Spinal Instability Research Articles

Lumbar Arthrosynovial Cyst: An Unusual Cause of Sciatica

We report the case of a 46-year-old female patient with hyperalgesic sciatica caused by a lumbar arthrosynovial cyst (ASK). Lumbar arthrosynovial cysts are relatively rare degenerative lesions of the spine. They may be completely asymptomatic or cause symptoms through compression of nerve structures. They most often develop at the L4/L5 level, where spinal mobility is greatest. Their aetiopathogenesis is uncertain, but degenerative spinal instability is the determining factor in their development. MRI is the examination of choice for diagnosing these lesions. Conservative treatment is not very effective. Surgical resection of the cyst, with or without arthrodesis, remains the most appropriate treatment option.

Thoracic spine infection caused by Pseudomonas fluorescens: A case report and review of literature

BACKGROUND The clinical incidence of spinal infection is gradually increasing, and its onset is insidious, easily leading to missed diagnosis and misdiagnosis, which may lead to serious complications such as nervous system dysfunction, spinal instability and/or deformity, and cause a huge burden on society and families. Early identification of the causative agent and precision medicine will greatly reduce the suffering of patients. At present, the main pathogenic bacteria that cause spinal infection are Staphylococcus aureus , Streptococcus, Pneumococcus, Escherichia coli , and Klebsiella. There are no reports of spinal infection caused by Pseudomonas fluorescens . CASE SUMMARY We report a 32-year-old female patient with spinal infection. She presented with flank pain, initially thought to be bone metastases or bone tuberculosis, and had a family background of tumors. Her clinical features and changes in imaging and laboratory tests led to the suspicion of thoracic spine infection. Histopathology of the lesion showed inflammation, tissue culture of the lesion was negative several times, and the possible pathogen - Pseudomonas fluorescens was found after gene sequencing of the lesion. The patient recovered completely after a full course of antibiotic treatment. CONCLUSION This report increases the range of pathogens involved in spinal infections, highlights the unique advantages of gene sequencing technology in difficult-to-diagnose diseases, and validates conservative treatment with a full course of antibiotics for spinal infections without complications.

Full-Endoscopic Discectomy and Debridement for Iatrogenic Spondylodiscitis After a Lumbar Peritoneal Shunt

Lumbar peritoneal shunt (LPS) is the standard treatment for nonobstructive hydrocephalus. Shunt infection, overdrainage, bleeding, and cerebrospinal fluid leaks have been reported as LPS complications. We present a 70-year-old man who developed iatrogenic spondylodiscitis 2 weeks after LPS placement, experiencing severe back pain and neurological deficits. Despite the empiric antibiotics, his symptoms persisted. The patient underwent fully endoscopic debridement and drainage (FEDD) to address the infection without LPS removal. After the procedure, the patient experienced a significant reduction in pain. Even though pathogen cultures were negative, the empiric antibiotic treatment continued for 6 full weeks. The patient was able to ambulate with a thoracolumbar orthosis due to the lumbar kyphotic deformity. FEDD, in conjunction with effective antibiotics, offers rapid pain relief and functional improvement in iatrogenic spondylodiscitis, even with LPS placement. However, FEDD may not correct spinal deformities and is unsuitable for advanced spinal disease or instability. Early detection of spondylodiscitis is crucial for improved outcomes.

Intraoperative radiotherapy combined with spinal stabilization surgery—a novel treatment strategy for spinal metastases based on a first single-center experiences

IntroductionCurrent treatment of spinal metastases (SM) aims on preserving spinal stability, neurological status, and functional status as well as achieving local control. It consists of spinal surgery followed by radiotherapy and/or systemic treatment. Adjuvant therapy usually starts with a delay of a few weeks to prevent wound healing issues. Intraoperative radiotherapy (IORT) has previously been successfully applied during brain tumor, breast and colorectal carcinoma surgery but not in SM, including unstable one, to date. In our case series, we describe the feasibility, morbidity and mortality of a novel treatment protocol for SM combining stabilization surgery with IORT.MethodsSingle center case series on patients with SM. Single session stabilization by navigated open or percutaneous procedure using a carbon screw-rod system followed by concurrent 50 kV photon-IORT (ZEISS Intrabeam). The IORT probe is placed via a guide canula using navigation, positioning is controlled by IOCT or 3D-fluroscopy enabling RT isodose planning in the OR.Results15 (8 female) patients (71 ± 10y) received this treatment between 07/22 and 09/23. Median Spinal Neoplastic Instability Score was 8 [7–10] IQR. Most metastasis were located in the thoracic (n = 11, 73.3%) and the rest in the lumbar (n = 4, 26.7%) spine. 9 (60%) patients received open, 5 (33%) percutaneous stabilization and 1 (7%) decompression only. Mean length of surgery was 157 ± 45 min. Eleven patients had 8 and 3 had 4 screws placed. In 2 patients radiotherapy was not completed due to bending of the guide canula with consecutive abortion of IORT. All other patients received 8 Gy isodoses at mdn. 1.5 cm [1.1–1.9, IQR] depth during 2-6 min. The patients had Epidural Spinal Cord Compression score 1a-3. Seven patients (46.7%) experienced adverse events including 2 surgical site infection (one 65 days after surgery).Conclusion50 kV photon IORT for SM and consecutive unstable spine needing surgical intervention is safe and feasible and can be a promising technique in selected cases.

Predicting the Need for Occipitocervical Fusion for Patients with Lower Clival Chordoma: A Single-Center Retrospective Study

To assess the impact of tumor extension into the occipital condyle (OC) in lower clival chordoma management and the need for occipito-cervical fusion (OCF). A retrospective analysis was conducted on 35 patients with lower clival chordoma. The preoperative area of the intact OCs, Hounsfield units, and the integrity of the apical ligament and the tectorial membrane were assessed using preoperative imaging. Seven (20%) patients were in the OCF group. The OCF group exhibited a higher prevalence of preoperative pain in the neck or head (p = 0.006), ligament absence (p = 0.022), and increased propensity for postoperative wound issues (p = 0.022) than the non-OCF group. The OCF group had less intact OCs (p < 0.001) and higher spinal instability neoplastic score (p = 0.002) than the non-OCF group. All patients with intact OCs<60% underwent OCF, and those with OCs≥70% were treated without OCF. Those with OCs between 60% and 69% underwent OCF if the ligaments were eroded, and did not undergo OCF if the ligaments were intact. Treatment strategies varied, with endoscopic endonasal approach (EEA) alone being common. Radiation therapy was administered to 89% of patients. All three patients treated with OCF after tumor resection had wound issues; none treated with OCF before resection had wound issues. None developed atlanto-occipital instability. Survival rates did not significantly differ between groups. In the absence of mobility-related neck pain, patients with lower clival chordoma and intact OC≥60%, intact apical ligament, and intact tectorial membrane, may not require OCF.

6. Persistent spinal pain syndrome type 2.

Persistent Spinal Pain Syndrome (PSPS) refers to chronic axial pain and/or extremity pain. Two subtypes have been defined: PSPS-type 1 is chronic pain without previous spinal surgery and PSPS-type 2 is chronic pain, persisting after spine surgery, and is formerly known as Failed Back Surgery Syndrome (FBSS) or post-laminectomy syndrome. The etiology of PSPS-type 2 can be gleaned using elements from the patient history, physical examination, and additional medical imaging. Origins of persistent pain following spinal surgery may be categorized into an inappropriate procedure (eg a lumbar fusion at an incorrect level or for sacroiliac joint [SIJ] pain); technical failure (eg operation at non-affected levels, retained disk fragment, pseudoarthrosis), biomechanical sequelae of surgery (eg adjacent segment disease or SIJ pain after a fusion to the sacrum, muscle wasting, spinal instability); and complications (eg battered root syndrome, excessive epidural fibrosis, and arachnoiditis), or undetermined. The literature on the diagnosis and treatment of PSPS-type 2 was retrieved and summarized. There is low-quality evidence for the efficacy of conservative treatments including exercise, rehabilitation, manipulation, and behavioral therapy, and very limited evidence for the pharmacological treatment of PSPS-type 2. Interventional treatments such as pulsed radiofrequency (PRF) of the dorsal root ganglia, epidural adhesiolysis, and spinal endoscopy (epiduroscopy) might be beneficial in patients with PSPS-type 2. Spinal cord stimulation (SCS) has been shown to be an effective treatment for chronic, intractable neuropathic limb pain, and possibly well-selected candidates with axial pain. The diagnosis of PSPS-type 2 is based on patient history, clinical examination, and medical imaging. Low-quality evidence exists for conservative interventions. Pulsed radiofrequency, adhesiolysis and SCS have a higher level of evidence with a high safety margin and should be considered as interventional treatment options when conservative treatment fails.

Can the Mismatch of Measured Pelvic Morphology vs. Lumbar Lordosis Predict Chronic Low Back Pain Patients?

Background: Measures of lumbar lordosis (LL) and elliptical modeling variables have been shown to discriminate between normal and chronic low back pain (CLBP) patients. Pelvic morphology influences an individual's sagittal lumbar alignment. Our purpose is to investigate the sensitivity and specificity of lumbar sagittal radiographic alignment and modeling variables to identify if these can discriminate between normal controls and CLBP patients. Methods: We conducted a computer analysis of digitized vertebral body corners on lateral lumbar radiographs of normal controls and CLBP patients. Fifty normal controls were attained from a required pre-employment physical examination (29 men; 21 women; mean age of 27.7 ± 8.5 years), with no history of low back pain, a normal spinal examination, no pathologies, anomalies, or instability. Additionally, 50 CLBP patients (29 men; 29.5 ± 8 years of age) were randomly chosen and matched to the characteristics of the controls. The inclusion criteria required no abnormalities on lumbar spine radiographs. The parameters included the following: ARA L1-L5 lordosis, ARA T12-S1 lordosis, Cobb T12-S1, b/a elliptical modelling ratio, sacral base angle (SBA), and S1 posterior tangent to vertical (PTS1). Two measures of pelvic morphology were determined for each person-the angle of pelvic incidence (API) and posterior tangent pelvic incidence angle (PTPIA)-and the relationships between API - ARA T12-S1, API - Cobb T12-S1, and API - ARA L1-5 was determined. Descriptive statistics and correlations among the primary variables were determined. The receiver operating characteristic curves (ROC curves) for primary variables were analyzed. Results: The mean values of LL were statistically different between the normal and CLBP groups (p < 0.001), indicating a hypo-lordotic lumbar spine for the CLBP group. The mean b/a ratio was lower in the chronic pain group (p = 0.0066). The pelvic morphology variables were similar between the groups (p > 0.05). API had a stronger correlation to the SBA and Cobb T12-S1 than PTPIA did, while PTPIA had a stronger correlation to the S1 tangent and ARA T12-S1 than API did. While CLBP patients had a stronger correlation of ARA T12-S1 and Cobb T12-S1 relative to the pelvic morphology, they also had a reduced correlation of ARA L1-L5 lordosis relative to their SBA and pelvic morphology measures. API - T12-S1, API - L1-L5, and API - Cobb T12-S1 were statistically different between the groups, p < 0.001. Using ROC curve analyses, it was identified that ARA L1-L5 lordosis of 36° and ARA T12-S1 of 68° have a good sensitivity and specificity to discriminate between normal and CLBP patients. ROC curve analyses identified that lordosis ARAT12-S1 < 68° (AUC = 0.83), lordosis ARAL1-L5 < 36° (AUC = 0.78), API - ARA T12-S1 < -18° (AUC = 0.75), API - ARAL1-L5 > 35° (AUC = 0.71), and API - Cobb T12-S1 < -5° (AUC = 0.69) had moderate to good discrimination between groups (AUC = 0.83, 0.78, 0.75, and 0.72). Conclusions: Pelvic morphology is similar between normal and CLBP patients. CLBP patients have an abnormal 'fit' of their API - ARAT12-S1 and L1-L5 lumbar lordosis relative to their pelvic morphology and sacral tilt shown as a hypolordosis.

Senescent-like macrophages mediate angiogenesis for endplate sclerosis via IL-10 secretion in male mice

Endplate sclerosis is a notable aspect of spine degeneration or aging, but the mechanisms remain unclear. Here, we report that senescent macrophages accumulate in the sclerotic endplates of lumbar spine instability (LSI) or aging male mouse model. Specifically, knockout of cdkn2a (p16) in macrophages abrogates LSI or aging-induced angiogenesis and sclerosis in the endplates. Furthermore, both in vivo and in vitro studies indicate that IL-10 is the primary elevated cytokine of senescence-related secretory phenotype (SASP). Mechanistically, IL-10 increases pSTAT3 in endothelial cells, leading to pSTAT3 directly binding to the promoters of Vegfa, Mmp2, and Pdgfb to encourage their production, resulting in angiogenesis. This study provides information on understanding the link between immune senescence and endplate sclerosis, which might be useful for therapeutic approaches.

Clinical Outcome of Chemotherapy and Radiation Therapy Versus Chemotherapy, Radiation Therapy, and Multilevel Vertebroplasty or Kyphoplasty for Multiple Myeloma.

Vertebral augmentation including vertebroplasty and kyphoplasty may restore function without interfering with the therapeutic regimen of patients with multiple myeloma. We sought to evaluate the effects of adding multilevel vertebral augmentation to conventional therapy protocols for patients with multiple myeloma. Forty-four patients recently diagnosed with multiple myeloma were randomly assigned to two groups. One group received multilevel vertebral augmentation (kyphoplasty or vertebroplasty) in addition to conventional therapy (MVA), and the other group received conventional therapy alone (CTA). Patients were evaluated before treatment and at 3 months, 6 months, 1 year, 2 years, 3 years, 4 years, and 5 years after treatment by using the Oswestry Disability Index (ODI), the Stanford Score (SS), and the Spinal Instability Neoplastic Score (SINS). The mean ODI, SS, and SINS were nearly equal before treatment, being 34.19 (68.38%), 4.58, and 12.30, respectively, for the MVA group and 32.29 (64.58%), 4.63, and 13.88, respectively, for the CTA group. There were significant differences in the ODI, SS, and SINS between the two groups at all follow-up intervals. The ODI and SINS were statistically significantly different between the two groups (P=.020 and P<.001, respectively). There was an insignificant difference in SS between the two groups. This study found that performing kyphoplasty and vertebroplasty in addition to conventional therapy for patients with multiple myeloma resulted in enhanced morbidity and functional outcomes. [Orthopedics. 2024;47(4):225-231.].

Lumbar parafacetal cyst-spinal segmental instability is the cause and stabilization is the treatment: A clinical report of eight surgically-treated patients.

The authors report the results of "only-fixation" of the affected spinal segment without any decompression of the bones or soft tissue or manipulation of the cyst wall or contents in eight cases having lumbar parafacetal cyst (LPFC). This surgical strategy was based on the concept that LPFCs are secondary to spinal instability, has a protective or adaptive role, and is reversible following stabilization. During the period from January 2018 to January 2023, eight consecutive patients having LPFC were surgically treated. There were 5 males and 3 females, and their ages ranged from 48 to 72 years (average 63 years). Seven patients had a single cyst and one patient had multiple cysts. The patients presented with symptoms classically attributed to lumbar canal stenosis. Apart from the cyst-affected spinal segment, degenerative alterations were observed in adjoining spinal segments in six out of seven patients having a single cyst. All patients underwent "only fixation" of the unstable spinal segments without any kind of bone or soft-tissue resection and without any manipulation or handling of the cyst wall or contents. During the follow-up period that ranged from 12 to 57 months (average 29 months), all patients improved from their symptoms. The recovery was observed in the immediate postoperative period and was lasting. LPFCs are one of the several secondary alterations observed in spinal degeneration. Identification of unstable spinal segments and their fixation constitutes rational treatment of lumbar parafacetal cysts. Direct handling and resection of cysts are unnecessary.

Long-term efficacy of microendoscopic laminotomy for lumbar spinal stenosis in advanced degenerative spondylolisthesis with or without dynamic spinal instability: a propensity score-matching analysis.

In this study, the authors aimed to determine the mid- to long-term outcomes of microendoscopic laminotomy (MEL) for lumbar spinal stenosis (LSS) with degenerative spondylolisthesis (DS) and identify preoperative predictors of poor mid- to long-term outcomes. The authors retrospectively reviewed the medical records of 274 patients who underwent spinal MEL for symptomatic LSS. The minimum postoperative follow-up duration was 5 years. Patients were classified into two groups according to DS: those with DS (the DS+ group) and those without DS (the DS- group). The patients were subjected to propensity score matching based on sex, age, BMI, surgical segments, and preoperative leg pain visual analog scale scores. Clinical outcomes were evaluated 1 year and > 5 years after surgery. Surgical outcomes of MEL for LSS were not significantly different between the DS+ and DS- groups at the final follow-up (mean 7.8 years) in terms of Oswestry Disability Index (p = 0.498), satisfaction (p = 0.913), and reoperation rate (p = 0.154). In the multivariate analysis, female sex (standard β -0.260), patients with slip angle > 5° in the forward bending position (standard β -0.313), and those with dynamic progression of Meyerding grade (standard β -0.325) were at a high risk of poor long-term outcomes. MEL may have good long-term results in patients with DS without dynamic instability. Women with dynamic instability may require additional fusion surgery in approximately 25% of cases for a period of ≥ 5 years.

Standalone Anterior Reconstruction Approach in Traumatic Cervical Spine Instability Lesions

Standalone Anterior Reconstruction Approach in Traumatic Cervical Spine Instability Lesions

Effects of Preoperative Glucocorticoid Use on Patients Undergoing Single-Level Lumbar Fusions: A Retrospective Propensity Score-Matched Registry Study.

Objective Spinal fusions are gaining popularity as a means of treating spinal deformity and instability from a range of pathologies. The prevalence of glucocorticoid use has also increased in recent decades, and their systemic effects are well-documented. Although commonly used in the preoperative period, the effects of steroids on outcomes amongpatients undergoing spinal fusions are inadequately described. This study compares the oddsof developing complications amongpatients who underwent single-level lumbar fusions with and without preoperative glucocorticoid use in hopes of establishing more evidence-based parameters for guiding preoperative steroid use. Methods The TriNetX multi-institutional electronic health record database was used to perform a retrospective, propensity score-matched analysis of clinical outcomes of two cohorts of patients who underwent posterior or posterolateral single-level lumbar fusions with and without interbody fusion, those who used glucocorticoids for at least one week within a year of fusion and those who did not. The outcomes of interest were examined within 30 days of the operation and included death, reoperation, deep or superficial surgical site infection (SSI), pneumonia, reintubation, ventilator dependence, tracheostomy, acute kidney injury (AKI), renal insufficiency, pulmonary embolism (PE) or deep venous thrombosis (DVT), urinary tract infection (UTI), emergency department (ED) visit, sepsis, and myocardial infarction (MI). Results The odds of developing pneumonia within 30 days of spinal fusion in the cohort that used glucocorticoids within one year of operation compared to the cohort without glucocorticoid use was 0.67 (p≤0.001, 95% CI: 0.59-0.69). The odds of requiring a tracheostomy within 30 days of spinal fusion in the cohort that used glucocorticoids within one year of operation compared to the cohort without glucocorticoid use was 0.39 (p≤0.001, 95% CI: 0.26-0.60).The odds of reoperation, deep and superficial SSI, and ED visits within 30 days of operation were significantly higher for the same glucocorticoid-receiving cohort, with odds ratios of 1.4 (p=0.003, 95% CI: 1.11-1.65), 1.86 (p≤0.001, 95% CI: 1.31-2.63), 2.28 (p≤0.001, 95% CI: 1.57-3.31), and 1.25 (p≤0.001, 95% CI: 1.17-1.33), respectively. After propensity score-matching, there was no significant difference between the odds of death, DVT, PE, MI, UTI, AKI, sepsis, reintubation, and ventilator dependence between the two cohorts. Conclusion In support of much of the current literature regarding preoperative glucocorticoid use and rates of complications, patients who underwent a single-level lumbar fusion and have used glucocorticoids for at least a week within a year of operation experienced significantly higher odds of reoperation, deep and superficial SSI, and ED visits. However, these patients using glucocorticoids were also found to have lower odds of developing pneumonia, renal insufficiency, and tracheostomy requirement than those who did not use steroids within a year of surgery.

Epidemiology of Spondylolisthesis: A Nationwide Study From 2001 to 2016 in the Italian Population.

Epidemiological study. This study aimed to evaluate the annual incidence of spondylolisthesis requiring surgery in Italy and the epidemiological characteristics of the patients. The health care system continues to incur considerable costs as a result of low-back pain. Segmental instability of the lumbar spine has attracted significant interest from researchers as a potential mechanism leading to mechanical low back pain. The Italian Ministry of Health's National Hospital Discharge Reports database in the 2001-2016 period was considered. A total of 55,804 hospital admissions for spondylolisthesis were performed in Italy. The cumulative incidence was 6.8 interventions for every 100,000 Italian adult residents. The highest amount of procedures was recorded in the 65-69 years of age group. The overall patient's age was 56.8 ± 15.1 years. The 62.2% of patients were females. The average hospital stay length was 8.1 ± 7.3 days. On average, older patients require more days of hospital stay. Over the study period, it was observed a decreasing trend in the average number of days of hospital stay. The main primary diagnoses included were "acquired spondylolisthesis" [International Classification of Diseases (ICD) code: 738.4; 57.8%] and "spondylolisthesis" (ICD code: 756.12; 42.2%). By far, the main primary procedure performed was "lumbar and lumbosacral fusion of the anterior column, posterior technique" (ICD code: 81.08; 60.3%). Spondylolisthesis is a problem in Italy and a leading cause requiring spine surgery. Females were the majority of patients requiring surgery for spondylolisthesis. However, for younger age groups, males showed superior or equal need for spine surgery. The socioeconomic impact of spondylolisthesis in Italy is relevant, affecting patients still in the working population. The increasing trend of spine surgery for spondylolisthesis in Italy may be attributable to the widespread diffusion of modern diagnostic and surgical technologies. Level II.

Analyzing isolated degeneration of lumbar facet joints: implications for degenerative instability and lumbar biomechanics using finite element analysis.

The facet joint contributes to lumbar spine stability as it supports the weight of body along with the intervertebral discs. However, most studies on the causes of degenerative lumbar diseases focus on the intervertebral discs and often overlook the facet joints. This study aimed to investigate the impact of facet joint degeneration on the degenerative changes and diseases of the lumbar spine. A finite element model of the lumbar spine (L1-S1) was fabricated and validated to study the biomechanical characteristics of the facet joints. To simulate degeneration of the facet joint, the model was divided into four grades based on the number of degenerative segments (L4-L5 or L4-S1) and the contact condition between the facet joint surfaces. Finite element analysis was performed on four spine motions: flexion, extension, lateral bending, and axial torsion, by applying a pure moment to the upper surface of L1. Important parameters that could be used to confirm the effect of facet joint degeneration on the lumbar spine were calculated, including the range of motion (ROM) of the lumbar segments, maximum von Mises stress on the intervertebral discs, and reaction force at the facet joint. Facet joint degeneration affected the biomechanical characteristics of the lumbar spine depending on the movements of the spine. When analyzed by dividing it into degenerative onset and onset-adjacent segments, lumbar ROM and the maximum von Mises stress of the intervertebral discs decreased as the degree of degeneration increased in the degenerative onset segments. The reaction force at the facet joint decreased with flexion and increased with lateral bending and axial torsion. In contrast, lumbar ROM of the onset-adjacent segments remained almost unchanged despite severe degeneration of the facet joint, and the maximum von Mises stress of the intervertebral discs increased with flexion and extension but decreased with lateral bending and axial torsion. Additionally, the facet joint reaction force increased with extension, lateral bending, and axial rotation. This analysis, which combined the ROM of the lumbar segment, maximum von Mises stress on the intervertebral disc, and facet joint reaction force, confirmed the biomechanical changes in the lumbar spine due to the degeneration of isolated facet joints under the load of spinal motion. In the degenerative onset segment, spinal instability decreased, whereas in the onset-adjacent segment, a greater load was applied than in the intact state. When conducting biomechanical studies on the lumbar spine, considering facet joint degeneration is important since it can lead to degenerative spinal diseases, including adjacent segment diseases.

Abstract 3339: TTFields for the management of spinal metastases in in vitro and in vivo models

Abstract Spine metastases often affect cancer patients, leading to significant morbidity and mortality. Their prevalence has increased over time due to the progressive improvements in cancer management which led to a longer survival of these individuals. Radiation therapy is the mainstay treatment for local control of these lesions, with surgery reserved for selected cases (e.g., spinal instability, neurological deficits secondary to neural compression requiring urgent decompression, separation surgery). Chemotherapy addresses the diffusely metastatic spread. However, when spinal metastases progress despite using all the appropriate available treatment, there follows a progressive decline in function and further treatment options are limited, highlighting the need for development of novel therapies. Tumor treating fields (TTFields) has demonstrated to impair tumor cell replication and are influenced by surrounding tissue, such as bone (presents non-conductive properties). Our goal was to investigate the effects of TTFields in in vitro and in vivo spinal metastasis models. We hypothesize that the deposition of TTFields is increased in bone, and this would ultimately result in vertebral metastasis growth suppression. A computational model using a simulated spine resection cavity with metallic hardware was used to investigate the TTFields intensity in various tissues. For in vitro studies, luciferase tagged KRIB osteosarcoma and A549 lung adenocarcinoma cell lines were cultured in demineralized human bone graft. These were treated with TTFields and cell viability was quantified. In vivo assays were performed using a previous validated murine orthotopic tumor model. The effects of TTFields in these animals were monitored with imaging (bioluminescence and MRI) and clinical findings (progressive neurological deficits milestones that corresponds to the degree of spinal cord compression). At the end of the study, tissue was collected for histologic analysis. Sham stimulation was used for control groups. Computational simulation demonstrated an elevated TTFields intensity in the tumor-bone interface of the resected vertebral body. In all experimental models, TTFields significantly suppressed tumor cell growth. In vivo models, this effect on cell proliferation prevented tumor growth into the spinal canal, delaying, or even preventing, neurological deficits. TTFields inhibited tumor growth in three-dimensional cultures and orthotopic murine models of spinal metastases, preventing functional loss. The bony environment surrounding the tumor demonstrated to enhance the intensity of electric fields on a computational simulation, which stands as an advantage with the use of TTFields for vertebral tumors. These results provide solid evidence supporting future clinical trials investigating the effects of this novel and promising technology for the treatment of spine metastases. Citation Format: Romulo Augusto Andrade de Almeida, Daniel Ledbetter, Xizi Wu, Ariel Naveh, Chirag Patel, Queena Gonzalez, Thomas H. Beckham, Robert Y. North, Laurence Rhines, Christopher A. Alvarez-Breckenridge, Claudio E. Tatsui. TTFields for the management of spinal metastases in in vitro and in vivo models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3339.

Microendoscopic Tailored Spine Decompression as a Less-Invasive, Stability-Preserving Surgical Option to Instrumented Correction in Complex Spine Deformities: A Preliminary Multicenter Experience

Study designA series of 32 patients, submitted to a tailored stability-preserving micro-endoscopic decompression for lumbar spine degenerative disease was retrospectively analyzed. ObjectivesThe aim of this study is to explore the effectiveness of a less invasive posterior spine decompression in complex deformities. We studied the potential advantages of the micro-endoscopic approach, supplemented by the piezoelectric technique, to decompress both sides of the vertebral canal, from a one side approach to preserve spine stability, ensuring an adequate neural decompression. MethodsThe patients were submitted to a selective bilateral decompression, using a monolateral approach, without the skeletonization of the opposite side. For the omo- and the contralateral decompression, we used a microscopic endoscopy-assisted approach, with the assistance of Piezosurgery, for a safe work near the exposed dura mater. Piezoelectric osteotomy is extremely effective in bone removal while safe on soft tissues. ResultsIn all patients an adequate decompression was achieved with a high rate of spine stability preservation. The approach was essential in minimizing the opening, so reducing the risk of spine instability. Piezoelectric osteotomy was useful to safely perform the undercutting of the base of the spinous process, for a better contralateral vision and decompression without damaging the exposed dura. In all patients a various degree of neurological improvement was observed, with no immediate spine decompensation. ConclusionsIn selected cases, the tailored micro-endoscopic monolateral approach for bilateral spine decompression, with piezosurgery assistance, is adequate and safe and showed excellent results in terms of spine decompression and stability preservation.

Navigating the Indeterminate Zone: Surgeons' Decision-Making Factors in Treating Vertebral Metastases with Spinal Instability Scores of 7–12

BackgroundThe Spinal Instability Neoplastic Score (SINS) classification system, is a validated and the most widely accepted instrument for defining instability in vertebral metastasis (VM), in which lesions scoring between 7 – 12 are defined as indeterminate and the treatment is controversial. This study aimed to determine which variables more frequently are considered by spine surgeons for choosing between the conservative and the surgical treatment of VMs among patients with an indeterminate SINS. Material and MethodsA single-round online survey was conducted in ten spine surgeons with expertise in the management of VMs from our AO Spine Region. In this survey, each surgeon independently reviewed demographic and cancer-related variables of 36 real-life cases of patients with vertebral metastases scored between 7 – 12 in the SINS. Bivariate and multivariate analyses were performed to identify significant SINS and non-SINS variables influencing the decision-making on surgical treatment. ResultsThe most commonly variables considered important, were the SINS element ‘mechanical pain’, rated important for 44.4% of the cases, ‘lesion type’ for 36.1%, ‘degree of vertebral collapse’ and the non-SINS factor ‘tumor histology’ rated for 13.9% of cases. By far the factor most commonly rated unimportant was ‘posterior element compromise’ (in 72.2% of cases). ConclusionsSurgeons relied on mechanical pain and type of metastatic lesion for treatment choices. Vertebral collapse, spinal malalignment, and mobility were less influential. Spinal mobility was a predictor of surgical versus non-surgical treatment. The only variables not identified either by surgeons themselves or as a predictor of surgery selection was the presence/degree of posterolateral/posterior element involvement.

Use of Recombinant Human Bone Morphogenetic Protein-2 After Anterior Cervical Corpectomy and Fusion for the Treatment of Vertebral Osteomyelitis

To report the operative outcomes after treating vertebral osteomyelitis patients with an anterior cervical corpectomy and fusion procedure using recombinant human bone morphogenetic protein-2 as graft material. A retrospective review of electronic medical records of 26 adult patients who underwent an anterior cervical corpectomy and fusion procedure for cervical osteomyelitis using rhBMP-2 at the University of Puerto Rico University District Hospital was performed. Indication, preoperative laboratory results, levels of corpectomy, preoperative ASIA score, complications, fusion evaluation at 12 months, and ASIA score at 12 months was reviewed. For the cohort of patients, mean age was 47±13 years and 65% were male. Spinal instability was present in 54%. The levels of corpectomy were: one-level in 2 cases, two-level in 15 cases, three-level in 8 cases and five-level in 1 case. 4 patients had complications and of these, 2 experienced dysphagia. The fusion rate was 100% and no reoperations were performed. An improvement in ASIA score was seen for 54% patients at 12 months follow up. This study demonstrates a fusion rate of 100% with no reoperations reported. Recombinant human bone morphogenetic protein-2 could be considered and further researched as grafting material for anterior cervical corpectomy and fusion procedures in cervical osteomyelitis patients.

Predicting Skeletal-related Events Using SINS.

Predictive study utilized retrospectively collected data. The primary objective was to evaluate the predictive association between the Spine Instability Neoplastic Score (SINS) and Skeletal-related events (SREs). Secondary objectives included examining characteristics of cases with SINS < 6 among those who developed SRE, and evaluating the impact of additional predictors on prediction accuracy. Advances in cancer treatment have prolonged the lives of cancer patients, emphasizing the importance of maintaining quality of life. Skeletal-related events from metastatic spinal tumors significantly impact quality of life. However, currently, there is no scientifically established method to predict the occurrence of SRE. SINS, developed by the Spine Oncology Study Group, assesses spinal instability using six categories. Therefore, the predictive performance of SINS for SRE occurrence is of considerable interest to clinicians. This predictive study utilized retrospectively collected data from a single-center registry comprising over 1,000 patients with metastatic spinal tumors. SINS and clinical data were collected. Logistic regression was used to create a prediction equation for SRE using SINS. Additional analyses explored factors associated with SRE in patients with SINS < 6. The study included 1,041 patients with metastatic spinal tumors. SRE occurred in 121 cases (12%). The prediction model for SRE using SINS demonstrated an area under the curve (AUC) of 0.832. Characteristics associated with SRE included lower female prevalence, surgeries to primary sites, bone metastases to non-spinal sites, and metastases to other organs. A post hoc analysis incorporating additional predictors improved the AUC to 0.865. The SINS demonstrated reasonable predictive performance for SRE within one month of the initial visit. Incorporating additional factors improved prediction accuracy. The study emphasizes the need for a comprehensive clinical prediction model for SRE in metastatic spinal tumors.