Paradigm changes in spine surgery: evolution of minimally invasive techniques

Advances and Challenges in Minimally Invasive Spine Surgery

Minimally invasive spine surgery continues to grow and develop. Over the past 50 years, there has been immense growth within this subspecialty of neurosurgery. A deep understanding of the historical context and future directions of this subspecialty is imperative to developing safe adoption and targeted innovation. This review aims to describe the advancements, and challenges that we face today in minimally invasive spine surgery.

Learning curve analyses in spine surgery: a systematic simulation-based critique of methodologies

BACKGROUND CONTEXT

Various statistical approaches exist to delineate learning curves in spine surgery. Techniques range from dividing cases into intervals for metric comparison, to employing regression and cumulative summation (CUSUM) analyses. However, their inherent inconsistencies and methodological flaws limit their comparability and reliability.

PURPOSE

To critically evaluate the methodologies used in existing literature for studying learning curves in spine surgery and to provide recommendations for future research.

STUDY DESIGN

Systematic literature review.

METHODS

A comprehensive literature search was conducted using PubMed, Embase, and Scopus databases, covering articles from January 2010 to September 2023. For inclusion, articles had to evaluate the change in a metric of performance during human spine surgery across time/a case series. Results had to be reported in sufficient detail to allow for evaluation of individual performance rather than group/institutional performance. Articles were excluded if they included cadaveric/nonhuman subjects, aggregated performance data or no way to infer change across a number of cases. Risk of bias was assessed using the Risk of Bias in Nonrandomized Studies of Interventions (ROBINS-I) tool. Surgical data were simulated using Python 3 and then examined via multiple commonly used analytic approaches including division into consecutive intervals, regression and CUSUM techniques. Results were qualitatively assessed to determine the effectiveness and limitations of each approach in depicting a learning curve.

RESULTS

About 113 studies met inclusion criteria. The majority of the studies were retrospective and evaluated a single-surgeon's experience. Methods varied considerably, with 66 studies using a single proficiency metric and 47 using more than 1. Operating time was the most commonly used metric. Interval division was the simplest and most commonly used method yet inherent limitations prevent collective synthesis. Regression may accurately describe the learning curve but in practice is hampered by sample size and model choice. CUSUM analyses are of widely varying quality with some being fundamentally flawed and widely misinterpreted however, others provide a reliable view of the learning process.

CONCLUSION

There is considerable variation in the quality of existing studies on learning curves in spine surgery. CUSUM analyses, when correctly applied, offer the most reliable estimates. To improve the validity and comparability of future studies, adherence to methodological guidelines is crucial. Multiple or composite performance metrics are necessary for a holistic understanding of the learning process.

Characterizing utilization patterns and reoperation risk factors of interspinous process devices: analysis of a national claims database

INTRODUCTION

Interspinous process devices (IPDs) were developed as minimally invasive alternatives to open decompression surgery for spinal stenosis. However, given high treatment failure and reoperation rates, there has been minimal adoption by spine surgeons. This study leveraged a national claims database to characterize national IPD usage patterns and postoperative outcomes after IPD implantation.

METHOD

Using the PearlDiver database, we identified all patients who underwent 1- or 2-level IPD implantation between 2010 and 2018. Univariate and multivariable logistic regression was performed to identify predictors of the number of IPD levels implanted and reoperation up to 3 years after the index surgery. Right-censored Kaplan-Meier curves were plotted for duration of reoperation-free survival and compared with log-rank tests.

RESULTS

Patients (n = 4865) received 1-level (n = 3246) or 2-level (n = 1619) IPDs. Patients who were older (adjusted odds ratio [aOR] 1.02, 95% confidence interval [CI] 1.01-1.03, P < .001), male (aOR 1.31, 95% CI 116-1.50, P < .001), and obese (aOR 1.19, 95% CI 1.05-1.36, P < .01) were significantly more likely to receive a 2-level IPD than to receive a 1-level IPD. The 3-year reoperation rate was 9.3% of patients when mortality was accounted for during the follow-up period. Older age decreased (aOR 0.97, 95% CI 0.97-0.99, P = .0039) likelihood of reoperation, whereas 1-level IPD (aOR 1.37, 95% CI 1.01-1.89, P = .048), Charlson Comorbidity Index (aOR 1.07, 95% CI 1.01-1.14, P = .018), and performing concomitant open decompression increased the likelihood of reoperation (aOR 1.68, 95% CI 1.35-2.09, P = .0014).

CONCLUSION

Compared with 1-level IPDs, 2-level IPDs were implanted more frequently in older, male, and obese patients. The 3-year reoperation rate was 9.3%. Concomitant open decompression with IPD placement was identified as a significant risk factor for subsequent reoperation and warrants future investigation.

Multimodal management strategies for chronic pain after spinal surgery: a comprehensive review

"Chronic pain after spinal surgery" (CPSS) is a nonspecific term for cases in which the end result of surgery generally does not meet the preoperative expectations of the patient and surgeon. This term has replaced the previous term i.e., failed back surgery syndrome. CPSS is challenging for both patients and doctors. Despite advancements in surgical techniques and technologies, a subset of patients continue to experience persistent or recurrent pain postoperatively. This review provides an overview of the multimodal management for CPSS, ranging from conservative management to revision surgery. Drawing on recent research and clinical experience, we aimed to offer insights into the diverse strategies available to improve the quality of life of CPSS patients.

Pros and Cons of Minimally Invasive Spine Surgery

This paper reviews current knowledge on minimally invasive spine surgery (MISS). Although it has significant advantages, such as less postoperative pain, short hospital stay, quick return to work, better cosmetics, and less infection rate, there are also disadvantages. The long learning curve, the need for special instruments and types of equipment, high costs, lack of tactile sensation and biplanar imaging, some complications that are hard to treat, and more radiation to the surgeon and surgical team are the disadvantages.Most studies remark that the outcomes of MISS are similar to traditional surgery. Although patients demand it more than surgeons, we predict the broad applications of MISS will replace most of our classical surgical approaches.

Machine Learning Predicts Decompression Levels for Lumbar Spinal Stenosis Using Canal Radiomic Features from Computed Tomography Myelography

BACKGROUND

The accurate preoperative identification of decompression levels is crucial for the success of surgery in patients with multi-level lumbar spinal stenosis (LSS). The objective of this study was to develop machine learning (ML) classifiers that can predict decompression levels using computed tomography myelography (CTM) data from LSS patients.

METHODS

A total of 1095 lumbar levels from 219 patients were included in this study. The bony spinal canal in CTM images was manually delineated, and radiomic features were extracted. The extracted data were randomly divided into training and testing datasets (8:2). Six feature selection methods combined with 12 ML algorithms were employed, resulting in a total of 72 ML classifiers. The main evaluation indicator for all classifiers was the area under the curve of the receiver operating characteristic (ROC-AUC), with the precision-recall AUC (PR-AUC) serving as the secondary indicator. The prediction outcome of ML classifiers was decompression level or not.

RESULTS

The embedding linear support vector (embeddingLSVC) was the optimal feature selection method. The feature importance analysis revealed the top 5 important features of the 15 radiomic predictors, which included 2 texture features, 2 first-order intensity features, and 1 shape feature. Except for shape features, these features might be eye-discernible but hardly quantified. The top two ML classifiers were embeddingLSVC combined with support vector machine (EmbeddingLSVC_SVM) and embeddingLSVC combined with gradient boosting (EmbeddingLSVC_GradientBoost). These classifiers achieved ROC-AUCs over 0.90 and PR-AUCs over 0.80 in independent testing among the 72 classifiers. Further comparisons indicated that EmbeddingLSVC_SVM appeared to be the optimal classifier, demonstrating superior discrimination ability, slight advantages in the Brier scores on the calibration curve, and Net benefits on the Decision Curve Analysis.

CONCLUSIONS

ML successfully extracted valuable and interpretable radiomic features from the spinal canal using CTM images, and accurately predicted decompression levels for LSS patients. The EmbeddingLSVC_SVM classifier has the potential to assist surgical decision making in clinical practice, as it showed high discrimination, advantageous calibration, and competitive utility in selecting decompression levels in LSS patients using canal radiomic features from CTM.

When Does Intervention End and Surgery Begin? The Role of Interventional Pain Management in the Treatment of Spine Pathology

PURPOSE OF REVIEW

Recent advances in the field of interventional pain management (IPM) involve minimally invasive procedures such as percutaneous lumbar decompression, interspinous spacer placement, interspinous-interlaminar fusion and sacroiliac joint fusion. These developments have received pushback from surgical professional societies, who state spinal instrumentation and arthrodesis should only be performed by spine surgeons. The purpose of this review is to evaluate the validity of this claim. A literature search was conducted on Google Scholar and PubMed databases. Articles were included which examined IPM in the following contexts: credentialing and procedural privileging guidelines, fellowship training and education, and procedural outcomes compared to those of surgical specialties. Our primary research question is: "Should interventionalists be performing decompression and fusion procedures?".

FINDINGS

Advanced percutaneous spine procedures are not universally incorporated into pain fellowship curriculums. Trainees attempt to compensate for these deficiencies through industry-led training, which has been criticized for lacking central regulation. There is also a paucity of studies comparing procedural outcomes between surgeons and interventionalists for complex spine procedures, including decompression and fusion. Pain fellowship curriculums have not kept pace with some of procedural advancements within the field. Interventionalists are also not trained to manage potential complications of spinal instrumentation and arthrodesis, which has been recognized as an essential requirement for procedural privileging. Decompression and fusion may therefore be outside the scope of an interventionalist's practice.

Advances and Evolving Challenges in Spinal Deformity Surgery

BACKGROUND

Surgical intervention is a critical tool to address adult spinal deformity (ASD). Given the evolution of spinal surgical techniques, we sought to characterize developments in ASD correction and barriers impacting clinical outcomes.

METHODS

We conducted a literature review utilizing PubMed, Embase, Web of Science, and Google Scholar to examine advances in ASD surgical correction and ongoing challenges from patient and clinician perspectives. ASD procedures were examined across pre-, intra-, and post-operative phases.

RESULTS

Several factors influence the effectiveness of ASD correction. Standardized radiographic parameters and three-dimensional modeling have been used to guide operative planning. Complex minimally invasive procedures, targeted corrections, and staged procedures can tailor surgical approaches while minimizing operative time. Further, improvements in osteotomy technique, intraoperative navigation, and enhanced hardware have increased patient safety. However, challenges remain. Variability in patient selection and deformity undercorrection have resulted in heterogenous clinical responses. Surgical complications, including blood loss, infection, hardware failure, proximal junction kyphosis/failure, and pseudarthroses, pose barriers. Although minimally invasive approaches are being utilized more often, clinical validation is needed.

CONCLUSIONS

The growing prevalence of ASD requires surgical solutions that can lead to sustained symptom resolution. Leveraging computational and imaging advances will be necessary as we seek to provide comprehensive treatment plans for patients.

Unilateral Minimally Invasive Across-Midline Vertebral Column Resection Partially Corrects Thoracolumbar Kyphosis - A Case Series

OBJECTIVE

The goal of this study was to describe the indirect and partial correction of spine kyphotic deformities (secondary to various pathologies) achieved by minimally invasive posterolateral extracavitary approach (MIS PLECA) for corpectomy.

METHODS

The authors retrospectively reviewed a consecutive case series of 12 patients undergoing MIS PLECA in a single institution. Perioperative data were collected and follow-up computed tomographies and radiographs were reviewed to assess for interbody arthrodesis.

RESULTS

The mean age was 60.7 ± 20.8 years (58.4% males). The etiologies of deformity included pathological fracture (41.6%), acute trauma (30%), and infection. An expandable cage was used in 66.7% of patients for anterior reconstruction. The mean total estimated blood loss was 764.1 ± 332.9 ml. The mean operative time was 413.3 ± 98.8 minutes. The average length of hospital stay was 5.8 ± 2.5 days. A consistent degree of focal correction of sagittal alignment was seen in all patients with a mean correction of sagittal angle of 7.4 ± 4.3° (P < 0.0001). The mean duration of rehabilitation was 8.5 ± 6.7 days. All patients remained neurologically stable at the last follow-up with a mean follow-up period of 20.1 ± 12.8 months. Successful fusion was achieved in 91.7% at the last follow-up.

CONCLUSIONS

MIS PLECA for corpectomy appears to be a feasible, safe, and effective MIS technique for select patients, particularly those who cannot tolerate the traditional open approach. Additionally, a focal sagittal deformity correction can be achieved using MIS corpectomy.

Fully Endoscopic Spine Separation Surgery in Metastatic Disease-Case Series, Technical Notes, and Preliminary Findings

Objective: This report aims to describe the surgical methodology and potential effectiveness of endoscopic separation surgery (ESS) in patients with metastatic spine disease. This concept may reduce the invasiveness of the procedure, which can potentially speed up the wound healing process and, thus, the possibility of faster application of radiotherapy. Materials and Methods: In this study, separation surgery for preparing patients for stereotactic body radiotherapy (SBRT) was performed with fully endoscopic spine surgery (FESS) followed by percutaneous screw fixation (PSF). Results: Three patients with metastatic spine disease in the thoracic spine were treated with fully endoscopic spine separation surgery. The first case resulted in the progression of paresis symptoms that resulted in disqualification from further oncological treatment. The remaining two patients achieved satisfactory clinical and radiological effects and were referred for additional radiotherapy. Conclusions: With advancements in medical technology, such as endoscopic visualization, and new tools for coagulation, we can treat more and more spine diseases. Until now, spine metastasis was not an indication for the use of endoscopy. This method is very technically challenging and risky, especially at such an early stage of application, due to variations in the patient's condition, morphological diversity, and the nature of metastatic lesions in the spine. Further trials are needed to determine whether this new approach to treating patients with spine metastases is a promising breakthrough or a dead end.

Bibliometric analysis and description of research trends on transforaminal full-endoscopic approach on the spine for the last two-decades

OBJECTIVE

The study aims to assess the current development status of transforaminal full-endoscopic spine surgery (TFES) by exploring and analyzing the published literature to obtain an overview of this field and discover the evolution and emerging topics that are underrepresented.

METHODS

Using Bibliometrix, CiteSpace, and VOSviewer, we analyzed the bibliometric data selected from the Web of Science Core Collection between January 2002 and November 2022. The descriptive and evaluative analyses of authors, institutes, countries, journals, keywords, and references are compiled. The quantity of research productivity was measured by the number of publications that were published. A quality indicator was thought to be the number of citations. In the bibliometric analysis of authors, areas, institutes, and references, we calculated and ranked the research impact by various metrics, such as the h-index and m-index.

RESULTS

A total of 628 articles were identified in the field of TFES by the 18.73% annual growth rate of research on the subject from 2002 to 2022, constituting the documents are by 1961 authors affiliated with 661 institutions in 42 countries or regions and published in 117 journals. The USA (n = 0.20) has the highest international collaboration rate, South Korea has the highest H-index value (h = 33), and China is ranked as the most productive country (n = 348). Brown univ., Tongji univ., and Wooridul Spine represented the most productive institutes ranked by the number of publications. Wooridul Spine Hospital demonstrated the highest quality of paper publication. The Pain Physician had the highest h-index (n = 18), and the most cited journal with the earliest publication year in the area of FEDS is Spine (t = 1855).

CONCLUSION

The bibliometric study showed a growing trend of research on transforaminal full-endoscopic spine surgery over the past 20 years. It has shown a significant increase in the number of authors, institutions, and international collaborating countries. South Korea, the United States, and China dominate the related areas. A growing body of evidence has revealed that TFES has leapfrogged from its infancy stage and gradually entered a mature development stage.

Bone Healing Gone Wrong: Pathological Fracture Healing and Non-Unions-Overview of Basic and Clinical Aspects and Systematic Review of Risk Factors

Bone healing is a multifarious process involving mesenchymal stem cells, osteoprogenitor cells, macrophages, osteoblasts and -clasts, and chondrocytes to restore the osseous tissue. Particularly in long bones including the tibia, clavicle, humerus and femur, this process fails in 2-10% of all fractures, with devastating effects for the patient and the healthcare system. Underlying reasons for this failure are manifold, from lack of biomechanical stability to impaired biological host conditions and wound-immanent intricacies. In this review, we describe the cellular components involved in impaired bone healing and how they interfere with the delicately orchestrated processes of bone repair and formation. We subsequently outline and weigh the risk factors for the development of non-unions that have been established in the literature. Therapeutic prospects are illustrated and put into clinical perspective, before the applicability of biomarkers is finally discussed.

The Evolution of Minimally Invasive Spine Tumor Resection and Stabilization: From K-Wires to Navigated One-Step Screws

Minimization of the surgical approaches to spinal extradural metastases resection and stabilization was advocated by the 2012 Oncological Guidelines for Spinal Metastases Management. Minimally invasive approaches to spine oncology surgery (MISS) are continually advancing. This paper will describe the evolution of minimally invasive surgical techniques for the resection of metastatic spinal lesions and stabilization in a single institute. A retrospective analysis of patients who underwent minimally invasive extradural spinal metastases resection during the years 2013-2019 by a single surgeon was performed. Medical records, imaging studies, operative reports, rates of screw misplacement, operative time and estimated blood loss were reviewed. Detailed description of the surgical technique is provided. Of 138 patients operated for extradural spinal tumors during the study years, 19 patients were treated in a minimally invasive approach and met the inclusion criteria for this study. The mortality rate was significantly improved over the years with accordance of improve selection criteria to better prognosis patients. The surgical technique has evolved over the study years from fluoroscopy to intraoperative 3D imaging and navigation guidance and from k-wire screw insertion technique to one-step screws. Minimally invasive spinal tumor surgery is an evolving technique. The adoption of assistive devices such as intraoperative 3D imaging and one-step screw insertion systems was safe and efficient. Oncologic patients may particularly benefit from the minimization of surgical decompression and fusion in light of the frailty of this population and the mitigated postoperative outcomes associated with MIS oncological procedures.

Bibliometric and visualized analysis of research relating to minimally invasive spine surgery reported over the period 2000-2022

Background

Since entering the 21st century, there has been an increasing interest in minimally invasive surgery for spinal diseases, which has led to the continued development of minimally invasive spine surgery (MISS), with major breakthroughs in technology and technical skills. However, in recent years, there is little relevant research using bibliometrics to analyze the field of MISS research. The purpose of this study is to sort out the publication situation and topic trends of articles in the field of MISS research from the perspective of bibliometrics.

Methods

The articles and reviews related to MISS from 2000 to 2022 were retrieved and downloaded from the Web of Science Core Collection (WOSCC). Visualization and knowledge mapping were performed using three bibliometric tools, including online bibliometric platform, CiteSpace and VOSviewer software. Curve fitting and correlation analysis were performed using Microsoft Excel software. The global research publication output, contributions of countries, institutions, authors, and journals, average citations per item (ACI), Hirsch index (H-index), research hot keywords, etc., in this field were analyzed.

Results

A total of 2384 papers were retrieved, including 2135 original papers and 249 review papers. In the past 22 years, the number of annual publications of MISS research has shown a steady growth trend. China contributed the most papers, and the United States ranked second, but the United States had the highest total citations, and H-index value. The most prolific institutions were Soochow University, Capital Medical University and Wooridul Spine Hospital. In this field, Professors Lee SH, Ahn Y and Yang HL have made significant achievements. However, there is relatively little international collaboration between institutions or researchers. World Neurosurgery is the most published journal on MISS research. According to the keyword co-occurrence analysis, recent keywords mainly focus on researches on minimally invasive modalities, techniques and prognosis, while on the keyword analysis of the ongoing bursts, percutaneous transforaminal endoscopic discectomy, lumbar diskectomy, spinal stenosis, recompression, diskectomy, endoscopic spine surgery, laminectomy, transforaminal lumbar interbody fusion, etc., will likely continue to be a research hotspot in the near future.

Conclusion

Looking at the temporal trend in the number of publications per year, the number of publications for the MISS study will increase in the near future. China has the highest number of publications, but the US has the highest quality publications. International cooperation needs to be further strengthened. Our findings can provide useful information for the academic community and identify possible research fronts and hotspots in the coming years.

Novel Pedicle Navigator Based on Micro Inertial Navigation System (MINS) and Bioelectric Impedance Analysis (BIA) to Facilitate Pedicle Screw Placement in Spine Surgery: Study in a Porcine Model

STUDY DESIGN

A porcine model.

OBJECTIVE

The study aims to design a novel pedicle navigator based on micro-inertial navigation system (MINS) and bioelectrical impedance analysis (BIA) to assist place pedicle screw placement and validate the utility of the system in enhancing pedicle screw placement.

SUMMARY OF BACKGROUND DATA

The incidence of pedicle screw malpositioning in complicated spinal surgery is still high.Procedures such as computed tomography image-guided navigation, and robot-assisted surgery have been used to improve the precision of pedicle screw placement, but it remains an unmet clinical need.

METHODS

The miniaturized integrated framework containing MINS was mounted inside the hollow handle of the pedicle finder. The inner core was complemented by a high-intensity electrode for measuring bioelectric impedance. Twelve healthy male Wuzhishan minipigs of similar age and weight were used in this experiment and randomized to the MINS-BIA or freehand (FH) group. Pedicle screw placement was determined according to the modified Gertzbein-Robbins grading system on computed tomography images. An impedance detected by probe equal to the baseline value for soft tissue was defined as cortical bone perforation.

RESULTS

A total of 216 screws were placed in 12 minipigs. There were 15 pedicle breaches in the navigator group and 31 in the FH group; the detection rates of these breaches were 14 of 15 (93.3%) and 25 of 31 (80.6%), respectively, with a statistically significant difference between groups. The mean offsets between the planned and postoperatively measured tilt angles of the screw trajectory were 4.5° ± 5.5° in the axial plane and 4.8° ± 3.3° in the sagittal plane with the navigator system and 7.0° ± 5.1° and 7.7° ± 4.7°, respectively, with the FH technique; the differences were statistically significant.

CONCLUSION

A novel and portable navigator based on MINS and BIA could be beneficial for improving or maintaining accuracy while reducing overall radiation exposure.

Complete resection of dual ependymoma spinal metastasis using a fixed tubular retractor-a pediatric case report

There are no specific guidelines regarding best treatment for focal, distant metastasis in ependymoma in the context of a well-controlled primary site. A combination using maximal safe resection and adjuvant radiotherapy is usually advised. As wound healing might be hindered by repeated radiotherapy, and delay future radiation treatment if needed, there is a growing interest in less invasive surgeries to reduce post-operative pain and wound healing complications. Those approaches have been extensively used and studied in adult but never in the pediatric population. Here, we present a pediatric case of a 12-year-old boy known for a posterior fossa ependymoma completely resected 18 months earlier who presented with a dual lumbosacral intradural ependymoma metastasis. A single-stage complete resection was achieved using a fixed tubular retractor with no complication. Post-operative course was favorable with rapid healing and discharge, minimal post-operative pain, and a rapid return to normal activities. Re-irradiation could be performed 2 weeks later without any problem. To our knowledge, this is the first report of the use of minimally invasive techniques to achieve complete resection of dual intradural metastasis of an ependymoma in the pediatric population. We demonstrate its feasibility and safety as well as its advantages.

Critical appraisal of minimally invasive keyhole surgery for intracranial meningioma in a large case series

Background

Meningioma surgery has evolved over the last 20 years with increased use of minimally invasive approaches including the endoscopic endonasal route and endoscope-assisted and gravity-assisted transcranial approaches. As the “keyhole” concept remains controversial, we present detailed outcomes in a cohort series.

Methods

Retrospective analysis was done for all patients undergoing meningioma removal at a tertiary brain tumor referral center from 2008–2021. Keyhole approaches were defined as: use of a minimally invasive “retractorless” approach for a given meningioma in which a traditional larger approach is often used instead. The surgical goal was maximal safe removal including conservative (subtotal) removal for some invasive locations. Primary outcomes were resection rates, complications, length of stay and Karnofsky Performance Scale (KPS). Secondary outcomes were endoscopy use, perioperative treatments, tumor control and acute MRI FLAIR/T2 changes to assess for brain manipulation and retraction injury.

Results

Of 329 patients, keyhole approaches were utilized in 193(59%) patients (mean age 59±13; 30 (15.5%) had prior surgery) who underwent 213 operations; 205(96%) were skull base location. Approaches included: endoscopic endonasal (n = 74,35%), supraorbital (n = 73,34%), retromastoid (n = 38,18%), mini-pterional (n = 20,9%), suboccipital (n = 4,2%), and contralateral transfalcine (n = 4,2%). Primary outcomes: Gross total/near total (>90%) resection was achieved in 125(59%) (5% for petroclival, cavernous sinus/Meckel’s cave, spheno-cavernous locations vs 77% for all other locations). Major complications included: permanent neurological worsening 12(6%), CSF leak 2(1%) meningitis 2(1%). There were no DVTs, PEs, MIs or 30-day mortality. Median LOS decreased from 3 to 2 days in the last 2 years; 94% were discharged to home with favorable 90-day KPS in 176(96%) patients. Secondary outcomes: Increased FLAIR/T2 changes were noted on POD#1/2 MRI in 36/213(17%) cases, resolving in all but 11 (5.2%). Endoscopy was used in 87/139(63%) craniotomies, facilitating additional tumor removal in 55%. Tumor progression occurred in 26(13%) patients, mean follow-up 42±36 months.

Conclusions & relevance

Our experience suggests minimally invasive keyhole transcranial and endoscopic endonasal meningioma removal is associated with comparable resection rates and low complication rates, short hospitalizations and high 90-day performance scores in comparison to prior reports using traditional skull base approaches. Subtotal removal may be appropriate for invasive/adherent meningiomas to avoid neurological deficits and other post-operative complications, although longer follow-up is needed. With careful patient selection and requisite experience, these approaches may be considered reasonable alternatives to traditional transcranial approaches.

Efficacy of Single-Position Oblique Lateral Interbody Fusion Combined With Percutaneous Pedicle Screw Fixation in Treating Degenerative Lumbar Spondylolisthesis: A Cohort Study

Objective

To investigate the surgical outcomes of single-position oblique lateral interbody fusion (OLIF) combined with percutaneous pedicle screw fixation (PPSF) in treating degenerative lumbar spondylolisthesis (DLS).

Methods

We retrospectively analyzed 85 patients with DLS who met the inclusion criteria from April 2018 to December 2020. According to the need to change their position during the operation, the patients were divided into a single-position OLIF group (27 patients) and a conventional OLIF group (58 patients). The operation time, intraoperative blood loss, hospitalization days, instrumentation accuracy and complication rates were compared between the two groups. The visual analog scale (VAS) and Oswestry Disability Index (ODI) were used to evaluate the clinical efficacy. The surgical segment's intervertebral space height (IDH) and lumbar lordosis (LL) angle were used to evaluate the imaging effect.

Results

The hospital stay, pedicle screws placement accuracy, and complication incidence were similar between the two groups (P > 0.05). The operation time and intraoperative blood loss in the single-position OLIF group were less than those in the conventional OLIF group (P < 0.05). The postoperative VAS, ODI, IDH and LL values were significantly improved (P < 0.05), but there was no significant difference between the two groups (P > 0.05).

Conclusions

Compared with conventional OLIF, single-position OLIF combined with PPSF is also safe and effective, and it has the advantages of a shorter operation time and less intraoperative blood loss.

Simulation Training in Spine Surgery

Simulated surgery is part of a growing paradigm shift in surgical education as a whole. Various modalities from cadaver models to virtual reality have been developed and studied within the context of surgical education. Simulation training in spine surgery has an immense potential to improve education and ultimately improve patient safety. This is due to the inherent risk of operating the spine and the technical difficulty of modern techniques. Common procedures in the modern orthopaedic armamentarium, such as pedicle screw placement, can be simulated, and proficiency is rapidly achieved before application in patients. Furthermore, complications such as dural tears can be simulated and effectively managed in a safe environment with simulation. New techniques with steeper learning curves, such as minimally invasive techniques, can now be safely simulated. Hence, augmenting surgical education through simulation has great potential to benefit trainees and practicing orthopaedic surgeons in modern spine surgery techniques. Additional work will aim to improve access to such technologies and integrate them into the current orthopaedic training curriculum.

A systematic review of robotic surgery: From supervised paradigms to fully autonomous robotic approaches

BACKGROUND

From traditional open surgery to laparoscopic surgery and robot-assisted surgery, advances in robotics, machine learning, and imaging are pushing the surgical approach to-wards better clinical outcomes. Pre-clinical and clinical evidence suggests that automation may standardise techniques, increase efficiency, and reduce clinical complications.

METHODS

A PRISMA-guided search was conducted across PubMed and OVID.

RESULTS

Of the 89 screened articles, 51 met the inclusion criteria, with 10 included in the final review. Automatic data segmentation, trajectory planning, intra-operative registration, trajectory drilling, and soft tissue robotic surgery were discussed.

CONCLUSION

Although automated surgical systems remain conceptual, several research groups have developed supervised autonomous robotic surgical systems with increasing consideration for ethico-legal issues for automation. Automation paves the way for precision surgery and improved safety and opens new possibilities for deploying more robust artificial intelligence models, better imaging modalities and robotics to improve clinical outcomes.

Trans-Sacral Epiduroscopic Ho:YAG Laser Ablation of the Ligamentum Flavum in a Live Pig

Introduction

For the aging population, surgery for lumbar spinal canal stenosis (LSCS) requires minimally invasive procedures. Recently, trans-sacral epiduroscopic laser decompression for lumbar disc herniation has been reported with good results. In this study, we devised a new method to perform trans-sacral epiduroscopic laser ablation of the ligamentum flavum (LF), known to be the major cause of LSCS. Using a live pig, this study aims to evaluate the efficacy, safety, and drawbacks of this procedure.

Methods

Using an epiduroscope, we observed intra-spinal canal structures and then examined the feasibility and problems of a decompression procedure to ablate the LF using holmium:YAG (Ho:YAG) laser. The pig was observed for behavioral changes and neurological deficits after the procedure. Histological analysis was performed to evaluate the amount of tissue ablation and damage to surrounding tissues.

Results

Although it was possible to partially ablate the LF using the Ho:YAG laser under epiduroscopy, it was difficult to maintain a clear field of view, and freely decompressing the target lesion has been a challenge. After the first two experiments, the pig neither showed abnormal behavior nor any signs of pain or paresis. However, in the third experiment, the pig died during the operation. On autopsy, no thermal or mechanical injury was noted around the ablated site, including the dura mater and nerve root. Histological analysis showed that the LF and lamina were deeply ablated as the laser power increased, and no damage was noted on surrounding tissues beyond a depth of 500 μm.

Conclusions

Although Ho:YAG laser could ablate the ligamentum and bone tissues without causing damage to surrounding tissues, it was difficult to completely decompress the LF under epiduroscopy. This method is a potentially highly invasive procedure that requires caution in its clinical application and needs further improvement in terms of the instruments and techniques used.

Minimally Invasive Discectomy and Decompression for Lumbar Spine using Tubular Retractor System: Technique, Learning Curve and Outcomes

Objective To study the indications, technical nuances, learning curve, and outcomes associated with minimally invasive tubular discectomy of spine (MITDS) and minimally invasive tubular decompression (MITD) using the tubular retractor system and compare the outcomes with open microdiscectomy and open decompression.

Materials and Methods All patients who underwent MITDS and MITD received a trial of conservative management for 6 weeks prior to surgery. Patients who had undergone open microdiscectomy and open decompression during the same period were used as controls. Operating time, intraoperative blood loss, preop and postop visual analogue scale (VAS) scores, preop and postop Oswestry disability index (ODI) scores, duration of hospital stay, complications, and need for redo surgery were analyzed.

Results Thirty-two patients who underwent MITDS and 8 patients who underwent MITD were compared with an equal number of patients who underwent open microdiscectomy and open decompression, respectively. MITDS and MITD were associated with shorter hospital stay. Short-term pain outcome was better in MITDS and MITD group, although it was not statistically significant in MITD group. Functional outcome measured in terms of ODI at 6 months was not statistically significant between minimally invasive and open procedures.

Conclusion Both MITDS and MITD have a significant learning curve and have a distinct advantage of shorter hospital stay. MITDS has the distinct advantage of better short-term pain relief compared with open procedures. For MITD, comparison of short-term pain relief requires a larger sample size. To establish long-term advantages of MITDS and MITD, larger sample size and long-term follow-up are needed.

Evolution of Complex Spine Surgery in Neurosurgery: From Big to Minimally Invasive Surgery for the Treatment of Spinal Deformity

Spinal instrumentation for adult spinal deformity dates back to the surgical correction of secondary complications from infectious processes, such as Pott's disease and poliomyelitis [1]. With the population aging at a longer life expectancy today, advanced degenerative spinal diseases and idiopathic scoliosis supersede as the most common causes of adult spinal deformity. Correction of the thoracolumbar malignment, specifically, has rapidly evolved with the burgeoning success of spinal instrumentation. The objective of this chapter is to review the metamorphosis of operative principles for adult thoracolumbar deformity, from aggressive osteotomies in the posterior bony elements to minimally invasive surgery (MIS) at the intervertebral disc space.

Comparison of Outcomes between Robot-Assisted Minimally Invasive Transforaminal Lumbar Interbody Fusion and Oblique Lumbar Interbody Fusion in Single-Level Lumbar Spondylolisthesis

Objective

To compare the safety and effectiveness of robot‐assisted minimally invasive transforaminal lumbar interbody fusion (Mis‐TLIF) and oblique lumbar interbody fusion (OLIF) for the treatment of single‐level lumbar degenerative spondylolisthesis (LDS).

Methods

This is a retrospective study. Between April 2018 and April 2020, a total of 61 patients with single‐level lumbar degenerative spondylolisthesis and treated with robot‐assisted OLIF (28 cases, 16 females, 12 males, mean age 50.4 years) or robot‐assisted Mis‐TLIF (33 cases, 18 females, 15 males, mean age 53.6 years) were enrolled and evaluated. All the pedicle screws were implanted percutaneously assisted by the TiRobot system. Surgical data included the operation time, blood loss, and length of postoperative hospital stay. The clinical and functional outcomes included Oswestry Disability Index (ODI), Visual Analog scores (VAS) for back and leg pain, complication, and patient's satisfaction. Radiographic outcomes include pedicle screw accuracy, fusion status, and disc height. These data were collected before surgery, at 1 week, 3 months, 6 months, and 12 months postoperatively.

Results

There were no significantly different results in preoperative measurement between the two groups. There was significantly less blood loss (142.4 ± 89.4 vs 291.5 ± 72.3 mL, P < 0.01), shorter hospital stays (3.2 ± 1.8 vs 4.2 ± 2.5 days, P < 0.01), and longer operative time (164.9 ± 56.0 vs 121.5 ± 48.2 min, P < 0.01) in OLIF group compared with Mis‐TLIF group. The postoperative VAS scores and ODI scores in both groups were significantly improved compared with preoperative data (P < 0.05). VAS scores for back pain were significantly lower in OLIF group than Mis‐TLIF group at 1 week (2.8 ± 1.2 vs 3.5 ± 1.6, P < 0.05) and 3 months postoperatively (1.6 ± 1.0 vs 2.1 ± 1.1, P < 0.05), but there was no significant difference at further follow‐ups. ODI score was also significantly lower in OLIF group than Mis‐TLIF group at 3 months postoperatively (22.3 ± 10.0 vs 26.1 ± 12.8, P < 0.05). There was no significant difference in the proportion of clinically acceptable screws between the two groups (97.3% vs 96.2%, P = 0.90). At 1 year, the OLIF group had a higher interbody fusion rate compared with Mis‐TLIF group (96.0% vs 87%, P < 0.01). Disc height was significantly higher in the OLIF group than Mis‐TLIF group (12.4 ± 3.2 vs 11.2 ± 1.3 mm, P < 0.01). Satisfaction rates at 1 year exceeded 90% in both groups and there was no significant difference (92.6% for OLIF vs 91.2% for Mis‐TLIF, P = 0.263).

Conclusion

Robot‐assisted OLIF and Mis‐TLIF both have similar good clinical outcomes, but OLIF has the additional benefits of less blood loss, less postoperative hospital stays, higher disc height, and higher fusion rates. Robots are an effective tool for minimally invasive spine surgery.

Risk of reoperation and infection after percutaneous endoscopic lumbar discectomy and open lumbar discectomy : a nationwide population-based study

AIMS

Open discectomy (OD) is the standard operation for lumbar disc herniation (LDH). Percutaneous endoscopic lumbar discectomy (PELD), however, has shown similar outcomes to OD and there is increasing interest in this procedure. However despite improved surgical techniques and instrumentation, reoperation and infection rates continue and are reported to be between 6% and 24% and 0.7% and 16%, respectively. The objective of this study was to compare the rate of reoperation and infection within six months of patients being treated for LDH either by OD or PELD.

METHODS

In this retrospective, nationwide cohort study, the Korean National Health Insurance database from 1 January 2007 to 31 December 2018 was reviewed. Data were extracted for patients who underwent OD or PELD for LDH without a history of having undergone either procedure during the preceding year. Individual patients were followed for six months through their encrypted unique resident registration number. The primary endpoints were rates of reoperation and infection during the follow-up period. Other risk factors for reoperation and infection were also evalulated.

RESULTS

Out of 549,531 patients, 522,640 had undergone OD (95.11%) and 26,891 patients had undergone PELD (4.89%). Reoperation rates within six months were 2.28% in the OD group, and 5.38% in the PELD group. Infection rates were 1.18% in OD group and 0.83% in PELD group. The risk of reoperation was lower for patients with OD than for patients with PELD (adjusted hazard ratio (HR) 0.38). The risk of infection was higher for patients with OD than for patients undergoing PELD (HR, 1.325).

CONCLUSION

Compared with the OD group, the PELD group showed higher reoperation rates and lower infection rates. Cite this article: Bone Joint J 2021;103-B(8):1392-1399.

Minimally invasive resection of pediatric osteoid osteomas: A report of two cases

Background:

Spinal osteoid osteomas (OOs) are common benign bone tumors that most frequently affect the posterior elements. They occasionally (e.g., 10% of the time) necessitate surgical resection for intractable pain. Given their small size and posterior positions, many may be amenable to minimally invasive surgical approaches.

Case Description:

We describe two cases of spinal OOs involving patients 11 and 17 years of age with lesions, respectively, at T7 and C4.

Conclusion:

Minimally invasive approaches for resection of small bony spinal OOs are safe and technically achievable approaches.

Conjoint Nerve Root an Intraoperative Challenge in Minimally Invasive Tubular Discectomy

Conjoint nerve root (CNR) is an embryological nerve root anomaly that mainly involves the lumbosacral region. The presence of CNR during tubular discectomy raises the chances of failure in spinal surgery and the risk of neural injuries. Tubular discectomy can be challenging in the presence of CNR owing to limited visualization. Here, we present a technical note on two cases of L5–S1 disc prolapse in the presence of conjoint S1 nerve root that was operated via a minimally invasive tubular approach. Any intraoperative suspicion of CNR while using the tubular approach should prompt the surgeon to perform a thorough tubular decompression prior to nerve root retraction. In patients with a large disc, disc should be approached via the axilla because the axillary area between the dura and the medial boarder of the root is very easy to approach in the presence of CNR. Safe performance of tubular discectomy is possible even in the presence of CNR in the lumbar spine.

Endoscopic Versus Open Laminectomy for Lumbar Spinal Stenosis: An International, Multi-Institutional Analysis of Outcomes and Adverse Events

STUDY DESIGN

Retrospective cohort study and systematic review.

OBJECTIVES

Endoscopic decompression offers a minimally invasive alternative to traditional, open laminectomy. However, comparison of these surgical techniques has been largely limited to small, single-center studies. In this study, we perform the first international, multicenter comparison of both with regard to their associated rates of mortality, complications, readmissions, and reoperations.

METHODS

The 2017 American College of Surgeons' National Surgical Quality Improvement Program (ACS-NSQIP) database, containing data from over 650 hospitals internationally, was queried to evaluate the effect of endoscopic guidance on adverse events. Operative time, length of stay, readmission and reoperation rates, as well as the incidence of peri- and postoperative complications, were compared between endoscopic and open groups. The PubMed/MEDLINE database was queried for studies comparing the techniques.

RESULTS

A total of 10 726 single-level lumbar decompression patients were identified and included in this study, 34 (0.32%) of whom were operated upon endoscopically. Apart from 2 (5.88%) readmissions, among which only 1 was unplanned, there were no reported surgical complications within the endoscopic group. The mean length of stay for these patients was 0.86 ± 1.44 days, with procedures lasting an average of 91.89 ± 46.72 minutes. However, these endpoints did not differ significantly from the open group. On literature review, 16 studies met the inclusion criteria, and largely consisted of single-center, retrospective analyses.

CONCLUSIONS

Endoscopically guided approaches to single-level lumbar decompression did not reduce the incidence of adverse events, length of stay or operative time, perhaps due to advances among certain nonendoscopic techniques, such as microsurgery.

Clinical Comparison of Full-Endoscopic and Microscopic Unilateral Laminotomy for Bilateral Decompression in the Treatment of Elderly Lumbar Spinal stenosis: A Retrospective Study with 12-Month Follow-Up

Purpose

Although lumbar spinal stenosis (LSS) is the most common spinal disease in the elderly, there is still a confusion about the appropriate surgical treatment strategy. The aim of this study was to compare the safety and efficacy of full-endoscopic and microscopic unilateral laminotomy for bilateral decompression (ULBD) for LSS in elderly patients.

Patients and Methods

A retrospective analysis of 61 consecutive elderly patients with LSS who underwent either full-endoscopic (FE group) or microscopic (Micro group) unilateral laminotomy for bilateral decompression was performed. Clinical data were assessed before 2 weeks, 3 months, 6 months and 12 months after surgery using the Visual Analog Scale (VAS), the Oswestry Disability Index (ODI) and the modified MacNab criteria.

Results

There are no significant differences in VAS (back and leg) and ODI between the two groups. However, the VAS back pain in the FE group was significantly improved compared to the Micro group at 2 weeks. The rate of excellent or good outcomes was 87.88% and 85.71% in the FE and Micro group, respectively (P>0.05). The hospital stay and early ambulation in FE group were shorter than those in Micro group, but the operation time was longer (P<0.05). The complications between the FE group (18.18%) and the Micro group (17.86%) were minor (P>0.05).

Conclusion

Both full-endoscopic and microscopic decompression have achieved favorable clinical results in treating elderly lumbar spinal stenosis, and the complications are minor. Full-endoscopic decompression has the advantages of small incision and rapid recovery, which can be used as an alternative for the treatment of lumbar spinal stenosis, especially the elderly with comorbidities.

Microdiscectomy for Lumbar Disc Herniation: A Single-Center Observational Study

OBJECTIVE

To examine outcomes and complications following first-time lumbar microdiscectomy.

METHODS

Prospective data for patients operated on between May 2007 and July 2016 were obtained from the Norwegian Registry for Spine Surgery. The primary outcome was change in Oswestry Disability Index (ODI) score at 1 year. Secondary endpoints were change in quality of life measured with EuroQol 5 Dimensions, back and leg pain measured with numeric rating scales, and perioperative complications within 3 months of surgery.

RESULTS

For all enrolled patients (N = 1219) enrolled, mean improvement in ODI at 1 year was 33.3 points (95% confidence interval [CI] 31.7 to 34.9, P < 0.001). Mean improvement in EuroQol 5 Dimensions at 1 year of 0.52 point (95% CI 0.49 to 0.55, P < 0.001) represents a large effect size (Cohen's d = 1.6). Mean improvements in back pain and leg pain numeric rating scales were 3.9 points (95% CI 3.6 to 4.1, P < 0.001) and 5.0 points (95% CI 4.8 to 5.2, P < 0.001), respectively. There were 18 surgical complications in 1219 patients and 63 medical complications in 846 patients. The most common complication was micturition problems at 3 months following surgery (n = 25, 2.1%). In multivariate analysis, ODI scores of 21-40 (hazard ratio [HR] 14.5, 95% CI 1.1 to 27.9, P = 0.035), 41-60 (HR 27.5, 95% CI 13.4 to 41.7, P < 0.001), 61-80 (HR 47.4, 95% CI 33.4 to 61.4, P < 0.001) and >81 (HR 66.7, 95% CI 51.1 to 82.2, P < 0.001) were identified as positive predictors for ODI improvement at 1 year, whereas age ≥65 (HR -0.9, 95% CI -0.3 to -1.5, P = 0.004) was identified as a negative predictor for ODI improvement.

CONCLUSIONS

Microdiscectomy for lumbar disc herniation is an effective and safe treatment.

Pedicle screw placement in spinal neurosurgery using a 3D-printed drill guide template: a systematic review and meta-analysis

Background

Many surgeons believe that the use of a 3D-printed drill guide template shortens operative time and reduces intraoperative blood loss compared with those of the free-hand technique. In this study, we investigated the effects of a drill guide template on the accuracy of pedicle screw placement (the screw placed completely in the pedicle), operative time, and intraoperative blood loss.

Materials/Methods

We systematically searched the major databases, such as Medline via PubMed, EMBASE, Ovid, Cochrane Library, and Google Scholar, regarding the accuracy of pedicle screw placement, operative time, and intraoperative blood loss. The χ² test and I² statistic were used to examine heterogeneity. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to calculate the accuracy rate of pedicle screw placement, and weighted mean differences (WMDs) with 95% CIs were utilized to express operative time and intraoperative blood loss.

Results

This meta-analysis included 13 studies (seven randomized controlled trials and six prospective cohort studies) involving 446 patients and 3375 screws. The risk of research bias was considered moderate. Operative time (WMD = − 20.75, 95% CI − 33.20 ~ − 8.29, P = 0.001) and intraoperative blood loss (WMD = − 106.16, 95% CI − 185.35 ~ − 26.97, P = 0.009) in the thoracolumbar vertebrae, evaluated by a subgroup analysis, were significantly different between groups. The 3D-printed drill guide template has advantages over the free-hand technique and improves the accuracy of pedicle screw placement (OR = 2.88; 95% CI, 2.39~3.47; P = 0.000).

Conclusion

The 3D-printed drill guide template can improve the accuracy rate of pedicle screw placement, shorten operative time, and reduce intraoperative blood loss.

[Minimally invasive spinal surgery: stages of development]

In recent decades, spinal surgery has changed significantly. The active use of modern knowledge of anatomy, various diagnostic modules, specialized surgical equipment and high-tech tools has made it possible to transform classical surgical techniques into a new area of spinal neurosurgery - minimally invasive spine surgery (MISS). Its main goals are to reduce damage to the skin and adjacent tissues, significantly reduce the level of pain, reduce the duration of inpatient treatment and fully restore functional status in the shortest possible time. This article reflects the main criteria for MISS compliance and types of surgical interventions, provides information on the advantages of minimally invasive surgical technologies and their possible disadvantages. Currently, the use of MISS is observed in all areas of vertebrology - for degenerative diseases, tumors, inflammatory and traumatic lesions of the spine. At the same time, minimizing surgical aggression while maximizing the achievement of goal becomes the main rule of modern spinal surgery.

Microdecompression versus Open Laminectomy and Posterior Stabilization for Multilevel Lumbar Spine Stenosis: A Randomized Controlled Trial

Background

Lumbar spinal stenosis most often results from a gradual, degenerative ageing process. Open or wide decompressive laminectomy was formerly the standard treatment. However, in recent years, a growing tendency towards less invasive decompressive procedures has emerged. The purpose of this study was to compare the results of microdecompression with those of open wide laminectomy and posterior stabilization for patients with symptomatic multilevel lumbar spinal stenosis who failed to respond to conservative treatment.

Methods

This randomized controlled study was conducted between January 2016 and October 2018. One hundred patients were involved in this study. All these patients suffered from radicular leg pain with MRI features of multilevel lumbar spinal stenosis and were treated by conservative treatment of medical treatment and physiotherapy without benefit for 6 months. Those patients were divided into two groups: Group A, 50 microdecompression, and Group B, 50 patients who were treated by open wide laminectomy and posterior stabilization. Both groups of patients were followed up with ODI (Oswestry disability index) and VAS (visual analogue score) for the back and leg pain for one year.

Results

The results showed that both groups got significant improvement regarding the Oswestry disability index. Regarding back pain, there was a significant improvement in both groups with better results in group A due to minimal tissue injury as the advantage of the minimal invasive technique. In both groups, there was marked improvement of radicular leg pain postoperatively.

Conclusions

Both microdecompression and wide open laminectomy with posterior stabilization were effective in treatment of multilevel lumbar spinal stenosis with superior results of microdecompression regarding less back pain postoperatively with less blood loss and soft tissue dissection. Clinical trial number: NCT04087694.

Three-Dimensional Printing in Minimally Invasive Spine Surgery

PURPOSE OF REVIEW

To summarize the recent advances in 3D printing technology as it relates to spine surgery and how it can be applied to minimally invasive spine surgery.

RECENT FINDINGS

Most early literature about 3D printing in spine surgery was focused on reconstructing biomodels based on patient imaging. These biomodels were used to simulate complex pathology preoperatively. The focus has shifted to guides, templates, and implants that can be used during surgery and are specific to patient anatomy. However, there continues to be a lack of long-term outcomes or cost-effectiveness analyses. 3D printing also has the potential to revolutionize tissue engineering applications in the search for the optimal scaffold material and structure to improve bone regeneration without the use of other grafting materials. 3D printing has many potential applications to minimally invasive spine surgery requiring more data for widespread adoption.

Primary Dural Closure in Minimally Invasive Spine Surgery Using an Extracorporeal Knot: Technical Note

BACKGROUND

Minimally invasive spine surgeries (MISS) are currently used for a wide variety of intradural spinal pathologies. Although MISS techniques have brought great benefits, primary dural closure can prove a challenge due to the narrow corridor of the tubular retractor systems.

OBJECTIVE

To present the surgical technique we developed for dural closure using an extracorporeal knot that is simple and reproducible.

METHODS

We describe the use of an extracorporeal knot for primary dural closure in MISS surgeries using standard instrumental. We illustrate this operative technique with figures and its application in a surgical case with images and demonstration video2.

RESULTS

Using our surgical technique, a watertight dural closure with separated knots was performed without specific instruments.

CONCLUSION

The use of extracorporeal knots facilitates primary dural closure in MISS surgeries.

Timing of surgical fixation in traumatic spinal fractures: A systematic review

BACKGROUND

The optimal timing of fracture fixation following spinal injury is controversial. Many spinal fractures occur as part of polytrauma requiring a complex management strategy. Whilst the decision to stabilize unstable spinal column injuries is without debate, the duration between injury and definitive fixation can impact on the incidence of post-operative complications. This study was designed to systemically summarize and compare the complication profile of early vs late stabilization of spinal injuries, in an attempt to unveil an appropriate treatment protocol for traumatic spinal fractures.

METHODS

A comprehensive search strategy was performed on the PubMed, Cochrane, and Google Scholar databases using key words. The search strategy provided 1120 results. Forty-six articles were reviewed for full-text. Reference lists were analysed for potential additional texts.

RESULTS

Sixteen articles met the inclusion criteria and were included for systematic review. Studies were controversial and the overall result was inconclusive. Several studies favour early stabilisation to reduce post-surgical complication rates, especially in cases of patients with high Injury Severity Scale (ISS) scores. However, this is challenged by a small number of studies reporting a higher mortality rate in the early-stabilisation cohort.

CONCLUSION

Due to limited studies and a small overall cohort, the authors would cautiously recommend the early surgical fixation of unstable spine fractures in the stable trauma patient. For severely injured patients, the discordance among literature warrants the need for further investigation.

Long Term Outcomes and Effects of Surgery on Degenerative Spinal Deformity: A 14-Year National Cohort Study

Degenerative spinal deformity (DSD) has become a prevalent cause of disability and pain among the aging population worldwide. Though surgery has emerged as a promising option for DSD, the natural course, outcomes, and effects of surgery on DSD have remained elusive. This cohort study used a national database to comprehensively follow up patients of DSD for all-cause mortality, respiratory problems, and hip fracture-related hospitalizations. All patients were grouped into an operation or a non-operation group for comparison. An adjustment of demographics, comorbidities, and propensity-score matching was conducted to ameliorate confounders. A Cox regression hazard ratio (HR) model and Kaplan-Meier analysis were also applied. The study comprised 21,810 DSD patients, including 12,544 of the operation group and 9266 of the non-operation group. During the 14 years (total 109,591.2 person-years) of follow-up, the operation group had lower mortality (crude hazard ratio = 0.40), lower respiratory problems (cHR = 0.45), and lower hip fractures (cHR = 0.63) than the non-operation group (all p < 0.001). After adjustment, the risks for mortality and respiratory problems remained lower (adjusted HR = 0.60 and 0.65, both p < 0.001) in the operation than the non-operation group, while hip fractures were indifferent (aHR = 1.08, p > 0.05). Therefore, surgery for DSD is invaluable since it could reduce the risks of mortality and of hospitalization for respiratory problems.

Analysis of the Surgical Technique and Outcome of the Thoracic and Lumbar Intradural Spinal Tumor Excision Using Minimally Invasive Tubular Retractor System

Background:

Conventionally, intradural spinal tumor excision requires longer skin incision, bilateral subperiosteal muscle stripping, and total laminectomy, thereby decreasing the stability of the spine and increasing the morbidity. Minimally invasive surgery (MIS) for intradural spinal tumor excision preserves the posterior supporting structures of the spine in the midline and on the contralateral side and decreases morbidity and achieves the resection of the tumor.

Aims:

The aim is to analyze the surgical technique and outcome of the thoracic and lumbar intradural spinal tumor excision using minimally invasive tubular retractor system.

Patients and Methods:

A retrospective study was conducted in patients admitted with thoracic and lumbar intradural spinal tumors who had undergone tumor excision using minimally invasive tubular retractor system and satisfied the inclusion and exclusion criteria. Intradural tumors involving one or two vertebral levels were included in the study. Intramedullary spinal tumor, intradural tumor extending into intervertebral foramen, and intradural tumor involving more than two vertebral levels were excluded from the study. The study included the data of the 13 patients, who were operated between January 2017 and October 2018. The age and sex of the patients were noted. Gadolinium-enhanced magnetic resonance imaging scan and X-ray of the spine were taken in all the patients. The pre- and postoperative data analyzed include pain using visual analog scale (VAS), power using Medical Research Council (MRC) grading, myelopathy using Nurick's grade, sensory changes, and bowel and bladder symptoms. The steps involved in the surgical technique, extent of resection, intraoperative blood loss, duration of surgery, postoperative complications, duration of stay after the surgery, and postoperative X-ray were analyzed.

Results:

Out of 13 patients, one case of dorsally placed meningioma was converted to open laminectomy and excision due to nonvisualization of the spinal cord and increased bleeding from the tumor. Hence, data of the remaining 12 patients were analyzed. The histopathology of these cases was meningioma (6), schwannoma (5), and neurenteric cyst (1). There were 5 men and 7 women with age group of 27–70 years (mean: 48 years). There were 8 thoracic and 4 lumbar tumors. The duration of symptoms was 2 days to 72 months (mean: 35 months). Eight cases were predominantly occupying on the right side and 4 cases on the left side within the spinal canal. The skin incision length was 25 mm to 35 mm (mean: 28 mm). We used tubular retractors with diameter ranging from 22 mm to 30 mm (mean: 24 mm). Expandable retractors were used in 9 cases (75%) and nonexpandable in 3 cases (25%). Tubular retractor of company Jayon (India) was used in 5 cases and PITKAR (India) in 7 cases. We have not found any significant difference in the usage of both the systems. The tumor size (craniocaudal) was ranging from 9.5 mm to 38 mm (mean: 19 mm). Intraoperative blood loss was 75–200 ml (mean: 115 ml). Gross total resection was achieved in 8 cases and near-total resection in 4 cases. Dura was sutured primarily in all the cases. The dural closure was done with continuous sutures in 6 (50%) cases and interrupted in 6 (50%) cases. Polypropylene suture was used in 10 cases and polyglactin suture in 2 cases of dural closure. The authors found it easy to suture the dura using 7-0 polypropylene. Fibrin sealant was used in 9 (75%) cases. The duration of the surgery was ranging from 160 min to 390 min (mean: 260 min). Cerebrospinal fluid leak and pseudomeningocele were noted in one case. One patient developed suture site infection. VAS for pain, sensory symptoms, Nurick's grade for myelopathy, and MRC grading for power were improved in all the affected patients. Out of two patients with constipation, one patient improved and the other developed incontinence, which was recovered on follow-up after 2 weeks. Out of the 4 patients with urinary symptoms, 3 were improved. Another patient of preoperative normal micturition developed urinary retention due to exacerbation of benign prostatic hypertrophy. Postoperative X-ray showed preserved spinous process and facet joints in all cases. The duration of the hospital stay was ranging from 2 days to 11 days (mean: 6 days).

Conclusion:

Anteriorly or laterally placed intradural spinal tumors confined to the spinal canal can be excised safely and effectively using tubular retractor system, with adding the advantages of the MIS surgery. When in doubt, always convert the MIS to open surgery to avoid injury to vital structures.

Management - spinal metastases

Due to a worldwide increase of cancer incidence and a longer life expectancy of patients with metastatic cancer, a rise in the incidence of symptomatic vertebral metastases has been observed. Metastatic spinal disease is one of the most dreaded complications of cancer as it is not only associated with severe pain, but also with paralysis, sensory loss, sexual dysfunction, urinary and fecal incontinency when the neurologic elements are compressed. Rapid diagnosis and treatment have been shown to improve both the quality and length of remaining life. This chapter on vertebral metastases with epidural disease and intramedullary spinal metastases will be discussed in terms of epidemiology, pathophysiology, demographics, clinical presentation, diagnosis, and management. With respect to treatment options, our review will summarize the evolution of conventional palliative radiation to modern stereotactic body radiotherapy for spinal metastases and the surgical evolution from traditional open procedures to minimally invasive spine surgery. Lastly, we will review the most common clinical prediction and decision rules, framework and algorithms, and guidelines that have been developed to guide treatment decision making.

Feasibility of Full Endoscopic Spine Surgery in Patients Over the Age of 70 Years With Degenerative Lumbar Spine Disease

Background/Aims

Degenerative spine disease, encompassing disc prolapse and stenosis, is a common ailment in old age. This prospective study was undertaken to evaluate the role of endoscopic spine surgery in elderly patients (above 70 years of age) with clinical and radiological follow-up.

Methods

In this study, a retrospective analysis was conducted of 53 patients with lumbar disc prolapse or spinal stenosis who were treated with percutaneous endoscopic discectomy or decompression from November 2015 to June 2017. Clinical follow-up was done at 1 week, 3 months, and 1 year, and at yearly intervals thereafter. The outcomes were assessed using the modified Macnab criteria, a visual analogue scale, and the Oswestry Disability Index.

Results

Of the 53 patients, 21 were men and 32 were women. Their mean age was 76±4 years. The mean follow-up period was 17 months. Percutaneous endoscopic discectomy was performed in 24 patients and endoscopic decompression in 24 patients, while 5 patients underwent combined surgery. An excellent outcome in terms of the MacNab criteria was observed in 9 patients (16.98%), a good outcome in 38 patients (71.7%), and a poor outcome in 6 patients (11.3%). Of the 6 patients with a poor outcome, 5 (9.4%, 5 of 53) developed recurrent disc prolapse, and 1 developed hematoma with motor weakness. All 6 of these cases required revision surgery.

Conclusion

Managing degenerative spine disease in elderly patients with multiple comorbidities is a challenging task. Percutaneous endoscopic spine surgery is pivotal for addressing this concern. The authors have shown that optimal results can be achieved with various types of disc prolapse and stenosis with favorable long-term outcomes.

Surgeon Reimbursement Relative to Hospital Payments for Spinal Fusion: Trends From 10-year Medicare Analysis

STUDY DESIGN

Retrospective, economic analysis.

OBJECTIVE

The aim of this study was to analyze the trend in hospital charge and payment adjusted to corresponding surgeon charge and payment for cervical and lumbar fusions in a Medicare sample population from 2005 to 2014.

SUMMARY OF BACKGROUND DATA

Previous studies have reported trends and variation in hospital charges and payments for spinal fusion, but none have incorporated surgeon data in analysis. Knowledge of the fiscal relationship between hospitals and surgeons over time will be important for stakeholders as we move toward bundled payments.

METHODS

A 5% Medicare sample was used to capture hospital and surgeon charges and payments related to cervical and lumbar fusion for degenerative disease between 2005 and 2014. We defined hospital charge multiplier (CM) as the ratio of hospital/surgeon charge. Similarly, the hospital/surgeon payment ratio was defined as hospital payment multiplier (PM). The year-wise and regional trend in patient profile, length of stay, discharge disposition, CM, and PM were studied for all fusion approaches separately.

RESULTS

A total of 40,965 patients, stratified as 15,854 cervical and 25,111 lumbar fusions, were included. The hospital had successively higher charges and payments relative to the surgeon from 2005 to 2014 for all fusions with an inverse relation to hospital length of stay. Increasing complexity of fusion such as for anterior-posterior cervical fusion had higher hospital reimbursements per dollar earned by the surgeon. There was regional variation in how much the hospital charged and received per surgeon dollar.

CONCLUSION

Hospital charge and payment relative to surgeon had an increasing trend despite a decreasing length of stay for all fusions. Although the hospital can receive higher payments for higher-risk patients, this risk is not reflected proportionally in surgeon payments. The shift toward value-based care with shared responsibility for outcomes and cost will likely rely on better aligning incentives between hospital and providers.

LEVEL OF EVIDENCE

3.

3D Printing Applications in Minimally Invasive Spine Surgery

3D printing (3DP) technology continues to gain popularity among medical specialties as a useful tool to improve patient care. The field of spine surgery is one discipline that has utilized this; however, information regarding the use of 3DP in minimally invasive spine surgery (MISS) is limited. 3D printing is currently being utilized in spine surgery to create biomodels, hardware templates and guides, and implants. Minimally invasive spine surgeons have begun to adopt 3DP technology, specifically with the use of biomodeling to optimize preoperative planning. Factors limiting widespread adoption of 3DP include increased time, cost, and the limited range of diagnoses in which 3DP has thus far been utilized. 3DP technology has become a valuable tool utilized by spine surgeons, and there are limitless directions in which this technology can be applied to minimally invasive spine surgery.

Minimally Invasive Placement of Spinal Cord Stimulator Paddle Electrodes Is Associated With Improved Perioperative and Long-Term Experience Among Neuropathic Pain Patients

STUDY DESIGN

Prospective, observational cohort study.

OBJECTIVE

This study compared in-hospital and long-term outcomes among spinal cord stimulation (SCS) patients undergoing paddle insertion by open or minimally invasive surgery (MIS) approaches.

SUMMARY OF BACKGROUND DATA

Patients with treatment-refractory extremity neuropathic pain may benefit from SCS. Conventional placement of surgical paddles for an external neurostimulation trial is through open laminectomy, but MIS techniques may offer advantages.

METHODS

Twenty SCS patients were prospectively assessed. Open patients underwent caudal thoracic laminectomy for multicolumnar electrode paddle placement. MIS patients underwent paddle placement through interlaminar flavectomy using tubular retractors. Demographic data included age, sex, underlying diagnosis, and preoperative visual analog scale (VAS) extremity scores. Intraoperative data included operative duration, blood loss, and number of device passages to achieve final position. Perioperative data included VAS back pain scores; trial data included time-to-trial and time-to-decision. Postoperative data included 1 month VAS back pain scores and 1 year follow-up device complications.

RESULTS

No demographic differences were observed among surgical cohorts. MIS procedures had shorter operative duration (P = 0.03), less blood loss (P < 0.001), and similar median number of device passages (2 vs 1.5, P = 0.71). MIS patients reported less perioperative surgical back pain (P < 0.05). External neurostimulation trials began sooner among MIS patients who also made sooner decision whether to implant the SCS device (2.8 ± 1.4 vs 4.3 ± 1.0 days, P = 0.013). Similar 1 month back pain scores were reported between surgical cohorts (P = 0.08).

CONCLUSION

MIS techniques for SCS surgical paddle implantation is associated with less perioperative morbidity and surgical site back pain, shorter external neurostimulator trial duration, and long-term device stability benefits.

LEVEL OF EVIDENCE

2.

Short-Term Outcome Comparison Between Full-Endoscopic Interlaminar Approach and Open Minimally Invasive Microsurgical Technique for Treatment of Lumbar Disc Herniation

OBJECTIVE

To compare postoperative pain control and functional outcome between full-endoscopic interlaminar approach (FEIA) and open minimally invasive microsurgical technique (MMST) for lumbar discectomy.

METHODS

All consecutive patients treated with FEIA were prospectively followed. Clinical outcome parameters (low back and leg numeric rating scale and Quebec Back Pain Disability Scale) were measured. Analgesics use after surgery was quantified. Results were compared with a cohort of patients treated in the same period with MMST. The decision regarding which surgical technique to use was based on endoscope availability only.

RESULTS

There were 26 patients treated with FEIA and 18 treated with MMST. Baseline patient characteristics were comparable. Sciatic pain was treated in both groups. Postoperative back pain was significantly lower in the FEIA group (numeric rating scale scores 1.5, 0.3, and 0.2 at 1, 2, and 4 weeks after FEIA vs. 3.6, 2.4, and 1.6 after MMST). In the FEIA group, 61.5% of patients did not take any pain medication. The average number of analgesics taken within 30 days was 4.0 in the FEIA group and 27.2 in the MMST group. The average Quebec Back Pain Disability Scale score decreased from 57.7 to 25.0, 18.0, and 14.2 at 1, 2, and 4 weeks after FEIA compared with a decrease from 58.8 to 41.1, 34.7, and 23.0 in the MMST group. No approach-related complications were reported.

CONCLUSIONS

With less analgesic use, back and leg pain relief after 1 week in the FEIA group was comparable to that achieved in the MMST group after 1 month. This was also true for overall ability of patients to perform daily activities.

Minimally Invasive Versus Open Laminectomy/Discectomy, Transforaminal Lumbar, and Posterior Lumbar Interbody Fusions: A Systematic Review

Minimally invasive spine surgeries (MISS) are becoming increasingly favored as alternatives to open spine procedures because of the reduced blood loss, postoperative pain, and recovery time. Studies have shown mixed results regarding the efficacy and safety of minimally invasive procedures compared to the traditional, open counterparts. The objectives of this systematic analysis are to compare clinical outcomes between the three MISS and open procedures: (1) laminectomy/discectomy, (2) transforaminal lumbar interbody fusion (TLIF), and (3) posterior lumbar interbody fusion (PLIF). The Cochrane and PubMed databases were queried according to the preferred reporting items for systematic review and meta-analyses (PRISMA) statement. The primary outcome measures included the visual analog scale (VAS), the Oswestry disability index (ODI), and blood loss. A total of 32 studies were included in the analysis. Of the three procedures investigated, only MISS TLIF showed significantly improved VAS for leg pain (p = 0.02), ODI (p = 0.05), and reduced blood loss (p = 0.005). MISS-laminectomy/discectomy, TLIF, and PLIF appear to be similar in terms of postoperative pain and perioperative blood loss. MISS TLIF is perhaps more effective in specific outcome measures and results in less intraoperative blood loss than open TLIF.

Increase in spinal deformity surgery in patients age 60 and older is not associated with increased complications

BACKGROUND CONTEXT

Surgical treatment for adult spinal deformity improves patient quality of life; however, trends in surgical utilization in the elderly, who may be at higher risk for complications, remain unclear.

PURPOSE

To identify trends in the utilization of adult deformity and determine complication rates among older patients.

STUDY DESIGN

This is a retrospective database analysis.

PATIENT SAMPLE

The Nationwide Inpatient Sample database was queried from 2004 to 2011 to identify adult patients who underwent spinal fusion of eight or more levels using International Classification of Diseases, Ninth Revision (ICD-9) coding.

OUTCOME MEASURES

Incidence of surgery, complication rates, length of stay, and total hospital charges.

METHODS

The incidence of surgery was normalized to United States census data by age group. Trends in complications, length of stay, and inflation-adjusted hospital charges were determined using linear regression and Cochran-Armitage trend testing.

RESULTS

An estimated 29,237 patients underwent adult spinal deformity surgery with an increase from 2,137 to 5,030 cases per year from 2004 to 2011. Surgical incidence among patients 60 years and older increased from 1.9 to 6.5 cases per 100,000 people from 2004 to 2011 (p<.001), whereas utilization in patients younger than 60 increased from 0.59 to 0.93. Linear regression revealed that the largest increase in surgical utilization was for patients aged 65-69 years with an increase of 0.68 patients per 100,000 people per year (p<.001), followed by patients aged 70-74 years with a rate of 0.56 patients per 100,000 people per year (p=.001). Overall complication rates were 22.5% in 2004 and 26.7% in 2011. Although complication risk increased with age (≥60 vs. <60: relative risk 1.91 [1.83, 1.99], p<.001), within-age group rates were stable over time. Mean length of stay was 9.6 days in 2004 and 9.0 days in 2011. Inflation-adjusted mean hospital charges increased from $171,517 in 2004 to $303,479 in 2011 (p<.001).

CONCLUSIONS

Operative management of adult spinal deformity increased 3.4-fold among patients ≥60 years from 2004 to 2011, with an associated 1.8-fold increase in hospital charges. Although the exact reasons for the striking increase in hospital charges remain unclear, some of the increase is likely related to decreasing reimbursement of charges by payors over the same period of time. The large majority of cases were performed in large academic centers, and growth in deformity trained spine specialists in these centers may have contributed to this trend. Despite the increased utilization of surgery for adult spinal deformity, in-hospital complications remained stable across all ages.