Image-Guided Spine Surgery

The realm of spine surgery is undergoing a transformative shift, thanks to the integration of image-guided navigation technology. This innovative system seamlessly blends real-time imaging data with precise location tracking. While the indispensable expertise of experienced spine surgeons remains irreplaceable, navigation systems bring a host of valuable advantages to the operating room. By offering a comprehensive view of the surgical anatomy, these systems empower surgeons to conduct procedures with accuracy, while minimizing radiation exposure for both patients and medical professionals. Moreover, image-guided navigation paves the way for integration of other state-of-the-art technologies, such as augmented reality and robotics. These innovations promise to further revolutionize the field, providing greater precision and expanding the horizons of what is possible in the world of spinal procedures. This article explores the evolution, classification, and impact of image-guided spine surgery, underscoring its pivotal role in enhancing efficacy and safety while setting the stage for the incorporation of future technological advancements.

Expandable cages that expand both height and lordosis provide improved immediate effect on sagittal alignment and short-term clinical outcomes following minimally invasive transforaminal lumbar interbody fusion (MIS TLIF)

Background

Failure to restore lordotic alignment is not an uncommon problem following minimally invasive transforaminal lumbar interbody fusion (MIS TLIF), even with expandable cages that increase disc height. This study aims to investigate the effect of the expandable cage that is specifically designed to expand both height and lordosis. We evaluated the outcomes of MIS TLIF in restoring immediate postoperative sagittal alignment by comparing two different types of expandable cages. One cage is designed to solely increase disc height (Group H), while the other can expand both height and lordosis (Group HL).

Methods

Patients undergoing MIS TLIF using expandable cages were retrospectively reviewed, including 40 cases in Group H and 109 cases in Group HL. Visual analog scores of back and leg pain, and Oswestry disability index were collected. Disc height, disc angle, and sagittal alignment were measured. Complications were recorded, including early subsidence which was evaluated with computed tomography.

Results

Clinical and radiographic outcomes significantly improved in both groups postoperatively. Group HL showed superior improvement in segmental lordosis (4.4°±3.5° vs. 2.1°±4.8°, P=0.01) and disc angle (6.3°±3.8 vs. 2.2°±4.3°, P<0.001) compared to Group H. Overall incidence of early subsidence was 23.3%, predominantly observed during initial cases as part of the learning curve, but decreased to 18% after completion of the first 20 cases.

Conclusions

Expandable cages with a design specifically aimed at increasing lordotic angle can provide favorable outcomes and effectively improve immediate sagittal alignment following MIS TLIF, compared to conventional cages that only increase in height. However, regardless of the type of expandable cage used, it is crucial to avoid applying excessive force to achieve greater disc height or lordosis, as this may contribute to subsidence and a possible reduction in lordotic alignment restoration. Long-term results are needed to evaluate the clinical outcome, fusion rate, and maintenance of the sagittal alignment.

Presentation, Management, and Outcomes of Thoracic, Thoracolumbar, and Lumbar Spine Trauma in East Africa: A Cohort Study

BACKGROUND

Trauma to the thoracic, thoracolumbar (TL), and lumbar spine is common and can cause disability and neurological deficits. Using a cohort of patients suffering from thoracic, TL, and lumbar spine trauma in a tertiary hospital in East Africa, the current study sought to: (1) describe demographics and operative treatment patterns, (2) assess neurologic outcomes, and (3) report predictors associated with undergoing surgery, neurologic improvement, and mortality.

METHODS

A retrospective cohort study of patient records from September 2016 to December 2020 was conducted at a prominent East Africa referral center. The study collected data on demographics, injury, and operative characteristics. Surgical indications were assessed using the AO (Arbeitsgemeinschaft für Osteosynthesefragen) TL fracture classification system and neurological function. Logistic regression analysis identified predictors for operative treatment, neurologic improvement, and mortality.

RESULTS

The study showed that 64.9% of the 257 TL spine trauma patients underwent surgery with a median postadmission day of 17.0. The mortality rate was 1.2%. Road traffic accidents caused 43.6% of the injuries. The most common fracture pattern was AO Type A fractures (78.6%). Laminectomy and posterolateral fusion were performed in 97.6% of the surgical cases. Patients without neurological deficits (OR: 0.27, 95% CI: 0.13-0.54, P < 0.001) and those with longer delays from injury to admission were less likely to have surgery (OR: 0.95, 95% CI: 0.92-0.99, P = 0.007). The neurologic improvement rate was 11.1%. Univariate analysis showed a significant association between surgery and neurologic improvement (OR: 3.83, 95% CI: 1.27-16.61, P < 0.001). However, this finding was lost in multivariate regression.

CONCLUSIONS

This study highlights various themes surrounding the management of TL spine trauma in a low-resource environment, including lower surgery rates, delays from admission to surgery, safe surgery with low mortality, and the potential for surgery to lead to neurologic improvement.

CLINICAL RELEVANCE

Despite challenges such as surgical delays and limited resources in East Africa, there is potential for surgical intervention to improve neurologic outcomes in thoracic, TL, and lumbar spine trauma patients.

LEVEL OF EVIDENCE: 4

Reliability of a Novel Classification System for Thoracic Disc Herniations

STUDY DESIGN

This is a cross-sectional survey.

OBJECTIVE

The aim was to assess the reliability of a proposed novel classification system for thoracic disc herniations (TDHs).

SUMMARY OF BACKGROUND DATA

TDHs are complex entities varying substantially in many factors, including size, location, and calcification. To date, no comprehensive system exists to categorize these lesions.

METHODS

Our proposed system classifies 5 types of TDHs using anatomic and clinical characteristics, with subtypes for calcification. Type 0 herniations are small (≤40% of spinal canal) TDHs without significant spinal cord or nerve root effacement; type 1 are small and paracentral; type 2 are small and central; type 3 are giant (>40% of spinal canal) and paracentral; and type 4 are giant and central. Patients with types 1 to 4 TDHs have correlative clinical and radiographic evidence of spinal cord compression. Twenty-one US spine surgeons with substantial TDH experience rated 10 illustrative cases to determine the system's reliability. Interobserver and intraobserver reliability were determined using the Fleiss kappa coefficient. Surgeons were also surveyed to obtain consensus on surgical approaches for the various TDH types.

RESULTS

High agreement was found for the classification system, with 80% (range 62% to 95%) overall agreement and high interrater and intrarater reliability (kappa 0.604 [moderate to substantial agreement] and kappa 0.630 [substantial agreement], respectively). All surgeons reported nonoperative management of type 0 TDHs. For type 1 TDHs, most respondents (71%) preferred posterior approaches. For type 2 TDHs, responses were roughly equivalent for anterolateral and posterior options. For types 3 and 4 TDHs, most respondents (72% and 68%, respectively) preferred anterolateral approaches.

CONCLUSIONS

This novel classification system can be used to reliably categorize TDHs, standardize description, and potentially guide the selection of surgical approach. Validation of this system with regard to treatment and clinical outcomes represents a line of future study.

Evaluating the Feasibility and Outcomes of a Scoliosis Surgical Camp in a Resource-Limited Setting in Sub-Saharan Africa

BACKGROUND

In sub-Saharan Africa, the estimated prevalence of scoliosis ranges from 3.3% to 5.5%. The management of these deformities is restricted due to lack of infrastructure and access to deformity spine surgeons. Utilizing surgical camps has been demonstrated to be efficient in transferring skills to low-resource environments; however, this has not been documented concerning deformity surgery.

METHODS

We conducted a cross-sectional study. The scoliosis camp was held at a major referral spine center in East Africa. We documented information about the organization of the course. We also collected clinical and demographic patient data. Finally, we assessed the knowledge and confidence among surgeon participants on the management scoliosis.

RESULTS

The camp lasted 5 days and consisted of lectures and case discussions, followed by casting and surgical sessions. Five patients were operated during the camp. All the patients in the study were diagnosed with AIS, except one with a congenital deformity. The primary curve in the spine was in the thoracic region for all patients. Six months postoperative Scoliosis Research Society-22R Scoring System (SRS-22R) score ranged from 3.3-4.5/5. 87.5% of the participants found the course content satisfactory.

CONCLUSIONS

To the best of our knowledge, this is the first time an African scoliosis camp has been established. The study highlights the difficulty of conducting such a course and illustrates the feasibility of executing these complex surgeries in a resource-limited environment.

Telemedical Support Using Smartphones for Spine Surgery in Low- and Middle-Income Countries

Objective: Low- and middle-income countries (LMICs) face many challenges compared to industrialized nations, most notably in regard to the health care system. Patients often have to travel long distances to receive medical care with few reliable transportation mechanisms. In time-critical emergencies, this is a significant disadvantage. One specialty that is particularly affected by this is spine surgery. Within this field, traumatic injuries and acutely compressive pathologies are often time-critical. Increasing global networking capabilities through internet access offers the possibility for telemedical support in remote regions. Recently, high-performance cameras and processors became available in commercially available smartphones. Due to their wide availability and ease of use, this could provide a unique opportunity to offer telemedical support in LMICs. Methods: We conducted a feasibility study with a neurosurgical institution in east Africa. To ensure telemedical support, a commercially available smartphone was selected as the experimental hardware. Preoperatively, resolution, contrast, brightness, and color reproduction were assessed under theoretical conditions using a test chart. Intraoperatively, the image quality was assessed under different conditions. In the first step, the instrumentation table was displayed, and the mentor surgeon marked an instrument that the mentee surgeon should recognize correctly. In the next evaluation step, the surgical field was shown on film and the mentor surgeon marked an anatomical structure, and in the last evaluation step, the screen of the X-ray machine was captured, and the mentor surgeon again marked an anatomical structure. Subjective image quality was rated by two independent reviewers using the similar modified Likert scale as before on a scale of 1-5, with 1 indicating inadequate quality and 5 indicating excellent quality. Results: The image quality during the video calls was rated as sufficient overall. When evaluating the test charts, a quality of 97% ± 5 on average was found for the chart with the white background and a quality of 84% ± 5 on average for the chart with the black background. The color reproduction, the contrast, and the reproduction of brightness were rated excellent. Intraoperatively, the visualization of the instrument table was also rated excellent. Visualization of the operative site was rated 1.5 ± 0.5 on average and it was not possible to recognize relevant anatomical structures with the required confidence for surgical procedures. Image quality of the X-ray screen was rated 1.5 ± 0.9 on average. Conclusion: Current generation smartphones have high imaging performance, high computing power, and excellent connectivity. However, relevant anatomical structures during spine surgery procedures and on the X-ray screen in the operating room could not be identified with reliability to provide adequate surgical support. Nevertheless, our study showed the potential in smartphones supporting surgical procedures in LMICs, which could be helpful in other surgical fields.

Finite element modeling to predict the influence of anatomic variation and implant placement on performance of biological intervertebral disc implants

Background

Tissue-engineered intervertebral disc (TE-IVD) constructs are an attractive therapy for treating degenerative disc disease and have previously been investigated in vivo in both large and small animal models. The mechanical environment of the spine is notably challenging, in part due to its complex anatomy, and implants may require additional mechanical support to avoid failure in the early stages of implantation. As such, the design of suitable support implants requires rigorous validation.

Methods

We created a FE model to simulate the behavior of the IVD cages under compression specific to the anatomy of the porcine cervical spine, validated the FE model using an animal model, and predicted the effects of implant location and vertebral angle of the motion segment on implant behavior. Specifically, we tested anatomical positioning of the superior vertebra and placement of the implant. We analyzed corresponding stress and strain distributions.

Results

Results demonstrated that the anatomical geometry of the porcine cervical spine led to concentrated stress and strain on the posterior side of the cage. This stress concentration was associated with the location of failure of the cages reported in vivo, despite superior mechanical properties of the implant. Furthermore, placement of the cage was found to have profound effects on migration, while the angle of the superior vertebra affected stress concentration of the cage.

Conclusions

This model can be utilized both to inform surgical procedures and provide insight on future cage designs and can be adopted to models without the use of in vivo animal models.

Neurosurgical Education in Tanzania: The Dar es Salaam Global Neurosurgery Course

BACKGROUND

Postgraduate neurosurgical training is essential to develop a neurosurgical workforce with the skills and knowledge to address patient needs for neurosurgical care. In Tanzania, the number of neurosurgeons and neurosurgical services offered have expanded in the past 40 years. Training opportunities within the country, however, are not sufficient to meet the needs of residents, specialists, and nurses in neurosurgery, forcing many to train outside the country incurring associated costs and burdens. We report on the Dar es Salaam Global Neurosurgery Course, which aims to provide local training to neurosurgical health care providers in Tanzania and surrounding countries.

METHODS

We report the experience of the Global Neurosurgery Course held in March 2023 in Dar es Salaam, Tanzania. We describe the funding, planning, organization, and teaching methods along with participant and faculty feedback.

RESULTS

The course trained 121 participants with 63 faculty-42 from Tanzania and 21 international faculty. Training methods included lectures, hands-on surgical teaching, webinars, case discussions, surgical simulation, virtual reality, and bedside teaching. Although there were challenges with equipment and Internet connectivity, participant feedback was positive, with overall improvement in knowledge reported in all topics taught during the course.

CONCLUSIONS

International collaboration can be successful in delivering topic-specific training that aims to address the everyday needs of surgeons in their local setting. Suggestions for future courses include increasing training on allied topics to neurosurgery and neurosurgical subspecialty topics, reflecting the growth in neurosurgical capacity and services offered in Tanzania.

Ten-step minimally invasive slalom unilateral laminotomy for bilateral decompression (sULBD) with navigation

BACKGROUND

Unilateral laminotomy for bilateral decompression (ULBD) is a MIS surgical technique that offers safe and effective decompression of lumbar spinal stenosis (LSS) with a long-term resolution of symptoms. Advantages over conventional open laminectomy include reduced expected blood loss, muscle damage, mechanical instability, and less postoperative pain. The slalom technique combined with navigation is used in multi-segmental LSS to improve the workflow and effectiveness of the procedure.

METHODS

We outline ten technical steps to achieve a slalom unilateral laminotomy for bilateral decompression (sULBD) with navigation. In a retrospective case series, we included patients with multi-segmental LSS operated in our institution using the sULBD between 2020 and 2022. The primary outcome was a reduction in pain measured by Visual Analogue Scale (VAS) for back pain and leg pain and Oswestry Disability Index (ODI).

RESULTS

In our case series (N = 7), all patients reported resolution of initial symptoms on an average follow-up of 20.71 ± 9 months. The average operative time and length of hospital stay were 196.14 min and 1.67 days, respectively. On average, VAS (back pain) was 4.71 pre-operatively and 1.50 on long-term follow-up of an average of 19.05 months. VAS (leg pain) decreased from 4.33 to 1.21. ODI was reported as 33% pre-operatively and 12% on long-term follow-up.

CONCLUSION

The sULBD with navigation is a safe and effective MIS surgical procedure and achieves the resolution of symptoms in patients presenting with multi-segmental LSS. Herein, we demonstrate the ten key steps required to perform the sULBD technique. Compared to the standard sULBD technique, the incorporation of navigation provides anatomic localization without exposure to radiation to staff for a higher safety profile along with a fast and efficient workflow.

Intraoperative occipital to C2 angle and external acoustic meatus-to-axis angular measurements for optimizing alignment during posterior fossa decompression and occipitocervical fusion for complex Chiari malformation

Background

Excess flexion or extension during occipitocervical fusion (OCF) can lead to postoperative complications, such as dysphagia, respiratory problems, line of sight issues, and neck pain, but posterior fossa decompression (PFD) and OCF require different positions that require intraoperative manipulation.

Objective

The objective of this study was to describe quantitative fluoroscopic morphometrics in Chiari malformation (CM) patients with symptoms of craniocervical instability (CCI) and demonstrate the intraoperative application of these measurements to achieve neutral craniocervical alignment while leveraging a single axis of motion with the Mayfield head clamp locking mechanism.

Methods

A retrospective cohort study of patients with CM 1 and 1.5 and features of CCI who underwent PFD and OCF at a single-center institution from March 2015 to October 2020 was performed. Patient demographics, preoperative presentation, radiographic morphometrics, operative details, complications, and clinical outcomes were analyzed.

Results

A total of 39 patients met the inclusion criteria, of which 37 patients (94.9%) did not require additional revision surgery after PFD and OCF. In this nonrevision cohort, preoperative to postoperative occipital to C2 angle (O-C2a) (13.5° ± 10.4° vs. 17.5° ± 10.1°, P = 0.047) and narrowest oropharyngeal airway space (nPAS) (10.9 ± 3.4 mm vs. 13.1 ± 4.8 mm, P = 0.007) increased significantly. These measurements were decreased in the two patients who required revision surgery due to postoperative dysphagia (mean difference - 16.6°° in O C2a and 12.8°° in occipital and external acoustic meatus to axis angle). Based on these results, these fluoroscopic morphometrics are intraoperatively assessed, utilizing a locking Mayfield head clamp repositioning maneuver to optimize craniocervical alignment prior to rod placement from the occipital plate to cervical screws.

Conclusion

Establishing a preoperative baseline of reliable fluoroscopic morphometrics can guide surgeons intraoperatively in appropriate patient realignment during combined PFD and OCF, and may prevent postoperative complications.

Use of a High-Fidelity Training Simulator for Minimally Invasive Lumbar Decompression Increases Working Knowledge and Technical Skills Among Orthopedic and Neurosurgical Trainees

STUDY DESIGN

Prospective comparative study.

OBJECTIVE

To quantify the educational benefit to surgical trainees of using a high-fidelity simulator to perform minimally invasive (MIS) unilateral laminotomy for bilateral decompression (ULBD) for lumbar stenosis.

METHODS

Twelve orthopedic and neurologic surgery residents performed three MIS ULBD procedures over 2 weeks on a simulator guided by established AO Spine metrics. Video recording of each surgery was rated by three blinded, independent experts using a global rating scale. The learning curve was evaluated with attention to technical skills, skipped steps, occurrence of errors, and timing. A knowledge gap analysis evaluating participants' current vs desired ability was performed after each trial.

RESULTS

From trial 1 to 3, there was a decrease in average procedural time by 31.7 minutes. The cumulative number of skipped steps and surgical errors decreased from 25 to 6 and 24 to 6, respectively. Overall surgical proficiency improved as indicated by video rating of efficiency and smoothness of surgical maneuvers, most notably with knowledge and handling of instruments. The greatest changes were noted in junior rather than senior residents. Average knowledge gap analysis significantly decreased by 30% from the first to last trial (P = .001), signifying trainees performed closer to their desired technical goal.

CONCLUSION

Procedural metrics for minimally invasive ULBD in combination with a realistic surgical simulator can be used to improve the skills and confidence of trainees. Surgical simulation may offer an important educational complement to traditional methods of skill acquisition and should be explored further with other MIS techniques.

Endoscopic odontoidectomy for brainstem compression in association with posterior fossa decompression and occipitocervical fusion

OBJECTIVE

Endonasal endoscopic odontoidectomy (EEO) is an alternative to transoral surgery for symptomatic ventral compression of the anterior cervicomedullary junction (CMJ), allowing for earlier extubation and feeding. Because the procedure destabilizes the C1-2 ligamentous complex, posterior cervical fusion is often performed concomitantly. The authors' institutional experience was reviewed to describe the indications, outcomes, and complications in a large series of EEO surgical procedures in which EEO was combined with posterior decompression and fusion.

METHODS

A consecutive, prospective series of patients who underwent EEO between 2011 and 2021 was studied. Demographic and outcome metrics, radiographic parameters, extent of ventral compression, extent of dens removal, and increase in CSF space ventral to the brainstem were measured on the preoperative and postoperative scans (first and most recent scans).

RESULTS

Forty-two patients (26.2% pediatric) underwent EEO: 78.6% had basilar invagination, and 76.2% had Chiari type I malformation. The mean ± SD age was 33.6 ± 3.0 years, with a mean follow-up of 32.3 ± 4.0 months. The majority of patients (95.2%) underwent posterior decompression and fusion immediately before EEO. Two patients underwent prior fusion. There were 7 intraoperative CSF leaks but no postoperative CSF leaks. The inferior limit of decompression fell between the nasoaxial and rhinopalatine lines. The mean ± SD vertical height of dens resection was 11.98 ± 0.45 mm, equivalent to a mean ± SD resection of 74.18% ± 2.56%. The mean increase in ventral CSF space immediately postoperatively was 1.68 ± 0.17 mm (p < 0.0001), which increased to 2.75 ± 0.23 mm (p < 0.0001) at the most recent follow-up (p < 0.0001). The median (range) length of stay was 5 (2-33) days. The median time to extubation was 0 (0-3) days. The median time to oral feeding (defined as, at minimum, toleration of a clear liquid diet) was 1 (0-3) day. Symptoms improved in 97.6% of patients. Complications were rare and mostly associated with the cervical fusion portion of the combined surgical procedures.

CONCLUSIONS

EEO is safe and effective for achieving anterior CMJ decompression and is often accompanied by posterior cervical stabilization. Ventral decompression improves over time. EEO should be considered for patients with appropriate indications.

Feasibility of High-Fidelity Simulator Models for Minimally Invasive Spine Surgery in a Resource-Limited Setting: Experience From East Africa

BACKGROUND

Spine surgery is a rapidly evolving specialty with a continuous need to learn new skills. In resource-limited settings such as Africa, the need for training is greater. The use of simulation-based training is important in different stages of skill acquisition, especially for high-stake procedures such as spine surgery. Among the available methods of simulation, the use of synthetic models has gained popularity among trainers.

METHOD

Twenty participants of a neurosurgery training course, most of whom (65%) were neurosurgery residents and fellows, were recruited. They had hands-on training sessions using a high-fidelity lumbar degenerative spine simulation model and hands-on theater experience. After this, they completed a survey to compare their experience and assess the effectiveness of the lumbar spine model in stimulating real patient and surgery experiences.

RESULTS

The participants were from four African countries, and the majority were neurosurgery residents. There were varying levels of experience among the participants in minimally invasive spine surgery, with the majority either having no experience or having only observed the procedure. All the participants said that the high-fidelity lumbar spine model effectively simulated real minimally invasive spine setup and real bone haptics and was effective in learning new techniques. Most of the participants agreed that the model effectively simulated real dura and nerve roots (95%), real muscle (90%), real bleeding from bones and muscles (95%), and real cerbrospinal fluid in the subarachnoid space. Among them, 95% agreed that the model is effective in lumbar minimally invasive spine training in resource-limited settings.

CONCLUSION

With the development of new and better surgical techniques, the use of high-fidelity models provides a good opportunity for learning and training, especially in resource-poor settings where there is a paucity of training facilities and personnel.

Natural History of Degenerative Spondylolisthesis: A Systematic Review and Meta-analysis

OBJECTIVE

The optimal treatment algorithm for patients with degenerative lumbar spondylolisthesis has not been clarified. Part of the reason for this is that the natural history of degenerative spondylolisthesis (DS) has not been sufficiently studied. Comprehension of the natural history is essential for surgical decision making. We aimed to determine 1) the proportion of patients that develop de novo DS during follow-up; and 2) the proportion of patients with progression of preexistent DS by conducting a systematic review and meta-analysis of the literature.

METHODS

This systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Ovid, EMBASE, and the Cochrane Library were searched from their inception through April 2022. Demographic values of the study populations, grade of slip, rate of slippage before and after the follow-up period, and percentage of patients with slip in the populations at baseline and after follow-up were the extracted parameters.

RESULTS

Of the 1909 screened records, eventually 10 studies were included. Of these studies, 5 reported the development of de novo DS and 9 reported on the progression of preexistent DS. Proportions of patients developing de novo DS ranged from 12% to 20% over a period ranging from 4 to 25 years. The proportion of patients with progression of DS ranged from 12% to 34% over a period ranging from 4 to 25 years.

CONCLUSIONS

Systematic review and metanalysis of DS on the basis of radiologic parameters revealed both an increasing incidence over time and an increasing progression of the slip rate in up to a third of the patients older than 25 years, which is important for counseling patients and surgical decision making. Importantly, two thirds of patients did not experience slip progression.

Artificial Intelligence in Neurosurgery: A State-of-the-Art Review from Past to Future

In recent years, there has been a significant surge in discussions surrounding artificial intelligence (AI), along with a corresponding increase in its practical applications in various facets of everyday life, including the medical industry. Notably, even in the highly specialized realm of neurosurgery, AI has been utilized for differential diagnosis, pre-operative evaluation, and improving surgical precision. Many of these applications have begun to mitigate risks of intraoperative and postoperative complications and post-operative care. This article aims to present an overview of the principal published papers on the significant themes of tumor, spine, epilepsy, and vascular issues, wherein AI has been applied to assess its potential applications within neurosurgery. The method involved identifying high-cited seminal papers using PubMed and Google Scholar, conducting a comprehensive review of various study types, and summarizing machine learning applications to enhance understanding among clinicians for future utilization. Recent studies demonstrate that machine learning (ML) holds significant potential in neuro-oncological care, spine surgery, epilepsy management, and other neurosurgical applications. ML techniques have proven effective in tumor identification, surgical outcomes prediction, seizure outcome prediction, aneurysm prediction, and more, highlighting its broad impact and potential in improving patient management and outcomes in neurosurgery. This review will encompass the current state of research, as well as predictions for the future of AI within neurosurgery.

Regulation, approval, and access of spinal implants in low-middle-income countries: a narrative review and case study

INTRODUCTION

Spinal implants play a vital role in healthcare delivery, and regulations are necessary to ensure their quality, approval, access, and use. In this article, we examine the current state of regulation and approval procedures for medical devices in low- and middle-income countries (LMICs), emphasizing the situation in Tanzania.

AREAS COVERED

We conducted a systematic literature search and interviewed a local spine implant representative to investigate the approval, availability, and access of surgical and spinal implants in LMICs, particularly in Africa. Out of the 18 included articles, six referred to African regulations, with no mention of spinal implants. Our analysis revealed that LMICs face challenges in accessing implants due to affordability, poor supply chain, and lack of expertise for their application. However, surgeons have found alternative solutions, such as using lower-cost implants from Turkish manufacturers. The Tanzania Medical Devices and Drugs Authority oversees the local regulatory and approval process for implants.

EXPERT OPINION

Regulation and accessibility of spinal implants in LMICs, particularly in Africa, are limited and negatively impact patient care and best medical practice. Potential solutions include capacity building within and collaboration among regulatory organizations to improve regulatory processes and allocating financial resources to qualitative and quantitative implant access.

Affordability impacts therapeutic intensity of acute management of severe traumatic brain injury patients: An exploratory study in Tanzania

Introduction

Quality health care in low and middle-income countries (LMICs) is constrained by financing of care.

Research question

What is the effect of ability to pay on critical care management of patients with severe traumatic brain injury (sTBI)?

Material and Methods

Data on sTBI patients admitted to a tertiary referral hospital in Dar-es-Salaam, Tanzania, were collected between 2016 and 2018, and included payor mechanisms for hospitalization costs. Patients were grouped as those who could afford care and those who were unable to pay.

Results

Sixty-seven patients with sTBI were included. Of those enrolled, 44 (65.7%) were able to pay and 15 (22.3%) were unable to pay costs of care upfront. Eight (11.9%) patients did not have a documented source of payment (unknown identity or excluded from further analysis). Overall mechanical ventilation rates were 81% (n=36) in the affordable group and 100% (n=15) in the unaffordable group (p=0.08). Computed tomography (CT) rates were 71.6% (n=48) overall, 100% (n=44) and 0% respectively (p<0.01); Surgical rates were 16.4% (n=11) overall, 18.2% (n=8) vs. 13.3% (n=2) (p=0.67) respectively. Two-week mortality was 59.7% overall (n=40), 47.7% (n=21) in the affordable group and 73.3% (n=11) in the unaffordable group (p=0.09) (adjusted OR 0.4; 95% CI: 0.07-2.41, p=0.32).

Discussion and Conclusion

Ability to pay appears to have a strong association with the use of head CT and a weak association with mechanical ventilation in the management of sTBI. Inability to pay increases redundant or sub-optimal care, and imposes a financial burden on patients and their relatives.

Presentation, Management, and Outcomes of Traumatic Spinal Injuries Following Coconut Tree Fall in Tanzania: A Retrospective Study of 44 Cases

BACKGROUND

In nations where tree harvesting constitutes a significant aspect of the economy, such as Tanzania, falls from trees represent a prevalent cause of traumatic injuries. This study investigates the characteristics of traumatic spinal injuries (TSIs) resulting from falls from coconut trees. (CTFs).

METHODS

This was a retrospective study of a prospectively maintained spine trauma database at Muhimbili Orthopedic Institute (MOI). We included patients older than 14 years, admitted for TSI secondary to CTF, and with a traumatism not more than 2 months before the admission. Our study analyzed patient data from January 2017 to December 2021. We compiled demographic and clinical information and details such as the distance from the site of trauma to the hospital, American Spinal Injury Association Impairment (ASIA) scale assessment, time to surgery, AOSpine classification, and discharge status. Descriptive analysis was done using data management software. No statistical computing was done.

RESULTS

We included 44 patients, all of whom were male, with a mean age of 34.3 ± 12.1 years. At admission, 47.7% of the patients had an ASIA A injury, with the lumbar spine being the most commonly fractured level at 40.9%. In contrast, only 13.6% of the cases involved the cervical spine. Most (65.9%) of the fractures were classified as type A compression fractures (AO classification). Nearly all patients admitted (95.5%) had surgical indications, but only 52.4% received surgical treatment. The overall mortality rate was 4.5%. With respect to neurologic improvement, only 11.4% experienced an improvement in their ASIA score at discharge, the majority of who were in the surgical group.

CONCLUSIONS

The present study demonstrates that CTFs in Tanzania constitute a substantial source of TSIs, frequently resulting in severe lumbar injuries. These findings underscore the need for the implementation of educational and preventive measures.

The effect of the Dar es Salaam neurosurgery training course on self-reported neurosurgical knowledge and confidence

Introduction

The Muhimbili Orthopaedic Institute in collaboration with Weill Cornell Medicine organises an annual neurosurgery training course in Dar es Salaam, Tanzania. The course teaches theory and practical skills in neurotrauma, neurosurgery, and neurointensive care to attendees from across Tanzania and East Africa. This is the only neurosurgical course in Tanzania, where there are few neurosurgeons and limited access to neurosurgical care and equipment.

Research question

To investigate the change in self-reported knowledge and confidence in neurosurgical topics amongst the 2022 course attendees.

Material and methods

Course participants completed pre and post course questionnaires about their background and self-rated their knowledge and confidence in neurosurgical topics on a five point scale from one (poor) to five (excellent). Responses after the course were compared with those before the course.

Results

Four hundred and seventy participants registered for the course, of whom 395(84%) practiced in Tanzania. Experience ranged from students and newly qualified professionals to nurses with more than 10 years of experience and specialist doctors. Both doctors and nurses reported improved knowledge and confidence across all neurosurgical topics following the course. Topics with lower self-ratings prior to the course showed greater improvement. These included neurovascular, neuro-oncology, and minimally invasive spine surgery topics. Suggestions for improvement were mostly related to logistics and course delivery rather than content.

Discussion and conclusion

The course reached a wide range of health care professionals in the region and improved neurosurgical knowledge, which should benefit patient care in this underserved region.

Prevalence of Long-Term Low Back Pain After Symptomatic Lumbar Disc Herniation

OBJECTIVE

Lumbar disc herniation (LDH) is a global issue associated with potentially debilitating long-term consequences, including chronic low back pain (LBP). Short-term outcomes (<2 years) of patients with LDH have been extensively studied and demonstrate improvements in back and leg pain for both operative and conservative management. However, these improvements may not be sustained long-term (>2 years); patients with LDH may develop recurrent disc herniations, progressive degenerative disc disease, and LBP regardless of management strategy. Therefore, our objective is to determine the prevalence of chronic LBP after LDH, understand the relationship between LDH and chronic LBP, and investigate the relationship between radiological findings and postoperative pain outcomes.

METHODS

We performed a literature review on the PubMed database via a combination medical subject heading and keyword-based approach for long-term LBP outcomes in patients with LDH.

RESULTS

Fifteen studies (2019 patients) evaluated surgical and/or nonoperative outcomes of patients with LDH . Regardless of surgical or nonoperative management, 46.2% of patients with LDH experienced some degree of LBP long-term (range 2-27 years) as compared to a point prevalence of LBP in the general population of only 11.9%.

CONCLUSIONS

Patients with LDH are more likely to experience long-term LBP compared to the general population (46.2% vs. 11.9%). Additionally, understanding the relationship between radiological findings and pain outcomes remains a major challenge as the presence of radiological changes and the degree of LBP do not always correlate. Therefore, higher quality studies are needed to better understand the relationship between radiological findings and pain outcomes.

Variation in Cervical Pedicle Morphology: Important Considerations for Posterior Cervical Procedures

BACKGROUND

Safe posterior cervical spine surgery requires in-depth understanding of the surgical anatomy and common variations. The cervical pedicle attachment site to the vertebral body (VB) affects the location of exiting nerve roots and warrants preoperative evaluation. The relative site of attachment of the cervical pedicle has not been previously described.

OBJECTIVE

To describe the site of the pedicle attachment to the VB in the subaxial cervical spine.

METHODS

Cervical spine computed tomography scans without any structural, degenerative, or traumatic pathology as read by a board-certified neuroradiologist during 2021 were reviewed. Multiplanar reconstructions were created and cross-registered. The pedicle's attachment to the VB was measured relative to the VB height using a novel calculation system.

RESULTS

Fifty computed tomography scans met inclusion criteria yielding 600 total pedicles between C3-T1 (100 per level). The average patient age was 26 ± 5.3 years, and 21/50 (42%) were female. 468/600 (78%) pedicles attached in the cranial third of the VB, 132/600 (22%) attached in the middle third, and 0 attached to the caudal third. The highest prevalence of variant anatomy occurred at C3 (36/100 C3 pedicles; 36%).

CONCLUSION

In the subaxial cervical spine, pedicles frequently attach to the top third of the VB, but significant variation is observed. The rate of variation is highest at C3 and decreases linearly with caudal progression down the subaxial cervical spine to T1. This is the first report investigating this morphological phenomenon.

Current Treatment Management of Aneurysmal Subarachnoid Hemorrhage with Prevailing Trends and Results in Tanzania: A Single-Center Experience at Muhimbili Orthopedic and Neurosurgery Institute

BACKGROUND

In Africa, no cerebral aneurysm treatment guidelines exist. Epidemiology, management, and outcomes after aneurysmal subarachnoid hemorrhage (aSAH) remain poorly understood, with many underdiagnosed cases. Muhimbili Orthopaedic and Neurosurgery Institute (MOI) is the only neurosurgical referral center in Tanzania. The aim of this study is to describe the current aSAH management with regional outcomes and limitations.

METHODS

Patients with aSAH confirmed by computed tomography/magnetic resonance angiography between February 2019 and June 2021 were retrospectively studied. The analyzed parameters included demographics, clinical/radiologic characteristics, injury characteristics, and the modified Rankin Scale (mRS) score.

RESULTS

In total, 22 patients, with a female/male ratio of 1.4 and a median age of 54 years (interquartile range [IQR], 47.2-63 years) harboring 24 aneurysms were analyzed. Thirteen patients (59.1%) paid out of pocket. The median distance traveled by patients was 537 km (IQR, 34.7-635 km). The median time between admission and treatment was 12 days (IQR, 3.2-39 days). The most common symptoms were headache (n = 20; 90.9%) and high blood pressure (n = 10; 45.4%). Nine patients (40.9%) had Fisher grade 1 and 12 (54.5%) World Federation of Neurosurgical Societies grade I. The most common aneurysms were of the middle cerebral artery (7/29.2%). Fourteen patients (63.6%) underwent clipping; of those, only 4 (28.6%) were operated on within 72 hours. Mortality was 62.5% in the nonsurgical group. Among clipped patients, 78.6% showed favorable outcomes, with no mortality. Endovascular treatment is not available in Tanzania.

CONCLUSIONS

To our best knowledge, this is the first study highlighting aSAH management in Tanzania, with its assets and shortcomings. Our data show pertinent differences among international treatment guidelines, with the resultant outcomes, such as high preoperative mortality resulting from delayed/postponed treatment. Regional difficult circumstances notwithstanding, our long-term goal is to significantly improve the overall management of aSAH in Tanzania.

Predictors of spinal trauma care and outcomes in a resource-constrained environment: a decision tree analysis of spinal trauma surgery and outcomes in Tanzania

OBJECTIVE

The burden of spinal trauma in low- and middle-income countries (LMICs) is immense, and its management is made complex in such resource-restricted settings. Algorithmic evidence-based management is cost-prohibitive, especially with respect to spinal implants, while perioperative care is work-intensive, making overall care dependent on multiple constraints. The objective of this study was to identify determinants of decision-making for surgical intervention, improvement in function, and in-hospital mortality among patients experiencing acute spinal trauma in resource-constrained settings.

METHODS

This study was a retrospective analysis of prospectively collected data in a cohort of patients with spinal trauma admitted to a tertiary referral hospital center in Dar es Salam, Tanzania. Data on demographic, clinical, and treatment characteristics were collected as part of a quality improvement neurotrauma registry. Outcome measures were surgical intervention, American Spinal Injury Association (ASIA) Impairment Scale (AIS) grade improvement, and in-hospital mortality, based on existing treatment protocols. Univariate analyses of demographic and clinical characteristics were performed for each outcome of interest. Using the variables associated with each outcome, a machine learning algorithm-based regression nonparametric decision tree model utilizing a bootstrapping method was created and the accuracy of the three models was estimated.

RESULTS

Two hundred eighty-four consecutively admitted patients with acute spinal trauma were included over a period of 33 months. The median age was 34 (IQR 26-43) years, 83.8% were male, and 50.7% had experienced injury in a motor vehicle accident. The median time to hospital admission after injury was 2 (IQR 1-6) days; surgery was performed after a further median delay of 22 (IQR 13-39) days. Cervical spine injury comprised 38.4% of the injuries. Admission AIS grades were A in 48.9%, B in 16.2%, C in 8.5%, D in 9.5%, and E in 16.6%. Nearly half (45.1%) of the patients underwent surgery, 12% had at least one functional improvement in AIS grade, and 11.6% died in the hospital. Determinants of surgical intervention were age ≤ 30 years, spinal injury level, admission AIS grade, delay in arrival to the referral hospital, undergoing MRI, and type of insurance; admission AIS grade, delay to arrival to the hospital, and injury level for functional improvement; and delay to arrival, injury level, delay to surgery, and admission AIS grade for in-hospital mortality. The best accuracies for the decision tree models were 0.62, 0.34, and 0.93 for surgery, AIS grade improvement, and in-hospital mortality, respectively.

CONCLUSIONS

Operative intervention and functional improvement after acute spinal trauma in this tertiary referral hospital in an LMIC environment were low and inconsistent, which suggests that nonclinical factors exist within complex resource-driven decision-making frameworks. These nonclinical factors are highlighted by the authors' results showing clinical outcomes and in-hospital mortality were determined by natural history, as evidenced by the highest accuracy of the model predicting in-hospital mortality.

Ten-Step 3-Dimensional-Navigated Single-Stage Lateral Surgery With Microtubular Decompression: A Case Series

BACKGROUND

Single-stage lateral lumbar interbody fusion is a safe and effective procedure that relies on indirect decompression and fusion to treat various lumbar pathologies. This technique, however, has an overall 9% rate of indirect decompression failure, which may require additional surgery to achieve adequate direct decompression. To address this concern, we modified this technique by adding a minimally invasive, direct tubular decompression in lateral position when indicated. No study has described the technical nuances of incorporating a microtubular decompression into the single-stage lateral lumbar interbody fusion workflow (SSLLIF+).

OBJECTIVE

To report on the procedural steps and clinical outcomes of the SSLLIF+.

METHODS

In this retrospective case series of prospectively collected data, we present the detailed surgical approach of the SSLLIF+ with a single-center case series over a 5-year period. Surgical and clinical outcomes are presented.

RESULTS

A total of 7 patients underwent a SSLLIF+ with a total of 18 levels fused and 7 levels decompressed. The SSLLIF+ was successfully performed in all cases without the occurrence of intraoperative complications in this case series. There was 1 revision after 20 months of follow-up because of adjacent segment disease. There was no need for further direct decompression in a delayed fashion.

CONCLUSION

SSLLIF with direct microtubular decompression in lateral position is a safe and effective procedure in patients where indirect decompression alone may not achieve the surgical goal. Adherence to minimally invasive spine surgery principles and thoughtful patient selection facilitate the successful management of these patients while demonstrating short hospital stay and low-risk of perioperative complications.

Microsurgical Tubular Resection of Intradural Extramedullary Spinal Tumors With 3-Dimensional-Navigated Localization

BACKGROUND

The safety and efficacy of minimally invasive spine surgical (MISS) approaches have stimulated interest in adapting MISS principles for more complex pathology including intradural extramedullary (IDEM) tumors. No study has characterized a repeatable approach integrating the MISS surgical technique and 3-dimensional intraoperative navigated localization for the treatment of IDEM tumors.

OBJECTIVE

To describe a safe and reproducible technical guide for the navigated MISS technique for the treatment of benign intradural and extradural spinal tumors.

METHODS

Retrospective review of prospectively collected data on 20 patients who underwent navigated microsurgical tubular resection of intradural extramedullary tumors over a 5-year period. We review our approach to patient selection and report demographic and outcomes data for the cohort.

RESULTS

Our experience demonstrates technical feasibility and safety with a 100% rate of gross total resection with no patients demonstrating recurrence during an average follow-up of 20.2 months and no instances of perioperative complications. We demonstrate favorable outcomes regarding blood loss, operative duration, and hospital length of stay.

CONCLUSION

Navigated localization and microsurgical tubular resection of IDEM tumors is safe and effective. Adherence to MISS principles and thoughtful patient selection facilitate successful management of these patients.

Future Directions for Global Clinical Neurosurgical Training: Challenges and Opportunities

OBJECTIVE

Expanded access to training opportunities is necessary to address 5 million essential neurosurgical cases not performed annually, nearly all in low- and middle-income countries. To target this critical neurosurgical workforce issue and advance positive collaborations, a summit (Global Neurosurgery 2019: A Practical Symposium) was designed to assemble stakeholders in global neurosurgical clinical education to discuss innovative platforms for clinical neurosurgery fellowships.

METHODS

The Global Neurosurgery Education Summit was held in November 2021, with 30 presentations from directors and trainees in existing global neurosurgical clinical fellowships. Presenters were selected based on chain referral sampling from suggestions made primarily from young neurosurgeons in low- and middle-income countries. Presentations focused on the perspectives of hosts, local champions, and trainees on clinical global neurosurgery fellowships and virtual learning resources. This conference sought to identify factors for success in overcoming barriers to improving access, equity, throughput, and quality of clinical global neurosurgery fellowships. A preconference survey was disseminated to attendees.

RESULTS

Presentations included in-country training courses, twinning programs, provision of surgical laboratories and resources, existing virtual educational resources, and virtual teaching technologies, with reference to their applicability to hybrid training fellowships. Virtual learning resources developed during the coronavirus disease 2019 pandemic and high-fidelity surgical simulators were presented, some for the first time to this audience.

CONCLUSIONS

The summit provided a forum for discussion of challenges and opportunities for developing a collaborative consortium capable of designing a pilot program for efficient, sustainable, accessible, and affordable clinical neurosurgery fellowship models for the future.

Augmented Reality to Improve Surgical Workflow in Minimally Invasive Transforaminal Lumbar Interbody Fusion - A Feasibility Study With Case Series

OBJECTIVE

Minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) is a highly reproducible procedure for the fusion of spinal segments. We recently introduced the concept of "total navigation" to improve workflow and eliminate fluoroscopy. Imageguided surgery incorporating augmented reality (AR) may further facilitate workflow. In this study, we developed and evaluated a protocol to integrate AR into the workflow of MISTLIF.

METHODS

A case series of 10 patients was the basis for the evaluation of a protocol to facilitate tubular MIS-TLIF by the application of AR. Surgical TLIF landmarks were marked on a preoperative computed tomography (CT)-scan using dedicated software. This marked CT scan was fused intraoperatively with the low-dose navigation CT scan using elastic image fusion, and the markers were transferred to the intraoperative scan. Our experience with this workflow and the surgical outcomes were collected.

RESULTS

Our AR protocol was safely implemented in all cases. The TLIF landmarks could be preoperatively planned and transferred to the intraoperative imaging. Of the 10 cases, 1 case had additionally a synovial cyst resection and in 2 cases an additional bony decompression was performed due to central stenosis. The average procedure time was 160.6 ± 31.9 minutes. The AR implementation added 1.72 ± 0.37 minutes to the overall procedure time. No complications occurred.

CONCLUSION

Our findings support the idea that total navigation with AR may further facilitate the workflow, especially in cases with more complex anatomy and for teaching and training purposes. More work is needed to simplify the software and make AR integration more user-friendly.

Safety and Feasibility of Augmented Reality Assistance in Minimally Invasive and Open Resection of Benign Intradural Extramedullary Tumors

OBJECTIVE

Surgical resection of benign intradural extramedullary tumors (BIETs) is effective for appropriately selected patients. Minimally invasive surgical (MIS) techniques have been described for successful resection of BIET while minimizing soft tissue injury. Augmented reality (AR) is a promising new technology that can accurately allow for intraoperative localization from skin through the intradural compartment. We present a case series evaluating the timing, steps, and accuracy at which this technology is able to enhance BIET resection.

METHODS

A protocol for MIS and open AR-guided BIET resection was developed and applied to determine the feasibility. The tumor is marked on diagnostic magnetic resonance imaging (MRI) using AR software. Intraoperatively, the planning MRI is fused with the intraoperative computed tomography. The position and size of the tumor is projected into the surgical microscope and directly into the surgeon's field of view. Intraoperative orientation is performed exclusively via navigation and AR projection. Demographic and perioperative factors were collected.

RESULTS

Eight patients were enrolled. The average operative time for MIS cases was 128 ± 8 minutes and for open cases 206 ± 55 minutes. The estimated intraoperative blood loss was 97 ± 77 mL in MIS and 240 ± 206 mL in open procedures. AR tumor location and margins were considered sufficiently precise by the surgeon in every case. Neither correction of the approach trajectory nor ultrasound assistance to localize the tumor were necessary in any case. No intraoperative complications were observed.

CONCLUSION

Current findings suggest that AR may be a feasible technique for tumor localization in the MIS and open resection of benign spinal extramedullary tumors.

Progressive superficial siderosis from Chronic CSF leak as a long-term complication of cervical anterior corpectomy: A case report and review of the literature

Background:

Superficial siderosis of the central nervous system (SSCNS) is a rare progressive neurological disorder resulting from chronic subarachnoid hemorrhage and subsequent subpial hemosiderin deposition. A prolonged cerebrospinal fluid (CSF) leak is a known cause of SSCNS. We present a novel case where progressive SSCNS resulted from a chronic CSF leak related to an anterior cervical corpectomy.

Case Description:

A 73-year-old man presented with gait ataxia and progressive hearing loss. Thirteen years before, he had undergone a combined anterior-posterior cervical decompression for symptomatic ossification of the posterior longitudinal ligament (OPLL). The presenting MR imaging showed extensive superficial siderosis and focal spinal cord herniation at the site of a ventral dural defect at the corpectomy site. A CT myelogram showed extensive CSF leakage into the corpectomy surgical site and a communicating pseudomeningocele in the anterior neck.

Conclusion:

This is the first reported case of progressive SSCNS as a long-term complication of an anterior cervical corpectomy for OPLL. Clinicians should be aware of SSCNS secondary to a chronic CSF leak in patients with a prior corpectomy.

Challenges Hindering Widespread Adoption of Minimally Invasive Spinal Surgery

Minimally invasive spinal surgery (MISS) techniques offer several beneficial prospects and are being increasingly requested by patients. However, these techniques have not been uniformly adopted by spinal surgeons, and they remain controversial among some. Several barriers have prevented widespread adoption of MISS. These include concerns regarding high start-up costs, limited evidence base, and lack of surgeon training. In addition, the unique approaches involved in MISS expose spinal surgeons to unfamiliar anatomy. Further, while MISS can address a growing spectrum of spinal pathology, some conditions, as well as complications encountered during MISS procedures, require open surgery. This requires surgeons to not only acquire the new and specialized MISS skillset but also maintain their ability to perform open surgery. These factors present challenges common to developing and innovative surgical techniques. Here, we review the barriers preventing wider adoption of MISS and present a framework to promote the safe and effective growth of MISS.

Lumbar Giant Disk Herniations Treated With a Unilateral Approach for Bilateral Decompression

BACKGROUND

Disk herniations that obstruct the spinal canal by more than 50% are named "giant disk herniations" (GDHs). GDHs are challenging to treat from a surgical perspective because of their size and the risk of iatrogenic manipulation during resection resulting in additional neurological compromise. As a result, the appropriateness of minimally invasive tubular approaches for the treatment of lumbar GDHs remains controversial.

OBJECTIVE

To report our experience in treating lumbar GDHs using tubular minimally invasive surgery.

METHODS

A total number of 228 disk herniations were evaluated for the criteria of GDH. In addition, the presence of neurological deficits such as cauda equina syndrome, pain as measured by a visual analog scale, operating time, complications, estimated intraoperative blood loss, and number of surgical revisions were assessed. The standard tubular diskectomy technique was modified to include unilateral laminectomy for bilateral decompression before the diskectomy to create a sufficient working space for removal of the disk fragments.

RESULTS

Twenty-three (10%) patients met the criteria for GDH. Clinically significant motor weakness was present in 21 patients (91.3%) before surgery, and 3 patients (13%) presented with cauda equina syndrome. The average mean visual analog scale (±SD) for the preoperative pain score was 8.3 and decreased to 2.4 at follow-up after surgery. All cases of cauda equina syndrome resolved postoperatively.

CONCLUSION

Unilateral tubular minimally invasive surgery diskectomy seems to be a safe and effective treatment alternative for lumbar GDHs, combined with the "over-the-top" decompression, which provides bilateral decompression and working space.

The Future of Minimally Invasive Spinal Surgery

Strong forces are pushing minimally invasive spinal surgery (MISS) to the forefront of spine care. Less-invasive surgical techniques have been enabled by a variety of technical advances. Despite the promise of MISS, however, several factors, including few training opportunities, perception of a steep learning curve, and high upfront costs, have limited the adoption of these techniques. The "6 T's" is a framework highlighting key factors that must be accounted for to ensure safe and effective MISS as techniques continually evolve. Further, technological advancement in endoscopy, robotics, and augmented/virtual reality is enhancing minimally invasive surgeries to make them even less invasive and safer for patients. The evolution of these new techniques and technologies is driving the future of MISS.

Novel MIS 3D NAV Single Step Pedicle Screw System (SSPSS): Workflow, Accuracy and Initial Clinical Experience

STUDY DESIGN

Prospective case series.

OBJECTIVE

SSPSS (single step pedicle screw system) was developed for minimally invasive spine surgery. We performed this study to report on safety, workflow, and our initial clinical experience with this novel technique.

METHODS

The prospective study was conducted on patients who underwent pedicle screw fixation between October 2017 and April 2018 using a novel single step 3D navigated pedicle screw system for MIS. Outcome measurements were obtained from intraoperative computerized tomography. The images were evaluated to determine pedicle wall penetration. We used a grading system to assess the severity of the pedicle wall penetration. Breaches were classified as grade 1 (<2 mm), grade 2 (2-4 mm), or grade 3 (<4 mm),¹ and as cranial, caudal, medial, and lateral.

RESULTS

Our study includes 135 screws in 24 patients. SSPSS eliminated K-wires and multiple steps traditionally necessary for MIS pedicle screw insertion. The median time per screw was 2.45 minutes. 3 screws were corrected intraoperatively. Pedicle wall penetration occurred in 14 screws (10%). Grade 1 breaches occurred in 4 screws (3%) and grade 2 breaches occurred in 10 screws (7%). Lateral breaches were observed more often than medial breaches. The accuracy rate in our study was 90% (Grade 0 breach). No revision surgeries were needed and no complications occurred.

CONCLUSIONS

Our study suggests that SSPSS could be a safe, accurate, and efficient tool. Our accuracy rate is comparable to that found in the literature.

Minimally Invasive Spine Surgery: An Overview

Spinal surgery is undergoing a major transformation toward a minimally invasive paradigm. This shift is being driven by multiple factors, including the need to address spinal problems in an older and sicker population, as well as changes in patient preferences and reimbursement patterns. Increasingly, minimally invasive surgical techniques are being used in place of traditional open approaches due to significant advancements and implementation of intraoperative imaging and navigation technologies. However, in some patients, due to specific anatomic or pathologic factors, minimally invasive techniques are not always possible. Numerous algorithms have been described, and additional efforts are underway to better optimize patient selection for minimally invasive spinal surgery (MISS) procedures in order to achieve optimal outcomes. Numerous unique MISS approaches and techniques have been described, and several have become fundamental. Investigators are evaluating combinations of MISS techniques to further enhance the surgical workflow, patient safety, and efficiency.

Treatment of Odontoid Fractures in Elderly Patients Using C1/C2 Instrumented Fusion Supplemented With Bilateral Atlantoaxial Joint Spacers: A Case Series

BACKGROUND

Spinal fractures are among the most common traumatic injuries in elderly patients, with the odontoid process being frequently affected. As this patient group usually has high rates of comorbidity and chronic diseases, a nonoperative approach may offer a reasonable solution for a favorable fracture pattern.

OBJECTIVE

We modified the procedure by implanting a bilateral atlantoaxial joint spacer (model DTRAX) into the joint space and review our experience utilizing this technique for the treatment of patients with a fracture of the odontoid process.

METHODS

A retrospective evaluation was performed on patients treated surgically for unstable traumatic fractures of the odontoid process. The stabilization was performed using a dorsal rod and screw instrumentation of the lateral mass of the atlas and the pars interarticularis of the axis. The procedure was further modified by implanting a bilateral atlantoaxial joint spacer (DTRAX) into the joint space bilaterally after the removal of the articular cartilage. Patients older than 70 years with a traumatic fracture of the odontoid process were included. Pain was assessed pre- and postoperatively using the visual analog scale (VAS). To verify fusion during follow-up, either x-ray imaging of the cervical spine or magnetic resonance imaging or computed tomography were performed.

RESULTS

A total of 5 patients were included in our study. Four patients had an American Society of Anesthesiology score of 3 and 1 had a score of 4. The average duration of surgery was 187 ± 38.1 minutes. The average blood loss during the procedure was 340 ± 270 mL. The average radiological follow-up period was 21.2 ± 17.5 months. Preoperatively, the average VAS pain score was 2.3 ± 3.3. Postoperatively, the mean VAS decreased to 0.6 ± 0.9. The average follow-up period for pain was 27.2 ± 19 months. No patient showed neurological deficits before or after surgery. Follow-up demonstrated solid fusion in all cases.

CONCLUSION

The fusion of the atlantoaxial joint with bilateral atlantoaxial joint spacers represents a suitable and feasible option for achieving high fusion rates in elderly patients with odontoid fractures.

CLINICAL RELEVANCE

A significant percentage of patients who are treated non-operatively will experience nonunion, which may cause instability of the atlantoaxial joint. Posterior fixation with screws and rods is a treatment option, but it leaves the cartilaginous joint surface in place, which can be an impediment to the fusion process. In other cases, degenerative collapse of the C1/C2 joint can cause compression of the C2 nerve root.

LEVEL OF EVIDENCE: 4

Feasibility of smart glasses in supporting spinal surgical procedures in low- and middle-income countries: experiences from East Africa

OBJECTIVE

Telemedicine technology has been developed to allow surgeons in countries with limited resources to access expert technical guidance during surgical procedures. The authors report their initial experience using state-of-the-art wearable smart glasses with wireless capability to transmit intraoperative video content during spine surgery from sub-Saharan Africa to experts in the US.

METHODS

A novel smart glasses system with integrated camera and microphone was worn by a spine surgeon in Dar es Salaam, Tanzania, during 3 scoliosis correction surgeries. The images were transmitted wirelessly through a compatible software system to a computer viewed by a group of fellowship-trained spine surgeons in New York City. Visual clarity was determined using a modified Snellen chart, and a percentage score was determined on the smallest line that could be read from the 8-line chart on white and black backgrounds. A 1- to 5-point scale (from 1 = unrecognizable to 5 = optimal clarity) was used to score other visual metrics assessed using a color test card including hue, contrast, and brightness. The same scoring system was used by the group to reach a consensus on visual quality of 3 intraoperative points including instruments, radiographs (ability to see pedicle screws relative to bony anatomy), and intraoperative surgical field (ability to identify bony landmarks such as transverse processes, pedicle screw starting point, laminar edge).

RESULTS

All surgeries accomplished the defined goals safely with no intraoperative complications. The average download and upload connection speeds achieved in Dar es Salaam were 45.21 and 58.89 Mbps, respectively. Visual clarity with the modified white and black Snellen chart was 70.8% and 62.5%, respectively. The average scores for hue, contrast, and brightness were 2.67, 3.33, and 2.67, respectively. Visualization quality of instruments, radiographs, and intraoperative surgical field were 3.67, 1, and 1, respectively.

CONCLUSIONS

Application of smart glasses for telemedicine offers a promising tool for surgical education and remote training, especially in low- and middle-income countries. However, this study highlights some limitations of this technology, including optical resolution, intraoperative lighting, and internet connection challenges. With continued collaboration between clinicians and industry, future iterations of smart glasses technology will need to address these issues to stimulate robust clinical utilization.

Clinical Significance of Redundant Nerve Roots in Patients with Lumbar Stenosis Undergoing Minimally Invasive Tubular Decompression

OBJECTIVE

Symptomatic lumbar spinal stenosis (LSS) is a common indication for surgery in the elderly. Preoperative radiographic evaluation of patients with LSS often reveals redundant nerve roots (RNRs). The clinical significance of RNRs is uncertain. RNRs have not been studied in the setting of minimally invasive surgery. This study investigates the relationship between RNRs and clinical outcomes after minimally invasive tubular decompression.

METHODS

Chart review was performed for patients with degenerative LSS who underwent minimally invasive decompression. Preoperative magnetic resonance imaging parameters were assessed, and patient-reported outcomes were analyzed.

RESULTS

Fifty-four patients underwent surgery performed at an average of 1.8 ± 0.8 spinal levels. Thirty-one patients (57%) had RNRs. Patients with RNRs were older (median = 72 years vs. 66 years, P = 0.050), had longer median symptom duration (32 months vs. 15 months, P < 0.01), and had more levels operated on (2.1 vs. 1.4; P < 0.01). The median follow-up after surgery was 2 months (range = 1.3-12 months). Preoperative and postoperative patient-reported outcomes were similar based on RNR presence. Patients without RNRs had larger lumbar cross-sectional areas (CSAs) (median = 121 mm² vs. 95 mm², P = 0.014) and the index-level CSA (52 mm² vs. 34 mm², P = 0.007). The CSA was not correlated with RNR morphology or location.

CONCLUSIONS

Preoperative RNRs are associated with increased age, symptom duration, and lumbar stenosis severity. Patients improved after minimally invasive decompression regardless of RNR presence. RNR presence had no effect on short-term clinical outcomes. Further study is required to assess their long-term significance.

Casemix, management, and mortality of patients rreseceiving emergency neurosurgery for traumatic brain injury in the Global Neurotrauma Outcomes Study: a prospective observational cohort study

BACKGROUND

Traumatic brain injury (TBI) is increasingly recognised as being responsible for a substantial proportion of the global burden of disease. Neurosurgical interventions are an important aspect of care for patients with TBI, but there is little epidemiological data available on this patient population. We aimed to characterise differences in casemix, management, and mortality of patients receiving emergency neurosurgery for TBI across different levels of human development.

METHODS

We did a prospective observational cohort study of consecutive patients with TBI undergoing emergency neurosurgery, in a convenience sample of hospitals identified by open invitation, through international and regional scientific societies and meetings, individual contacts, and social media. Patients receiving emergency neurosurgery for TBI in each hospital's 30-day study period were all eligible for inclusion, with the exception of patients undergoing insertion of an intracranial pressure monitor only, ventriculostomy placement only, or a procedure for drainage of a chronic subdural haematoma. The primary outcome was mortality at 14 days postoperatively (or last point of observation if the patient was discharged before this time point). Countries were stratified according to their Human Development Index (HDI)-a composite of life expectancy, education, and income measures-into very high HDI, high HDI, medium HDI, and low HDI tiers. Mixed effects logistic regression was used to examine the effect of HDI on mortality while accounting for and quantifying between-hospital and between-country variation.

FINDINGS

Our study included 1635 records from 159 hospitals in 57 countries, collected between Nov 1, 2018, and Jan 31, 2020. 328 (20%) records were from countries in the very high HDI tier, 539 (33%) from countries in the high HDI tier, 614 (38%) from countries in the medium HDI tier, and 154 (9%) from countries in the low HDI tier. The median age was 35 years (IQR 24-51), with the oldest patients in the very high HDI tier (median 54 years, IQR 34-69) and the youngest in the low HDI tier (median 28 years, IQR 20-38). The most common procedures were elevation of a depressed skull fracture in the low HDI tier (69 [45%]), evacuation of a supratentorial extradural haematoma in the medium HDI tier (189 [31%]) and high HDI tier (173 [32%]), and evacuation of a supratentorial acute subdural haematoma in the very high HDI tier (155 [47%]). Median time from injury to surgery was 13 h (IQR 6-32). Overall mortality was 18% (299 of 1635). After adjustment for casemix, the odds of mortality were greater in the medium HDI tier (odds ratio [OR] 2·84, 95% CI 1·55-5·2) and high HDI tier (2·26, 1·23-4·15), but not the low HDI tier (1·66, 0·61-4·46), relative to the very high HDI tier. There was significant between-hospital variation in mortality (median OR 2·04, 95% CI 1·17-2·49).

INTERPRETATION

Patients receiving emergency neurosurgery for TBI differed considerably in their admission characteristics and management across human development settings. Level of human development was associated with mortality. Substantial opportunities to improve care globally were identified, including reducing delays to surgery. Between-hospital variation in mortality suggests changes at an institutional level could influence outcome and comparative effectiveness research could identify best practices.

FUNDING

National Institute for Health Research Global Health Research Group.

Navigation-Guided Single-Position Lumbar Lateral Interbody Fusion and Minimally Invasive Tubular Decompression: 2-Dimensional Operative Video

Lateral lumbar interbody fusion (LLIF) has several advantages over the other fusion techniques; by allowing the placement of a larger implant, LLIF results in better indirect decompression and increased disk height, foraminal height, and cross-sectional area of the dural sac.1,2 However, one of the primary drawbacks of the LLIF has been the need for repositioning to perform posterior stabilization. Furthermore, patients with severe central and lateral recess stenosis were found to be prone to indirect decompression failure after the LLIF procedure.3 In this video, we demonstrate a step-by-step technique for intraoperative navigation-guided lateral single-position LLIF with pedicle screw instrumentation and minimally invasive tubular decompression. We present a case of a 64-year-old female patient with a history of low back pain which radiates to the buttocks and posterior legs to her knees. The patient was treated by a single-position LLIF with posterior pedicle screw fixation using a portable intraoperative computed tomography scanner (Airo, Brainlab AG), combined with 3-dimensional computer navigation and minimally invasive tubular decompression at the L3-4 level. The patient was discharged at postoperative day 1 with excellent long-term clinical outcomes. Patient consent was obtained before performing the procedure. The participants and any identifiable individuals consented to publication of his/her image.

Single-Position Fluoroscopy-Guided Lateral Lumbar Interbody Fusion With Intraoperative Computed Tomography-Navigated Posterior Pedicle Screw Fixation: Technical Report and Literature Review

Lateral lumbar interbody fusion (LLIF) is a powerful tool in minimally invasive spine surgery with high rates of fusion, excellent indirect decompression, and deformity correction. LLIF offers advantages compared with anterior lumbar interbody fusion including a more favorable complication profile. Traditionally, the interbody fusion is performed in the lateral position and fluoroscopy-assisted pedicle screw fixation performed with the patient repositioned prone. The evolution of both pedicle screw technology and intraoperative navigation has enhanced the feasibility of single (lateral)-position surgery. Early reports using fluoroscopy-assisted pedicle screws and computer or robotic navigation suggest this technique can be performed safely and accurately. The purpose of this brief report is to provide the technical steps, workflow, as well as pearls and pitfalls for single-position LLIF with true intraoperative computed tomography navigation-guided percutaneous pedicle screw fixation. A case example is included for illustration.

Safety and Feasibility of DTRAX Cervical Cages in the Atlantoaxial Joint for C1/2 Stabilization

BACKGROUND

Pathological changes in the atlantoaxial joint often lead to instability, pain, and neurological deterioration. One treatment option is the surgical stabilization of the atlantoaxial joint. In other areas of the spine, fusion rates have been improved by the introduction of an interbody cage. Our aim was to use cervical interbody spacers, originally designed to augment fusion across subaxial posterior cervical facets, to optimize the conditions for atlantoaxial fusion.

OBJECTIVE

To evaluate the safety and efficacy of implanting cervical cages in the atlantoaxial joint for C1/2 stabilization.

METHODS

Our retrospective study evaluated patients who had undergone C1/2 cervical fusions by the Harms/Goel technique. This technique was modified by implanting a titanium cervical interbody spacer into the joint space. Mean overall pain, as measured by a 0 to 10 visual analog scale (VAS) and neurological outcomes were measured preoperatively and postoperatively. In addition, radiological outcomes were collected using follow-up imaging.

RESULTS

Nine patients were included in this case series. The mean preoperative VAS for overall pain was 5.0 ± 4.0, which changed to a mean VAS of 2.0 ± 3.0 after an average follow-up period of 41.4 ± 20.4 (P = .043). All patients showed a bony fusion in our case series. None of the radiological imaging during follow-up showed screw loosening, hardware breakage, implant migration, or nonunion.

CONCLUSION

The implantation of cervical titanium cages into the atlantoaxial joint in combination with posterior fixation appears to be a safe and effective method for achieving C1/2 fusion.

Pediatric Hydrocephalus in Northwest Tanzania: a descriptive cross-sectional study of clinical characteristics and early surgical outcomes from the Bugando Medical Centre

OBJECTIVES

In this study, we present data from a neurosurgical training program in Tanzania for the treatment of pediatric hydrocephalus. The objectives of the study were to identify the demographics and clinical characteristics of pediatric patients with hydrocephalus who were admitted to Bugando Medical Centre in Mwanza, Tanzania, as well as to describe their surgical treatment and early clinical outcomes.

METHODS

This cross-sectional study included 38 pediatric patients. Physical examinations were conducted pre- and postoperatively, and their mothers completed a questionnaire providing demographic and clinical characteristics.

RESULTS

There was a slight preponderance of male sex (21/38; 55.3%) with median age at the time of admission of 98.5 days. The majority of patients were surgically treated (33/38; 86.8%). Among those surgically treated, most received a ventriculoperitoneal shunt (23/33; 69.7%), whereas 7 were treated with an endoscopic third ventriculostomy (7/33; 21.2%). At the time of admission, the majority of patients (86%) had head circumferences that met criteria for macrocephaly. The median time between admission and surgery was 23 days (2-49 days). Overall, 5 patients (13.2%) died, including 2 who did not receive surgical intervention.

CONCLUSIONS

We found that in our population, pediatric patients with hydrocephalus often present late for treatment with additional significant delays prior to receiving any surgical intervention. Five patients died, of whom 2 had not undergone surgery. Our study reinforces that targeted investments in clinical services are needed to enable access to care, improve surgical capacity, and alleviate the burden of neurosurgical disease from pediatric hydrocephalus in sub-Saharan Africa.

Cost-Effectiveness of Operating on Traumatic Spinal Injuries in Low-Middle Income Countries: A Preliminary Report From a Major East African Referral Center

STUDY DESIGN

Retrospective cost-effectiveness analysis.

OBJECTIVES

While the incidence of traumatic spine injury (TSI) is high in low-middle income countries (LMICs), surgery is rarely possible due to cost-prohibitive implants. The objective of this study was to conduct a preliminary cost-effectiveness analysis of operative treatment of TSI patients in a LMIC setting.

METHODS

At a tertiary hospital in Tanzania from September 2016 to May 2019, a retrospective analysis was conducted to estimate the cost-effectiveness of operative versus nonoperative treatment of TSI. Operative treatment included decompression/stabilization. Nonoperative treatment meant 3 months of bed rest. Direct costs included imaging, operating fees, surgical implants, and length of stay. Four patient scenarios were chosen to represent the heterogeneity of spine trauma: Quadriplegic, paraplegic, neurologic improvement, and neurologically intact. Disability-adjusted-life-years (DALYs) and incremental-cost-effectiveness ratios were calculated to determine the cost per unit benefit of operative versus nonoperative treatment. Cost/DALY averted was the primary outcome (i.e., the amount of money required to avoid losing 1 year of healthy life).

RESULTS

A total of 270 TSI patients were included (125 operative; 145 nonoperative). Operative treatment averaged $731/patient. Nonoperative care averaged $212/patient. Comparing operative versus nonoperative treatment, the incremental cost/DALY averted for each patient outcome was: quadriplegic ($112-$158/DALY averted), paraplegic ($47-$67/DALY averted), neurologic improvement ($50-$71/DALY averted), neurologically intact ($41-$58/DALY averted). Sensitivity analysis confirmed these findings without major differences.

CONCLUSIONS

This preliminary cost-effectiveness analysis suggests that the upfront costs of spine trauma surgery may be offset by a reduction in disability. LMIC governments should consider conducting more spine trauma cost-effectiveness analyses and including spine trauma surgery in universal health care.

Challenges in the Development of Biological Approaches for the Treatment of Degenerative Disc Disease

There are numerous innovative and promising approaches aimed at slowing, reversing, or healing degenerative disc disease. However, multiple treatment-specific impediments slow progress toward realizing the benefits of these therapies. First, the exact pathophysiology underlying degenerative disc disease remains complicated and challenging to study. In addition, the study of the spine and intervertebral disc in animal models is difficult to translate to humans, hindering the utility of preclinical research. Biological treatments are subject to the complex biomechanical environment in which native discs degenerate. The regulatory approval environment for these therapeutics will likely involve a high degree of scrutiny. Finally, patient selection and assessment of outcomes are a particular challenge in this clinical setting.

Innovative Biological Treatment Methods for Degenerative Disc Disease

Low back pain is the leading cause of work absences and years lived with disability, and it is often associated with degenerative disc disease. In recent years, biological treatment approaches such as the use of growth factors, cell injections, annulus fibrosus (AF) repair, nucleus pulposus replacement, and tissue-engineered discs have been explored as means for preventing or reversing degenerative disc disease. Both animal and clinical studies have shown promising results for cell-based therapy on the grounds of its regenerative potential. Clinical data also indicate that stem cell injection is safe when appropriately performed, albeit its long-term safety and efficacy are yet to be explored. Numerous challenges also remain to be overcome, such as isolating, differentiating, and preconditioning the disc cells, as well as managing the nutrient-deficient and oxygen-deficient micromilieu of the intervertebral disc (IVD). AF repair methods including devices used in clinical trials have shown success in decreasing reherniation rates and improving overall clinical outcomes. In addition, recent studies that combined AF repair and nucleus pulposus replacement have shown improved biomechanical stability in IVDs after the combined treatment. Tissue-engineered IVDs for total disc replacement are still being developed, and future studies are necessary to overcome the challenges in their delivery, efficacy, and safety.

Fundamentals of Intervertebral Disc Degeneration

Lumbar disc degeneration is one of the leading causes of chronic low back pain. The degenerative cascade is often initiated by an imbalance between catabolic and anabolic processes in the intervertebral discs. As a consequence of extracellular matrix degradation, neoinnervation and neovascularization take place. Ultimately, this degenerative process results in disc bulging and loss of nucleus pulposus and water content and subsequent loss of disc height. Most patients respond to conservative management and surgical interventions well initially, yet a significant number of patients continue to suffer from chronic low back pain. Because of the high prevalence of long-term discogenic pain, regenerative biological therapies, including gene therapies, growth factors, cellular-based injections, and tissue-engineered constructs, have attracted significant attention in light of their potential to directly address the degenerative process. Understanding the pathophysiology of degenerative disc disease is important in both refining existing technologies and developing innovative techniques to reverse the degenerative processes in the discs. In this review, we aimed to cover the underlying pathophysiology of degenerative disc disease as well as its associated risk factors and give a comprehensive summary about the developmental, structural, radiological, and biomechanical properties of human intervertebral discs.

Increase in clivo-axial angle is associated with clinical improvement in children undergoing occipitocervical fusion for complex Chiari malformation: patient series

BACKGROUND

The authors analyzed the pre- and postoperative morphometric properties of pediatric patients with complex Chiari malformation undergoing occipitocervical fusion (OCF) to assess clinical outcomes and morphometric properties that might influence postoperative outcomes.

OBSERVATIONS

The authors retrospectively reviewed 35 patients younger than 22 years with Chiari malformation who underwent posterior fossa decompression and OCF with or without endoscopic endonasal odontoidectomy at their institution (13 with and 22 without odontoidectomy). Clivo-axial angle (CXA), pB-C2, atlantodental interval, basion-dens interval, basion-axial interval, and canal diameter at the level of C1 were measured on preoperative and approximately 3-month postoperative computed tomography or magnetic resonance imaging. The authors further stratified the patient cohort into three age groups and compared the three cohorts. The most common presenting symptoms were headache, neck/shoulder pain, and dysphagia; 80% of the cohort had improved clinical outcomes. CXA increased significantly after surgery. When stratified into those who showed postoperative improvement and those who did not, only the former showed a significant increase in CXA. After age stratification, the significant changes in CXA were observed in the 7- to 13-year-old and 14- to 21-year-old cohorts.

LESSONS

CXA may be the most important morphometric predictor of clinical outcomes after OCF in pediatric patients with complex Chiari malformation.