Pars interarticularis screws for posterior cervical fusion - investigating a new trajectory using a CT-based multiplanar reconstruction: Part I.

BACKGROUND: Lateral mass screw fixation is the standard for posterior cervical fusion between C3 and C6. Traditional trajectories stabilize but carry risks, including nerve root and vertebral artery injuries. Minimally invasive spine surgery (MISS) is gaining popularity, but trajectories present anatomical challenges. RESEARCH QUESTION: This study proposes a novel pars interarticularis screw trajectory to address these issues and enhance in-line instrumentation with cervical pedicle screws. MATERIALS AND METHODS: A retrospective analysis of reformatted cervical CT scans included 10 patients. Measurements of the pars interarticularis morphology were performed on 80 segments (C3-C6). Two pars interarticularis screw trajectories were evaluated: Trajectory A (upper outer quadrant entry, horizontal trajectory) and Trajectory B (lower outer quadrant entry, cranially pointed trajectory). These were compared to standard lateral mass and cervical pedicle screw trajectories, assessing screw lengths, angles, and potential risks to the spinal canal and transverse foramen. RESULTS: Trajectory B showed significantly longer pars lengths (15.69 ± 0.65 mm) compared to Trajectory A (12.51 ± 0.24 mm; p < 0.01). Lateral mass screw lengths were comparable to pars interarticularis screw lengths using Trajectory B. Both trajectories provided safe angular ranges, minimizing the risk to delicate structures. DISCUSSION: and Conclusion. Pars interarticularis screws offer a viable alternative to lateral mass screws for posterior cervical fusion, especially in MISS contexts. Trajectory B, in particular, presents a feasible and safe alternative, reducing the risk of vertebral artery and spinal cord injury. Preoperative assessment and intraoperative technologies are essential for successful implementation. Biomechanical validation is needed before clinical application.

Multicenter external validation of prediction models for clinical outcomes after spinal fusion for lumbar degenerative disease.

BACKGROUND: Clinical prediction models (CPM), such as the SCOAP-CERTAIN tool, can be utilized to enhance decision-making for lumbar spinal fusion surgery by providing quantitative estimates of outcomes, aiding surgeons in assessing potential benefits and risks for each individual patient. External validation is crucial in CPM to assess generalizability beyond the initial dataset. This ensures performance in diverse populations, reliability and real-world applicability of the results. Therefore, we externally validated the tool for predictability of improvement in oswestry disability index (ODI), back and leg pain (BP, LP). METHODS: Prospective and retrospective data from multicenter registry was obtained. As outcome measure minimum clinically important change was chosen for ODI with ≥ 15-point and ≥ 2-point reduction for numeric rating scales (NRS) for BP and LP 12 months after lumbar fusion for degenerative disease. We externally validate this tool by calculating discrimination and calibration metrics such as intercept, slope, Brier Score, expected/observed ratio, Hosmer-Lemeshow (HL), AUC, sensitivity and specificity. RESULTS: We included 1115 patients, average age 60.8 ± 12.5 years. For 12-month ODI, area-under-the-curve (AUC) was 0.70, the calibration intercept and slope were 1.01 and 0.84, respectively. For NRS BP, AUC was 0.72, with calibration intercept of 0.97 and slope of 0.87. For NRS LP, AUC was 0.70, with calibration intercept of 0.04 and slope of 0.72. Sensitivity ranged from 0.63 to 0.96, while specificity ranged from 0.15 to 0.68. Lack of fit was found for all three models based on HL testing. CONCLUSIONS: Utilizing data from a multinational registry, we externally validate the SCOAP-CERTAIN prediction tool. The model demonstrated fair discrimination and calibration of predicted probabilities, necessitating caution in applying it in clinical practice. We suggest that future CPMs focus on predicting longer-term prognosis for this patient population, emphasizing the significance of robust calibration and thorough reporting.

The Influence of Preoperative Anticoagulant and Antiplatelet Therapy on Rebleeding Rates in Patients Suffering from Spinal Metastatic Cancer: A Retrospective Cohort Study.

INTRODUCTION: The age of patients requiring surgery for spinal metastasis, primarily those over 65, has risen due to improved cancer treatments. Surgical intervention targets acute neurological deficits and instability. Anticoagulants are increasingly used, especially in the elderly, but pose challenges in managing bleeding complications. The study examines the correlation between preoperative anticoagulant/antiplatelet use and bleeding risks in spinal metastasis surgery, which is crucial for optimizing patient outcomes. MATERIAL AND METHODS: In a retrospective study at our department from 2010 to 2023, spinal tumor surgery patients were analyzed. Data included demographics, neurological status, surgical procedure, preoperative anticoagulant/antiplatelet use, intra-/postoperative coagulation management, and the incidence of rebleeding. Coagulation management involved blood loss assessment, coagulation factor administration, and fluid balance monitoring post-surgery. Lab parameters were documented at admission, preop, postop, and discharge. RESULTS: A cohort of 290 patients underwent surgical treatment for spinal metastases, predominantly males (63.8%, n = 185) with a median age of 65 years. Preoperatively, 24.1% (n = 70) were on oral anticoagulants or antiplatelet therapy. Within 30 days, a rebleeding rate of 4.5% (n = 9) occurred, unrelated to preoperative anticoagulation status (p > 0.05). A correlation was found between preoperative neurologic deficits (p = 0.004) and rebleeding risk and the number of levels treated surgically, with fewer levels associated with a higher incidence of postoperative bleeding (p < 0.01). CONCLUSIONS: Surgical intervention for spinal metastatic cancer appears to be safe regardless of the patient's preoperative anticoagulation status. However, it remains imperative to customize preoperative planning and preparation for each patient, emphasizing meticulous risk-benefit analysis and optimizing perioperative care.

Cadaveric study of ergonomics and performance using a robotic exoscope with a head-mounted display in spine surgery.

The conventional microscope has the disadvantage of a potentially unergonomic posture for the surgeon, which can affect performance. Monitor-based exoscopes could provide a more ergonomic posture, as already shown in pre-clinical studies. The aim of this study was to test the usability and comfort of a novel head-mounted display (HMD)-based exoscope on spinal surgical approaches in a simulated OR setting. A total of 21 neurosurgeons naïve to the device were participated in this prospective trial. After a standardized training session with the device, participants were asked to perform a single-level thoracolumbar decompression surgery on human cadavers using the exoscope. Subsequently, all participants completed a comfort and safety questionnaire. For the objective evaluation of the performance, all interventions were videotaped and analyzed. Twelve men and nine women with a mean age of 34 (range: 24-57) were participating in the study. Average time for decompression was 15 min (IqR 9.6; 24.2); three participants (14%) terminated the procedure prematurely. In these dropouts, a significantly higher incidence of back/neck pain (p = 0.002 for back, p = 0.046 for neck pain) as well as an increased frequency of HMD readjustments (p = 0.045) and decreased depth perception (p = 0.03) were documented. Overall, the surgeons' satisfaction with the exoscope was 84% (IqR 75; 100). Using a standardized, pre-interventional training, it is possible for exoscope-naïve surgeons to perform sufficient spinal decompression using the HMD-based exoscope with a high satisfaction. However, inaccurate HMD setup prior to the start of the procedure may lead to discomfort and unsatisfactory results.

Minimally Invasive Instrumentation of the Cervical Spine: Past, Present, and Future.

Posterior cervical instrumentation and fusion procedures are becoming more and more common with the aging population and rising numbers of multisegmental and revision procedures. The instrumentation of the cervical spine has so far been performed almost exclusively via open approaches. Over the past two decades, minimally invasive surgery (MIS) techniques have gained increasing popularity. To date, only a few attempts to instrument the cervical spine in a minimally invasive fashion have been reported. The following article, after a detailed review of the currently available literature, overviews MIS in dorsal cervical instrumentation and past, present and future techniques, and it discusses the current limitations. Nevertheless, and because of the multiple advantages of MIS instrumentation, a lot of work remains to be carried out to fully establish MIS procedures for posterior cervical instrumentation.

Health-related quality of life 2 years after pedicle subtraction osteotomy for sagittal imbalance: a single-center experience of 65 patients.

PURPOSE: Pedicle subtraction osteotomy (PSO) as an invasive procedure with high reoperation and complication rates in an often elderly population has often been questioned. The purpose of our study was to evaluate the impact of PSO for sagittal imbalance (SI) on patient-reported outcomes including self-reported satisfaction and health-related quality of life 2 years postoperatively. METHODS: Consecutive patients who underwent correction of their spinal deformity by thoracolumbar PSO were assessed using self-reporting questionnaires 2 years postoperatively. Outcome was measured by visual analogue scale (VAS) for back and leg pain, Oswestry Disability Index (ODI), and EQ-5D scores. Additionally, a Patient Satisfaction Index (PSI) rated in four grades (A: very satisfied to D: not satisfied), walking range, and the Timed Up and Go (TUG) Test were evaluated. RESULTS: Sixty-five patients were included, and each parameter was assessed preoperatively and 24 months postoperatively. The intervention led to significant improvements in back pain (8.1 ± 1.2 vs. 2.9 ± 1.9; p < 0.001), as well as ODI scores (57.7 ± 13.9 vs. 32.6 ± 18.9; p < 0.001), walking range (589 ± 1676 m vs. 3265 ± 3405 m; p < 0.001), and TUG (19.2 s vs. 9.7 s; p < 0.05). 90.7% of patients (n = 59/65) reported a PSI grade "A" or "B" 24 months postoperatively. CONCLUSION: Patient satisfaction 24 months after PSO for SI is high. Quality of life improved significantly by restoring sagittal balance.

The effect of various options for decompression of degenerated lumbar spine motion segments on the range of motion: a biomechanical in vitro study.

BACKGROUND: Lumbar spinal stenosis is a common disease in the aging population. Decompression surgery represents the treatment standard, however, a risk of segmental destabilization depending on the approach and extent of decompression is discussed. So far, biomechanical studies on techniques were mainly conducted on non-degenerated specimens. This biomechanical in vitro study aimed to investigate the increase in segmental range of motion (ROM) depending on the extent of decompression in degenerated segments. METHODS: Ten fresh frozen lumbar specimens were embedded in polymethyl methacrylate (PMMA) and loaded in a spine tester with pure moments of ± 7.5 Nm. The specimens were tested in their intact state for lateral bending (LB), flexion/extension (FE) and axial rotation (AR). Subsequently, four different decompression techniques were performed: unilateral interlaminar decompression (DC1), unilateral with "over the top" decompression (DC2), bilateral interlaminar decompression (DC3) and laminectomy (DC4). The ROM of the index segment was reported as percent (%) of the native state. RESULTS: Specimens were measured in their intact state prior to decompression. The mean ROM was defined as 100% (FE:6.3 ± 2.3°; LB:5.4 ± 2.8°; AR:3.0 ± 1.6°). Interventions showed a continuous ROM increase: FE (DC1: + 4% ± 4.3; DC2: + 4% ± 4.5; DC3: + 8% ± 8.3;DC4: + 20% ± 15.9), LB(DC1: + 4% ± 6.0; DC2: + 5% ± 7.3; DC3: + 8% ± 8.3; DC4: + 11% ± 9.9), AR (DC1: + 7% ± 6.0; DC2: + 9% ± 7.9; DC3: + 15% ± 11.5; DC4: + 19% ± 10.5). Significant increases in ROM for all motion directions (p < 0.05) were only obtained after complete laminectomy (DC4). CONCLUSION: Unilateral and/or bilateral decompressive surgery resulted in a statistically insignificant ROM increase, whereas complete laminectomy showed statistically significant ROM increase. If this ROM increase also has an impact on the clinical outcome and how to identify segments at risk for secondary lumbar instability should be evaluated in further studies.

Minimally invasive versus open transforaminal lumbar interbody fusion: a prospective, controlled observational study of short-term outcome.

Instrumented stabilization with intersomatic fusion can be achieved by open (O-TLIF) or minimally invasive (MIS-TLIF) transforaminal surgical access. While less invasive techniques have been associated with reduced postoperative pain and disability, increased manipulation and insufficient decompression may contradict MIS techniques. In order to detect differences between both techniques in the short-term, a prospective, controlled study was conducted. Thirty-eight patients with isthmic or degenerative spondylolisthesis or degenerative disk disease were included in this prospective, controlled study (15 MIS-TLIF group vs. 23 O-TLIF group) after failed conservative treatment. Patients were examined preoperatively, on the first, third, and sixth postoperative day as well as after 2, 4, and 12 weeks postoperatively. Outcome parameters included blood loss, duration of surgery, pre- and postoperative pain (numeric rating scale [NRS], visual analog scale [VAS]), functionality (Timed Up and Go test [TUG]), disability (Oswestry Disability index [ODI]), and quality of life (EQ-5D). Intraoperative blood loss (IBL) as well as postoperative blood loss (PBL) was significantly higher in the O-TLIF group ([IBL O-TLIF 528 ml vs. MIS-TLIF 213 ml, p = 0.001], [PBL O-TLIF 322 ml vs. MIS-TLIF 30 ml, p = 0.004]). The O-TLIF cohort showed significantly less leg pain postoperatively compared to the MIS-TLIF group ([NRS leg 3rd postoperative day, p = 0.027], [VAS leg 12 weeks post-op, p = 0.02]). The MIS group showed a significantly better improvement in the overall ODI (40.8 ± 13 vs. 56.0 ± 16; p = 0.05). After 3 months in the short-term follow-up, the MIS procedure tends to have better results in terms of patient-reported quality of life. MIS-TLIF offers perioperative advantages but may carry the risk of increased nerve root manipulation with consecutive higher radicular pain, which may be related to the learning curve of the procedure.

Technical nuances and approach-related morbidity of anterolateral and posterolateral lumbar corpectomy approaches-a systematic review of the literature.

PURPOSE: Approaches for lumbar corpectomies can be roughly categorized into anterolateral (AL) and posterolateral (PL) approaches. It remains controversial to date whether one approach is superior to the other, and no comparative studies exist for the two approaches for lumbar corpectomies. METHODS: A systematic review of the literature was performed through a MEDLINE/PubMed search. Studies and case reports describing technique plus outcomes and possible complications were included. Thereafter, estimated blood loss (EBL), length of operation (LOO), utilized implants, neurological outcomes, complication rates, and reoperation rates were analyzed. RESULTS: A total of 64 articles reporting on 702 patients including 513 AL and 189 PL corpectomies were included in this paper. All patients in the PL group were instrumented via the same approach used for corpectomy, while in the AL group the majority (68.3%) of authors described the use of an additional approach for instrumentation. The EBL was higher in the AL group (1393 ± 1341 ml vs. 982 ± 567 ml). The LOO also was higher in the AL group (317 ± 178 min vs. 258 ± 93 min). The complication rate (20.5% vs. 29.1%, p = 0.048) and the revision rate (3.1% vs. 9.5%, p = 0.004) were higher in the PL group. Neurological improvement rates were 43.8% (AL) vs. 39.2% (PL), and deterioration was only noted in the AL group (6.0%), while 50.2% (AL) and 60.8% (PL) showed no change from initial presentation to the last follow-up. CONCLUSION: While neurological outcomes of both approaches are comparable, the results of the present review demonstrated lower complication and revision rates in anterolateral corpectomies. Nevertheless, individual patient characteristics must be considered in decision-making.

Does preoperative opioid therapy in patients with a single lumbar disc herniation positively influence the postoperative outcome detected by quantitative sensory testing?

The importance of the type of pain medication in spinal disease is an ongoing matter of debate. Recent guidelines recommend acetaminophen and NSAIDs as first-line medication for lumbar disc herniation. However, opioid pain medication is commonly used in patients with chronic pain, and therefore also in patients with sciatica. The aim of this study is to evaluate if opioids have an impact on the outcome in patients suffering from lumbar disc herniation. To assess this objectively quantitative sensory testing (QST) was applied. In total, 52 patients with a single lumbar disc herniation confirmed on magnetic resonance imaging (MRI) and treated by lumbar sequesterectomy were included in the trial. Patients were analysed according to their preoperative opioid intake: 35 patients who did not receive opioids (group NO) and 17 patients, who received opioids preoperatively (group O). Further evaluation included detailed medical history, physical examination, various questionnaires, and QST. No pre- and postoperative differences were detected in thermal or mechanical thresholds (p > 0.05). Wind-up ratio (WUR) differed significantly between groups 1 week postoperatively (p = 0.025). The NRS for low back pain was rated significantly higher in the non-opioid group (NO) after 1-week follow-up (p = 0.026). Radicular pain tended to be higher in the NO group after 12 months of follow-up (p = 0.023). Opioids seem to be a positive predictor for the postoperative pain outcome in early follow-up in patients undergoing lumbar sequesterectomy. Furthermore, patients presented with less radicular pain 1 year after surgery.

FUSE-ML: development and external validation of a clinical prediction model for mid-term outcomes after lumbar spinal fusion for degenerative disease.

BACKGROUND: Indications and outcomes in lumbar spinal fusion for degenerative disease are notoriously heterogenous. Selected subsets of patients show remarkable benefit. However, their objective identification is often difficult. Decision-making may be improved with reliable prediction of long-term outcomes for each individual patient, improving patient selection and avoiding ineffective procedures. METHODS: Clinical prediction models for long-term functional impairment [Oswestry Disability Index (ODI) or Core Outcome Measures Index (COMI)], back pain, and leg pain after lumbar fusion for degenerative disease were developed. Achievement of the minimum clinically important difference at 12 months postoperatively was defined as a reduction from baseline of at least 15 points for ODI, 2.2 points for COMI, or 2 points for pain severity. RESULTS: Models were developed and integrated into a web-app ( https://neurosurgery.shinyapps.io/fuseml/ ) based on a multinational cohort [N = 817; 42.7% male; mean (SD) age: 61.19 (12.36) years]. At external validation [N = 298; 35.6% male; mean (SD) age: 59.73 (12.64) years], areas under the curves for functional impairment [0.67, 95% confidence interval (CI): 0.59-0.74], back pain (0.72, 95%CI: 0.64-0.79), and leg pain (0.64, 95%CI: 0.54-0.73) demonstrated moderate ability to identify patients who are likely to benefit from surgery. Models demonstrated fair calibration of the predicted probabilities. CONCLUSIONS: Outcomes after lumbar spinal fusion for degenerative disease remain difficult to predict. Although assistive clinical prediction models can help in quantifying potential benefits of surgery and the externally validated FUSE-ML tool may aid in individualized risk-benefit estimation, truly impacting clinical practice in the era of "personalized medicine" necessitates more robust tools in this patient population.

Flexing a standard hinge-powered operating table for lumbosacral three-column osteotomy (3-CO) site closure in 84 consecutive patients.

Three-column osteotomy (3-CO) is a powerful technique in adult deformity surgery, and pedicle subtraction osteotomy (PSO) is the workhorse to correct severe kyphotic spinal deformities. Aging of the population, increasing cases of iatrogenic flat back deformities and understanding the importance of sagittal balance have led to a dramatic increase of this surgical technique. Surgery, however, is demanding and associated with high complication rates so that every step of the procedure requires meticulous technique. Particularly, osteotomy closure is associated with risks like secondary fracture, translation, or iatrogenic stenosis. This step is traditionally performed by compression or a cantilever maneuver with sometimes excessive forces on the screws or instrumentation. Implant loosening or abrupt subluxation resulting in construct failure and/or neurological deficits can result. The aim of this prospective registry study was to assess the efficacy and safety of our surgical PSO technique as well as the osteotomy closure by flexing a hinge-powered OR table. In a series of 84 consecutive lumbosacral 3-CO, a standardized surgical technique with special focus on closure of the osteotomy was prospectively evaluated. The surgical steps with the patients positioned prone on a soft frame are detailed. Osteotomy closure was achieved by remote controlled bending of a standard OR table without compressive or cantilever forces in all 84 cases. This technique carries a number of advantages, particularly the reversibility and the slow speed of closure with minimum force. There was not a single mechanical intraoperative complication such as vertebral body fracture, subluxation, or adjacent implant loosening during osteotomy closure, compared to external cohorts using the cantilever technique (p = 0.130). The feasibility of controlled 3-CO closure by flexing a standard OR table is demonstrated. This technique enables a safe, gentle closure of the osteotomy site with minimal risk of implant failure or accidental neurological injury.

A scoring system for the preoperative evaluation of prognosis in spinal infection: the MSI-20 score.

BACKGROUND CONTEXT: Spinal infection (SI) is a life-threatening condition and its treatment remains challenging. Recent studies have supported early and aggressive surgery, but mortality still reaches 5% to 10% and it remains unclear, if an aggressive surgical strategy also applies for severely sick patients. PURPOSE: The aim of this analysis was to generate an assessment score to predict mortality of SI in order to facilitate decision-making. STUDY DESIGN: Retrospective risk factor analysis. PATIENT SAMPLE: Two hundred fifty-two patients were retrospectively analyzed. OUTCOME MEASURES: Physiologic measures, functional measures. METHODS: Diagnosis was based on clinical presentation, imaging findings and inflammatory markers. Factors associated with mortality were identified by multivariate analysis, weighted according to their relative risk ratio (RR) and included in the novel assessment score. RESULTS: Eight parameters were included: (1) BMI, (2) ASA score, (3) presence of sepsis, (4) age-adjusted Charlson Comorbidity Index, (5) presence and degree of renal failure, (6) presence of hepatopathy, (7) neurological deficits and (8) CRP levels at diagnosis. Each parameter was assigned a certain range of points, resulting in a maximum total score of 20. The mortality in spinal infection (MSI-20) score - indicating poorer status with higher values - was obtained for each patient and correlated with mortality. CONCLUSION: An MSI-20 score of 11 or more points seems to identify the small group of patients being "too sick to undergo surgery," while early surgery can be recommended in the remainder (MSI-20 ≤10). Our results need to be confirmed in prospective studies, but may give guidance for indicating surgery even in rather sick and comorbid patients.

The Impact of the COVID-19 Pandemic on Spine Surgery in Central Europe: A Questionnaire-Based Study.

OBJECTIVE: The severe acute respiratory coronavirus 2 (SARS-CoV2) crisis led to many restrictions in daily life and protective health care actions in all hospitals to ensure basic medical supply. This questionnaire-based study among spinal surgeons in central Europe was generated to investigate the impact of coronavirus disease 2019 (COVID-19) and consecutively the differences in restrictions in spinal surgery units. METHODS: An online survey consisting of 32 questions on the impact of the COVID-19 pandemic and the related restrictions on spinal surgery units was created. Surgical fellows and consultants from neurosurgical, orthopedic, and trauma departments were included in our questionnaire-based study with the help of Austrian, German, and Swiss scientific societies. RESULTS: In a total of 406 completed questionnaires, most participants reported increased preventive measurements at daily clinical work (split-team work schedule [44%], cancellation of elective and/or semielective surgeries [91%]), reduced occurrence of emergencies (91%), decreased outpatient work (45%) with increased telemedical care (73%) and a reduced availability of medical equipment (75%) as well as medical staff (30%). Although most physicians considered the political restrictive decisions to be not suitable, most considered the medical measures to be appropriate. CONCLUSIONS: The COVID-19 pandemic resulted in comparable restrictive measures for spinal surgical departments in central Europe. Elective surgical interventions were reduced, providing additional resources reserved for severe acute respiratory coronavirus 2-positive patients. Although similar restrictions were introduced in most participants' departments, the supply of personal protective equipment and the outpatient care remained insufficient and should be re-evaluated intensively for future global health care crises.

Kyphotic deformity of the lumbar spine due to a monostotic fibrous dysplasia of the second lumbar vertebra: a case report and its surgical management.

Monostotic fibrous dysplasia (MFD) of the lumbar spine represents an exceedingly rare lesion. A 26-year-old patient presented with a progressive osteolytic lesion of the vertebral body L2 and the diagnosis of MFD. A minimally invasive left-sided eXtreme Lateral Interbody Fusion (XLIF) approach with resection of the vertebral body L2 with placement of a mesh cage was performed. No complications were observed perioperatively and the symptoms rapidly improved. Minimally invasive piecemeal resection with a combined dorsolateral approach showed a favorable clinical and radiological outcome and seems to be a safe and reliable technique for MFD.

Early surgery may lower mortality in patients suffering from severe spinal infection.

PURPOSE: Spinal infection (SI) is a life-threatening condition and treatment remains challenging. Numerous factors influence the outcome of SI and both conservative and operative care can be applied. As SI is associated with mortality rates between 2 and 20% even in developed countries, the purpose of the present study was to investigate the occurrence and causes of death in patients suffering from SI. METHODS: A retrospective analysis was performed on 197 patients, categorized into two groups according to their outcome: D (death) and S (survival). The diagnosis was based on clinical and imaging (MRI) findings. Data collected included demographics, clinical characteristics, comorbidities, infection parameters, treatment details, outcomes, and causes of death. RESULTS: The number of deaths was significantly higher in the conservative group (n = 9/51, 18%) compared with the operative counterpart (n = 8/146, 6%; p = 0.017). Death caused by septic multiorgan failure was the major cause of fatalities (n = 10/17, 59%) followed by death due to cardiopulmonary reasons (n = 4/17, 24%). The most frequent indication for conservative treatment in patients of group D included "highest perioperative risk" (n = 5/17, 29%). CONCLUSION: We could demonstrate a significantly higher mortality rate in patients solely receiving conservative treatment. Mortality is associated with number and type of comorbidities, but also tends to be correlated with primarily acquired infection. As causes of death are predominantly associated with a septic patient state or progression of disease, our data may call for an earlier and more aggressive treatment. Nevertheless, prospective clinical trials will be mandatory to better understand the pathogenesis and course of spinal infection, and to develop high quality, evidence-based treatment recommendations.

Defining the MIS-TLIF: A Systematic Review of Techniques and Technologies Used by Surgeons Worldwide.

STUDY DESIGN: Systematic review. OBJECTIVE: To date there is no consensus among surgeons as to what defines an MIS-TLIF (transforaminal lumbar interbody fusion using minimally invasive spine surgery) compared to an open or mini-open TLIF. This systematic review aimed to examine the MIS-TLIF techniques reported in the recent body of literature to help provide a definition of what constitutes the MIS-TLIF, based on the consensus of the majority of surgeons. METHODS: We created a database of articles published about MIS-TLIF between 2010 and 2018. We evaluated the technical components of the MIS-TLIF including instruments and incisions used as well the order in which key steps are performed. RESULTS: We could identify several patterns for MIS-TLIF performance that seemed agreed upon by the majority of MIS surgeons: use of paramedian incisions; use of a tubular retractor to perform a total facetectomy, decompression, and interbody cage implantation; and percutaneous insertion of the pedicle-screw rod constructs with intraoperative imaging. CONCLUSION: Based on this review of the literature, the key features used by surgeons performing MIS TLIF include the use of nonexpandable or expandable tubular retractors, a paramedian or lateral incision, and the use of a microscope or endoscope for visualization. Approaches using expandable nontubular retractors, those that require extensive subperiosteal dissection from the midline laterally, or specular-based retractors with wide pedicle to pedicle exposure are far less likely to be promoted as an MIS-based approach. A definition is necessary to improve the communication among spine surgeons in research as well as patient education.

Tandem Microscopic Slalom Technique: The Use of 2 Microscopes Simultaneously Performing Unilateral Laminotomy for Bilateral Decompression in Multilevel Lumbar Spinal Stenosis.

STUDY DESIGN: Technical note, retrospective case series. OBJECTIVE: Lumbar stenosis can be effectively treated using tubular unilateral laminotomy for bilateral decompression (ULBD). For multilevel stenosis, a multilevel ULBD through separate, alternating crossover approaches has been described as the "slalom technique." To increase efficacy, we introduced this approach with 2 microscopes simultaneously. METHODS: We collected data on 13 patients, with multilevel lumbar stenosis, operated at our institution between 2015 and 2016 by the aforementioned technique. We assessed surgical time (ST), estimated blood loss (EBL), complications, and revision surgeries. Furthermore, we provide a stepwise instruction for performing the tandem microscopic slalom technique in a safe and efficient manner. RESULTS: The mean age of the patients was 68 ± 8 years. The ST per level was 68 ± 19 minutes with an EBL per level of 39 ± 30 mL. We had no intraoperative complications and none of our patients required a revision surgery during a mean follow-up of 12 months. CONCLUSIONS: We have shown that this technique is feasible and can be performed safely for multisegmental lumbar spinal stenosis with minimal tissue trauma and low EBL. Furthermore, randomized controlled studies with a larger sample size may be necessary to drive any final conclusions.

The impact of obesity and smoking on young individuals suffering from lumbar disc herniation: a retrospective analysis of 97 cases.

The negative impact on spinal diseases may apply not only to obesity but also to smoking. To investigate the influence of obesity and smoking on the development and recovery of lumbar disc herniation in young adults. Retrospective analysis of 97 patients who presented with lumbar disc herniation at the authors' department between 2010 and 2017. Data were collected using the patients' digital health records including demographics, clinical and neurological characteristics, treatment details, and outcomes. Ninety-seven patients between 17 and 25 years were included in this retrospective analysis. Patients were categorized into two groups according to their body mass index: obese (O, ≥ 30 kg/m2) and non-obese (NO, < 30 kg/m2). The proportion of obese patients in our cohort vs. in the overall population differed significantly (19.4% vs. 3.8-7.1%, RR 3.17; p < 0.01). Group NO showed a trend toward faster recovery of motor deficits (p = 0.067) and pain (p = 0.074). Also, the proportion of regular smokers differed significantly from the numbers of known smokers of the same age (62.4% vs. 30.2%, RR 2.0; p = 0.01). Obesity plus smoking showed a significantly negative impact on motor deficits postoperatively (p = 0.015) and at discharge (p = 0.025), as well as on pain values (p = 0.037) and on analgesic consumption (p = 0.034) at 6 weeks follow-up. The negative impact of obesity and smoking on the occurrence of lumbar disc herniation could be demonstrated for individuals aged 25 or younger. Furthermore, a trend to earlier recovery of motor deficits and significantly lower pain scales for non-obese and non-smoking patients could be shown.