Perioperative complications of total en bloc spondylectomy for spinal tumours

Perioperative complications of en bloc resection and anterior column reconstruction for thoracic and lumbar spinal tumors

PURPOSE

To evaluate the perioperative clinical outcomes of en bloc resection and anterior column reconstruction for thoracolumbar spinal tumors.

METHODS

This study conducted a retrospective analysis of prospective data collection of 86 consecutive patients, including 40 males and 46 females, with an average age of 39 years (ranged from 10 to 71 years). There were 35 cases of a malignant primary tumor,42 cases of an aggressive benign tumor, and nine cases of metastases. The main lesions were located in 65 cases of thoracic spine, 17 cases of lumbar spine, and 4 cases of thoracolumbar spine. Tumors involved one level in 45 patients, two levels in 12 patients, three levels in 21 patients, four levels in five patients, five levels in two patients, and six levels in one patient.

RESULTS

According to the Weinstein-Boriani-Biagini surgical staging system, all patients achieved en bloc resections, including 74 cases of total en bloc spondylectomy and 12 cases of sagittal resections. The mean surgical time was 559 min (210-1208 min), and the mean total blood loss was 1528 ml (260-5500 ml). A total of 122 complications were observed in 62(72.1%) patients, of which 18(20.9%) patients had 25 major complications and one patient (1.2%) died of complications. The combined approach (P = 0.002), total blood loss (P = 0.003), staged surgery (P = 0.004), previous surgical history (P = 0.045), the number of involved vertebrae (P = 0.021) and lumbar location (P = 0.012) were statistically significant risk factors for major complication. When all above risk factors were incorporated in multivariate analysis, only the combined approach (P = 0.052) still remained significant.

CONCLUSIONS

En bloc resection and anterior column reconstruction is accompanied by a high incidence of complications, especially when a combined approach is necessary.

Two-step osteotomy/discectomy through cannulated screw (TOCS) technique for en bloc resection of spine tumor: surgical technique and preliminary results

PURPOSE

We have developed a novel technique for osteotomy/discectomy during en bloc resection of spine tumors named two-step osteotomy/discectomy through cannulated screw (TOCS). This study aims at describing the procedure of TOCS technique and assessing its efficiency and safety.

METHODS

We retrospectively reviewed fourteen patients who underwent en bloc resection for spine tumors using TOCS technique in our center between August 2018 and September 2022. The technique was based on a specially designed "slotted" cannulated screw which was a cannulated screw with a longitudinal slot to provide the accessibility of T-saw. During osteotomy/discectomy, the "slotted" cannulated screw was inserted obliquely along the plane between the dura and the posterior wall of spine in light of the planned osteotomy/discectomy plane under routine fluoroscopic imaging guidance. The T-saw was introduced through the screw, and the osteotomy/discectomy was performed sequentially in two steps under the guidance of the screw by turning the slot away and toward the dura. The intra-/perioperative complication, neurological function (determined by Frankel grading), surgical margin (determined by a pathologist using AJCC R system), follow-up details were documented.

RESULTS

The mean duration of surgery was 599.3 (360-890) min with a mean volume of intra-operative hemorrhage of 2021.4 (800-5000) mL. The intra-/perioperative complications were found in four patients (28.6%). R0 and R1 resections were achieved in nine and five patients, respectively. There was no R2 resection. After a mean follow-up period of 30.6 (10-67) months, all patients were alive except one patient died ten months after surgery due to unrelated cause. No recurrence and implant failure were found. Thirteen patients (92.9%) exhibited completely normal neurological function same as their preoperative neurological status.

CONCLUSION

Using TOCS technique can facilitate a precise, complete and safe osteotomy/discectomy procedure during en bloc resection for spine tumor without the aid of intra-operative navigation.

A new era in the management of spinal metastasis

Despite the recent advances in cancer treatment, the incidence of patients with spinal metastases continues to grow along with the total number of cancer patients. Spinal metastases can significantly impair activities of daily living (ADL) and quality of life (QOL), compared with other types of bone metastases, as they are characterized with severe pain and paralysis caused by skeletal-related events. Reduced ADL can also lead to treatment limitations as certain anticancer agents and radiation therapy are not compatible treatments; thus, leading to a shorter life expectancy. Consequently, maintaining ADLs in patients with spinal metastases is paramount, and spine surgeons have an integral role to play in this regard. However, neurosurgeon, orthopedic and spinal surgeons in Japan do not have a proactive treatment approach to spinal metastases, which may prevent them from providing appropriate treatment when needed (clinical inertia). To overcome such endemic inertia, it is essential for 1) spine surgeons to understand and be more actively involved with patients with musculoskeletal disorders (cancer locomo) and cancer patients; 2) the adoption of a multidisciplinary approach (coordination and meetings not only with the attending oncologist but also with spine surgeons, radiologists, rehabilitation specialists, and other professionals) to preemptive treatment such as medication, radiotherapy, and surgical treatment; and 3) the integration of the latest findings associated with minimally invasive spinal treatments that have expanded the indications for treatment of spinal metastases and improved treatment outcomes. This heralds a new era in the management of spinal metastases.

Complications and local recurrence of chondrosarcoma and chordoma treated by total tumor resection in thoracic and lumbar spine

BACKGROUND

En bloc resection of spinal tumors is challenging and associated with a high incidence of complications; however, it offers the potential to reduce the risk of recurrence when a wide margin is achieved. This research aims to investigate the safety and efficacy of en bloc resection in treating thoracic and lumbar chondrosarcoma/chordoma.

METHODS

Data from patients diagnosed with chondrosarcoma and chordoma in the thoracic or lumbar region, who underwent total en bloc or piecemeal resection at our institution over a 7-year period, were collected and regularly followed up. The study analyzed overall perioperative complications and compared differences in complications and local tumor recurrence between the two surgical methods.

RESULTS

Seventeen patients were included, comprising 12 with chondrosarcoma and 5 with chordoma. Among them, 5 cases underwent intralesional piecemeal resection, while the remaining 12 underwent planned en bloc resection. The average surgical time was 684 min (sd = 287), and the mean estimated blood loss was 2300 ml (sd = 1599). Thirty-five complications were recorded, with an average of 2.06 perioperative complications per patient. 82% of patients (14/17) experienced at least one perioperative complication, and major complications occurred in 64.7% (11/17). Five patients had local recurrence during the follow-up, with a mean recurrence time of 16.2 months (sd = 7.2) and a median recurrence time of 20 months (IQR = 12.5). Hospital stays, operation time, blood loss, and complication rates did not significantly differ between the two surgical methods. The local recurrence rate after en bloc resection was lower than piecemeal resection, although not statistically significant (P = 0.067).

CONCLUSIONS

The complication rates between the two surgical procedures were similar. Considering safety and local tumor control, en bloc resection is recommended as the primary choice for patients with chondrosarcoma/chordoma in the thoracic and lumbar regions who are eligible for this treatment.

Prognostic factors for surgical site infection in patients with spinal metastases and following surgical treatment

There were few articles reviewed prognostic factors of surgical site infection (SSI) in patients with spinal metastases following surgery. The purpose of the present study was to systematically: (1) investigate the incidence rates of SSI following spinal metastases surgery; (2) identify the factors which were independently associated with postoperative wound infection. One hundred sixty-seven consecutive adult patients with spinal metastases and underwent surgical treatment were retrospectively enrolled from January 2011 to February 2022. Demographic data, disease and operation-related indicators were extracted and analyzed. Univariate and multivariate logistic analysis model were performed respectively to determine independent risk factors of SSI. 17 cases infection were collected in this study. The overall incidence of SSI after surgery of spinal metastases patients was 10.2%. Univariate regression analysis showed that age (P = .028), preoperative ALB level (P = .024), operation time (P = .041), intraoperative blood loss (P = .030), Karnofsky Performance Status score (P = .000), body mass index (P = .013), American Society of Anesthesiologists > 2 (P = .010), Tobacco consumption (P = .035), and number of spinal levels involved in surgical procedure (P = .007) were associated with wound infection. Finally, the multivariate logistic model demonstrated that body mass index (P = .043; OR = 1.038), preoperative ALB level (P = .018; OR = 1.124), and number of spinal levels (P = .003; OR = 1.753) were associated with SSI occurrence. Surgery on multiple vertebral levels for spinal metastases significantly increases the risk of SSI and weight management, nutritional support and palliative surgery have the positive significance in reducing wound complications. Orthopedist should focus on identifying such high-risk patients and decrease the incidence of wound infection by formulating comprehensive and multi-disciplinary care strategy.

Nomogram for predicting postoperative pulmonary complications in spinal tumor patients

OBJECTIVES

Although several independent risk factors for postoperative pulmonary complications (PPCs) after spinal tumor surgery have been studied, a simple and valid predictive model for PPC occurrence after spinal tumor surgery has not been developed.

PATIENTS AND METHODS

We collected data from patients who underwent elective spine surgery for a spinal tumor between 2013 and 2020 at a tertiary hospital in China. Data on patient characteristics, comorbidities, preoperative examinations, intraoperative variables, and clinical outcomes were collected. We used univariable and multivariable logistic regression models to assess predictors of PPCs and developed and validated a nomogram for PPCs. We evaluated the performance of the nomogram using the area under the receiver operating characteristic curve (ROC), calibration curves, the Brier Score, and the Hosmer-Lemeshow (H-L) goodness-of-fit test. For clinical use, decision curve analysis (DCA) was conducted to identify the model's performance as a tool for supporting decision-making.

RESULTS

Among the participants, 61 (12.4%) individuals developed PPCs. Clinically significant variables associated with PPCs after spinal tumor surgery included BMI, tumor location, blood transfusion, and the amount of blood lost. The nomogram incorporating these factors showed a concordance index (C-index) of 0.755 (95% CI: 0.688-0.822). On internal validation, bootstrapping with 1000 resamples yielded a bias-corrected area under the receiver operating characteristic curve of 0.733, indicating the satisfactory performance of the nomogram in predicting PPCs. The calibration curve demonstrated accurate predictions of observed values. The decision curve analysis (DCA) indicated a positive net benefit for the nomogram across most predicted threshold probabilities.

CONCLUSIONS

We have developed a new nomogram for predicting PPCs in patients who undergo spinal tumor surgery.

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.

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.

The influence of costal resection on pulmonary function after total en bloc spondylectomy for spine tumor

BACKGROUND

Total en bloc spondylectomy (TES) is one of the surgical procedures which has been recognized as a complete resection for spine tumors. Although the surgery achieves favorable local control for solitary spinal lesion, performing the procedure in the thoracic spine requires circumferential dissection around the vertebral body and bilateral rib resections which might result in decline of pulmonary function postoperatively. This study aimed to clarify whether the number of rib resections negatively impacts pulmonary function after the procedure.

METHODS

This study included 31 patients who underwent vertebrectomy (17 males and 14 females) with a mean age of 54.2 years. Pulmonary function testing (PFT) was performed before surgery and at 1 month, 6 months, and 1 year postoperative visits. Patients with restrictive disorders such as space occupying lesions in the lung, obstructive problems such as a history of asthma, and smoking history were excluded from this study. Associations between the number of rib resections and PFT data were analyzed based on the resected level of the thoracic spine.

RESULTS

There was a significant decrease in forced vital capacity (FVC) at 1 month (72% of preoperative value), followed by gradual recovery at 6 months (89%) and 1 year (90%). The percentage of predicted forced expiratory volume in 1 s remained stable. Patients who underwent three pairs of rib resections showed a significant decrease in the FVC (83.5% of the preoperative value) and FEV1 (82.1% of the preoperative value) compared with one or two pairs of rib resections.

CONCLUSION

FVC decreased 1 month after vertebrectomy and returned to 90% of preoperative value at 1 year postoperatively. Three pairs of rib resections showed a significant decrease in FVC, suggesting the influence of a greater numbers of rib resections on pulmonary function.

Clinical Outcomes of Total En Bloc Spondylectomy for Previously Irradiated Spinal Metastases: A Retrospective Propensity Score-Matched Comparative Study

This study aimed to investigate the clinical outcomes of total en bloc spondylectomy (TES) for spinal metastases previously treated with radiotherapy (RT). This study enrolled 142 patients who were divided into two groups: those with and those without an RT history. Forty-two patients were selected from each group through propensity score matching, and postoperative complications, local recurrence, and overall survival rates were compared. The incidence of postoperative complications was significantly higher in the group with an RT history than in the group without an RT history (57.1% vs. 35.7%, respectively). The group with an RT history had a higher local recurrence rate than the group without an RT history (1-year rate: 17.5% vs. 0%; 2-year rate: 20.8% vs. 2.9%; 5-year rate: 24.4% vs. 6.9%). The overall postoperative survival tended to be lower in the group with an RT history; however, there was no significant difference between the two groups (2-year survival: 64.3% vs. 66.7%; 5-year survival: 47.3% vs. 57.1%). When planning a TES for irradiated spinal metastases, the risk of postoperative complications and local recurrence should be fully considered.

Biomechanical effects of transverse connectors on total en bloc spondylectomy of the lumbar spine: a finite element analysis

BACKGROUND

The influence of total en bloc spondylectomy (TES) on spinal stability is substantial, necessitating strong fixation to restore spinal stability. The transverse connector (TC) serves as a posterior spinal instrumentation that connects the left and right sides of the pedicle screw-rod system. Several studies have highlighted the potential of a TC in enhancing the stability of the fixed segments. However, contradictory results have suggested that a TC not only fails to improve the stability of the fixed segments but also might promote stress associated with internal fixation. To date, there is a lack of previous research investigating the biomechanical effects of a TC on TES. This study aimed to investigate the biomechanical effects of a TC on internal fixation during TES of the lumbar (L) spine.

METHODS

A single-segment (L3 segment) TES was simulated using a comprehensive L spine finite element model. Five models were constructed based on the various positions of the TC, namely the intact model (L1-sacrum), the TES model without a TC, the TES model with a TC at L1-2, the TES model with a TC at L2-4, and the TES model with a TC at L4-5. Mechanical analysis of these distinct models was conducted using the Abaqus software to assess the variations in the biomechanics of the pedicle screw-rod system, titanium cage, and adjacent endplates.

RESULTS

The stability of the surgical segments was found to be satisfactory across all models. Compared with the complete model, the internal fixation device exhibited the greatest constraint on overextension (95.2-95.6%), while showing the least limitation on left/right rotation (53.62-55.64%). The application of the TC had minimal effect on the stability of the fixed segments, resulting in a maximum reduction in segment mobility of 0.11° and a variation range of 3.29%. Regardless of the use of a TC, no significant changes in stress were observed for the titanium cage. In the model without the TC, the maximum von Mises stress (VMS) for the pedicle screw-rod system reached 136.9 MPa during anterior flexion. Upon the addition of a TC, the maximum VMS of the pedicle screw-rod system increased to varying degrees. The highest recorded VMS was 459.3 MPa, indicating a stress increase of 335.5%. Following the TC implantation, the stress on the adjacent endplate exhibited a partial reduction, with the maximum stress reduced by 27.6%.

CONCLUSION

The use of a TC in TES does not improve the stability of the fixed segments and instead might result in increased stress concentration within the internal fixation devices. Based on these findings, the routine utilisation of TC in TES is deemed unnecessary.

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.

Three-dimensional simulation/printing-assisted surgery for symptomatic metastatic epidural spinal cord compression of posterior column: efficacy assessment based on 2-year follow-up

Background

Surgical intervention is necessary for resolving the symptoms of the spinal cord and nerve compression caused by symptomatic metastatic epidural spinal cord compression. However, surgeons are constantly seeking ways to improve surgical efficiency and safety. This study aims to evaluate the efficacy of 3D simulation/printing-assisted surgery for symptomatic metastatic epidural spinal cord compression of the posterior column.

Methods

We retrospectively analyzed the clinical data of patients who underwent surgical treatment for symptomatic metastatic epidural spinal cord compression of the posterior column in our hospital from January 2015 to January 2020. The simulated group underwent a 3D digital simulation of the lesion area using imaging data before surgery. Twelve patients in the simulated group also received 3D printing, while the direct surgery group did not receive any 3D simulation or printing. All patients were followed up for at least 2 years. We collected clinical data, including operation time, intraoperative blood loss, pedicle screw adjustment rate, intraoperative fluoroscopy times, the incidence of dural injury and cerebrospinal fluid leakage, VAS score, postoperative neurological function improvement, and tumor recurrence. Statistical analysis was performed using SPSS23.0, and P < 0.05 was considered statistically significant.

Results

A total of 46 patients were included in this study, with 20 in the simulated group and 26 in the non-simulated group. The simulated group had better operation time, intraoperative blood loss, screw adjustment rate, fluoroscopy times, and incidence of dural injury/cerebrospinal fluid leakage compared to the non-simulated group. The VAS scores of the two groups improved significantly after the operation and at the last follow-up compared to before the operation. However, there was no statistically significant difference between the two groups. There was also no statistically significant difference in neurological function improvement between the two groups. In the simulated group, 25% of patients relapsed, while in the non-simulated group, 34.61% of patients relapsed. However, there was no statistical difference between the two groups.

Conclusion

Preoperative 3D simulation/printing-assisted surgery is a practical and feasible approach for treating symptomatic metastatic epidural spinal cord compression of the posterior column.

Complications and prognosis of primary thoracic and lumbar giant cell tumors treated by total tumor resection

BACKGROUND

Spinal giant cell tumor (SGCT) is a relatively rare primary tumor. En bloc resection is the preferred surgical procedure for it due to its aggressiveness, meanwhile leading to more complications. We reported the characteristics of perioperative complications and local control of total tumor resection including en bloc resection and piecemeal resection for primary thoracic and lumbar spinal giant cell tumors in a single center over 10 years.

METHODS

This is a retrospective cross-sectional and cohort study. Forty-one consecutive patients with SGCTs who underwent total tumor resection from 2010 to 2020 at our institution and were followed up for at least 24 months were reviewed. Surgery data, complication characteristics and local tumor control were collected and compared by different surgical procedure.

RESULTS

Forty-one patients were included, consisting of 18 males and 23 females, with a mean age of 34.2 years. Thirty-one had thoracic vertebra lesions, and 10 had lumbar vertebra lesions. Thirty-five patients were primary cases, and 6 patients were recurrent cases. Eighteen patients were treated by total en bloc spondylectomy (TES), 12 patients underwent en bloc resection according to WBB surgical system, and 11 patients underwent piecemeal resection. The average surgical time was 498 min, and the mean estimated blood loss was 2145 ml. A total of 58 complications were recorded, and 30 patients (73.2%) had at least one perioperative complication. All patients were followed up after surgery for at least 2 years. A total of 6 cases had postoperative internal fixation failure, and 4 cases presented local tumor recurrence (9.8%).

CONCLUSIONS

Although the surgical technique is difficult and accompanied by a high rate of perioperative complications, en bloc resection can achieve favorable local control in SGCT. When it is too difficult to complete en bloc resection, thoroughly piecemeal resection without residual is also acceptable, given the relatively low recurrence rate.

Development and Validation of a Prognostic Model for Overall Survival in Patients with Primary Pelvis and Spine Osteosarcoma: A Population-Based Study and External Validation

Background: Primary pelvis and spine osteosarcoma (PSOS) is a specific type of osteosarcoma that is difficult to treat and has a poor prognosis. In recent years, the research on osteosarcoma has been increasing, but there have been few studies on PSOS; in particular, there have been a lack of analyses with a large sample size. This study aimed to construct and validate a model to predict the overall survival (OS) of PSOS patients, as currently there are no tools available for assessing their prognosis. Methods: Data including demographic information, clinical characteristics, and follow-up information on patients with PSOS were collected from the Surveillance, Epidemiology, and End Results (SEER) database, as well as from the Spine Tumor Center of Changzheng Hospital. Variable selection was achieved through a backward procedure based on the Akaike Information Criterion (AIC). Prognostic factors were identified by univariate and multivariate Cox analysis. A nomogram was further constructed for the estimation of 1-, 3-, and 5-year OS. Calibration plots, the concordance index (C-index), and the receiver operating characteristic (ROC) were used to evaluate the prediction model. Results: In total, 83 PSOS patients and 90 PSOS patients were separately collected from the SEER database and Changzheng Hospital. In the SEER cohort, liver metastasis, lung metastasis, and chemotherapy were recognized as independent prognostic factors for OS (p < 0.05) and were incorporated to construct the initial nomogram. However, the initial nomogram showed poor predictive accuracy in internal and external validation. Then, we shifted our focus to the Changzheng data. Lung metastasis involving segments, Eastern Cooperative Oncology Group (ECOG) performance score, alkaline phosphatase (ALP) level, and en bloc resection were ultimately identified as independent prognostic factors for OS (p < 0.05) and were further incorporated to construct the current nomogram, of which the bias-corrected C-index was 0.834 (0.824–0.856). The areas under the ROC curves (AUCs) of the current nomogram regarding 1-, 3-, and 5-year OS probabilities were 0.93, 0.96, and 0.92, respectively. Conclusion: We have developed a predictive model with satisfactory performance and clinical practicability, enabling effective prediction of the OS of PSOS patients and aiding clinicians in decision-making.

Characteristics and risk factors of instrumentation failure following total en bloc spondylectomy

AIMS

The aim of this study was to investigate the incidence and characteristics of instrumentation failure (IF) after total en bloc spondylectomy (TES), and to analyze risk factors for IF.

METHODS

The medical records from 136 patients (65 male, 71 female) with a mean age of 52.7 years (14 to 80) who underwent TES were retrospectively reviewed. The mean follow-up period was 101 months (36 to 232). Analyzed factors included incidence of IF, age, sex, BMI, history of chemotherapy or radiotherapy, tumour histology (primary or metastasis; benign or malignant), surgical approach (posterior or combined), tumour location (thoracic or lumbar; junctional or non-junctional), number of resected vertebrae (single or multilevel), anterior resection line (disc-to-disc or intravertebra), type of bone graft (autograft or frozen autograft), cage subsidence (CS), and local alignment (LA). A survival analysis of the instrumentation was performed, and relationships between IF and other factors were investigated using the Cox regression model.

RESULTS

A total of 44 patients (32.4%) developed IF at a median of 31 months (interquartile range 23 to 74) following TES. Most IFs were rod fractures preceded by a mean CS of 6.1 mm (2 to 18) and LA kyphotic enhancement of 10.8° (-1 to 36). IF-free survival rates were 75.8% at five years and 56.9% at ten years. The interval from TES to IF peaked at two to three years postoperatively and continued to occur over a period of time thereafter; the early IF-developing group had greater CS at one month postoperatively (CS1M) and more lumbar TES. CS1M ≥ 3 mm and sole use of frozen autografts were identified as independent risk factors for IF.

CONCLUSION

IF is a common complication following TES. We have demonstrated that robust spinal reconstruction preventing CS, and high-quality bone grafting are necessary for successful reconstruction.Cite this article: Bone Joint J 2023;105-B(2):172-179.

Clinical results of total en bloc spondylectomy using a single posterior approach in spinal metastasis patients: Experiences from Thailand

AIM

To demonstrate a single posterior approach, total en bloc spondylectomy (TES) could be performed safely without preoperative embolization in spinal metastasis patients.

MATERIALS AND METHODS

Thirteen solitary spinal metastasis patients (five males) underwent single posterior approach TES at the thoracolumbar spine without preoperative embolization from January 2018 to January 2020. The primary sites were the breast (n = 4), hepatocellular carcinoma (n = 2), colon (n = 2), and others (n = 5). All patients underwent single posterior TES. The Eastern Cooperative Oncology Group, Frankel neurological status, operative time and blood loss, and any complications were all recorded. The patients were regularly followed-up with radiography, computed tomography, and magnetic resonance imaging to detect any local recurrences.

RESULTS

The mean operative time was 354.6 min, and the mean operative blood loss was 2134.62 ml. None of the patients experienced any perioperative complications. Within the follow-up period (3-24 months), no local recurrences were detected. Two patients (15.38%) were found to have distant metastasis to adjacent and remote vertebrae. Three patients were lost to follow-up, and three patients died of disease. Six patients showed an improved ECOG functional status by at least one grade. Four of Frankel A patients improved their neurological status by at least one grade.

CONCLUSION

Even without embolization, single posterior TES at the thoracolumbar spine is safe and effective for short-term local control in solitary spinal metastasis. However, TES cannot prevent distant metastasis. Longer-term follow-up studies will be able to further identify the benefits of TES for the long-term local control of diseases.

The Combination of Separation Surgery and Intensity Modulated Radiation Therapy (IMRT) for a Primary Osteosarcoma of the Spine: A Case Report and Literature Review

Background

Primary spinal osteosarcoma is a rare and intractable disease. Although en bloc resection is favorable for longer survival, it is not always achievable. Separation surgery, a partial resection with circumferential separation to safely deliver high-dose irradiation including intensity-modulated radiation therapy (IMRT), has been recently indicated for patients with spinal cord compression secondary to solid tumor metastases. However, little evidence regarding this combination approach to spinal osteosarcoma exists.

Case presentation

We report a 55-year-old male patient with a T1 tumor who underwent urgent decompression surgery for epidural spinal cord compression. Pathological findings revealed primary osteosarcoma. Separation surgery, IMRT, and adjuvant chemotherapy were applied to reduce the symptoms of epidural spinal cord compression. The patient was alive without local recurrence at the 5-year follow-up.

Conclusions

Separation surgery with IMRT can be a relatively safe and effective treatment option in patients with osteosarcoma adjacent to spinal cord when en-bloc resection is challenging.

Medium to Long-Term Clinical Outcomes of Spinal Metastasectomy

The prolonged survival of metastatic cancer patients highlights the importance of the local control of spinal metastases, which reduce patient performance status. This retrospective study examined the medium to long-term outcomes of spinal metastasectomy by evaluating 124 patients who underwent metastasectomy for isolated spinal metastases (2006-2018) with a postoperative follow-up for a minimum of 3 years. The findings present information on patient demographics (i.e., performance status, location of non-spinal metastases, and history of systemic therapy) and postoperative outcomes, including perioperative complications, disease progression of non-operated metastases, and additional excisional surgeries. Additionally, postoperative survival, local tumor control in the operated spine, and maintenance of spinal reconstruction without instrumentation failure were determined using Kaplan-Meier analyses. The primary malignancy was kidney and thyroid cancer in 51 and 14 patients, respectively, low-grade sarcoma and lung cancer in 13 patients, breast cancer in 12 patients, and other malignancies in 21 patients. The 3-year and 5-year survival rates were 70% and 60%, respectively. We found that patients with thyroid cancer had the best survival results, with local tumor recurrence and instrumentation failure at 10% and 22%, respectively. These findings suggest that for certain patients with isolated and removable spine metastases, metastasectomy can improve function and survival.

The role of surgery in the treatment of metastatic bone tumor

Surgery for bone metastasis has two primary goals-palliative care to relieve pain, instability and paralysis, and tumor resection for curing the disease. Oncologically en bloc resection, followed by a reconstruction of the bone defect is the treatment of choice in single bone metastasis from renal cell carcinoma or thyroid cancer. Bone metastases may occur in the extremities, pelvis, or spine, and different resection and reconstruction methods depend on the regional anatomy. For instance, multiple options are available for reconstruction of the pelvis, especially for the acetabulum, including anatomical reconstruction using custom-made implants or recycled autologous bone grafting when a long-term prognosis is expected. Recently, for the spine, total en bloc spondylectomy is extensively performed despite the initial limitations of surgical invasiveness, such as blood loss. Principally, palliative surgery aims to maintain lasting bony stability with minimal surgical invasiveness. Intramedullary nails and plate fixation are frequently used in the extremities but the postoperative failure rate is relatively high. Therefore, surgeons should consider the use of long intramedullary nails and long-type stems for endoprosthesis reconstruction along with cement fixation to reduce the failure rate. Although short-term complications, such as dislocation, have been observed with endoprosthesis reconstruction, it is stable in the long-term follow-up. Percutaneous bone cement injection into the spine and pelvis is also effective and less invasive.

Surgical Metastasectomy in the Spine: A Review Article

BACKGROUND

The use of surgical metastasectomy (SM) has increased across cancer types in recent decades despite the increasing efficacy of modern systemic treatment modalities. Symptomatic spinal metastases severely compromise patients' performance status. However, as spinal SM is a complex surgery with potentially significant complications, it is not considered the treatment of choice.

METHODS

We reviewed the articles on SM in several primary cancers with different types of metastatic lesions and extracted the data from relevant articles to provide a comprehensive review including the surgical techniques, indications, reported outcomes, and future prospects of SM in spinal metastases.

RESULTS

Total en bloc spondylectomy (TES) is a method of spinal SM associated with a lower risk of tumor recurrence and complications. Intralesional transpedicular osteotomy using a fine threadwire saw allows prevention of spinal cord and nerve root injuries. Spinal SM is considered suitable for patients with controlled primary disease having no evidence of disseminated extraspinal metastases, a completely resectable solitary lesion in the spine, and adequate cardiopulmonary reserve to tolerate the surgery. Metastatic lesions from kidney and thyroid cancers have been reported as the best candidates for spinal SM. Although data about spinal SM are limited, the reported outcomes are favorable with acceptable local recurrence rates in long-term follow-up.

CONCLUSION

In patients with isolated resectable spinal metastases, complete SM including TES is a useful option as it can improve function and survival. However, appropriate patient selection and surgical feasibility remain the most important aspects of management.

IMPLICATIONS FOR PRACTICE

Surgical metastasectomy for spinal metastases may be a potentially curative treatment option with a low risk of local recurrence and lead to prolonged long-term survival if appropriate patients are selected and if the surgery is carried out by experienced surgeons in high-volume centers.