Total en bloc spondylectomy for locally aggressive and primary malignant tumors of the lumbar spine

Long-term Titanium mesh cage implant failure after total en bloc spondylectomy due to spinal chondrosarcoma

OBJECTIVE

To report an unusual titanium mesh cage failure after ten years of follow-up.

CLINICAL CASE

A 40-year-old woman diagnosed with low-grade spinal chondrosarcoma underwent a total en-bloc spondylenctomy (TES) surgery. This technique required a wide resection, anterior reconstruction with a titanium mesh cage (TMC), and posterior stabilization. For several years a favorable clinical outcome was achieved. After 10 years of follow-up, the patient developed acute non-traumatic low back pain without neurological repercussions. The images confirmed a rupture of the titanium cage. After ruling out tumor recurrence, the patient went through spinal instrumentation revision.

CONCLUSION

Isolated TMC rupture is a rare event scarcely reported in the literature. There is a strong recommendation to instrument two levels proximal and distal to the bone defect in 360° reconstructions after a TES. Stability had likely been lost over the years due to the slow resorption of the bone graft. We consider necessary studies with a higher casuistry and level of evidence to analyze the contributing factors for the event of TMC rupture.

Surgical Treatments and Long-Term Outcomes for Pediatric Patients With Lumbar Spinal Tumors

STUDY DESIGN

Retrospective case‒control study.

OBJECTIVES

This study aimed to report the effects of surgical intervention on spinal stability recovery and to assess the long-term outcomes of children and adolescents with lumbar tumors.

METHODS

From January 2016 to June 2021, 42 pediatric patients with lumbar tumors were selected and separated into different groups based on the surgical method used (total en bloc resection (TER) group, n = 21; piecemeal resection (PR) group, n = 21; titanium mesh (TM) group n = 23; artificial vertebrae (AV) group n = 19). The clinicopathological characteristics, treatments and related outcomes were described in detail and compared between groups, with P value ≤.05 indicating statistically significant differences.

RESULTS

The average follow-up duration was 24.89 months, and the mean age was 14.89 ± 2.41 years. There were no significant differences in the mean operation time, average blood loss, complication rate, or length of hospital stay between the groups. The ODI, VAS and JOA scores at the final follow-up (FF) were elevated after surgery in all groups. The FF local angular drift (LOD) and lumbar angular drift (LUD) were greater in the TM group than in the AV group (P = .03, P = .001).

CONCLUSIONS

After surgery, pediatric patients with lumbar tumors can obtain satisfactory spinal stability, effective relief of pain symptoms and substantial improvements in neurological function. There was no significant difference in the invasiveness, safety or timeliness between the 2 surgical methods, so TER is recommended due to its low postoperative recurrence rate and good local control. Spinal fusion in the AV group resulted in better spinal stability.

EnBloc Resection of a Chordoma of the Thoracic Spine by "L"-Shaped Osteotomy for Spinal Canal Preservation

Background/Objectives: EnBloc resections of bone tumors of the spine are very demanding as the target to achieve a tumor-free margin specimen (sometimes impossible due to the extracompartimental tumor extension) is sometimes conflicting with the integrity of neurological functions and spine stability. Methods: The surgical treatment of a huge multi-level chordoma of the thoracic spine with unusual extension is reported. Anteriorly, the tumor widely invaded the mediastinum and displaced the aorta; on the left side, it expanded in the subpleuric region; posteriorly, it was uncommonly distant 13 mm from the posterior wall. Results: EnBloc resection is largely performed for primary bone tumors of the spine and many reports have been published concerning brilliant solutions to difficult issues of surgical anatomy. One of the major challenges is still the compatibility between oncological and functional requirements. Conclusions: Oncological staging, careful imaging analysis, a multidisciplinary surgical team, and utilization of the most recent technologies like navigation and robotics have made an oncologically appropriate EnBloc resection of a multi-level chordoma of the thoracic spine possible without affecting the continuity of the spinal canal and without any involvement of its content by an original "L"-shaped osteotomy.

Early clinical efficacy of 3D-printed artificial vertebral body in spinal reconstruction after total en bloc spondylectomy for spinal tumors

BACKGROUND

Total en bloc spondylectomy (TES) is a recognized surgical approach for managing spinal tumors. With advancements in three-dimensional (3D) printing technology, the use of 3D-printed prosthetics for vertebral reconstruction post-tumor resection has gained traction. However, research on the clinical implications of these prosthetics remains limited.

METHODS

This retrospective study evaluated patients who underwent TES for primary and metastatic thoracolumbar tumors at the Department of Spinal Surgery, Tianjin Hospital, between October 2017 and September 2020. These patients received anterior reconstruction with 3D-printed artificial vertebral bodies.

RESULTS

14 patients completed the surgery, with intraoperative blood loss ranging from 1,400 to 4,200 ml (mean 2,767 ± 790 ml) and operative duration between 240 and 520 min (mean 382 ± 75.9 min). The follow-up period extended from 7 to 43 months, with an average of 19.9 ± 9.5 months. Standardized prefabricated prosthetics were utilized in nine patients, while five received customized prosthetics. Throughout the follow-up, there were no reports of posterior connecting rod, 3D-printed prosthetic, or pedicle screw failures. Notably, one patient presented with significant prosthetic subsidence resulting in screw loosening, and three cases of prosthetic subsidence were observed.

CONCLUSION

The incorporation of 3D-printed prosthetics in TES procedures yielded favorable clinical outcomes. Further research is warranted to optimize these prosthetics for enhanced postoperative stability and patient-specific applications.

Safety and risk analysis of total resection surgery for thoracic and lumbar spinal tumors: a decadal analysis of 103 cases

STUDY DESIGN

Retrospective cohort study.

PURPOSE

To explore the complications and risk factors for total resection (TR) of primary thoracic and lumbar spinal tumors over the past decade at our institution.

METHODS

Patients meeting inclusion criteria (primary spinal tumors, thoracic or lumbar location, TR at our center) were included. Demographic characteristics, surgical data, perioperative complications and management results were reviewed. Patients were stratified by tumor site, the number of excised segments, and recurrence status to elucidate distinctive characteristics.

RESULTS

The cohort comprised 103 patients, with a mean age of 35.8 years. On average, 1.83 vertebral segments were resected per patient. Perioperative complications were substantial, totaling 166 events, with 71 classified as major and 95 as minor, yielding an average of 1.61 complications per patient. No perioperative deaths occurred, but 79 patients (76.7%) experienced at least one complication. Multiple vertebral sections correlated with a higher complication rate (P = 0.031), and lumbar surgeries exhibited elevated risks of large vascular injury (P = 0.001), neurological deterioration, and cerebrospinal fluid leakage compared to thoracic cases. Conversely, thoracic spinal procedures showed a higher rate of pleural effusion (P = 0.004). Binary logistics stepwise regression identified multi-segmental resection as the independent risk factor for major perioperative complications.

CONCLUSIONS

TR of primary spinal tumors is associated with a high perioperative complication rate, although most events have a favorable prognosis. Complication characteristics vary based on the surgical site, number of excised segments, and surgical history. A nuanced preoperative evaluating approach considering patient age, surgical segments, and extent of resection is crucial.

Application of contralateral osteotomy for the en bloc resection of paraspinal and spinal tumours: a report of three cases

We herein report the effectiveness of contralateral osteotomy of the pedicle and posterolateral elements for en bloc resection (COPPER) of paraspinal and spinal tumours. This surgical method allows for complete resection of the localized tumour in the lateral posterior lesion without removing the entire vertebral body, as in total en bloc spondylectomy. Complete resection of paraspinal and spinal tumours is challenging for spinal surgeons because of anatomical complexities. Although the COPPER method has been introduced as a less invasive surgical procedure for wide resection of spinal tumours, no studies have reported the usefulness of this technique. We identified three patients with paraspinal or spinal tumours who underwent wide resection using the COPPER method and reviewed their clinical, radiological, and pathological outcomes. In all cases, we resected the spinal and paraspinal tumours extending to the anterior column and extravertebral component using the modified COPPER method. All patients underwent en bloc resection with a negative margin. We report three cases of spinal and paraspinal tumours extending to the anterior column and extravertebral component.

New technique of En bloc vertebral resection in the thoracolumbar region assisted by retroperitoneal laparoscopy in a single prone position: first results

PURPOSE

To describe the technique and review the oncological and surgical results of the En Bloc resection assisted by retroperitoneal laparoscopy in a single prone position for tumors in the thoracolumbar region.

METHODS

Monocentric retrospective case study. Procedure was performed in a single prone position by a dual team of spine and thoracovascular surgeons. An endoscopic balloon was inflated in the right retroperitoneal cavity. A plan was developed between the anterior spine and vena cava as well as abdominal aorta with segmental vessels ligation. Structures at risk were safely protected under endoscopy during horizontal or sagittal osteotomies.

RESULTS

From 2021, seven patients aged a median 52 years old (range, 34-67) were included. Involved spinal segments went from T11 to L3. Surgery was aborted in one case due to massive bleeding and ventilating difficulties. There were two partial and four total vertebral resections. Median operating duration and estimated blood loss were 405 min (range, 360-540) and 2.1 L (range, 1.2-19), respectively. Postoperative complications consisted of 1 urinary infection; 1 transient urinary retention; 1 posterior wound infection; 1 pneumothorax; 1 persistent partial motor deficit; 1 transient confusion; 1 pulmonary embolism; 1 CSF leak; 1 subdural hematoma; 1 retroperitoneal lymphocele. All margins were uncontaminated. All patients were alive and ambulatory at last follow-up.

CONCLUSION

Early results suggest En Bloc resection assisted by retroperitoneal videoscopy in tumors from T11 to L3/4 disk space is feasible, less invasive and safe. Careful surgical planning and experience in endoscopic vascular surgery are mandatory.

En-bloc spondylectomy in the lumbar spine: indications, results and complications in a series of 47 patients affected by primary malignant bone tumors

INTRODUCTION

Wide Surgery is the reference treatment for malignant and aggressive benign primary bone tumors in the spine. When located in the lumbar spine, En-Bloc Spondylectomy (EBS) remains a complex challenge. Moreover, surgery is complicated by the presence of the diaphragm in the thoracolumbar junction and the hinderance of the iliac wings at the lumbosacral levels. Therefore, EBS in the lumbar spine frequently requires combined approaches. The purpose of this study is to describe clinical presentation, tumor characteristics and results of a series of 47 consecutive patients affected by malignant primary bone tumors of the lumbar spine who underwent EBS.

MATERIALS AND METHODS

47 patients were reviewed. Complications were distinguished in early and late whether they occurred before or after 30 days from surgery. Overall survival (OS), disease-free survival (DFS) and local recurrence-free survival (LRFS) were calculated by the Kaplan-Meier product-limit method from surgery until relapse or death.

RESULTS

27 patients presented to observation after a first intralesional approach in a non-specialized center. Chordoma was the most represented histotype. Vertebrectomies were: 23 one-level, 10 two-level, 12 three-level and 2 four-level. Reconstructions were always carried out with screws and rods. The main postoperative complication was blood loss, while hardware failure was the main long-term complication. The 5-year LRFS was 75.5%, the 5-year DFS was 54.3%, and 5-year OS was 63.6%.

CONCLUSIONS

The surgical margin obtained during the index surgery was statistically associated with Local Recurrence, DFS and OS, underlining the importance of treating patients in reference centers.

Comparison of En Bloc Resection and Intralesional Excision for Re-resection of Giant Cell Tumors of the Spine

OBJECTIVE

Re-resection of spinal giant cell tumors is an exceedingly difficult procedure. Moreover, the prognosis of patients with en bloc resection or intralesional excision for re-resection has rarely been reported. This study aimed to compare the prognostic value of en bloc resection with that of intralesional excision in patients undergoing re-resection for giant cell tumors of the spine.

METHODS

This retrospective analysis evaluated patients who underwent revision surgeries for relapse of giant cell tumors of the spine at our center between January 2005 and January 2021. Local progression-free survival represents the duration between en bloc resection or intralesional excision and tumor recurrence. Neurological recovery, survival rates, local control, and complications were evaluated. The Kaplan-Meier estimator was used for survival analysis.

RESULTS

A total of 22 patients (nine men and 13 women) with a mean age of 34.1 (range 19-63) years were included. Significant statistical differences were found in the local tumor recurrence rate between patients treated with en bloc resection and those treated with intralesional excision (p < 0.05). The 5- and 10-year local progression-free survival rates were both 90% in the en bloc resection group, while in the intralesional excision group, the 5-year local progression-free survival rate was 80% with a 10-year rate of 45.7%. The en bloc resection group had a lower local tumor recurrence rate than that of the intralesional excision group (p < 0.05), but the former had a higher rate of complications (p = 0.015).

CONCLUSIONS

This study revealed a low local recurrence rate in patients who underwent en bloc resection for giant cell tumors, while the perioperative complication rate was high.

Surgical Strategy for Recurrent Giant Cell Tumor in the Thoracolumbar Spine

OBJECTIVE

Recurrent giant cell tumor (RGCT) of the spine represents a clinical challenge for surgeons, and the treatment strategy remains controversial. This study aims to describe the long-term follow-up outcomes and compare the efficacy of en bloc spondylectomy versus piecemeal spondylectomy in treating RGCT of the thoracolumbar spine.

METHODS

A total of 32 patients with RGCT of the thoracolumbar spine treated from June 2012 to June 2019 were retrospectively reviewed. A total of 15 patients received total en bloc spondylectomy (TES) with wide or marginal margin while 17 patients received total piecemeal spondylectomy (TPS) with intralesional margin. Postoperative Eastern Cooperative Oncology Group Performance Score (ECOG-PS), Frankel classification and recurrence-free survival (RFS) were evaluated after surgery. Survival curves were estimated by the Kaplan-Meier method and differences were analyzed with the log-rank test. Multivariate analysis was performed with Cox regression to identify the independent prognostic factors affecting RFS.

RESULTS

During a median follow-up of 41.9 ± 17.5 months, all patients with compromised neurologic functions exhibit significant improvement, with the mean ECOG-PS decreasing from 1.5 ± 1.3 to 0.13 ± 0.3 (p < 0.05). Among the 17 patients treated with TPS, eight patients developed local recurrence after a median time of 15.9 ± 6.4 months and four patients died from progressive disease. On the other hand, local recurrence were well managed with TES, since only one out of 15 patients experienced local relapse and all patients are alive with satisfied function at the latest follow-up. The median RFS for patients receiving TES and TPS are 75.0 months (95% CI: 67.5-82.5 m) and 38.3 months (95% CI: 27.3-49.3 m) respectively (p = 0.008). Multivariate analysis shows that the Ki67 index (p = 0.016), resection mode (p = 0.022), and denosumab (p = 0.039) are independent risk factors affecting RFS.

CONCLUSIONS

TES with wide/marginal margin should be offered to patients with RGCT whenever feasible, given its long-term benefits in local control and symptom alleviation. Additionally, patients with lower Ki67 index and application of denosumab tend to have a better prognosis.

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.

Implant failure and revision strategies after total spondylectomy for spinal tumors

Background

Although there have been several risk factors reported for implant failure (IF), little consensus exists. Potential applicable measures to protect patients from IF are relatively few. This study aimed to discover new risk factors for IF and explore potential protective measures from IF after total spondylectomy for spinal tumors.

Methods

A total of 145 patients undergoing total spondylectomy for thoracic and lumbar spinal tumors between 2010 and 2021 were included from three tertiary university hospitals. Patient demographic and surgical characteristics and follow-up outcomes were collected.

Results

During a mean follow-up of 53.77 months (range, 12 to 149 months), 22 of 145 patients (15.17%) developed IF. Patients undergoing thoracolumbar junctional region (T12/L1) resection were more likely to develop IF compared to those undergoing surgery at other vertebral levels (HR = 21.622, 95% CI = 3.567-131.084, P = 0.001). Patients undergoing titanium mesh cage reconstruction were more likely to develop IF compared to patients undergoing expandable titanium cage reconstruction (HR = 8.315, 95% CI = 1.482-46.645, P = 0.016). Patients with bone cement augmentation around the cage were less likely to develop IF compared to those not receiving bone cement augmentation (HR = 0.015, 95% CI = 0.002-0.107, P < 0.001). Of the 22 patients with IF, 14 (63.63%) accepted personalized revision surgery.

Conclusion

The use of an expandable cage and the use of bone cement augmentation around the anterior column support cage are protective measures against IF after total spondylectomy.

The Impact of Frailty on Postoperative Complications in Total En Bloc Spondylectomy for Spinal Tumors

Total en bloc spondylectomy (TES) is an effective treatment for spinal tumors. However, its complication rate is high, and the corresponding risk factors remain unclear. This study aimed to clarify the risk factors for postoperative complications after TES, including the patient's general condition, such as frailty and their levels of inflammatory biomarkers. We included 169 patients who underwent TES at our hospital from January 2011-December 2021. The complication group comprised patients who experienced postoperative complications that required additional intensive treatments. We analyzed the relationship between early complications and the following factors: age, sex, body mass index, type of tumor, location of tumor, American Society of Anesthesiologists score, physical status, frailty (categorized by the 5-factor Modified Frailty Index [mFI-5]), neutrophil-to-lymphocyte ratio, C-reactive protein/albumin ratio, preoperative chemotherapy, preoperative radiotherapy, surgical approach, and the number of resected vertebrae. Of the 169 patients, 86 (50.1%) were included in the complication group. Multivariate analysis showed that high mFI-5 scores (odds ratio [OR] = 2.99, p < 0.001) and an increased number of resected vertebrae (OR = 1.87, p = 0.018) were risk factors for postoperative complications. Frailty and the number of resected vertebrae were independent risk factors for postoperative complications after TES for spinal tumors.

Modified Total en Bloc Spondylectomy with Self-Made Intervertebral Hook Blade in Spinal Tumors: A Retrospective Study

OBJECTIVE

Total en bloc spondylectomy (TES) is an important surgical treatment for spinal tumors that can achieve en bloc resection of the affected vertebral body by using the T-saw. However, the conventional TES process and the surgical instruments currently in use have some inconveniences, which may lead to longer operative times and a higher incidence of complications. To address these obstacles, we developed a modified TES technique using a homemade intervertebral hook blade. The objectives of this study were to describe our modified total en bloc spondylectomy (TES) using a homemade intervertebral hook blade and to assess its clinical effects in patients with spinal tumors.

METHODS

Twenty-three consecutive patients with spinal tumors were included from September 2018 to November 2021. Eleven patients underwent a modified TES using an intervertebral hook blade, and 12 patients underwent a conventional TES using a wire saw. Details of the modified technique for TES were depicted, and the intraoperative blood loss, operative time, and improvement in pain symptom and neurological function measured by visual analog score (VAS) and American Spinal Injury Association (ASIA) score of all patients was reviewed and analyzed. Nonparametric analysis of covariates (ANCOVA) was performed to compare the clinical outcomes between patients treated with modified TES and conventional TES.

RESULTS

The modified TES significantly reduced operative time (F = 7.935, p = 0.010) and achieved favorable improvement of neurological function (F = 0.570, p = 0.459) and relief of pain (F = 3.196, p = 0.088) compared with the conventional TES group. The mean intraoperative blood loss in the modified TES group (2381.82 ml) was lower than that in the conventional TES group (3558.33 ml), although the difference was not statistically significant (F = 0.677, p = 0.420).

CONCLUSIONS

Modified TES using the intervertebral hook blade can effectively reduce the operation time and intraoperative bleeding, and meanwhile ensure the improvement of neurological function and relief of pain symptoms, suggesting that this modified technique is feasible, safe, and effective for spinal tumors.

A Systematic Review of Perioperative Complications in en Bloc Resection for Spinal Tumors

STUDY DESIGN

Systematic review.

OBJECTIVE

En bloc resection is a major, invasive surgical procedure designed to completely resect a vertebral tumor with a sufficient margin. It is technically demanding and potentially poses risks of perioperative complications. In this systematic review, we investigated the incidence of complications after en bloc resection for spinal tumors.

METHODS

We screened PubMed and Embase databases for relevant English publications, from 1980 to 2020, using the following terms: spine OR spinal AND en bloc AND tumor. Using a standard PRISMA template, after the initial screening, full-text articles of interest were evaluated.

RESULTS

Thirty-six studies with 961 patients were included. The overall mean age of patients was 49.6 years, and the mean follow-up time was 33.5 months. There were 560 complications, and an overall complication rate of 58.3% (560/961). The 5 most frequent complications were neurological damage (12.7%), hardware failure (12.1%), dural tear and cerebrospinal fluid leakage (10.6%), wound-related complications (7.6%) and vascular injury and bleeding (7.3%). The complication-related revision rate was 10.7% (103/961). The average incidence of complication-related death was 1.2% (12/961).

CONCLUSIONS

En bloc resection is a surgical procedure that is very invasive and technically challenging, and the possible risks of perioperative complications should not be neglected. The overall complication rate is high. However, complication-related death was rare. The advantages of surgery should be weighed against the serious perioperative morbidity associated with this technique.

Spinal tumours: recommendations of the Polish Society of Spine Surgery, the Polish Society of Oncology, the Polish Society of Neurosurgeons, the Polish Society of Oncologic Surgery, the Polish Society of Oncologic Radiotherapy, and the Polish Society of Orthopaedics and Traumatology

PURPOSE

The purpose of these recommendations is to spread the available evidence for evaluating and managing spinal tumours among clinicians who encounter such entities.

METHODS

The recommendations were developed by members of the Development Recommendations Group representing seven stakeholder scientific societies and organizations of specialists involved in various forms of care for patients with spinal tumours in Poland. The recommendations are based on data yielded from systematic reviews of the literature identified through electronic database searches. The strength of the recommendations was graded according to the North American Spine Society's grades of recommendation for summaries or reviews of studies.

RESULTS

The recommendation group developed 89 level A-C recommendations and a supplementary list of institutions able to manage primary malignant spinal tumours, namely, spinal sarcomas, at the expert level. This list, further called an appendix, helps clinicians who encounter spinal tumours refer patients with suspected spinal sarcoma or chordoma for pathological diagnosis, surgery and radiosurgery. The list constitutes a basis of the network of expertise for the management of primary malignant spinal tumours and should be understood as a communication network of specialists involved in the care of primary spinal malignancies.

CONCLUSION

The developed recommendations together with the national network of expertise should optimize the management of patients with spinal tumours, especially rare malignancies, and optimize their referral and allocation within the Polish national health service system.

Thoracoabdominal Aortic Replacement Together with Curative Oncological Surgery in Retroperitoneal and Spinal Tumours

Malignancies with an extended encasement or infiltration of the aorta were previously considered inoperable. This series demonstrates replacement and subsequent resection of the thoracoabdominal aorta and its large branches as an adjunct to curative radical retroperitoneal and spinal tumor resection. Five consecutive patients were enrolled between 2016 and 2020, suffering from cancer of unknown primary, pleomorphic carcinoma, chordoma, rhabdoid sarcoma, and endometrial cancer metastasis. Wide surgical resection was the only curative option for these patients. For vascular replacement, extracorporeal membrane oxygenation (ECMO) was used as a partial left-heart bypass. The early technical success rate was 100% for vascular procedures and all patients underwent complete radical tumour resection with negative margins. All patients required surgical revision (liquor leak, n = 2; hematoma, n = 3; bypass revision, n = 1; bleeding, n = 1; biliary leak, n = 1). During follow-up (average 47 months, range 22–70) primary patency rates of aortic reconstructions and arterial bypasses were 100%; no patient suffered from recurrent malignant disease. Thoracoabdominal aortic replacement with rerouting of visceral and renal vessels is feasible in oncologic patients. In highly selected young patients, major vascular surgery can push the limits of oncologic surgery further, allowing a curative approach even in extensive retroperitoneal and spinal malignancies.

En-bloc resection of a chordoma in L3 by a combined open posterior and less invasive retroperitoneal approach: technical description and case report

INTRODUCTION

To fulfill oncological criteria, extensive open anterior and posterior approaches are usually performed in the lumbar spine to obtain an appropriate en-bloc spondylectomy. It is commonly accepted that the price of a tumor-free margin includes such extensive incisions and soft-tissue damage, with consequent relevant blood loss and possible postoperative complications as delayed wound healing. In this article, a case of chordoma in L3 is presented, submitted to an oncologically appropriate en-bloc resection performed by an open posterior approach combined with a mini-retroperitoneal approach. The successful oncologic procedure was combined with a short and uneventful postoperative course.

MATERIALS AND METHODS

The authors present the surgical technique and the possible challenges of minimally invasive anterior oncologic surgery as a contribution to a limited literature.

RESULTS

Up to date, palliative care of single metastases has been the main setting in which anterior, minimally invasive surgery has been performed in the lumbar spine. The authors explained how, in selected cases, this approach can be performed in combination with an open posterior access for an oncologically appropriate treatment of a primary malignant tumor.

CONCLUSION

Anterior, minimally invasive surgery can have a role in selected patients with primary malignant tumors of the lumbar spine. The surgical team should have extensive training both in oncologic and minimally invasive surgery.

Comparison of the prognostic factors of total en bloc spondylectomy and total piecemeal spondylectomy in patients with Enneking stage III giant cell tumor in the thoracic and lumbar spine

PURPOSE

To compare total en bloc spondylectomy with marginal margins against piecemeal spondylectomy with intralesional margins in the surgical treatment of Enneking stage III spinal giant cell tumor (GCT) in terms of local recurrence.

METHODS

A retrospective survival analysis of patients with Enneking stage III GCT who underwent TES with marginal margins or total piecemeal spondylectomy with intralesional margins was performed between January 2006 and April 2020. Local recurrence-free survival (LRFS) was the time between the date of surgery and recurrence. Factors with p-values < 0.05 in the univariate analysis were included in the multivariate analysis using proportional hazard analysis.

RESULTS

Sixty patients (25 men and 35 women) with a mean age of 35.6 (range 11-71) years were included. The mean follow-up duration was 93 (range 24-198) months. Two patients were lost to follow-up 6 and 14 years after the procedure. Over a 10-year period, the recurrence rate was 13.3%. The 2-, 5-, and 10-year LRFS rates were 95%, 88%, and 78%, respectively. Univariate analysis identified total piecemeal spondylectomy and no adjuvant radiotherapy as prognostic factors for LRFS. Multivariate Cox-regression models showed a significant association between local recurrence and total piecemeal spondylectomy and no adjuvant radiotherapy.

CONCLUSION

TES with marginal margins is better than total piecemeal spondylectomy with intralesional margins owing to its lower postoperative recurrence rate. Adjuvant radiotherapy should be administered to reduce postoperative recurrence rates.

Biomechanical comparison of spinal column shortening - a finite element study

BACKGROUND

At present, research on spinal shortening is mainly focused on the safe distance of spinal shortening and the mechanism of spinal cord injury, but there is no research on the biomechanical characteristics of different shortening distances. The purpose of this study was to study the biomechanical characteristics of spine and internal fixation instruments at different shortening distances by the finite element (FE) method.

METHODS

An FE model of lumbar L1-S was established and referred to the previous in vitro experiments to verify the rationality of the model by verifying the Intradiscal pressure (IDP) and the range of motion (ROM) of the motion segment. Five element models of spinal shortening were designed under the safe distance of spinal shortening, and the entire L3 vertebra and both the upper and lower intervertebral discs were resected. Model A was not shortened, while models B-E were shortened by 10%, 20%, 30% and 50% of the vertebral body, respectively. Constraining the ROM of the sacrum in all directions, a 7.5 N ·m moment and 280 N follower load were applied on the L1 vertebra to simulate the motion of the lumbar vertebrae in three planes. The ROM of the operated segments, the Von Mises stress (VMS) of the screw-rod system, the VMS of the upper endplate at the interface between the titanium cage and the L4 vertebral body, and the ROM and the IDP of the adjacent segment (L5/S) were recorded and analysed.

RESULTS

All surgical models showed good stability at the operated segments (L1-5), with the greatest constraint in posterior extension (99.3-99.7%), followed by left-right bending (97.9-98.7%), and the least constraint in left-right rotation (84.9-86.3%) compared with the intact model. The VMS of the screw-rod system and the ROM and IDP of the distal adjacent segments of models A-E showed an increasing trend, in which the VMS of the screw-rod system of model E was the highest under flexion (172.5 MPa). The VMS of the endplate at the interface between the cage and L4 upper endplate of models A-E decreased gradually, and these trend were the most obvious in flexion, which were 3.03, 2.95, 2.83, 2.78, and 2.61 times that of the intact model, respectively.

CONCLUSION

When performing total vertebrae resection and correcting the spinal deformity, if the corrected spine has met our needs, the distance of spinal shortening should be minimized to prevent spinal cord injury, fracture of internal fixations and adjacent segment disease (ASD).

Factors associated with hardware failure after lateral thoracolumbar fusions - A ten year case series

OBJECTIVE

Thoracolumbar lateral interbody fusions (tLLIF) are one tool in the spine surgeon's toolbox to indirectly decompress neuroforamina while also improving segmental lordosis in a biomechanically distinct manner from posterior fusions. When part of a concomitant posterior construct, hardware failure (HF), sometimes requiring revision surgery, can occur. We sought to study the relationship between tLLIF and HF.

METHODS

We conducted a retrospective study on consecutive patents who underwent tLLIF at a single academic center between January 2012 and December 2021 by seven unique neurosurgeons. Patients were excluded if they had no posterior instrumentation within their construct or if they had less than six months of follow-up. Hardware failure was defined as screw breakage or rod fracture seen on postoperative imaging.

RESULTS

232 patients were identified; 6 (2.6 %) developed HF throughout a mean follow-up of 1182 days (range =748-1647 days). Adjacent segment disease was the most common pathology addressed (75 patients (32.3 %)). The amount of posterior instrumentation both in the surgery in question and in the total construct were significantly higher in the HF cohort (4.33 ± 1.52 levels, 5.83 ± 3.36 levels) versus the non-HF cohort (2.08 ± 0.296 levels, p = 0.014; 2.86 ± 0.316 levels, p = 0.003, respectively). The number of interbody devices added in the index surgery and in the entire construct were both significantly higher in the HF cohort (3.33 ± 0.666 interbody devices, 3.33 ± 0.666 devices) than in the non-HF cohort (1.88 ± 0.152 interbody devices, p = 0.002; 2.31 ± 0.158 devices, p = 0.036, respectively). Higher amounts of lateral levels of fusion approached significance for association with HF (HF: 2.67 ± 0.844 levels, no HF: 1.73 ± 1.26 levels, p = 0.076). On multivariate analysis, only the number of interbody devices added in the index surgery was predictive of HF (Odds ratio=2.3, 95 % confidence interval=1.25-4.23, p = 0.007).

CONCLUSION

Greater levels of posterior fusion, and greater numbers of interbody devices in an index surgery and in a construct as a whole, were associated with higher rates of HF in our cohort of patients with tLLIF. Greater numbers of lateral segments fused in this population may also be related to HF.

Augmented Reality Neuronavigation for En Bloc Resection of Spinal Column Lesions

BACKGROUND

Primary tumors involving the spine are relatively rare but represent surgically challenging procedures with high patient morbidity. En bloc resection of these tumors necessitates large exposures, wide tumor margins, and poses risks to functionally relevant anatomical structures. Augmented reality neuronavigation (ARNV) represents a paradigm shift in neuronavigation, allowing on-demand visualization of 3D navigation data in real-time directly in line with the operative field.

METHODS

Here, we describe the first application of ARNV to perform distal sacrococcygectomies for the en bloc removal of sacral and retrorectal lesions involving the coccyx in 2 patients, as well as a thoracic 9-11 laminectomy with costotransversectomy for en bloc removal of a schwannoma in a third patient.

RESULTS

In our experience, ARNV allowed our teams to minimize the length of the incision, reduce the extent of bony resection, and enhanced visualization of critical adjacent anatomy. All tumors were resected en bloc, and the patients recovered well postoperatively, with no known complications. Pathologic analysis confirmed the en bloc removal of these lesions with negative margins.

CONCLUSIONS

We conclude that ARNV is an effective strategy for the precise, en bloc removal of spinal lesions including both sacrococcygeal tumors involving the retrorectal space and thoracic schwannomas.

3D-printed vertebral body for anterior spinal reconstruction in patients with thoracolumbar spinal tumors

OBJECTIVE

A 3D-printed vertebral prosthesis can be used to reconstruct a bone defect more precisely because of its tailored shape, with its innermost porous structure inducing bone ingrowth. The aim of this study was to evaluate the clinical outcomes of using a 3D-printed artificial vertebral body for spinal reconstruction after en bloc resection of thoracolumbar tumors.

METHODS

This was a retrospective analysis of 23 consecutive patients who underwent surgical treatment for thoracolumbar tumors at our hospital. En bloc resection was performed in all cases, based on the Weinstein-Boriani-Biagini surgical staging system, and anterior reconstruction was performed using a 3D-printed artificial vertebral body. Prosthesis subsidence, fusion status, and instrumentation-related complications were evaluated. Stability of the anterior reconstruction method was evaluated by CT, and CT Hounsfield unit (HU) values were measured to evaluate fusion status.

RESULTS

The median follow-up was 37 (range 24-58) months. A customized 3D-printed artificial vertebral body was used in 10 patients, with an off-the-shelf 3D-printed artificial vertebral body used in the other 13 patients. The artificial vertebral body was implanted anteriorly in 5 patients and posteriorly in 18 patients. The overall fusion rate was 87.0%. The average prosthesis subsidence at the final follow-up was 1.60 ± 1.79 mm. Instrument failure occurred in 2 patients, both of whom had substantial subsidence (8.47 and 3.69 mm, respectively). At 3 months, 6 months, and 1 year postoperatively, the mean CT HU values within the artificial vertebral body were 1930 ± 294, 1997 ± 336, and 1994 ± 257, respectively, with each of these values being significantly higher than the immediate postoperative value of 1744 ± 321 (p < 0.05).

CONCLUSIONS

The use of a 3D-printed artificial vertebral body for anterior reconstruction after en bloc resection of the thoracolumbar spinal tumor may be a feasible and reliable option. The low incidence of prosthesis subsidence of 3D-printed endoprostheses can provide good stability instantly. Measurement of HU values with CT is a valuable method to evaluate the osseointegration at the bone-metal interface of a 3D-printed vertebral prosthesis.

Complication Avoidance in Surgical Management of Vertebral Column Tumors

The surgical management of spinal tumors has grown increasingly complex as treatment algorithms for both primary bone tumors of the spine and metastatic spinal disease have evolved in response to novel surgical techniques, rising complication rates, and additional data concerning adjunct therapies. In this review, we discuss actionable interventions for improved patient safety in the operative care for spinal tumors. Strategies for complication avoidance in the preoperative, intraoperative, and postoperative settings are discussed for approach-related morbidities, intraoperative hemorrhage, wound healing complications, cerebrospinal fluid (CSF) leak, thromboembolism, and failure of instrumentation and fusion. These strategies center on themes such as pre-operative imaging review and medical optimization, surgical dissection informed by meticulous attention to anatomic boundaries, and fastidious wound closure followed by thorough post-operative care.

Factors associated with spinal fixation mechanical failure after tumor resection: a systematic review and meta-analysis

Background

No available meta-analysis has been published that systematically assessed spinal fixation mechanical failure after tumor resection based on largely pooled data. This systematic review and meta-analysis aimed to investigate the spinal fixation failure rate and potential risk factors for hardware failure.

Methods

Electronic articles published between January 1, 1979, and January 30, 2021, were searched and critically evaluated. The authors independently reviewed the abstracts and extracted data on the spinal fixation failure rate and potential risk factors.

Results

Thirty-eight studies were finally included in the meta-analysis. The pooled spinal fixation mechanical failure rate was 10%. The significant risk factors for hardware failure included tumor level and cage subsidence. Radiotherapy was a potential risk factor.

Conclusion

The spinal fixation mechanical failure rate was 10%. Spinal fixation failure is mainly associated with tumor level, cage subsidence and radiotherapy. Durable reconstruction is needed for patients with these risk factors.

Proton Therapy for Primary Bone Malignancy of the Pelvic and Lumbar Region - Data From the Prospective Registries ProReg and KiProReg

PURPOSE/OBJECTIVES

Multimodality treatments together with local proton therapy (PT) are commonly used in unresectable primary bone malignancies in order to provide better tumor control rate while maintaining good feasibility. The aim of this study is to provide data on outcome of PT for the challenging cohort of pelvic and lumbar bone tumors.

METHODS AND MATERIALS

This retrospective study includes all patients with primary bone malignancy of the pelvis and lumbar spine receiving PT in our institution between May 2013 and December 2019 enrolled in the prospective registries KiProReg and ProReg collecting information on demographics, treatment, tumor characteristics, toxicities, and outcome.

RESULTS

Eighty-one patients were enrolled with a median age of 19.7 years (1.3-85.8). The median follow-up time was 27.5 months (1.2-83.2). The majority of patients was male (64.2%), ECOG status of 0-1 (75.2%), underwent only biopsy (50.6%), received chemotherapy (69.1%) and was assigned for definite PT (70.4%). The predominant tumor characteristics were as follows: Ewing's sarcoma histology (58%), negative nodal involvement (97.5%) and no metastasis at diagnosis (81.5%). Median maximal diameter of tumor was 8 cm (1.4-20). LC, EFS and OS rate were 76.5, 60, and 88.1% at two years and 72.9, 45.7, and 68.9% at three years, respectively. Age over 20 years was a significant negative factor for LC, EFS, and OS. Metastatic disease at initial diagnosis affected OS and ECOG status of 2-4 affected EFS only. Regarding 17 relapsed cases (21%), isolated distant relapse was the most common failure (46.9%) followed by local failure (40.6%). Eleven out of 14 evaluable patients relapsed within high-dose region of radiotherapy. Acute grade 3-4 toxicity was found in 41 patients (50.6%) and all toxicities were manageable. Late grade 3 toxicity was reported in 7 patients (10.4%) without any of grade 4. Most common higher grade acute and late side effects concerned hematologic and musculoskeletal toxicity.

CONCLUSION

Proton therapy resulted in good oncological outcomes when being part of the multimodality treatment for pelvic and lumbar primary bone malignancies. However, distant metastases and local failures within the high-dose region of radiotherapy are still a common issue. Acute and late toxicities of combined therapy were acceptable.

Partial sacrectomy with patient-specific osteotomy guides

Background

Chordomas are rare, locally aggressive, malignant tumors. Surgical resection with sufficient margins defines the outcome. However, the necessity for wide margins often leads to sacrifice of important neurological structures. 3D-printed osteotomy guides are a promising solution for precise execution of surgical resection. We present probably the first sacrococcygeal chordoma resection with 3D-printed guides.

Methods

The case of a 49-year-old woman with a sacrococcygeal chordoma, resected with help of 3-D pre-operative planning and patient-specific 3D-printed osteotomy guides, is reported in detail.

Results

A sufficient tumor excision could be performed successfully while sparing nerve root S4. The planed margin has been exactly maintained, as confirmed by histology. The patient demonstrated an excellent clinical outcome with no evidence of local recurrence.

Conclusions

3-D pre-operative planning and patient-specific osteotomy guides can be used for planning and performing en-bloc surgical resection of sacral chordomas.

Factors Related to Instrumentation Failure in Titanium Mesh Reconstruction for Thoracic and Lumbar Tumors: Retrospective Analysis of 178 Patients

Purpose

To investigate risk factors for instrumentation failure (IF) in titanium (Ti) mesh reconstruction for thoracic and lumbar tumors.

Patients and Methods

The clinical data of patients with thoracic or lumbar tumors who received Ti mesh reconstruction via the posterior approach in our hospital from 2013 to 2018 were analyzed retrospectively. The observation indexes included sex, age, BMI, the vertebra resection mode, the number of resected vertebral segments, application of bone cement, radiotherapy, chemotherapy, revision or primary surgery, and primary tumor metastasis. Correlations between these factors and IF were analyzed by Kaplan–Meier survival and logistics regression analyses.

Results

The 178 patients included 108 males and 70 females with a mean age of 48.09±16.21 (6–78) years and a mean follow-up period of 51.18 (24–90) months. The data showed that 17 patients (9.55%) were inflicted with IF, involving the thoracic vertebra in 11 cases, thoracolumbar vertebrae (T12–L1) in 2 cases, and lumbar vertebrae in 4 cases. The mean interval between surgery to IF was 35.18±14.17 (14–59) months. Univariate analysis showed that total vertebral body resection, the number of resected vertebral segments, radiotherapy and multiple tumor resection were potential factors for IF, while multivariate analysis showed that only total vertebral body resection, the number of resected vertebral segments and radiotherapy were independent factors.

Conclusion

Total vertebra resection, the number of resected vertebral segments (≥2) and radiotherapy before and after operation were significant risk factors related to IF.

Biomechanics of artificial pedicle fixation in a 3D-printed prosthesis after total en bloc spondylectomy: a finite element analysis

Background

This study compared the biomechanics of artificial pedicle fixation in spine reconstruction with a 3-dimensional (3D)-printed prosthesis after total en bloc spondylectomy (TES) by finite element analysis.

Methods

A thoracolumbar (T10–L2) finite element model was developed and validated. Two models of T12 TES were established in combination with different fixation methods: Model A consisted of long-segment posterior fixation (T10/11, L1/2) + 3D-printed prosthesis; and Model B consisted of Model A + two artificial pedicle fixation screws. The models were evaluated with an applied of 7.5 N·m and axial force of 200 N. We recorded and analyzed the following: (1) stiffness of the two fixation systems, (2) hardware stress in the two fixation systems, and (3) stress on the endplate adjacent to the 3D-printed prosthesis.

Results

The fixation strength of Model B was enhanced by the screws in the artificial pedicle, which was mainly manifested as an improvement in rotational stability. The stress transmission of the artificial pedicle fixation screws reduced the stress on the posterior rods and endplate adjacent to the 3D-printed prosthesis in all directions of motion, especially in rotation.

Conclusions

After TES, the posterior long-segment fixation combined with the anterior 3D printed prosthesis could maintain postoperative spinal stability, but adding artificial pedicle fixation increased the stability of the fixation system and reduced the risk of prosthesis subsidence and instrumentation failure.

Prediction of the early recurrence in spinal giant cell tumor of bone using radiomics of preoperative CT: Long-term outcome of 62 consecutive patients

•

Characteristics of 62 patients with spinal GCTB who underwent surgery.

•

A prognostic classification model was built based on features selected by SVM.

•

The combined histogram and texture features could predict recurrence of GCTB.

Objectives

To determine if radiomics analysis based on preoperative computed tomography (CT) can predict early postoperative recurrence of giant cell tumor of bone (GCTB) in the spine.

Methods

In a retrospective review, 62 patients with pathologically confirmed spinal GCTB from March 2008 to February 2018, with a minimum follow-up of 24 months, were identified. The mean follow-up was 73.7 months (range, 28.7–152.1 months). The clinical information including age, gender, lesion location, multi-vertebral involvement, and surgical methods, were obtained. CT images acquired before the operation were retrieved for radiomics analysis. For each case, the tumor regions of interest (ROI) was manually outlined, and a total of 107 radiomics features were extracted. The features were selected via the sequential selection process by using the support vector machine (SVM), then used to construct classification models with Gaussian kernels. The differentiation between recurrence and non-recurrence groups was evaluated by ROC analysis, using 10-fold cross-validation.

Results

Of the 62 patients, 17 had recurrence with a recurrence rate of 27.4%. None of the clinical information was significantly different between the two groups. Patients receiving curettage had a higher recurrence rate (6/16 = 37.5%) compared to patients receiving TES (6/26 = 23.1%) or intralesional spondylectomy (5/20 = 25%). The final radiomics model was built using 10 selected features, which achieved an accuracy of 89% with AUC of 0.78.

Conclusions

The radiomics model developed based on pre-operative CT can achieve a high accuracy to predict the recurrence of spinal GCTB. Patients who have a high risk of early recurrence should be treated more aggressively to minimize recurrence.

The use of autologous free vascularized fibula grafts in reconstruction of the mobile spine following tumor resection: surgical technique and outcomes

OBJECTIVE

Reconstruction of the mobile spine following total en bloc spondylectomy (TES) of one or multiple vertebral bodies in patients with malignant spinal tumors is a challenging procedure with high failure rates. A common reason for reconstructive failure is nonunion, which becomes more problematic when using local radiation therapy. Radiotherapy is an integral part of the management of primary malignant osseous tumors in the spine. Vascularized grafts may help prevent nonunion in the radiotherapy setting. The authors have utilized free vascularized fibular grafts (FVFGs) for reconstruction of the spine following TES. The purpose of this article is to describe the surgical technique for vascularized reconstruction of defects after TES. Additionally, the outcomes of consecutive cases treated with this technique are reported.

METHODS

Thirty-nine patients were treated at the authors' tertiary care institution for malignant tumors in the mobile spine using FVFG following TES between 2010 and 2018. Postoperative union, reoperations, complications, neurological outcome, and survival were reported. The median follow-up duration was 50 months (range 14-109 months).

RESULTS

The cohort consisted of 26 males (67%), and the median age was 58 years. Chordoma was the most prevalent tumor (67%), and the lumbar spine was most affected (46%). Complete union was seen in 26 patients (76%), the overall complication rate was 54%, and implant failure was the most common complication, with 13 patients (33%) affected. In 18 patients (46%), one or more reoperations were needed, and the fixation was surgically revised 15 times (42% of reoperations) in 10 patients (26%). A reconstruction below the L1 vertebra had a higher proportion of implant failure (67%; 8 of 12 patients) compared with higher resections (21%; 5 of 24 patients) (p = 0.011). Graft length, number of resected vertebrae, and docking the FVFG on the endplate or cancellous bone was not associated with union or implant failure on univariate analysis.

CONCLUSIONS

The FVFG is an effective reconstruction technique, particularly in the cervicothoracic spine. However, high implant failure rates in the lumbar spine have been seen, which occurred even in cases in which the graft completely healed. Methods to increase the weight-bearing capacity of the graft in the lumbar spine should be considered in these reconstructions. Overall, the rates of failure and revision surgery for FVFG compare with previous reports on reconstruction after TES.

Revision surgery for instrumentation failure after total en bloc spondylectomy: a retrospective case series

Background

There have been several reports of instrumentation failure after three-column resections such as total en bloc spondylectomy (TES) for spinal tumors; however, clinical outcomes of revision surgery for instrumentation failure after TES are seldom reported. Therefore, this study assessed the clinical outcomes of revision surgery for instrumentation failure after TES.

Methods

This study employed a retrospective case series in a single center and included 61 patients with spinal tumors who underwent TES between 2010 and 2015 and were followed up for > 2 years. Instrumentation failure rate, back pain, neurological deterioration, ambulatory status, operation time, blood loss, complications, bone fusion after revision surgery, and re-instrumentation failure were assessed. Data were collected on back pain, neurological deterioration, ambulatory status, and management for patients with instrumentation failure, and we documented radiological bone fusion and re-instrumentation failure in cases followed up for > 2 years after revision surgery.

Results

Of the 61 patients, 26 (42.6%) experienced instrumentation failure at an average of 32 (range, 11–92) months after TES. Of these, 23 underwent revision surgery. The average operation time and intraoperative blood loss were 204 min and 97 ml, respectively. Including the six patients who were unable to walk after instrumentation failure, all patients were able to walk after revision surgery. Perioperative complications of reoperation were surgical site infection (n = 2) and delayed wound healing (n = 1). At the final follow-up, bone fusion was observed in all patients. No re-instrumentation failure was recorded.

Conclusion

Bone fusion was achieved by revision surgery using the posterior approach alone.

A finite element analysis on comparing the stability of different posterior fixation methods for thoracic total en bloc spondylectomy

Objective

To compare the spinal stability with different fixation methods after thoracic TES using finite element analysis

Methods

The spinal finite element model was established from a healthy volunteer, and the validity was verified. The models of T8 thoracic total en bloc spondylectomy (TES) with and without artificial vertebral body were established combination with different fixation methods: the first was long segment fixation with fixed segments T5–7, T9–11; the second was short segment fixation with fixed segments T6–7, T9–10; the third was modified short segment with a pair of vertebral body screws on T7 and T9 added on the basis of short segment fixation. The motions of each model in standing state were simulated in software. The range of motion (ROM) and internal fixation stress changes were analyzed.

Results

When anterior support was effective, the three fixation methods could effectively maintain the stability of the spine. However, when anterior support failed, the ROM of the long segment fixation group and the short segment fixation group in the flexion-extension directions was significantly higher than that of when the anterior support existed, while the modified short segment fixation group had no significant changes. Meanwhile, the stress of internal fixation in the long segment fixation group and the short segment fixation group were greatly increased. However, there were no significant changes in modified short segment fixation group.

Conclusion

After TES, the presence of the thoracic cage gives partial anterior stabilization. When the anterior support failed, the modified short segment fixation method can provide better stability.

Free Vascularized Fibula Graft with Femoral Allograft Sleeve for Lumbar Spine Defects After Spondylectomy of Malignant Tumors: A Case Report

CASE

We present a 65-year-old man with an L4 conventional chordoma. Total en bloc spondylectomy (TES) of the involved vertebral bodies and surrounding soft tissues with reconstruction of the spine using a free vascularized fibula autograft (FVFG) is a proven technique, limiting complications and recurrence. However, graft fracture has occurred only in the lumbar spine in our institutional cases. We used a technique in our patient to ensure extra stability and support, with the addition of a femoral allograft sleeve encasing the FVFG.

CONCLUSIONS

Our technique for the reconstruction of the lumbar spine after TES of primary malignant spinal disease using a femoral allograft sleeve encasing the FVFG is viable to consider.

Median Sacral Artery Rupture as a Complication of Posterior-Only Approach of L4 Total En Bloc Spondilectomy: A Case Report

CASE

A 6-year-old patient with Ewing sarcoma at L4 who was treated with total en bloc spondilectomy (TES) through a posterior-only approach. During the dissection of the anterior L4 body, there was uncontrollable bleeding from an unknown origin, which needed packing, massive transfusion, and urgent laparotomy. A median sacral artery (MSA) rupture was identified as the cause of this massive bleeding. Eventually, the patient was successfully stabilized.

CONCLUSIONS

To our knowledge, this is the first reported intraoperative bleeding of the MSA related to a lumbar TES through posterior-only approach. This life-threatening complication should be considered when planning for this type of surgery.

Sagittal en bloc resection of primary tumors in the thoracic and lumbar spine: feasibility, safety and outcome

This study is to test feasibility, safety and the outcome of sagittal en bloc resection of paravertebral primary tumors in the thoracic and the lumbar spine. Sagittal en bloc resection was planned based on WBB classification and performed via combined anterior-posterior or anterior-posterior-lateral approach in 9 consecutive patients with aggressive benign or malignant paravertebral primary tumors in the thoracic and lumbar spine. Surgical margins were evaluated both radiologically and histopathologically. Follow-up data regarding survival rate, local control, morbidity, hardware failure and postoperative function were collected at around 2 years after surgery. En bloc resection was achieved in all patient with wide margin in 7/9 patients, marginal and intralesional margin in 2/9 patients. Survival rate and local control rate were 100%. There were 4/9 cases of major complications and 2/9 cases of minor complications with an overall morbidity rate of 67% (6/9). All but one patient with intraoperative spinal cord injury were free of neurological deficits and fully mobile in absence of any indication of hardware failure. With a careful choice of surgical procedure, sagittal en bloc resection of paravertebral primary tumor in the thoracic and lumbar spine is feasible, safe and effective.

Upper cervical spine reconstruction using customized 3D-printed vertebral body in 9 patients with primary tumors involving C2

Background

Reconstruction following resection of the primary tumors of the upper cervical spine is challenging, and conventional internal implants develop complications in this region. 3D printing, also known as additive manufacturing, can produce patient-specific porous implants in a particular shape for bone defect reconstruction. This study aimed to describe the clinical outcomes of upper cervical spine reconstruction using customized 3D-printed vertebral body in 9 patients with primary tumors involving C2.

Methods

Patients with primary tumors involving C2 who were treated in our institution between July 2014 and November 2018 were enrolled. A two-stage intralesional spondylectomy was performed using the posterior-anterior approach. Anterior reconstruction was accomplished using a customized 3D-printed vertebral body, which was fabricated by successive layering of melted titanium alloy powder using electron beam melting. No bone graft was used.

Results

Nine patients (2 males and 7 females) were included in the study with a mean age of 31.4 years (12 to 59 years). Seven patients demonstrated tumors located in C2 and 2 showed involvement of C2 and C3. During a mean follow-up of 28.6 months (range, 12–42 months), 1 patient died of systemic metastasis and 1 had local tumor recurrence, the other 7 patients were alive and functional in their daily living until the last follow-up without evidence of disease. The 3D-printed vertebral bodies were all stable with no sign of displacement or subsidence, evidence of implant osseointegration was observed on the imaging studies. For the posterior instrumentation systems, no screw loosening or rod breakage was found.

Conclusions

Spinal reconstruction in the upper cervical region using customized 3D-printed vertebral body is reliable. The tailored shape matching with the contact surfaces and the porous structure conductive to osseointegration provide both short- and long-term stability to the implant.

Single-stage posterior total en bloc spondylectomy in the treatment of lumbar spinal metastases

OBJECTIVE

To report the clinical and radiographic outcomes of single-stage posterior total en bloc spondylectomy (TES) of lumbar spinal metastases.

PATIENTS AND METHODS

From January 2012 to January 2015, 20 consecutive cases with lumbar spinal metastases who received single-stage posterior TES were retrospectively analyzed. A visual analog scale (VAS) was used to evaluate patients' pain status, American Spinal Injury Association (ASIA) classification was used to evaluate neurological status, and Eastern Cooperative Oncology Group (ECOG) score system was used to evaluate patients' performance status at pre- and post-operation and final follow-up. In addition, Intraoperative blood loss, operative time, postoperative complications, local kyphosis angle, and the postoperative duration of hospital stay were analyzed.

RESULTS

The median follow-up time was 16 months (ranging from 3 to 39 months), and 4 patients were still alive at the last follow-up. The mean amount of intraoperative blood loss and operation time was 970 mL and 232.5 min, respectively. The average VAS score improved from 7.5 preoperative to 2.8 postoperative and 3.2 at the last follow-up. Postoperative complications occurred in 3 cases. Sixteen patients died within 2 years after surgery, 10 of which died within 1 year. In the remaining 4 patients, the mean follow-up period was 37.25 months. One case of local recurrence occurred but no implant failure presented during follow-up.

CONCLUSIONS

Single-stage posterior TES is a challenging but rewarding procedure in the treatment of lumbar spinal metastases. Due to unique anatomy and biomechanics, surgeons should be aware of important vessels, and nerve root injury should be avoided.

Risk Factors for Instrumentation Failure After Total En Bloc Spondylectomy of Thoracic and Lumbar Spine Tumors Using Titanium Mesh Cage for Anterior Reconstruction

OBJECTIVE

The present study investigated the risk factors for instrumentation failure (IF) after total en bloc spondylectomy (TES) of thoracic and lumbar spine tumors using a titanium mesh cage (TMC) for anterior reconstruction.

METHODS

The data from patients who had undergone TES for thoracic and lumbar spine tumors in our institution were retrospectively reviewed. Anterior reconstruction was performed using a TMC filled with morcelized allograft or morcelized autograft. Posterior reconstruction was performed using pedicle fixation. Survival analysis from TES to IF was conducted. The Kaplan-Meier method was used for univariate analysis. Factors of statistical significance were included in the multivariate analysis using Cox regression analysis.

RESULTS

A total of 30 patients (20 men and 10 women), with a mean age of 37.1 ± 14.3 years (range, 14-65 years) were included. The mean follow-up period was 41.8 ± 21.3 months (range, 13-120 months). Bone fusion was achieved in 23 patients (76.7%). IF occurred in 8 patients. The mean interval from TES to the first IF was 31.8 ± 15.1 months (range, 13-64 months). On univariable analysis, a body mass index >28 kg/m², perioperative radiotherapy, and the TMC in an oblique position were associated with IF. On multivariable analysis, these 3 factors were entered into the Cox regression model and were also significant.

CONCLUSIONS

The use of TES can achieve durable oncological control. However, IF, a not uncommon late complication that leads to reoperation, should be a cause for concern. We found perioperative radiotherapy, a TMC in an oblique position, and a body mass index >28 kg/m² were significant predictive factors for IF.

Rod fracture and related factors after total en bloc spondylectomy

BACKGROUND CONTEXT

Several studies have reported favorable oncosurgical outcomes after total en bloc spondylectomy (TES) for treatment of primary malignant tumors or oligometastatic tumors. Considering that TES is indicated for patients with longer life expectancy, long-term instrumentation-related issues such as rod fracture needs to be addressed.

PURPOSE

To investigate delayed rod fracture and related factors after TES.

STUDY DESIGN

Multicenter, retrospective study.

PATIENT SAMPLE

Thirty-two patients who survived for more than 2 years after TES.

OUTCOME MEASURES

Rod fracture and related factors.

METHODS

The relationships between rod fracture and related factors were investigated using Kaplan-Meier survivorship analysis with log-rank test. The analyzed factors were sex, age (<60 or ≥60), tumor histology (primary or metastatic), location of resected tumor (thoracic [above T11], thoracolumbar [cases including T12-L1], or lumbar [below L2]), number of resected vertebrae (1, 2, or 3), anterior support method (expandable cage, mesh cage, or strut bone graft), rod diameter (5.5 mm or 6.0 mm), and history of radiotherapy including preoperative or postoperative radiotherapy.

RESULTS

The study population consisted of 18 men and 14 women, with a mean age of 49.0 years. Nineteen patients had primary tumors and 13 patients had metastatic tumors. The mean follow-up duration was 49.8 months (range, 24-166 months). Twelve of 32 patients (37.5%) experienced rod fractures at an average of 29.2 months (range, 8-93 months) after TES. Of these 12 patients, 8 underwent revision surgery caused by back pain aggravation (n = 7) or nonunion on computed tomography scan (n = 4). Location of resected tumor and history of radiotherapy were significantly associated with rod fracture (p = .004 and p = .019, respectively).

CONCLUSION

Rod fracture was not a rare complication after TES surgery. History of radiotherapy and TES at lumbar level were significant risk factors related to rod fracture. A robust strategy to obtain solid osseous fusion should be considered when planning TES.

Endothelin-1 Activates the Notch Signaling Pathway and Promotes Tumorigenesis in Giant Cell Tumor of the Spine

STUDY DESIGN

Experimental study.

OBJECTIVE

To examine the role of endothelin-1 (ET-1) and the Notch signaling pathway in giant cell tumor (GCT) of the spine.

SUMMARY OF BACKGROUND DATA

Previously published studies have shown that the Notch signaling pathway has a role in tumor invasion and that ET-1 is involved in tumor invasion and angiogenesis. However, the roles of both Notch signaling and ET-1 in GCT of the spine remain unknown.

METHODS

Expression of ET-1 in tissue samples from patients with spinal GCT, and adjacent normal tissue, were analyzed by immunohistochemistry and western blot. GCT stromal cells (GCTSCs) were isolated and ET-1 expression was demonstrated by immunofluorescence. Cell viability and cell migration of GCTSCs and human vascular endothelial cells following ET-1 treatment were assessed using the cell counting kit-8 assay and a transwell assay. Receptor activator of nuclear factor kappa-B ligand (RANKL) and osteoprotegerin (OPG) mRNA expression was determined following ET-1 treatment of GCTSCs using quantitative real-time polymerase chain reaction. In GCTSCs treated with ET-1 and the ET-1 signaling antagonist, BQ-123, levels of cyclin D1, vascular endothelial growth factor, matrix metalloproteinase-2 and -9 (MMP-2 and MMP-9), Jagged1, Hes1, Hey2, and Notch intracellular domain were examined by western blot.

RESULTS

Compared with normal adjacent tissue, ET-1 was highly expressed in GCT tissue. In GCTSCs studied in vitro, treatment with ET-1 significantly increased GCTSC and human vascular endothelial cells growth and migration and increased the expression of RANKL and OPG, meanwhile the ratio of RANKL/OPG was increased, in GCTSCs, it upregulated the production of cyclin D1, vascular endothelial growth factor, MMP-2, MMP-9, Jagged1, Hes1, Hey2, and Notch intracellular domain expression in a dose-dependent manner. Treatment with BQ-123 reversed these effects.

CONCLUSION

In GCT of the spine, ET-1 showed increased expression. In cultured GCTSCs, ET-1 treatment activated the Notch signaling pathway.

LEVEL OF EVIDENCE

2.

Motor and Sensory Impairments of the Lower Extremities After L2 Nerve Root Transection During Total en Bloc Spondylectomy

STUDY DESIGN

Retrospective study.

OBJECTIVE

The purpose of this study was to examine motor and sensory impairments of the lower extremities after L2 nerve root transection during total en bloc spondylectomy (TES) for spinal tumors.

SUMMARY OF BACKGROUND DATA

At our institute, for TES at L3 to L5 lumbar levels, the nerve roots are preserved. However, at the level of L1 and L2, the vertebral resection and spinal reconstruction via a posterior approach is employed with transection of the nerve roots during dissection and resection of the vertebra.

METHODS

This study included 13 patients who had undergone TES for spinal tumors involving L2 between 2007 and 2016. Postoperative motor function of the lower extremities was quantified using the Manual Muscle Testing grade for the iliopsoas (IP) and quadriceps femoris (QF) muscles, and a grade of the modified Frankel Classification. Postoperative sensory impairment was quantified by the sites of lower extremity pain and numbness.

RESULTS

An initial decrease in strength of the IP and QF muscles in more than 60% of the patients, with a decline in the modified Frankel grade in 76.9%, was observed at 1-week after surgery. All patients recovered by the final follow-up, with 12 of the 13 patients walking without a gait aid. The other patient, who had undergone a bilateral dissection of L3 nerve root during TES of L2 and L3, had a mild QF muscle weakness, requiring a cane for walking. Eleven of 13 patients developed pain or numbness in the groin or thigh area after surgery, with the most common area being the anterior aspect of the thigh.

CONCLUSION

Although IP and QF weakness was observed in the majority of patients who underwent bilateral transection of L2 nerve roots during TES, these deficits recovered over time and did not finally affect activities of daily living.

LEVEL OF EVIDENCE

4.

All-posterior total en bloc spondylectomy for thoracic spinal tumors

Total en bloc spondylectomy (TES) involves disruption of the bony neural ring via bilateral pediculotomy and posterior en bloc laminectomy followed by the en bloc vertebrectomy. All-posterior TES allows for resection of malignant and benign aggressive spine tumors with minimal morbidity. The purpose of this report is to describe two cases of all-posterior spondylectomy using the recently developed Resegone retractor (K2M, Leesburg, VA, USA) which facilitates an all-posterior resection. The technique is well described and generally includes 3 major portions: a resection of the posterior elements with bilateral costotransversectomy, passage of threadwire saws anterior to the vertebral bodies, and en bloc resection of the anterior column. With the device in place, the sawing of the bone can be performed without risking pull-through into the cord, while cutting through the desired path in a smooth and parallel fashion.

Total en bloc resection of primary and metastatic spine tumors

Primary and metastatic tumors of the spine represent a significant cause of patient morbidity, and present a management challenge to treating providers. From a neurosurgical standpoint, resection surgery may be warranted in cases of spinal instability, progressive disease, neurological compromise, or intractable symptoms. Removal of a tumor "en bloc" offers a more aggressive modality over more conservative resection techniques. En bloc resection entails the removal of the entirety of a tumor without violation of its capsule, and may offer improved rates of local control and overall survival in appropriately selected patients. Conversely, this technique carries a higher complication rate, and requires a unique set of technical skills as compared to more traditional resection. Here, we describe the technical aspects of en bloc resection, as well as specific indications and considerations when employing this operative technique.

Imaging features of primary spinal osseous tumors and their value in clinical diagnosis

This study explored the method of imaging diagnosis of primary spinal osseous tumors and the application value of imaging in clinical diagnosis. Sixty-nine patients with primary spinal osseous tumors who received treatment in Nankai Hospital from July 2016 to June 2017 were selected. All of them received X-ray, computed tomography (CT) and magnetic resonance imaging (MRI) examinations to analyze the imaging features of the three examination methods. Sensitivity (Sen), specificity (Spe), positive predictive value (PV⁺), negative predictive value (PV⁻) and accuracy (Acc) were compared. The consistency of the three examination methods in diagnosing primary spinal osseous tumors was analyzed. Sen, Acc and PV⁻ of the three examination methods in diagnosing spinal osseous tumors had obvious differences. MRI showed the highest Sen (P<0.05). MRI had relatively high consistency with CT scan in diagnosing primary spinal osseous tumors, and κ-value was 0.72. CT scan and X-ray had obvious difference in diagnosing primary spinal osseous tumors (P<0.05). The consistency between CT scan and X-ray in diagnosing primary spinal osseous tumors was relatively low, and κ-value was 0.47. MRI and X-ray had obvious difference in diagnosing primary spinal osseous tumors (P<0.05). The consistency between MRI and X-ray in diagnosing primary spinal osseous tumors was relatively low, and κ-value was 0.41. X-ray examination is easy to operate with high resolution. CT scan has obvious advantages in displaying lesions with complex structure, many of which locate in overlapping sites. MRI has more advantages and higher accuracy in judging the scope of the tumor. CT and MRI examinations have obviously higher efficacy than X-ray in diagnosing primary spinal osseous tumors. They are conducive in improving the accuracy of diagnosing primary spinal osseous tumors.

Total en bloc spondylectomy for primary tumors of the lumbar spine

This was a retrospective clinical study.This study aimed to evaluate our institution's experience with total en bloc spondylectomy (TES) in patients treated for primary lumbar spine tumors and investigate postoperative clinical outcomes.TES is a widely accepted by spinal and musculoskeletal surgical oncologists and results in favorable health-related quality of life outcomes. However, this procedure still imposes major risks and complications.The cases of TES performed for primary lumbar spine tumors between 1993 and 2015 were retrospectively analyzed. Primary outcome measures were the rates of perioperative complications and reoperation for instrumentation failure.We enrolled 30 patients (13 men and 17 women; median age and follow-up, 38 years and 87 months, respectively). Three, 7, and 5 cases involved previous radiotherapy, intralesional resection, and chemotherapy, respectively. The most common tumor was giant cell tumor (14 cases) followed by osteosarcoma (4 cases) and plasmacytoma (3 cases). The median estimated blood loss was 1450 mL, and the median operative time was 11 hours. At least 1 perioperative complication occurred in 26 patients (86.7%), with the most common being postoperative muscle weakness (24 patients, 80.0%) followed by surgical site infection and postoperative cerebrospinal fluid leakage (7 patients, respectively; 23.3% each). Revision surgery for instrumentation failure was required in 6 patients (20.0%) at a median of 33 months after the index TES. Four patients experienced local tumor recurrence (13.3%), and their 10-year disease-free rate was 75.0%.TES is a feasible and effective procedure for primary lumbar spine tumors, but the risks of perioperative complications and late instrumentation failure should be acknowledged. Surgical oncologic outcomes were good, especially in patients who underwent TES as their first surgical treatment. Therefore, being familiar with the indications for TES and the surgical technique is important.

Total En Bloc Spondylectomy for Lumbar Spinal Tumors by Paraspinal Approach

OBJECTIVE

To report and describe a modified posterior-only approach (paraspinal approach) for total en bloc spondylectomy (TES) of lumbar spinal tumors.

METHODS

From February 2013 to June 2014, 5 patients with lumbar spinal tumors who underwent TES through a posterior-only paraspinal approach were studied retrospectively; operative time, blood loss, complications, neurologic outcomes, and degree of resection were recorded to evaluate the efficacy of this surgical method.

RESULTS

Patients included 3 men and 2 women with a mean age of 48.4 years (range, 46-52 years). Two lesions were located in L2, 2 lesions were located in L3, and 1 lesion was located in L4. Three patients had solitary metastatic tumors (lung cancer in 2 cases, breast cancer in 1 case), and 2 patients had primary tumors (osteosarcoma and plasma cell tumor). According to the surgical classification of spinal tumors by Tomita et al., 4 cases were type 4 and 1 case was type 1. Mean operative time was 464 minutes (range, 420-510 minutes), and mean blood loss was 1280 mL (range, 1000-1500 mL). One patient had cerebrospinal fluid leakage, and 1 had transient motor weakness because of nerve root traction. Mean follow-up time was 20.6 months (range, 12-30 months), and all patients had improved or stable neurologic function. No local recurrence was observed at last follow-up.

CONCLUSIONS

The posterior-only paraspinal approach is a valid alternative for TES of lumbar spinal tumors, especially for overweight or muscular patients.