Evaluation of Conditions for the Development of Cryogenic Spinal Cord Injury Using a Canine Model: An Experimental Study on the Safety of Cryoablation for Metastatic Spinal Tumors.

BACKGROUND AND PURPOSE: Although the application of cryoablation to metastatic spinal tumors has been attempted, spinal cryoablation has the unique complication of cryogenic spinal cord injury. This study aimed to elucidate the conditions for the development of cryogenic spinal cord injury. MATERIALS AND METHODS: Fifteen canines were used in this study. A metal probe was inserted into the 13th thoracic vertebral body. Cryoablation was performed for 10 minutes by freezing the probe in liquid nitrogen. The control canine underwent probe insertion only. Spinal cord monitoring, epidural temperature measurement, motor function assessment, and pathologic examination of the spinal cord were performed. RESULTS: During the 10 minutes of cryoablation, the epidural temperature decreased and reached the lowest epidural temperature (LET) at the end of cryoablation. The LETs (degrees celsius [°C]) of each canine were -37, -30, -27, -8, -3, -2, 0, 1, 4, 8, 16, 18, 20, and 25, respectively. As the epidural temperature decreased, waveform amplitudes also decreased. At the end of cryoablation (10 minutes after the start of cryoablation), abnormal waves were observed in 92.9% (13/14) of canines. With epidural rewarming, the amplitude of the waveforms tended to recover. After epidural rewarming (2 hours after the start of cryoablation), abnormal waves were observed in 28.6% (4/14) of canines. The LETs (°C) of the canines with abnormal waves after epidural rewarming were -37, -30, -27, and -8. None of the canines with normal waves after epidural rewarming had any motor impairment. In contrast, all canines with remaining abnormal waves after epidural rewarming had motor impairment. In the pathologic assessment, cryogenic changes were found in canines with LETs (°C) of -37 -30, -27, -8, 0, and 1. CONCLUSIONS: This study showed that 10-minute spinal cryoablation with LETs (°C) of -37, -30, -27, -8, 0, and 1 caused cryogenic spinal cord injury. There was no evidence of cryogenic spinal cord injury in canines with LET of ≥4°C. The epidural temperature threshold for cryogenic spinal cord injury is between 1 and 4°C, suggesting that the epidural temperature should be maintained above at least 4°C to prevent cryogenic spinal cord injury.

Synchronous versus metachronous spinal metastasis: a comparative study of survival outcomes following neurosurgical treatment.

PURPOSE: Patients with spinal metastases (SM) from solid neoplasms typically exhibit progression to an advanced cancer stage. Such metastases can either develop concurrently with an existing cancer diagnosis (termed metachronous SM) or emerge as the initial indication of an undiagnosed malignancy (referred to as synchronous SM). The present study investigates the prognostic implications of synchronous compared to metachronous SM following surgical resection. METHODS: From 2015 to 2020, a total of 211 individuals underwent surgical intervention for SM at our neuro-oncology facility. We conducted a survival analysis starting from the date of the neurosurgical procedure, comparing those diagnosed with synchronous SM against those with metachronous SM. RESULTS: The predominant primary tumor types included lung cancer (23%), prostate cancer (21%), and breast cancer (11.3%). Of the participants, 97 (46%) had synchronous SM, while 114 (54%) had metachronous SM. The median overall survival post-surgery for those with synchronous SM was 13.5 months (95% confidence interval (CI) 6.1-15.8) compared to 13 months (95% CI 7.7-14.2) for those with metachronous SM (p = 0.74). CONCLUSIONS: Our findings suggest that the timing of SM diagnosis (synchronous versus metachronous) does not significantly affect survival outcomes following neurosurgical treatment for SM. These results support the consideration of neurosurgical procedures regardless of the temporal pattern of SM manifestation.

Clinical and oncologic outcomes of posterior only total en bloc spondylectomy for spinal metastasis involving third lumbar vertebra: A case series.

INTRODUCTION: A posterior-only total en bloc spondylectomy (TES) of the L3 level was deemed a highly intricate surgical procedure, necessitating the preservation of the L3 nerve root to prevent neurological deterioration. Despite bilateral preservation efforts of the L3 nerve roots, neurological deterioration proved unavoidable. This study aims to present the clinical, neurologic, and oncologic outcomes of spinal metastasis patients who underwent a posterior-only approach TES, encompassing the L3 vertebra. MATERIALS AND METHODS: All patients with L3-involved spinal metastasis undergoing posterior TES between January 2018 and January 2022 were investigated. The primary outcomes considered were the local recurrence rate and manual muscle testing of the lumbar myotome. Secondary outcomes included Frankel neurological status, operative time, blood loss, perioperative and postoperative complications, and Eastern Cooperative Oncology Group score. RESULTS: Five patients with TES involving L3 (three females) met the inclusion criteria. All patients had solitary metastases (three in the lungs, 2 in the breasts). Postoperatively, all patients experienced weakness of the hip flexors, but they were able to ambulate independently 12 months after surgery. One patient exhibited adjacent segment (L2) disease progression and underwent corpectomy 18 months after TES. No local recurrences at the surgical site were detected on magnetic resonance imaging at the 1-year follow-up. CONCLUSION: Posterior-only TES for L3-involved vertebrae yielded excellent results in the local control of metastatic disease. Despite hip flexor weakness, all patients were able to regain independent ambulation after 12 months. TES can offer favorable clinical and oncological outcomes in patients with solitary spinal metastases.

Customized 3-dimensional-printed Vertebral Implants for Spinal Reconstruction After Tumor Resection: A Systematic Review.

STUDY DESIGN: Systematic review. OBJECTIVE: To examine the outcomes of customized 3-dimensional (3D) printed implants for spinal reconstruction after tumor resection. SUMMARY OF BACKGROUND DATA: Various techniques exist for spinal reconstruction after tumor resection. Currently, there is no consensus regarding the utility of customized 3D-printed implants for spinal reconstruction after tumor resection. MATERIALS AND METHODS: A systematic review was registered with PROSPERO and performed according to "Preferred Reporting Items for Systematic Reviews and Meta-analyses" guidelines. All level I-V evidence studies reporting the use of 3D-printed implants for spinal reconstruction after tumor resection were included. RESULTS: Eleven studies (65 patients; mean age, 40.9 ± 18.1 y) were included. Eleven patients (16.9%) underwent intralesional resections with positive margins and 54 patients (83.1%) underwent en bloc spondylectomy with negative margins. All patients underwent vertebral reconstruction with 3D-printed titanium implants. Tumor involvement was in the cervical spine in 21 patients (32.3%), thoracic spine in 29 patients (44.6%), thoracolumbar junction in 2 patients (3.1%), and lumbar spine in 13 patients (20.0%). Ten studies with 62 patients reported perioperative outcomes radiologic/oncologic status at final follow-up. At the mean final follow-up of 18.5 ± 9.8 months, 47 patients (75.8%) had no evidence of disease, 9 patients (14.5%) were alive with recurrence, and 6 patients (9.7%) had died of disease. One patient who underwent C3-C5 en bloc spondylectomy had an asymptomatic subsidence of 2.7 mm at the final follow-up. Twenty patients that underwent thoracic and/or lumbar reconstruction had a mean subsidence of 3.8 ± 4.7 mm at the final follow-up; however, only 1 patient had a symptomatic subsidence that required revision surgery. Eleven patients (17.7%) had one or more major complications. CONCLUSION: There is some evidence to suggest that using customized 3D-printed titanium or titanium alloy implants is an effective technique for spinal reconstruction after tumor resection. There is a high incidence of asymptomatic subsidence and major complications that are similar to other methods of reconstruction. LEVEL OF EVIDENCE: Level V, systematic review of level I-V studies.

Cauda equina neuroendocrine tumors: A single institutional imaging review of cases over two decades.

Cauda Equina Neuroendocrine Tumors (CE-NET), previously referred to as paragangliomas are a rare subset of spinal tumors, with limited data on imaging. Herein, we present a retrospective review of clinical and imaging findings of CE-NETs in ten patients who were evaluated at our institution over the past two decades. All patients had well-defined intradural lesions in the lumbar spine which demonstrated slow growth. A review of imaging findings revealed the presence of an eccentric vascular pedicle along the dorsal aspect of the tumor in 8 of the 10 patients (eccentric vessel sign), a distinctive finding that has not previously been reported with this tumor and may help improve the accuracy of imaging-based diagnosis. In all cases, a gross-total resection was performed, with resolution of symptoms in most of the cases.

Technical aspects of total spondylectomy of C2.

BACKGROUND: Tumorous involvement of the second cervical vertebra is an infrequent, but severe disease. Primary tumors and solitary metastases can be addressed by a radical procedure, a complete removal of the whole compartment. The second cervical vertebra has a highly complex anatomy, and its operation requires considerable surgical skills. The aim of this retrospective study is to present technical aspects of complete resection of C2 for tumor indications, clinical and radiological evaluation of our group of patients and comparison of results of recent reports on surgery in this region in the literature. METHODS: Between 2006 and 2019 we performed 10 total resections of C2 for primary bone tumor or solitary metastasis at our department. Operation was indicated for chordoma in 4 cases and for other diagnoses (plasmacytoma, EWSA, metastases of papillary thyroid carcinoma, medullary thyroid carcinoma, lung carcinoma and sinonasal carcinoma) in one case each. The operative procedure was in all cases performed in two steps. It always started with the posterior approach. The anterior procedure was scheduled according to the patient's condition after an average interval of 16.9 days (range 7-21). RESULTS: A stable upper cervical spine was achieved in all patients. A solid bone fusion over the whole instrumentation was present in all living patients and they returned to their preoperative activity level. By the final follow-up 6 patients died: one patient died on the 5th postop day because of diffuse uncontrollable bleeding from surgical wound, three patients died of generalization of the underlying disease and two patients due to complications associated with local recurrence of the disease. In addition to regular follow-ups, the surviving patients (N.=4) were also examined upon completion of the study, i.e., on average 91 months (range 17-179 months) postoperatively. With exclusion of an early deceased patient, the average follow-up period of deceased patients was 34.6 months (range 9-55) (N.=5). The average follow-up of the whole group of patients was 59,7 months (N.=9). CONCLUSIONS: Total spondylectomy of C2 is an exceptional surgical procedure associated with risk of serious complications but offers chance for a complete recovery of the patient. Defining indications accurately, especially in solitary metastases, is very difficult even with current level of imaging and other testing. The quality of life of long-term surviving patients in our study was not significantly impacted.

Disparities in Primary Spinal Osseous Malignant Bone Tumor Survival by Medicaid Status: A National Population-Based Risk Analysis.

BACKGROUND: The impact of Medicaid status on survival outcomes of patients with spinal primary malignant bone tumors (sPMBT) has not been investigated. METHODS: Using the SEER-Medicaid database, adults diagnosed between 2006 and 2013 with sPMBT including chordoma, osteosarcoma, chondrosarcoma, Ewing sarcoma, or malignant giant cell tumor (GCT) were studied. Five-year survival analysis was performed using the Kaplan-Meier method. Adjusted survival analysis was performed using Cox proportional-hazards regression controlling for age, sex, marital status, cancer stage, poverty level, vertebral versus sacral location, geography, rurality, tumor diameter, tumor grade, tumor histology, and therapy. RESULTS: A total of 572 patients with sPMBT (Medicaid: 59, non-Medicaid: 513) were identified. Medicaid patients were more likely to be younger (P < 0.001), Black (P < 0.001), live in high poverty neighborhoods (P = 0.006), have distant metastases at diagnosis (P < 0.001), and less likely to receive surgery (P = 0.006). The 5-year survival rate was 65.7% (chondrosarcoma: 70.0%, chordoma: 91.5%, Ewing sarcoma: 44.6%, GCT: 90.0%, osteosarcoma: 34.2%). Medicaid patients had significantly worse 5-year survival than non-Medicaid patients (52.0% vs. 67.2%, P = 0.02). Minority individuals on Medicaid were associated with an increased risk of cancer-specific mortality compared with White non-Medicaid patients (adjusted hazard ratio [aHR] = 2.51, [95% CI 1.18-5.35], P = 0.017). Among Medicaid patients, those who received surgery had significantly better survival than those who did not (64.5% vs. 30.6%, P = 0.001). For all patients, not receiving surgery (aHR = 1.90 [1.23-2.95], P = 0.004) and tumor diameter >50 mm (aHR=1.89 [1.10-3.25], P = 0.023) were associated with an increased risk of mortality. CONCLUSIONS: Medicaid patients may be less likely to receive surgery and suffer from poorer survival. These disparities may be especially prominent among minorities.

The prognostic role of neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, and systemic immune-inflammation index on short- and long-term outcome following surgery for spinal metastases.

OBJECTIVE: Inflammatory markers such as neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and systemic immune-inflammation index (SII) have shown promise in predicting mortality in various types of cancer. The purpose of this study was to assess NLR, PLR, and SII in predicting 30-day mortality and overall survival (OS) among surgically treated patients with spinal metastasis. METHODS: This was a retrospective study including 153 patients who underwent surgery for spinal metastasis between 2012 and 2022. Electronic medical records were manually reviewed, and NLR, PLR, and SII were calculated from preoperative neutrophil, platelet, and lymphocyte counts. Receiver operating characteristic curves with areas under the curve were generated to determine cutoff values. Logistic regression was used to determine the odds ratios (ORs) for 30-day mortality. The Kaplan-Meier method and Cox regression were used to determine the hazard ratio (HR) for OS limited to 5 years postoperatively. RESULTS: Preoperative cutoff values were as follows: NLR > 10.2, PLR > 260, and SII > 2900. Overall, 35.9% (55/153) of patients had elevated NLR, 45.7% (70/153) had elevated PLR, and 30.7% (47/153) had elevated SII. The overall 30-day mortality was 8.5% (13/153). After controlling for confounders such as performance status and primary tumor type, high NLR (OR 5.20, 95% CI 1.21-22.28; p = 0.026) and SII (OR 4.92, 95% CI 1.17-20.63; p = 0.029) were associated with increased odds of 30-day postoperative mortality. The median OS time in the study population was 26 months (95% CI 12-40 months). After controlling for confounders such as Eastern Cooperative Oncology Group status, primary tumor, and hypoalbuminemia, high NLR was associated with shorter OS (HR 2.23, 95% CI 1.48-3.97; p = 0.003). CONCLUSIONS: High preoperative NLR and SII were independently associated with 30-day postoperative mortality in this study. Elevated NLR was also found to be associated with shorter OS. The prognostic role of these metrics warrants further investigation.

Long-Term Outcomes of Infantile Sacrococcygeal Teratoma: Results from a Multi-Institutional Retrospective Observational Study in Japan.

BACKGROUND: Tumor recurrence, anorectal and urinary dysfunction, and lower limb dysfunction after surgery are observed in infantile sacrococcygeal teratoma (SCT). In this paper, a multi-institutional retrospective observational study was conducted to clarify the long-term functional prognosis in Japan. METHODS: This study was conducted using a paper-based questionnaire distributed to 192 facilities accredited by the Japanese Society of Pediatric Surgeons, covering patients who underwent radical surgery at less than 1 year old and who survived for at least 180 days after birth from 2000 to 2019. RESULTS: A total of 355 patients were included in this analysis. Altman type was I-II in 248 and type III-IV in 107, and the median maximum tumor diameter was 6.1 (range: 0.6-36.0) cm. There were 269 mature teratomas, 69 immature teratomas, and 10 malignant tumors. Total resection was performed in 325, subtotal or partial resection in 27, and surgical complications were noted in 54. The median postoperative follow-up was 6.6 (0.5-21.7) years. Eighty-three patients (23.4 %) had functional sequelae, including 62 (17.5 %) with anorectal dysfunction, 56 (13.0 %) with urinary dysfunction, and 15 (4.2 %) with lower limb motor dysfunction. Recurrence occurred in 42 (11.8 %) at a median age of 16.8 (1.7-145.1) months old. Risk factors for dysfunction included preterm delivery, a large tumor diameter, Altman type III-IV, incomplete resection, and surgical complications. Risk factors for recurrence included immature teratoma or malignancy, incomplete resection, and surgical complications. CONCLUSIONS: Postoperative dysfunction was not low at 23.4 %, and 11.8 % of the patients experienced recurrence occurring more than 10 years after surgery, suggesting the need for periodic imaging and tumor markers evaluations in patients with risk factors. It is necessary to establish treatment guidelines for best practice monitoring of the long-term quality of life. LEVEL OF EVIDENCE: Level II Retrospective Study.

Updates in the Management of Metastatic Spine Disease.

The number of cancer diagnoses continues to increase each year in the United States, and given the propensity for bone metastases from solid organ malignancies, orthopaedic spine surgeons will inevitably encounter patients with metastatic spine disease and need to have a framework for approaching the evaluation and treatment of these complex patients. Many patients seeking care for spinal metastases already have a history of disseminated malignancy, but metastatic spine disease itself will be the presenting symptom of cancer in approximately 20% of patients. Because the first presentation of cancer may be to a spine surgeon, an appropriate strategy for the initial evaluation of a patient with a new spinal lesion is critical to establish the diagnosis of metastatic disease before undergoing treatment. Once the diagnosis of metastatic spine disease is confirmed, decisions regarding treatment should be made in coordination with a multidisciplinary team including radiation oncology and medical oncology. Spinal metastases are most often treated with radiation therapy. Direct circumferential decompression of the spinal cord with postoperative radiation therapy is considered for high-grade epidural spinal cord compression to preserve neurologic function. Mechanical spinal instability is another potential indication for surgery. When considering surgery, the patient's medical fitness, systemic burden of cancer, and overall prognosis all must be accounted for, and the importance of multidisciplinary evaluation and shared decision making cannot be overstated.

T1-Weighted, Dynamic Contrast-Enhanced MR Perfusion Imaging Can Differentiate between Treatment Success and Failure in Spine Metastases Undergoing Radiation Therapy.

BACKGROUND AND PURPOSE: Current imaging techniques have difficulty differentiating treatment success and failure in spinal metastases undergoing radiation therapy. This study investigated the correlation between changes in dynamic contrast-enhanced MR imaging perfusion parameters and clinical outcomes following radiation therapy for spinal metastases. We hypothesized that perfusion parameters will outperform traditional size measurements in discriminating treatment success and failure. MATERIALS AND METHODS: This retrospective study included 49 patients (mean age, 63 [SD, 13] years; 29 men) with metastatic lesions treated with radiation therapy who underwent dynamic contrast-enhanced MR imaging. The median time between radiation therapy and follow-up dynamic contrast-enhanced MR imaging was 62 days. We divided patients into 2 groups: clinical success (n = 38) and failure (n = 11). Failure was defined as PET recurrence (n = 5), biopsy-proved (n = 1) recurrence, or an increase in tumor size (n = 7), while their absence defined clinical success. A Mann-Whitney U test was performed to assess differences between groups. RESULTS: The reduction in plasma volume was greater in the success group than in the failure group (-57.3% versus +88.2%, respectively; P < .001). When we assessed the success of treatment, the sensitivity of plasma volume was 91% (10 of 11; 95% CI, 82%-97%) and the specificity was 87% (33 of 38; 95% CI, 73%-94%). The sensitivity of size measurements was 82% (9 of 11; 95% CI, 67%-90%) and the specificity was 47% (18 of 38; 95% CI, 37%-67%). CONCLUSIONS: The specificity of plasma volume was higher than that of conventional size measurements, suggesting that dynamic contrast-enhanced MR imaging is a powerful tool to discriminate between treatment success and failure.

Surgical treatment of male breast cancer metastasis to thoracic spine: A case report.

PURPOSE: We present a rare clinical case of a metastatic spinal tumor in the 7th thoracic spine from male breast cancer (MBC). METHOD: A 62-year-old man was referred as an outpatient, complaining of continuous pain in the back and right flank that began 2 weeks earlier. The patient had no neurologic signs or symptoms but had a medical history of left breast modified radical mastectomy because of MBC. Computed tomography and magnetic resonance imaging showed metastasis in the T7 vertebra and no other metastasis on positron emission tomography/computed tomography or bone scan. Separation surgery was performed with posterior corpectomy of T7 (en bloc excision), followed by stabilization with an expandable titanium cage and pedicle screws. The pathological examination of the excised T7 vertebra confirmed metastatic carcinoma with neuroendocrine differentiation from the breast. Adjuvant chemo-radiotherapy was performed after surgery. RESULTS: The patient had no symptoms at the 21-month follow-up. Radiologic studies showed no evidence of recurrent or metastatic lesions. CONCLUSION: MBC is extremely rare, with fewer cases of spinal metastases. Among these, patients who undergo separation surgery are even rarer. This case shows that radical surgery can be an option for MBC with spine metastasis if indicated.

The new clinical classification of metastatic spinal malignancies serves as a vital reference for surgical management: a retrospective case-control study.

BACKGROUND: It is commonly accepted that surgical treatment is an essential component of the comprehensive management of metastatic spinal malignancies. However, up until now, the clinical classification of metastatic spinal malignancies has not been well-structured. METHODS: After IRB approval, 86 patients with metastatic spinal malignancies were adopted. According to the vascular distribution, stability of vertebrae, and degree of nerve compression, metastatic spinal malignancies can be classified into five types. Tumors classified as type I typically appear in the vertebral body. Type II tumors are those that develop in the transverse processes, superior and inferior articular processes, and spinal pedicles. Type III denotes malignancies that are present in the spinous process and vertebral plate. Types IVa and IVb are included in type IV. Type IVa combines type I and type II, whereas type IVb combines type II and type III. Type V tumors are those of types I, II, and III that co-occur and spread in different directions into the spinal canal. 20 of included 86 patients who did not receive segmental arterial embolization were set as the non-embolization group. The embolization group included 24 patients who received segmental arterial embolization on both sides of the diseased vertebrae. 42 patients were included in the offending embolization group after receiving responsible arterial embolization. A surgical intervention was performed within 24 h following an embolization. Surgical intervention with the purpose of removing as much of the tumor as possible and providing an effective reconstruction of the spinal column. RESULTS: In comparison with the non-embolization group and embolization group, the offending embolization group presented unique advantages in terms of bleeding volume (p<0.001), operation time (p<0.001), and local recurrence rate within 12 months (p=0.006). CONCLUSION: By significantly reducing surgical trauma and local recurrence rate (12 months), responsible arterial vascular embolization procedures together with associated surgical protocols developed on the basis of the clinical classification of metastatic spinal malignancies, are worthy of clinical dissemination.

Denosumab for an inoperable giant cell tumour of the ischial bone.

Giant cell tumour of bone is a benign, locally aggressive osteolytic tumour that typically affects skeletally mature young individuals. It predominantly emerges within the metaphysis, extending towards the epiphysis of long bones, while occurrences in flat bones are exceptionally rare. We present a case of a woman in her late 20s who presented with a large right ischial mass. A biopsy confirmed the mass as a giant cell tumour. The tumour extended to the acetabulum, and due to the potential risk of significant bleeding and contamination during en bloc excision, a prudent approach involved initiating denosumab therapy, a monoclonal antibody targeting receptor activator of nuclear factor-κB ligand therapy, before proceeding with radical surgery. Denosumab therapy successfully rendered a previously inoperable tumour favourable for surgical intervention. We went on to perform a type 2 and 3 internal hemipelvectomy, followed by a reconstruction with a hip endoprosthesis replacement.

Antibiotic-loaded bone cement combined with negative pressure wound therapy for treating sacrococcygeal wound following sacral chordoma resection: a case report.

BACKGROUND: Sacral chordoma is a rare, malignant primary bone tumor with subtle clinical manifestations. The extensive cavity and soft tissue defect after radical resection of the tumor can lead to complications such as sacrococcygeal skin necrosis, infection, cerebrospinal fluid (CSF) leakage, and delayed healing or nonhealing. PURPOSE: To describe the treatment effect of the combination use of antibiotic-loaded bone cement (ALBC), a gluteus maximus muscle flap, and negative pressure wound therapy (NPWT) on the nonhealing sacrococcygeal wound after sacral chordoma resection. CASE REPORT: A 67-year-old woman with a sacrococcygeal wound following sacral chordoma resection was admitted to the hospital. In the 2-stage surgery, the internal fixation and synthetic dura substitute were exposed and CSF leakage was found after debridement, a gluteus maximus muscle flap was used to cover the synthetic dura substitute to address the CSF leakage, ALBC was used to cover the internal fixation, and a modified NPWT system was fixed to the wound for improved flushing and drainage. RESULTS: The previously nonhealing wound healed 3 weeks postoperatively, and satisfactory recovery was achieved by 6-month follow-up. CONCLUSION: This case report suggests that the combination use of ALBC, gluteus maximus muscle flap, and NPWT can effectively promote sacrococcygeal wound healing after chordoma resection.

Surgical outcomes and risk factors for surgical complications after en bloc resection following reconstruction with 3D-printed artificial vertebral body for thoracolumbar tumors.

BACKGROUND: The outcomes of patients with tumors of the thoracolumbar spine treated with en bloc resection (EBR) using three-dimensional (3D)-printed endoprostheses are underreported. METHODS: We retrospectively evaluated patients with thoracolumbar tumors who underwent surgery at our institution. Logistic regression analysis was performed to identify the potential risk factors for surgical complications. Nomograms to predict complications were constructed and validated. RESULTS: A total of 53 patients with spinal tumors underwent EBR at our hospital; of these, 2 were lost to follow-up, 45 underwent total en bloc spondylectomy, and 6 were treated with sagittal en bloc spondylectomy. The anterior reconstruction materials included a customized 3D-printed artificial vertebral body (AVB) in 10 cases and an off-the-shelf 3D-printed AVB in 41 cases, and prosthesis mismatch occurred in 2 patients reconstructed with the off-the-shelf 3D-printed AVB. The median follow-up period was 21 months (range, 7-57 months). Three patients experienced local recurrence, and 5 patients died at the final follow-up. A total of 50 perioperative complications were encountered in 29 patients, including 25 major and 25 minor complications. Instrumentation failure occurred in 1 patient, and no prosthesis subsidence was observed. Using a combined surgical approach was a dependent predictor of overall complications, while Karnofsky performance status score, lumbar spine lesion, and intraoperative blood loss ≥ 2000 mL were predictors of major complications. Nomograms for the overall and major complications were constructed using these factors, with C-indices of 0.850 and 0.891, respectively. CONCLUSIONS: EBR is essential for the management of thoracolumbar tumors; however, EBR has a steep learning curve and a high complication rate. A 3D-printed AVB is an effective and feasible reconstruction option for patients treated with EBR.

A rare case of skin metastasis from a chordoma.

Chordoma is an uncommon, indolent malignant tumor arising from notochordal remnants. The incidence of distant metastasis varies between 30 and 40% in different series. Even though local involvement of the skin by direct invasion of chordoma is common, distant skin metastasis are rare, with less than 30 cases reported in the literature. The present clinical case illustrates the slow-growing natural history of a sacral chordoma, which evolved with lung metastasis, followed three years later by skin metastasis, thus giving us the opportunity to review the diagnostic approach, as well as the clinical and histopathological characteristics of this rare tumor.