Bone Cement-Augmented Percutaneous Screw Fixation for Malignant Spinal Metastases: Is It Feasible?

Incidence of Cement Leakage and Potential Risk Factors in Surgery for Spinal Metastasis: A Systematic Review and Meta-Analysis

OBJECTIVES

The current meta-analysis was performed to gather available evidence regarding the incidence and risk factors of cement leakage (CL) in patients undergoing surgical procedures for spinal metastasis.

METHODS

Two authors independently searched the PubMed, Embase, and CENTRAL databases. Clinical studies reporting the incidence or risk factors of CL were included for analysis. The primary outcome analyzed was the incidence of various types of CL. Random-effects or fixed-effects single-proportion meta-analyses were conducted to pool the available evidence, based on the heterogeneity test. Subgroup analyses were conducted based on surgical procedures (percutaneous vertebroplasty, percutaneous kyphoplasty, and others). Risk factors of CL were synthesized narratively to identify the most commonly accepted factors.

RESULTS

A total of 26 studies, involving 2551 patients, were included. The number of operated spine segments was reported in 23 studies, accounting for 4101 vertebrae. The pooled incidences of general, intradiscal, paravertebral, spinal canal, and intravascular CLs were 0.18 (95% confidence interval [CI], 0.11-0.28), 0.14 (95% CI, 0.08-0.21), 0.13 (95% CI, 0.06-0.21), 0.11 (95% CI, 0.05-0.19), and 0.12 (95% CI, 0.08-0.17), respectively. Subgroup analyses revealed significantly different incidences of general CL (0.37 vs. 0.06 vs. 0.09, P < 0.01), intradiscal CL (0.22 vs. 0.06 vs. 0.12, P < 0.01), paravertebral CL (0.25 vs. 0.03 vs. 0.06, P < 0.01), and vascular CL (0.14 vs. 0.03 vs. 0.15, P < 0.01) among the three groups. Posterior wall disruption, pathologic fracture, and the number of treated vertebral levels were the most commonly identified independent risk factors for general CL. Posterior wall disruption was determined as a common significant risk factor for spinal canal CL.

CONCLUSIONS

This review provides insights into the incidence and risk factors associated with CL in surgical procedures for spinal metastasis. Understanding these risk factors can contribute to the development of tailored strategies aimed at minimizing CL occurrence and optimizing surgical outcomes for patients undergoing spinal metastatic surgery.

Percutaneous CT-Guided Microwave Ablation Combined with Pedicle Screw Fixation Followed by Vertebroplasty (MASFVA): Initial Experience of a Minimally Invasive Treatment of Vertebral Metastases with Extension to the Vertebral Pedicle

(1) Background: The aim of this study was to retrospectively evaluate the safety and efficacy of a combined CT-guided percutaneous microwave ablation (MWA) and pedicle screw fixation followed by vertebroplasty (MASFVA) for the treatment and stabilization of painful vertebral metastases with vertebral pedicle involvement. (2) Methods: from January 2013 to January 2017 11 patients with 16 vertebral metastatic lesions (7 men and 5 women; mean age, 65 ± 11 years) with vertebral metastases underwent CT-guided microwave ablation and screw fixation followed by vertebroplasty (MASFVA). Technical success, complication rate, pain evaluation using a visual analogue scale (VAS), Oswestry Disability Index (ODI) and local tumor control were examined. (3) Results: Technical success rate was 100%. No procedure-related major complications occurred. VAS score decreased from 6.8 ± 0.7 to 0.6 ± 0.6. ODI score decreased from 3.1 ± 0.7 to 1.2 ± 0.4. All patients could walk independently without neurological complication after one week from the procedure. No new bone fractures or local disease recurrence occurred during a median follow-up of 12 months. (4) Conclusions: Our results suggest that MWA and percutaneous pedicle screw fixation followed by vertebroplasty for the treatment of painful vertebral metastases is a safe and effective procedure for painful vertebral metastases with vertebral pedicle involvement, allowing pain relief and local tumor control.

Comparing the efficacy and safety of cement-augmented fenestrated pedicle screws and conventional pedicle screw in surgery for spinal metastases: a retrospective comparative cohort study

Background

The incidence of cancer patients with bone metastasis is increasing annually. With the advancement of medical treatment for malignant tumors, the survival time of patients with spinal metastases is gradually being prolonged, and adjacent segment vertebral metastases often occur after conventional pedicle screw (CPS) surgery, leading to spinal instability, pain and nerve function injury again, with repeated symptoms. Combined pedicle screw fixation can maintain or reconstruct the spinal stability. This study aimed to investigate the efficacy and safety of cement-augmented fenestrated pedicle screws in the posterior approach for spinal metastases by comparing with CPS.

Methods

From January 2017 to August 2019, 52 patients with spinal metastases who underwent separation surgery and internal fixation via posterior approach were retrospectively enrolled. Cases were divided into the cement-augmented pedicle screw (CAPS) group (28 cases) and the CPS group (24 cases). The baseline data [age, gender, surgical sites, surgical segment, Tomita classification, Tomita score, Tokuhashi score, spinal instability neoplastic score (SINS)], surgical information, and local progression-free survival (PFS) time were compared between the two groups. Every patient was followed-up every 3 months with imaging examination. The visual analog scale (VAS) score and Frankel grade of the two groups were recorded before and 3 months after the operation were used to evaluate the efficacy. The operation time, the amount of intraoperative blood loss, the amount of bone cement injected in the pedicle screw group, and the complications of the surgery were recorded to evaluate the safety of CAPS.

Results

The baseline characteristics were comparable between the two group. Compared with the CPS group, the CAPS group showed significantly longer operation time (163±20 vs. 138±18 min, P<0.001) and lower VAS scores (2.93±1.33 vs. 4.17±1.34, P=0.002). Adjacent segment vertebral metastasis occurred in 10 cases (2 in the CAPS group and 8 in the CPS group, P=0.017). Internal implant failure occurred in 8 cases (1 in the CAPS group and 7 in the CPS group, P=0.011). Compared with the CPS group, the CAPS group had a significantly longer local PFS time (P<0.05).

Conclusions

CAPS could be a safe and effective choice in surgery for spinal metastases with the posterior approach.

Osteolytic vs. Osteoblastic Metastatic Lesion: Computational Modeling of the Mechanical Behavior in the Human Vertebra after Screws Fixation Procedure

Metastatic lesions compromise the mechanical integrity of vertebrae, increasing the fracture risk. Screw fixation is usually performed to guarantee spinal stability and prevent dramatic fracture events. Accordingly, predicting the overall mechanical response in such conditions is critical to planning and optimizing surgical treatment. This work proposes an image-based finite element computational approach describing the mechanical behavior of a patient-specific instrumented metastatic vertebra by assessing the effect of lesion size, location, type, and shape on the fracture load and fracture patterns under physiological loading conditions. A specific constitutive model for metastasis is integrated to account for the effect of the diseased tissue on the bone material properties. Computational results demonstrate that size, location, and type of metastasis significantly affect the overall vertebral mechanical response and suggest a better way to account for these parameters in estimating the fracture risk. Combining multiple osteolytic lesions to account for the irregular shape of the overall metastatic tissue does not significantly affect the vertebra fracture load. In addition, the combination of loading mode and metastasis type is shown for the first time as a critical modeling parameter in determining fracture risk. The proposed computational approach moves toward defining a clinically integrated tool to improve the management of metastatic vertebrae and quantitatively evaluate fracture risk.

Spinal metastasis: narrative reviews of the current evidence and treatment modalities

The treatment for spinal metastasis has evolved significantly during the past decade. An advancement in systemic therapy has led to a prolonged overall survival in cancer patients, thus increasing the incidence of spinal metastasis. In addition, with the improved treatment armamentarium, the prediction of patient survival using traditional prognostic models may have limitations and these require the incorporation of some novel parameters to improve their prognostic accuracy. The development of minimally-invasive spinal procedures and minimal access surgical techniques have facilitated a quicker patient recovery and return to systemic treatment. These modern interventions help to alleviate pain and improve quality of life, even in candidates with a relatively short life expectancy. Radiotherapy may be considered in non-surgical candidates or as adjuvant therapy for improving local tumour control. Stereotactic radiosurgery has facilitated this even in radioresistant tumours and may even replace surgery in radiosensitive malignancies. This narrative review summarizes the current evidence leading to the paradigm shifts in the modern treatment of spinal metastasis.

10-Year Trends in the Surgical Management of Patients with Spinal Metastases: A Scoping Review

BACKGROUND

Spinal metastases are present in approximately 20% of patients with cancer, giving a risk for neurologic dysfunction and instability. In already frail patients, surgeons strive to improve quality of life. Our goal was to review a 10-year trend in the surgical management of spinal metastases.

METHODS

A scoping review was performed systematically using PubMed to assess trends in surgical treatment for spinal metastases. The search terms used were: metastas∗, "neoplasm metastasis"[Mesh], "Spine"[Mesh], spine, spinal, "vertebral column," "vertebral body," laser, robot, radiofrequency, screws, fixation, "separation surgery," corpectomy, vertebrectomy, spondylectomy, vertebroplasty, kyphoplasty, surgery, "open surgery," "mini open surgery," "minimally invasive surgery," endoscopy, thoracoscopy, corpectom∗, vertebrectom∗, spondylectom∗, "en bloc," and MIS. The variables of interest were neurologic improvement, tumor recurrence, reoperation, and overall survival.

RESULTS

A total of 2132 articles were found within the primary query. Fifty-six studies were selected for final review. The results were organized into main surgical practices: decompression, mechanical stabilization, and pain management. For separation surgery, clinical outcomes were overall 1-year survival, 40.7%-78.4%; recurrence rate, 4.3%-22%; reoperation, 5%; and complications, 5.4%-14%. For corpectomy, clinical outcomes were overall 1-year survival, 30%-92%; reoperation, 1.1%-50%; and recurrence rate, of 1.1%-28%. Complications and reoperations with spinal instrumentation were 0%-13.6% and 0%-15%, respectively. Cement augmentation achieved pain reduction rates of 56%-100%, neurologic improvement/stability 84%-100%, and complication rates 6%-56%. Laser achieved local tumor control rate of 71%-82% at 1 year follow-up, reoperation rate of 15%-31%, and complication rate of 5%-26%.

CONCLUSIONS

Minimally invasive techniques for decompression and stabilization seem to be the preferred method to surgically treat metastatic spine disease, with good outcomes. More research with high level of evidence is required to support the long-term outcomes of these approaches.