws using iCT (n = 1219), CBCT (n = 646), or rCBCT (n = 808) imaging during the first 24 months after the acquisition of each modality. Clinical and demographic data, workflow, handling, and screw assessment and accuracy were analyzed. RESULTS: Intraoperative CT showed image quality and workflow advantages for cervicothoracic cases, obese patients, and long-segment instrumentation, whereas CBCT and rCBCT offered independent handling, around-the-clock availability, and the option of performing 2D fluoroscopy. All modalities permitted reliable intraoperative screw assessment. Navigated screw revision was possible with each modality and yielded final accuracy rates > 92% in all groups (iCT 96.2% vs CBCT 92.3%, p < 0.001) without a difference in the accuracy of cervical pedicle screw placement or the rate of secondary screw revision surgeries. CONCLUSIONS: Continuous training and an individual setup of iCT, CBCT, and rCBCT has been shown to permit safe and precise navigated posterior instrumentation across the entire spine with reliable screw assessment and the option of immediate revision. The perceived higher image quality and larger scan area of iCT should be weighed against the around-the-clock availability of CBCT and rCBCT technology with the option of single-handed robotic image acquisition.

Spinal Cord Stimulation: A Reasonable Alternative Treatment in Patients With Symptomatic Adult Scoliosis for Whom Surgical Therapy Is Not Suitable? A Pilot Study.

INTRODUCTION: In adult scoliosis, dorsal instrumentation and fusion can provide significant improvement of pain and disability scores (Owestry Index); however, complication rates of up to 39% have been reported. As such, recent attempts have been made at expanding the surgical spectrum to include less invasive techniques in patients such as neuromodulation, specifically spinal cord stimulation (SCS). We therefore aimed to evaluate its use in a larger cohort of adult scoliosis patients in the form of a pilot study. MATERIALS AND METHODS: We analyzed prospectively collected data from 18 adult scoliosis patients receiving SCS treatment in our institution between February 2019 and May 2020. Clinical follow-up was performed at 3, 6, and 12 months following implantation of an epidural SCS System. Patients reported numeric rating scale (NRS) values for the categories of lower back pain (LBP) and regional pain (RP) both at rest and in motion. Further, SF-36, ADS-K, PSQI, and ODI forms were completed. The study was approved by the institutional Ethics Committee (EA2/093/13). RESULTS: Initial preoperative NRS of LBP at rest was significantly reduced following SCS at three (45% reduction, p = 0.005) and six (43% reduction, p = 0.009) months follow-up. LBP in motion was also reduced at three (27% reduction, p = 0.002) and six (33% reduction vs. preoperative, p = 0.005) months. RP at rest was reduced at three (38% reduction, p = 0.003) and six (37% reduction, p = 0.007) and in movement at three (29% reduction, 0.006) and six (32% reduction, p = 0.011). Loss of thoracic kyphosis and increased pelvic incidence were associated with worse NRS response to SCS stimulation at six months follow-up. DISCUSSION: In overweight, older adults for whom the risks of corrective surgery must be carefully considered, neuromodulation can significantly reduce LBP as well as regional pain in the first six months following implantation. These findings may provide a reasonable alternative in patients not willing or eligible to undergo extensive corrective surgery.

Surgical workflow for fully navigated high sacral amputation in sacral chordoma.

The method of choice for treatment of sacral chordomas is en bloc tumor removal via sacrectomy or sacral amputation in varying degrees depending on the initial tumor extent. Besides local tumor control, the preservation of neurological function is equally important to minimize postoperative bladder and bowel dysfunction. Removal of sacral tumors is complicated by the complex regional anatomy of the pelvis and the surrounding visceral and retroperitoneal structures. We aim to describe the surgical workflow for a fully navigated high sacral amputation facilitated by integration of an intraoperative computed tomography (iCT)-based spinal navigation system. An iCT-based spinal navigation system (AIRO® CT scanner, Brainlab AG, Feldkirchen, Germany) was used to perform intraoperative navigation with an image-guidance system and infrared tracking camera (BrainLab CurveTM, Brainlab AG, Feldkirchen, Germany) in combination with the spinal navigation set by Brainlab (Brainlab AG, Feldkirchen, Germany) to perform a fully navigated high sacral amputation. We demonstrate the successful implementation of iCT-based spinal navigation during high sacral amputation and the key advantages of this technique throughout the surgery. iCT-based spinal navigation is a useful complementing technique for en bloc high sacral amputations that renders the surgery safer and more accurate.

Radiofrequency denervation for treatment of sacroiliac joint pain-comparison of two different ablation techniques.

The radiofrequency treatment (RFD) for sacroiliac joint pain (SIP) is well-established, but there is still scarce evidence on its clinical outcome. The classical monopolar RFD is limited by a high recurrence rate. This might be caused by an incomplete denervation of the dorsal rami. The Simplicity III probe was invented to optimise pain fibre recruitment by its multi-electrode design. However, the clinical superiority of this procedure was never proven. The aim of this study was to illustrate the effectiveness of RFD and to compare both denervation techniques. One hundred twenty-one patients were included, and their clinical course was analysed. Fifty-seven patients received conventional treatment with multiple percutaneous monopolar RFDs (monolesion probe group, MoLG) and 64 patients with the Simplicity III probe (multilesion probe group, MuLG). All patients were followed 1, 3, 6 and 12 s after RFD. Clinical outcome scores were analysed (numeric pain rating scale (NPRS), Roland-Morris Disability Questionnaire, Oswestry Disability Index (ODI), Odom's criteria, Short Form 36 score). The MuLG showed a clearly advanced improvement concerning the clinically relevant pain relief (≥ 50%) (1 month/3 months /6 months/12 months = 72%, 55%, 36%, 27% vs. 1 month/3 months/6 months/12 months = 39%, 28%, 16%, 11%) as well as an advanced improvement of pain-associated disability and a higher satisfaction rating compared to the MoLG (NPRSMuLG_preop = 8,3; NPRSMuLG_12months = 5.8; NPRSMoLG_preop = 7,7; NPRSMoLG_12months = 5.8; ODIMuLG_preop = 52; ODIMuLG_12months = 42; ODIMoLG_preop = 52; ODIMoLG_12months = 47; ODOMSMuLG_good/excellent = 54%; ODOMSMoLG_good/excellent = 28%). RFD of the SIP with the Simplicity III probe is effective and delivers a distinct pain reduction even after 1 year of treatment. This technique shows clear advantages compared to the conventional monolesion technique and is a useful treatment for patients with recurrent SIP.

Two-level cervical corpectomy-long-term follow-up reveals the high rate of material failure in patients, who received an anterior approach only.

In contrast to a one-level cervical corpectomy, a multilevel corpectomy without posterior fusion is accompanied by a high material failure rate. So far, the adequate surgical technique for patients, who receive a two-level corpectomy, remains to be elucidated. The aim of this study was to determine the long-term clinical outcome of patients with cervical myelopathy, who underwent a two-level corpectomy. Outcome parameters of 21 patients, who received a two-level cervical corpectomy, were retrospectively analyzed concerning reoperations and outcome scores (VAS, Neck Disability Index (NDI), Nurick scale, modified Japanese Orthopaedic Association score (mJOAS), Short Form 36-item Health Survey Questionnaire (SF-36)). The failure rate was determined using postoperative radiographs. The choice over the surgical procedures was exercised by every surgeon individually. Therefore, a distinction between two groups was possible: (1) anterior group (ANT group) with a two-level corpectomy and a cervical plate, (2) anterior/posterior group (A/P group) with two-level corpectomy, cervical plate, and additional posterior fusion. Both groups benefitted from surgery concerning pain, disability, and myelopathy. While all patients of the A/P group showed no postoperative instability, one third of the patients of the ANT group exhibited instability and clinical deterioration. Thus, a revision surgery with secondary posterior fusion was needed. Furthermore, the ANT group had worse myelopathy scores (mJOASANT group = 13.5 ± 2.5, mJOASA/P group = 15.7 ± 2.2). Patients with myelopathy, who receive a two-level cervical corpectomy, benefitted from surgical decompression. However, patients with a sole anterior approach demonstrated a very high rate of instability (33%) and clinical deterioration in a long-term follow-up. Therefore, we recommend to routinely perform an additional posterior fusion after two-level cervical corpectomy.

Treatment results for lumbar epidural lipomatosis: Does fat matter?

PURPOSE: The lumbar epidural lipomatosis (LEL) is a rare disease that can cause sciatic pain syndrome or neurological deficits comparable to symptoms caused by a classical spinal canal stenosis. In severe cases surgical decompression was conducted. However, the outcome after decompressive surgery has only been investigated in small case series. In this study we compared the outcome of LEL patients after microsurgery with the outcome of patients with classical spinal stenosis (CSS). METHODS: Patients with LEL (n = 38) and patients with CSS (n = 51), who received microsurgical decompression, were followed in a prospective observational study for 3 years. The clinical results including the Oswestry Disability Index, Numeric Pain Rating Scale (NRS), Roland and Morris Disability Questionnaire, the Short Form-36 Score and the Walking Distance were analysed and compared between both groups. RESULTS: Patients with LEL improved significantly after microsurgical decompression in a 3-year follow-up concerning back pain, leg pain and pain-associated disability equal to patients with CSS (NRSback_LEL_preop. = 6.4; NRSback_CSS_preop. = 6.3; NRSback_LEL_3-years = 3.2; NRSback_CSS_3-years = 3.6; NRSleg_LEL_preop. = 6.3; NRSleg_CSS_preop. = 6.5; NRSleg_LEL_3-years = 2.5; NRSleg_CSS_3-years = 2.9; ODILEL_preop. = 52.7; ODICSS_preop = 51.8; ODILEL_3-years = 32.3; ODICSS_3-years = 27.6). The microsurgical decompression had a positive effect on the health-related quality of life, and patient satisfaction was high in both groups (LEL group-71%, CSS group-69%). CONCLUSIONS: LEL can influence the quality of life dramatically and cause a high degree of disability. A surgical decompression is a safe and effective procedure with a good clinical outcome comparable to the results in patients with an osteoligamentous spinal stenosis. Therefore, microsurgical decompression can be recommended in patients with LEL if conservative treatment fails. These slides can be retrieved under Electronic Supplementary Material.

Cell shape characterization and classification with discrete Fourier transforms and self-organizing maps.

Cells in their natural environment often exhibit complex kinetic behavior and radical adjustments of their shapes. This enables them to accommodate to short- and long-term changes in their surroundings under physiological and pathological conditions. Intravital multi-photon microscopy is a powerful tool to record this complex behavior. Traditionally, cell behavior is characterized by tracking the cells' movements, which yields numerous parameters describing the spatiotemporal characteristics of cells. Cells can be classified according to their tracking behavior using all or a subset of these kinetic parameters. This categorization can be supported by the a priori knowledge of experts. While such an approach provides an excellent starting point for analyzing complex intravital imaging data, faster methods are required for automated and unbiased characterization. In addition to their kinetic behavior, the 3D shape of these cells also provide essential clues about the cells' status and functionality. New approaches that include the study of cell shapes as well may also allow the discovery of correlations amongst the track- and shape-describing parameters. In the current study, we examine the applicability of a set of Fourier components produced by Discrete Fourier Transform (DFT) as a tool for more efficient and less biased classification of complex cell shapes. By carrying out a number of 3D-to-2D projections of surface-rendered cells, the applied method reduces the more complex 3D shape characterization to a series of 2D DFTs. The resulting shape factors are used to train a Self-Organizing Map (SOM), which provides an unbiased estimate for the best clustering of the data, thereby characterizing groups of cells according to their shape. We propose and demonstrate that such shape characterization is a powerful addition to, or a replacement for kinetic analysis. This would make it especially useful in situations where live kinetic imaging is less practical or not possible at all. © 2017 International Society for Advancement of Cytometry.

Time lapse in vivo microscopy reveals distinct dynamics of microglia-tumor environment interactions-a new role for the tumor perivascular space as highway for trafficking microglia.

Microglial cells are critical for glioma growth and progression. However, only little is known about intratumoral microglial behavior and the dynamic interaction with the tumor. Currently the scarce understanding of microglial appearance in malignant gliomas merely originates from histological studies and in vitro investigations. In order to understand the pattern of microglia activity, motility and migration we designed an intravital study in an orthotopic murine glioma model using CX3CR1-eGFP(GFP/wt) mice. We analysed the dynamics of intratumoral microglia accumulation and activity, as well as microglia/tumor blood vessel interaction by epi-illumination and 2-photon laser scanning microscopy. We further investigated cellular and tissue function, including the enzyme activity of intratumoral and microglial NADPH oxidase measured by in vivo fluorescence lifetime imaging. We identified three morphological phenotypes of tumor-associated microglia cells with entirely different motility patterns. We found that NADPH oxidase activation is highly divergent in these microglia subtypes leading to different production levels of reactive oxygen species (ROS). We observed that microglia motility is highest within the perivascular niche, suggesting relevance of microglia/tumor blood vessel interactions. In line, reduction of tumor blood vessels by antivascular therapy confirmed the relevance of the tumor vessel compartment on microglia biology in brain tumors. In summary, we provide new insights into in vivo microglial behavior, regarding both morphology and function, in malignant gliomas. GLIA 2016;64:1210-1226.

High prevalence of pharmacologically induced platelet dysfunction in the acute setting of brain injury.

BACKGROUND: The management of patients with traumatic brain injury (TBI), primary intracerebral hemorrhage (pICH) and primary subarachnoid hemorrhage (pSAH) remains a highly demanding challenge in critical care medicine. Antithrombotic agents are one of the most relevant risk factors for poor outcome. However, in the acute setting of brain injury, information on preexisting medication might not be available. This group of patients is insufficiently characterized regarding pharmacologically induced platelet impairment. METHODS: We retrospectively analyzed consecutive patients with TBI, pICH and pSAH admitted to our department with unknown preexisting medication. The impact of acetylsalicylic acid and ADP-receptor antagonists on platelet function was tested via the Multiplate analyzer. Patients' characteristics, management and the influence of platelet impairment on outcome were evaluated. RESULTS: Within 25 months 103 patients with TBI (61), pICH (32) or pSAH (10) and unknown antithrombotic medication were admitted to our department. In 54 (52.4 %) of the patients reduced platelet function was detected, mainly caused by acetylsalicylic acid. In the TBI group, 30 patients (49.2 %) were identified, while Multiplate analysis detected platelet dysfunction in 19 (59.4 %) subjects in the pICH group and 5 in the pSAH group (50 %). In multivariable analysis the pathological Multiplate result was not associated with worse outcome; however, in our cohort 47 (87 %) patients received hemostatic therapy following detection of impaired platelet function. CONCLUSION: Our results demonstrate the high frequency of pharmacologically impaired platelet function in patients with unknown preexisting medication. Early assessment of platelet function is an important tool to allow optimized treatment in these patients.

Study protocol for a prospective, randomized, multicenter trial to investigate the influence of peripheral nerve stimulation on patients with chronic sacroiliac joint syndrome (SILENCING).

BACKGROUND: The prevalence of sacroiliac joint pain (SIJP) is estimated to be 10-30% in patients with chronic low back pain. Numerous conservative and surgical treatment modalities for SIJP have been described with limited evidence regarding long-term pain relief. Spinal cord stimulation (SCS) is a well-established technique to treat patients with chronic low back pain. However, the effect on patients with SIJP is not consistent. Therefore, peripheral nerve stimulation (PNS) for chronic SIJP was implemented in experimental trials. Clinical data on PNS for SIJP is still lacking. The authors present a case series and a protocol for a prospective, multicenter study to determine the effect of PNS in patients with chronic intractable SIJP. METHOD: A multicenter, prospective randomized controlled trial was designed. Patients with chronic intractable SIJP will be recruited and randomized in a 4:3 ratio to either the peripheral nerve stimulation group or to the best medical treatment group. A total of 90 patients are planned to be enrolled (52 in the PNS group and 38 in the BMT group). Patients in the intervention group receive a percutaneous implantation of a unilateral or bilateral lead which is externalized for a trial phase for 3-14 days. After trial phase only patients with at least 50% reduction of pain receive an impulse generator for permanent stimulation. Regular visits for participants are planned on day 0, after 3 months (± 30 days), 6 months (± 30 days), and 12 months (± 60 days). The primary outcome measurements is the difference in Numeric Pain Rating Scale (NRS) between baseline and after 6 months. Secondary outcomes is improvement of pain associated disability (ODI) and improvement of health-related quality of life after 6 and 12 months. DISCUSSION: We have described the protocol for a prospective, multicenter, randomized trial evaluating the influence of PNS on patients with chronic sacroiliac joint syndrome. We believe that PNS on patients with chronic sacroiliac joint syndrome will show promising results regarding pain relief and quality of life in comparison to BMT after 12 months. The design of this trial promises high evidence in comparison to the data to date. TRIAL REGISTRATION: ClinicalTrials.gov, NCT05357300. Registered on April 26, 2022.

Influence of the sagittal spinal profile type on the long-term outcome of patients with symptomatic lumbar spinal stenosis after microsurgical decompression.

OBJECTIVE: Microsurgical decompression for patients with symptomatic lumbar spinal stenosis (LSS) has demonstrated long-term improvement concerning pain and function. Nonetheless, a considerable proportion of these patients do not experience satisfactory alleviation of symptoms. Previous studies have not found a direct influence of single sagittal parameters on patient outcomes. However, recent research indicates that a composite of parameters, presented in specific sagittal profile types (SPTs) that were defined by Roussouly and colleagues, may affect these outcomes. This study aims to investigate the impact of SPT on long-term outcomes of patients with LSS following microsurgical decompression. METHODS: This study is a prospective clinical observation. Patients with symptomatic LSS, who underwent microsurgical treatment and had long-term follow-up data for at least 36 months, were included. Patients with spinal deformity, fractures, or significant instability were excluded. Outcomes were measured using the numeric rating scale for pain, 36-Item Short Form Health Survey for quality of life, walking distance, Oswestry Disability Index, Roland-Morris Disability Questionnaire, and Odom's criteria. SPT was determined in blinded fashion by using preoperative long standing radiographs. RESULTS: The initial population of this observational study consisted of 128 patients, with long-term results available for 87 individuals, including 24 patients with SPT1, 20 with SPT2, 27 with SPT3, and 16 with SPT4. The average age was 70 years, with a slight male majority (56.3%) and a mean BMI of 27.9 kg/m2. After a median follow-up of 48 months, all groups showed significant improvement in walking distance, leg pain, and disability. Overall, 75% reported satisfaction with the surgery. However, patients with SPT1, which is characterized by low sacral slope and specific spinal curvatures, experienced significantly less improvement in back pain (p = 0.018) and related disability (p = 0.030), and lower satisfaction compared to other SPT groups (p = 0.008). CONCLUSIONS: The sagittal spinal type is influencing the long-term outcome of patients suffering from symptomatic LSS. Patients with a combination of a flat sacral slope and a low overall lumbar lordosis with a high lordosis in the lower lumbar spine (i.e., spinal SPT1) showed worse outcome concerning back pain and had decreased satisfaction with surgery than comparable subjects from other SPT groups. Consequently, the authors recommend the assessment of sagittal spinal types in patients diagnosed with symptomatic spinal stenosis prior to decompression surgery. Inclusion of SPT in the preoperative consultation process can provide valuable insights, potentially guiding practitioners to more tailored patient counseling.

Preoperatively-determined Red Distribution Width (RDW) predicts prolonged length of stay after single-level spinal fusion in elderly patients.

Introduction: Elderly patients receiving lumbar fusion surgeries present with a higher risk profile, which necessitates a robust predictor of postoperative outcomes. The Red Distribution Width (RDW) is a preoperative routinely determined parameter that reflects the degree of heterogeneity of red blood cells. Thereby, RDW is associated with frailty in hospital-admitted patients. Research question: This study aims to elucidate the potential of RDW as a frailty biomarker predictive of prolonged hospital stays following elective mono-segmental fusion surgery in elderly patients. Material and methods: In this retrospective study, we included all patients with age over 75 years that were treated via lumbar single-level spinal fusion from 2015 to 2022 at our tertiary medical center. Prolonged length of stay (pLOS) was defined as a length ≥ the 3rd quartile of LOS of all included patients. Classical correlation analysis, Receiver-operating characteristic (ROC) and new machine learning algorithms) were used. Results: A total of 208 patients were included in the present study. The median age was 77 (IQR 75-80) years. The median LOS of the patients was 6 (IQR 5-8) days. The data shows a significant positive correlation between RDW and LOS. RDW is significantly enhanced in the pLOS group. New machine learning approaches with the imputation of multiple variables can enhance the performance to an AUC of 71%. Discussion and conclusion: RDW may serve as a predictor for a pLOS in elderly. These results are compelling because the determination of this frailty biomarker is routinely performed at hospital admission. An improved prognostication of LOS could enable healthcare systems to distribute constrained hospital resources efficiently, fostering evidence-based decision-making processes.

Comparison of intraoperative CT- and cone beam CT-based spinal navigation for the treatment of atlantoaxial instability.

BACKGROUND CONTEXT: Due to the complexity of neurovascular structures in the atlantoaxial region, spinal navigation for posterior C1-C2 instrumentation is nowadays a helpful tool to increase accuracy of surgery and safety of patients. Many available intraoperative navigation devices have proven their reliability in this part of the spine. Two main imaging techniques are used: intraoperative CT (iCT) and cone beam computed tomography (CBCT). PURPOSE: Comparison of iCT- and CBCT-based technologies for navigated posterior instrumentation in C1-C2 instability. STUDY DESIGN: Retrospective study. PATIENT SAMPLE: A total of 81 consecutive patients from July 2014 to April 2020. OUTCOME MEASURES: Screw accuracy and operating time. METHODS: Patients with C1-C2 instability received posterior instrumentation using C2 pedicle screws, C1 lateral mass or pedicle screws. All screws were inserted using intraoperative imaging either using iCT or CBCT systems and spinal navigation with autoregistration technology. Following navigated screw insertion, a second intraoperative scan was performed to assess the accuracy of screw placement. Accuracy was defined as the percentage of correctly placed screws or with minor cortical breach (<2 mm) as graded by an independent observer compared to misplaced screws. RESULTS: A total of 81 patients with C1-C2 instability were retrospectively analyzed. Of these, 34 patients were operated with the use of iCT and 47 with CBCT. No significant demographic difference was found between groups. In the iCT group, 97.7% of the C1-C2 screws were correctly inserted; 2.3% showed a minor cortical breach (<2 mm); no misplacement (>2 mm). In the CBCT group, 98.9% of screws were correctly inserted; no minor pedicle breach; 1.1% showed misplacement >2 mm. Accuracy of screw placement demonstrated no significant difference between groups. Both technologies allowed sufficient identification of screw misplacement intraoperatively leading to two screw revisions in the iCT and three in the CBCT group. Median time of surgery was significantly shorter using CBCT technology (166.5 minutes [iCT] vs 122 minutes [CBCT]; p<.01). CONCLUSIONS: Spinal navigation using either iCT- or CBCT-based systems with autoregistration allows safe and reliable screw placement and intraoperative assessment of screw positioning. Using the herein presented procedural protocols, CBCT systems allow shorter operating time.

Peripheral nerve stimulation for the treatment of chronic knee pain.

The average age of our population is increasing, resulting in a high incidence of chronic degenerative knee pathologies. Several treatment options, including surgical procedures are available to help mitigate these pathologies. However, the percentage of subjects with chronic post-surgical knee pain is still estimated at 16-20%. Neuromodulation techniques such as spinal cord stimulation and dorsal root ganglion stimulation (DRGS) are treatment options for subjects with chronic knee pain. The evidence for peripheral nerve stimulation (PNS) is minimal due to a limited number of neuromodulation systems capable of targeting the distal part of the lower limbs. This study aimed to investigate the safety and efficacy externally powered PNS systems for the treatment of chronic intractable knee pain targeting the saphenous nerve. Patients suffering from chronic intractable post-surgical knee pain received landmark-guided peripheral nerve stimulation of the branches of the saphenous nerve. All implants were performed with an externally powered PNS system to avoid lead migration as a result of cross-joint lead positions tunneling towards an Implantable Pulse Generator to the trunk. Data were collected retrospectively. Subject-reported outcome was measured via numerical rating scale values on a 10-point scale measuring pain intensity at rest and in motion. Additional data were collected for the subjects treated at the Charité location, including quality of life with the SF-36 form, quality of sleep with the Pittsburgh Sleep Quality Index and mood states with the short form of the General Depression Scale. Thirty-three patients received direct to permanent implant, landmark-guided peripheral nerve stimulation of the saphenous nerve branches. Six (18.2%) subjects reported non-sufficient initial benefit from the therapy and were explanted. Two subjects were explanted due to wound infections. The total study population reported included 25 patients. These subjects reported significant improvements related to pain, quality of life, mood quality, and quality of sleep. Additionally, subjects were able to reduce their opioid medication significantly after PNS therapy. Externally powered PNS at the saphenous nerve branches is a straightforward, selective and safe technique for patients with chronic knee pain. The landmark-guided implantation technique is less invasive than classical neuromodulation techniques such as spinal cord or DRGS and complication rates remain low. Short-term results are promising and show considerable reductions in pain scores and opioid intake. Long-term results are pending.

Effectiveness of outpatient parenteral antimicrobial therapy (OPAT) for patients with cranial infection.

Objective: Outpatient parenteral antimicrobial therapy (OPAT) is a well-established and cost-effective method for improving the efficient use of healthcare resources. However, only a few centres in Germany perform it. Here we analysed OPAT for the treatment of patients with cranial infections in our neurosurgical department. Methods: This retrospective study analysed patients with cranial infections and the need for intravenous (i.v.) antimicrobial treatment between 2018 and 2021.All diagnosed intracranial infections were defined into two infection categories such as long-term antimicrobial treatment and short-term antimicrobial treatment. All included patients were discharged with a peripherally inserted central catheter (PICC) line. Prior to discharge, all patients received training in the safe administration of their medications via the PICC line. The duration of OPAT and the rate of readmission after OPAT were analysed. Results: We identified a total of 45 patients treated with OPAT for cranial infections. Intradural involvement was present in 40 cases (88.9%). The average length of hospital stay for this cohort after surgical treatment was 45 ± 15 days. 5 patients were treated for soft tissue/skin infection. Surgery was not required in this cohort. The mean hospital stay for this cohort was 8 ± 6 days. Gram-positive organisms were isolated in most cases (53.3%). The most common pathogens were Staphylococcus aureus followed by other Staphylococcus species. For all included patients, OPAT was performed after discharge for an average of 43.1 ± 14 days. There were five cases of readmission due to treatment failure. No serious adverse events or complications of OPAT were observed. Conclusion: OPAT enables better patient-centred healthcare close to home. The length of hospital stay can be reduced and adverse events due to prolonged hospitalisation can be avoided.