Proton versus photon adjuvant radiotherapy: a multicenter comparative evaluation of recurrence following spinal chordoma resection.

OBJECTIVE: Chordomas are rare tumors of the skull base and spine believed to arise from the vestiges of the embryonic notochord. These tumors are locally aggressive and frequently recur following resection and adjuvant radiotherapy. Proton therapy has been introduced as a tissue-sparing option because of the higher level of precision that proton-beam techniques offer compared with traditional photon radiotherapy. This study aimed to compare recurrence in patients with chordomas receiving proton versus photon radiotherapy following resection by applying tree-based machine learning models. METHODS: The clinical records of all patients treated with resection followed by adjuvant proton or photon radiotherapy for chordoma at Mayo Clinic were reviewed. Patient demographics, type of surgery and radiotherapy, tumor recurrence, and other variables were extracted. Decision tree classifiers were trained and tested to predict long-term recurrence based on unseen data using an 80/20 split. RESULTS: Fifty-three patients with a mean ± SD age of 55.2 ± 13.4 years receiving surgery and adjuvant proton or photon therapy to treat chordoma were identified; most patients were male. Gross-total resection was achieved in 54.7% of cases. Proton therapy was the most common adjuvant radiotherapy (84.9%), followed by conventional or external-beam radiation therapy (9.4%) and stereotactic radiosurgery (5.7%). Patients receiving proton therapy exhibited a 40% likelihood of having recurrence, significantly lower than the 88% likelihood observed in those treated with nonproton therapy. This was confirmed on logistic regression analysis adjusted for extent of tumor resection and tumor location, which revealed that proton adjuvant radiotherapy was associated with a decreased risk of recurrence (OR 0.1, 95% CI 0.01-0.71; p = 0.047) compared with photon therapy. The decision tree algorithm predicted recurrence with an accuracy of 90% (95% CI 55.5%-99.8%), with the lowest risk of recurrence observed in patients receiving gross-total resection with adjuvant proton therapy (23%). CONCLUSIONS: Following resection, adjuvant proton therapy was associated with a lower risk of chordoma recurrence compared with photon therapy. The described machine learning models were able to predict tumor progression based on the extent of tumor resection and adjuvant radiotherapy modality used.

Novel Approach to Difficult Spinal Reconstruction: Bilateral Simultaneous Rib and Iliac Crest Vascularized Bone Graft Spinoplastic Surgery.

Pseudoarthrosis is a severe complication of spinal fusion surgery with occurrence rates as high as 35%-40%. Current options of revision surgery to correct pseudoarthrosis frequently carry high failure rates and risk of developing junctional kyphosis. Pedicled vascularized bone grafts (VBGs) are an innovative approach to boost spinal fusion rates via improving structural integrity and increasing the delivery of blood to the donor site. This versatile technique can be performed at different spinal levels without additional skin incisions and with minimal added operative time. Here we present the first bilateral rib and iliac crest VBG spinoplastic surgery performed to augment spinal fusion in a 68-year-old woman with distal junctional kyphosis and severe positive sagittal balance with low back and neck pain and significant difficulty standing upright. The patient had history of multiple spinal operations with preoperative CT imaging demonstrating loosening and pull out of L3 and fracture of L2 screws. She underwent two-stage surgical treatment involving anterior lumbar interbody fusion L3-S1 followed by removal of hardware, T4 to pelvis fusion with L2-3 prone lateral interbody fusion, and T11-S1 posterior column osteotomies. The surgery was augmented by bilateral rib and iliac crest VBGs performed by plastic surgery. At three-month follow-up the patient demonstrated functional improvement, being able to maintain upright posture and walk; was satisfied with the result of the surgery; and demonstrated no graft-related complications. In conclusion, utilization of pedicled VBGs is a novel, promising approach to augment spinal surgery in high risk patients.

What Factors Predict the Development of Neurologic Deficits Following Resection of Intramedullary Spinal Cord Tumors: A Multi-Center Study.

BACKGROUND: Intramedullary spinal cord tumors are challenging to resect, and their postoperative neurological outcomes are often difficult to predict, with few studies assessing this outcome. METHODS: We reviewed the medical records of all patients surgically treated for Intramedullary spinal cord tumors at our multisite tertiary care institution (Mayo Clinic Arizona, Mayo Clinic Florida, Mayo Clinic Rochester) between June 2002 and May 2020. Variables that were significant in the univariate analyses were included in a multivariate logistic regression. "MissForest" operating on the Random Forest algorithm, was used for data imputation, and K-prototype was used for data clustering. Heatmaps were added to show correlations between postoperative neurological deficit and all other included variables. Shapley Additive exPlanations were implemented to understand each feature's importance. RESULTS: Our query resulted in 315 patients, with 160 meeting the inclusion criteria. There were 53 patients with astrocytoma, 66 with ependymoma, and 41 with hemangioblastoma. The mean age (standard deviation) was 42.3 (17.5), and 48.1% of patients were women (n = 77/160). Multivariate analysis revealed that pathologic grade >3 (OR = 1.55; CI = [0.67, 3.58], P = 0.046 predicted a new neurological deficit. Random Forest algorithm (supervised machine learning) found age, use of neuromonitoring, histology of the tumor, performing a midline myelotomy, and tumor location to be the most important predictors of new postoperative neurological deficits. CONCLUSIONS: Tumor grade/histology, age, use of neuromonitoring, and myelotomy type appeared to be most predictive of postoperative neurological deficits. These results can be used to better inform patients of perioperative risk.

Impact of preoperative spinal injections within 30 days of lumbar decompression on surgical outcomes: a matched institutional study.

OBJECTIVE: The authors sought to determine how the temporal proximity of lumbar epidural spinal injection prior to surgery impacts clinical outcomes (e.g., 30-day readmission, postoperative complications, CSF leak) in patients undergoing lumbar decompression without fusion. METHODS: The authors queried their institutional registry to identify patients who underwent elective lumbar decompression for spondylotic pathology between January 2019 and March 2022 at multiple centers within the same hospital network. Patients were divided into groups based on the time between their surgical date and the most recent preoperative spinal injection: group 1, patients with duration < 1 month; group 2, 1-3 months; and group 3, no spinal injection within 3 months. Primary outcomes of interest were the length of hospital stay, postoperative complications, rate of intraoperative CSF leak, and rates of reoperation and hospital readmission. For patients in groups 1 and 2, the authors also recorded the number of injections within 12 months prior to surgery to better understand the effect of multiple recent injections. The independent Student t-test and Pearson's chi-square test were mainly performed for univariate analyses of the continuous and categorical variables, respectively. RESULTS: A total of 121 and 283 patients received a spinal injection at < 1 month and 1-3 months prior to surgery, respectively, and were separately matched in a 3:1 ratio with 2562 patients with no history of preoperative spinal injection within 3 months before surgery. Among the matched cohorts, patients who received spinal injections < 1 month before lumbar decompression had significantly higher risks of 30-day complication (7.4% vs 0.8%, OR 9.6, p < 0.001), 30-day readmission (5.8% vs 2.2%, OR 3.5, p = 0.049), and 90-day readmission (9.1% vs 2.8%, OR 3.5, p = 0.003) than patients with no history of spinal injection. However, compared with patients with no history of spinal injection, the patients who received spinal injections 1-3 months before surgery were not at higher risk for postoperative complications or readmission. The CSF leak rates were significantly different between the three patient cohorts (10.7% vs 6.7% vs 4.9% for the < 1 month, 1-3 months, and no injection cohorts, respectively; p = 0.02). CONCLUSIONS: Lumbar decompression within 1 month of preoperative spinal injection was associated with higher risks of readmission and postoperative complications, including CSF leak. However, with the exception of CSF leak, these risks were no longer observed when spinal injection occurred 1-3 months prior to lumbar decompression.

Association between immunohistochemical markers and tumor progression following resection of spinal chordomas: a multicenter study.

OBJECTIVE: Chordomas are slow-growing tumors derived from notochord remnants. Despite margin-negative excision and postoperative radiation therapy, spinal chordomas (SCs) often progress. The potential of immunohistochemical (IHC) markers, such as epithelial membrane antigen (EMA), combined with machine learning algorithms to predict long-term (≥ 12 months) postoperative tumor progression, has been understudied. The authors aimed to identify IHC markers using trained tree-based algorithms to predict long-term (≥ 12 months) postoperative tumor progression. METHODS: The authors reviewed the records of patients who underwent resection of SCs between January 2017 and June 2021 across the Mayo Clinic enterprise. Demographics, type of treatment, histopathology, and other relevant clinical factors were abstracted from each patient's record. Low tumor progression was defined as more than a 94.3-mm3 decrease in the tumor size at the latest radiographic follow-up. Decision trees and random forest classifiers were trained and tested to predict the long-term volumetric progression after an 80/20 data split. RESULTS: Sixty-two patients diagnosed with and surgically treated for SC were identified, of whom 31 were found to have a more advanced tumor progression based on the tumor volume change cutoff of 94.3 mm3. The mean age was 54.3 ± 13.8 years, and most patients were male (62.9%) and White (98.4%). The most common treatment modality was subtotal resection with radiation therapy (35.5%), with proton beam therapy being the most common (71%). Most SCs were sacrococcygeal (41.9%), followed by cervical (32.3%). EMA-positive SCs had a postoperative progression risk of 67%. Pancytokeratin-positive SCs had a progression rate of 67%; however, patients with S100 protein-positive SCs had a 54% risk of progression. The accuracy of this model in predicting the progression of unseen test data was 66%. Pancytokeratin (mean minimal depth = 1.57), EMA (mean minimal depth = 1.58), cytokeratin A1/A3 (mean minimal depth = 1.59), and S100 protein (mean minimal depth = 1.6) predicted the long-term volumetric progression. Multiway variable importance plots show the relative importance of the top 10 variables based on three measures of varying significance and their predictive role. CONCLUSIONS: These IHC variables with tree-based machine learning tools successfully demonstrate a high capacity to identify a patient's tumor progression pattern with an accuracy of 66%. Pancytokeratin, EMA, cytokeratin A1/A3, and S100 protein were the IHC drivers of a low tumor progression. This shows the power of machine learning algorithms in analyzing and predicting outcomes of rare conditions in a small sample size.

Carbon-fiber-reinforced polyetheretherketone orthopedic implants in musculoskeletal and spinal tumors: imaging and clinical features.

Carbon-fiber-reinforced polyetheretherketone (CFR-PEEK) orthopedic implants are gaining popularity in oncologic applications as they offer many potential advantages over traditional metallic implants. From an imaging perspective, this instrumentation allows for improved evaluation of adjacent anatomic structures during radiography, computed tomography (CT), and magnetic resonance imaging (MRI). This results in improved postoperative surveillance imaging quality as well as easier visualization of anatomy for potential image-guided percutaneous interventions (e.g., pain palliation injections, or ablative procedures for local disease control). CFR-PEEK devices are also advantageous in radiation oncology treatment due to their decreased imaging artifact during treatment planning imaging and decreased dose perturbation during radiotherapy delivery. As manufacturing processes for CFR-PEEK materials continue to evolve and improve, potential orthopedic applications in the spine and appendicular skeleton increase. An understanding of the unique properties of CFR-PEEK devices and their impact on imaging is valuable to radiologists delivering care to orthopedic oncology patients in both the diagnostic and interventional settings. This multidisciplinary review aims to provide a comprehensive insight into the radiologic, surgical, and radiation oncology impact of these innovative devices.

Factors associated with greater patient satisfaction in outpatient neurosurgical clinics: Recommendation for surgery, older age, cranial chief complaint, and public health insurance.

OBJECTIVE: Patient satisfaction has increasingly played a role in determining care quality. Surveys are used to gauge patient experience, satisfaction of care, and likelihood to recommend providers and facilities. The aim of the study is to evaluate whether clinical and demographic data predict greater patient satisfaction with providers in the outpatient neurosurgery clinic. METHODS: Press-Ganey (Press Ganey Associates, South Bend, IL) evaluations of 1521 patients were reviewed in an academic neurosurgical clinic from January 1, 2019 through February 1, 2021. We analyzed associations between Press-Ganey ratings and patient demographics, chief complaint, psychiatric comorbidities, number of orders placed, medication prescriptions, surgical recommendation, payor status, and referral source. We used univariate logistic regression to assess for associations between independent variables and Press-Ganey ratings. Multivariable logistic regression was used for associated factors. RESULTS: For the Likelihood to Recommend question, older age (p = 0.003), cranial chief complaint (p = 0.046), and recommendations for surgery (p < 0.001) were significantly associated with "good" ratings. For the rating of Care Received, older age (p = 0.002), cranial chief complaint (p = 0.05), and recommendations for surgery (p = 0.002) were significantly associated with "good" ratings. For Confidence in Care Provider question, recommendations for surgery (p = <0.001) and government insurance type (p = 0.002) were significantly associated with "good" ratings. CONCLUSIONS: Patients with older age, cranial pathologies, a recommendation for surgery, and government health insurance were significantly associated with favorable patient satisfaction with providers in the outpatient neurosurgery clinic. Prospective studies should target patient populations who are younger, have spinal complaints, have non-surgical needs, and have commercial insurance to improve satisfaction.

A brief human history of ankylosing spondylitis: A scoping review of pathogenesis, diagnosis, and treatment.

Background: Ankylosing spondylitis (AS) is a chronic, progressive, inflammatory disease of the spine and SI joints. Diagnostic criteria and treatments have continued to evolve, necessitating a historical compendium of AS and its management. This paper aims to review the historical context underlying the discovery of AS, as well as the major diagnostic and therapeutic discoveries in the last two centuries. Methods: A scoping review of the literature pertaining to AS was performed via the Pubmed, Scopus, and Web of Science databases. Future directions of AS treatments were assessed by querying the clinicaltrials.gov website. Results: The history of AS can be traced as far back as ancient Egypt (as evidenced by the discovery of its presence in ancient Egyptian mummies) to the late 20th century, when the inherited nature of AS was linked to a genetic factor, HLA-B27. Each discovery made throughout the years led to further investigations into the pathophysiology, diagnosis, and treatment of AS. The criteria to differentiate AS from rheumatoid arthritis were first reported in 1893. Since then, diagnostic criteria for AS have undergone a series of changes before the present-day diagnostic criteria for AS were ultimately determined in 2009 by the Assessment of Spondyloarthritis International Society. Conclusion: As the pathophysiology of AS is better understood, healthcare providers are able to diagnose and treat the condition more effectively. In particular, earlier diagnosis and multiple treatment options have facilitated efficient and more effective treatment.

Anterior Thoracic Diskectomy and Fusion: Surgical Technique and Anatomic Considerations.

Ossification of the posterior longitudinal ligament (OPLL) is a rare condition that can lead to progressive spinal cord compression.1 Currently, surgical decompression remains the optimal treatment in symptomatic patients.2,3 In cases with significant thoracic stenosis and concern for ventral erosion of the dura, an anterior approach may be necessary for direct decompression.4 In Video 1, we demonstrate the successful application of a multidisciplinary approach for surgical resection of a large OPLL lesion located at the T2-3 disk space. A 37-year-old female with medical history significant for rickets presented a year after a fall with bilateral lower extremity paraparesis and saddle anesthesia. Exposure consisted of a manubrial window, followed by thoracic diskectomy and fusion with drilling of the calcified posterior longitudinal ligament. Major steps within this video include 1) a summary of the patient presentation and preoperative imaging, 2) exposure of thoracic vertebrae via a manubrial window approach, 3) thoracic diskectomy and fusion with take-down of calcified posterior longitudinal ligament, and 4) a review of the postoperative imaging. The patient tolerated the procedure well with immediate relief of symptoms and was subsequently discharged on postoperative day 1 with no complications. This operative video illustrates the technical steps and capabilities of an anterior approach, achieving near-complete gross total resection of an OPLL lesion using a multidisciplinary approach. The patient consented to this procedure.

Focused versus conventional radiotherapy in spinal oncology: is there any difference in fusion rates and pseudoarthrosis?

INTRODUCTION: Radiotherapy is considered standard of care for adjuvant peri-operative treatment of many spinal tumors, including those with instrumented fusion. Unfortunately, radiation treatment has been linked to increased risk of pseudoarthrosis. Newer focused radiotherapy strategies with enhanced conformality could offer improved fusion rates for these patients, but this has not been confirmed. METHODS: We performed a retrospective analysis of patients at three tertiary care academic institutions with primary and secondary spinal malignancies that underwent resection, instrumented fusion, and peri-operative radiotherapy. Two board certified neuro-radiologists used the Lenke fusion score to grade fusion status at 6 and 12-months after surgery. Secondary outcomes included clinical pseudoarthrosis, wound complications, the effect of radiation timing and radiobiological dose delivered, the use of photons versus protons, tumor type, tumor location, and use of autograft on fusion outcomes. RESULTS: After review of 1252 spinal tumor patients, there were 60 patients with at least 6 months follow-up that were included in our analyses. Twenty-five of these patients received focused radiotherapy, 20 patients received conventional radiotherapy, and 15 patients were treated with protons. There was no significant difference between the groups for covariates such as smoking status, obesity, diabetes, intraoperative use of autograft, and use of peri-operative chemotherapy. There was a significantly higher rate of fusion for patients treated with focused radiotherapy compared to those treated with conventional radiotherapy at 6-months (64.0% versus 30.0%, Odds ratio: 4.15, p = 0.036) and 12-months (80.0% versus 42.1%, OR: 5.50, p = 0.022). There was a significantly higher rate of clinical pseudoarthrosis in the conventional radiotherapy cohort compared to patients in the focused radiotherapy cohort (19.1% versus 0%, p = 0.037). There was no difference in fusion outcomes for any of the secondary outcomes except for use of autograft. The use of intra-operative autograft was associated with an improved fusion at 12-months (66.7% versus 37.5%, OR: 3.33, p = 0.043). CONCLUSION: Focused radiotherapy may be associated with an improved rate of fusion and clinical pseudoarthrosis when compared to conventional radiation delivery strategies in patients with spinal tumors. Use of autograft at the time of surgery may be associated with improved 12-month fusion rates. Further large-scale prospective and randomized controlled studies are needed to better stratify the effects of radiation delivery modality in these patients.

Burnout and Emotional Intelligence in Neurosurgical Advanced Practice Providers Across the United States: A Cross-Sectional Analysis.

OBJECTIVE: Although much research has examined nursing and physician burnout, the advanced practice provider (APP) population has not yet been studied. The goal of the present study was to survey APPs in neurosurgery to determine whether greater emotional intelligence (EI) is protective against burnout. METHODS: An 80-item survey was created that incorporated the Maslach Burnout Inventory Human Services Survey for Medical Personnel, the Trait Emotional Intelligence Questionnaire-short form, and original questions developed by us. The collective survey was distributed, administered, and collected using the web-based REDCap (Research Electronic Data Capture) platform. Statistical analyses were completed using a comparison between participants with and without burnout. RESULTS: A total of 106 neurosurgical APPs (26 men, 80 women) completed the survey, of whom, 57 (54%) reported current burnout. High average scores for personal accomplishment and global EI were inversely related to burnout (P = 0.034 and P = 0.003, respectively). In addition, the following factors were associated with burnout: inadequate support staff in the work place (P = 0.008), inadequate time off work (P < 0.001), inadequate administrative time (P = 0.009), not experiencing support from one's supervisor (P = 0.017), insufficient time for continuing medical education (P < 0.001), an inability to separate work from personal time (P < 0.001), and an inability to advance within one's professional field (P = 0.043). CONCLUSIONS: For neurosurgical APPs, EI is protective against burnout. Many opportunities exist at the individual and organizational level to alleviate burnout among neurosurgical APPs. Targeted strategies to improve work-life balance, EI, support systems, and opportunities for career development among neurosurgical APPs might enhance employment satisfaction and reduce burnout.

A multicenter analysis of the prognostic value of histone H3 K27M mutation in adult high-grade spinal glioma.

OBJECTIVE: High-grade spinal glioma (HGSG) is a rare but aggressive tumor that occurs in both adults and children. Histone H3 K27M mutation correlates with poor prognosis in children with diffuse midline glioma. However, the role of H3 K27M mutation in the prognosis of adults with HGSG remains unclear owing to the rarity of this mutation, conflicting reports, and the absence of multicenter studies on this topic. METHODS: The authors studied a cohort of 30 adult patients with diffuse HGSG who underwent histological confirmation of diagnosis, surgical intervention, and treatment between January 2000 and July 2020 at six tertiary academic centers. The primary outcome was the effect of H3 K27M mutation status on progression-free survival (PFS) and overall survival (OS). RESULTS: Thirty patients (18 males and 12 females) with a median (range) age of 50.5 (19-76) years were included in the analysis. Eighteen patients had H3 K27M mutation-positive tumors, and 12 had H3 K27M mutation-negative tumors. The median (interquartile range) PFS was 3 (10) months, and the median (interquartile range) OS was 9 (23) months. The factors associated with increased survival were treatment with concurrent chemotherapy/radiation (p = 0.006 for PFS, and p ≤ 0.001 for OS) and American Spinal Injury Association grade C or better at presentation (p = 0.043 for PFS, and p < 0.001 for OS). There were no significant differences in outcomes based on tumor location, extent of resection, sex, or H3 K27M mutation status. Analysis restricted to HGSG containing necrosis and/or microvascular proliferation (WHO grade IV histological features) revealed increased OS for patients with H3 K27M mutation-positive tumors (p = 0.017). CONCLUSIONS: Although H3 K27M mutant-positive HGSG was associated with poor outcomes in adult patients, the outcomes of patients with H3 K27M mutant-positive HGSG were somewhat more favorable compared with those of their H3 K27M mutant-negative HGSG counterparts. Further preclinical animal studies and larger clinical studies are needed to further understand the age-dependent effects of H3 K27M mutation.

Surgical Management of Retro-Odontoid Cystic Mass with Cervicomedullary Compression.

Retro-odontoid cysts are a rare cause of cervicomedullary compression. The etiology of these lesions is not completely understood. Previous trauma and instability at the cervicomedullary junction may be the precipitating event in the development of retro-odontoid cysts in rare cases. We discussed the neurosurgical evaluation of a patient who presented with progressive and rapid neurological deterioration secondary to cervicomedullary compression. Posterior occipitocervical fusion was performed. The patient made an excellent neurological recovery, and postoperative imaging studies demonstrated resolution of the compression and intramedullary cyst.

Cervical intradural intramedullary collision tumor of schwannoma and hemangioblastoma origin.

BACKGROUND: Primary spinal tumors are rare benign lesions that represent around 2-4% of all central nervous system neoplasms.[1,2] Intradural intramedullary tumors are predominately glial in origin and are most commonly astrocytomas or ependymomas. Intradural extramedullary tumors, on the other hand, are usually neurofibromas, schwannomas, or meningiomas.[2] Here, we report the case of an intradural intramedullary collision tumor of schwannoma-hemangioblastoma origin. CASE DESCRIPTION: A 61-year-old female presented with a 2-year history of the right arm numbness, weakness, and tingling. She reported some lower extremity numbness but an otherwise normal neurological examination. She had a prior carpal tunnel release that did not alleviate her symptoms. Noncontrast MRI of the cervical spine demonstrated a holocord syrinx from C2 to C7 and spondylolisthesis from C4 to C5. MRI with contrast then displayed an enhancing nodule behind the vertebral body of C4. A standard posterior approach and subperiosteal dissection were performed. Lateral mass screws were placed at C3-C5, and the laminectomy was performed en bloc. Intraoperative ultrasound was used to locate the lesion, and intraoperative dorsal column mapping was used to identify the midline before performing a midline myelotomy. The arachnoid over the lesion was opened and an extracapsular dissection was performed. Hemostasis was obtained, and a watertight dural closure was performed. CONCLUSION: The patient tolerated the procedure well and achieved relief from cervical myelopathy symptoms. Pathology indicated positive biomarkers for S-100, SOX10, and NSE indicating a schwannoma hemangioblastoma collision tumor. This is unusual in its nature given two benign lesions with differing underlying cell types of origin.

Carbon fiber-reinforced PEEK instrumentation in the spinal oncology population: a retrospective series demonstrating technique, feasibility, and clinical outcomes.

OBJECTIVE: The authors aimed to demonstrate the feasibility and advantages of carbon fiber-reinforced PEEK (CFRP) composite implants in patients with both primary and secondary osseous spinal tumors. METHODS: Twenty-eight spinal tumor patients who underwent fixation with CFRP hardware were retrospectively identified in a Spine Tumor Quality Database at a single institution. Demographic, procedural, and follow-up data were retrospectively collected. RESULTS: The study population included 14 females and 14 males with a mean age of 60 years (range 30-86 years). Five patients had primary bone tumors, and the remaining patients had metastatic tumors. Breast cancer was the most common metastatic tumor. The most common presenting symptom was axial spine pain (25 patients, 89%), and the most common Spine Instability Neoplastic Score was 7 (range 6-14). Two patients in this series had anterior cervical procedures. The remaining patients underwent posterior thoracolumbar fixation. The average fusion length included 4.6 vertebral segments (range 3-8). The mean clinical follow-up time with surgical or oncology teams was 6.5 months (range 1-23 months), and the mean interval for last follow-up imaging (CT or MRI) was 6.5 months (range 1-22 months). Eighteen patients received postoperative radiation at the authors' institution (16 with photon therapy, 2 with proton therapy). Eleven of the patients (39%) in this series died. At the last clinical follow-up, 26 patients (93%) had stable or improved neurological function compared with their preoperative status. At the last imaging follow-up, local disease control was observed in 25 patients (89%). Two patients required reoperation in the immediate postoperative period, one for surgical site infection and the other for compressive epidural hematoma. One patient was noted to have lucencies around the most cephalad screws 3 months after surgery. No hardware fracture or malfunction occurred intraoperatively. No patients required delayed surgery for hardware loosening, fracture, or other failure. Early tumor recurrence was detected in 3 patients. Early detection was attributed to the imaging characteristics of the CFRP hardware. CONCLUSIONS: CFRP spinal implants appear to be safe and comparable to conventional titanium implants in terms of functionality. The imaging characteristics of CFRP hardware facilitate radiation planning and assessment of surveillance imaging. CFRP hardware may enhance safety and efficacy, particularly with particle therapy dosimetry. Larger patient populations with longer-term follow-up are needed to confirm the various valuable aspects of CFRP spinal implants.

Cervical chordomas: multicenter case series and meta-analysis.

BACKGROUND: En bloc spondylectomy is the gold standard for surgical resection of sacral chordomas (CHO), but the effect of extent of resection on recurrence and survival in patients with CHO of the cervical spine remains elusive. METHODS: MEDLINE, Embase, Scopus, and Cochrane were systematically reviewed. Patients with cervical CHO treated at three tertiary-care academic institutions were reviewed for inclusion. We performed an individual participant data meta-analysis to assess the overall survival (OS) and progression free survival (PFS) after en bloc-gross total resection (GTR) and intralesional-GTR compared to subtotal resection (STR). We then performed an intention-to-treat analysis including all patients with attempted en bloc resection in the en bloc group, regardless of the surgical margins. RESULTS: There was a total of 13 series including 161 patients with cervical CHO, including our current series of 22 patients. GTR (en bloc-GTR + intralesional-GTR) was associated with a significant decrease in the risk of local progression (pooled hazard ratio (PHR) = 0.22; 95% CI 0.08-0.59; p = 0.003) and risk of death (PHR 0.31; 95%; CI 0.12-0.83; p = 0.020). A meta-regression analyses determined that intralesional-GTR improved PFS (PHR 0.35; 95% CI 0.16-0.76; p = 0.009) as well as OS (PHR 0.25; 95% CI 0.08-0.79; p = 0.019) when compared to STR. En bloc-GTR was associated with a significant reduction in the risk of local progression (PHR 0.06; 95% CI 0.01-0.77; p = 0.030), but not a decreased OS (PHR 0.50; 95% CI 0.19-1.27; p = 0.145). Our intention-to-treat analyses revealed a near significant improvement in OS for the en bloc group (PHR: 0.15; 95% CI 0.02-1.22; p = 0.054), and nearly identical improvement in PFS. Radiation data was not available for the studies included in the meta-analysis. CONCLUSION: This is the first and only meta-analysis of patients with cervical CHO. We found that both en bloc-GTR and intralesional-GTR resulted in improved local tumor control when compared to STR.

A Technical Nuance to Avoid Lumbar Five Radiculopathy with Anterior Lumbar Fusion and Posterior Instrumentation.

The anterior lumbar interbody fusion (ALIF) is a well-established procedure used to treat a multitude of spinal pathologies. When performed at the L5-S1 level, the ALIF is often supplemented with posterior pedicle screw and rod fixation. Because the interbody device can restore disk and foraminal height, one benefit of the ALIF procedure is indirect neural decompression in the spinal canal and neural foramina. If the contour of the posterior rod is not matched to the exact position of the tulip heads on the pedicle screws, spondylolisthesis can be introduced, leading to foraminal stenosis and nerve compression. This concern is particularly germane when the posterior instrumentation is placed percutaneously without any direct foraminal decompression. In this report, we describe a patient who had an L4-S1 ALIF, resulting in new L5-S1 retrolisthesis and worsening L5 radiculopathy. Technical nuances and avoidance strategies are discussed.