Minimally invasive option using percutaneous pedicle screw for instability of metastasis involving thoracolumbar and lumbar spine : a case series in a single center

The Evolution of Minimally Invasive Spine Tumor Resection and Stabilization: From K-Wires to Navigated One-Step Screws

Minimization of the surgical approaches to spinal extradural metastases resection and stabilization was advocated by the 2012 Oncological Guidelines for Spinal Metastases Management. Minimally invasive approaches to spine oncology surgery (MISS) are continually advancing. This paper will describe the evolution of minimally invasive surgical techniques for the resection of metastatic spinal lesions and stabilization in a single institute. A retrospective analysis of patients who underwent minimally invasive extradural spinal metastases resection during the years 2013-2019 by a single surgeon was performed. Medical records, imaging studies, operative reports, rates of screw misplacement, operative time and estimated blood loss were reviewed. Detailed description of the surgical technique is provided. Of 138 patients operated for extradural spinal tumors during the study years, 19 patients were treated in a minimally invasive approach and met the inclusion criteria for this study. The mortality rate was significantly improved over the years with accordance of improve selection criteria to better prognosis patients. The surgical technique has evolved over the study years from fluoroscopy to intraoperative 3D imaging and navigation guidance and from k-wire screw insertion technique to one-step screws. Minimally invasive spinal tumor surgery is an evolving technique. The adoption of assistive devices such as intraoperative 3D imaging and one-step screw insertion systems was safe and efficient. Oncologic patients may particularly benefit from the minimization of surgical decompression and fusion in light of the frailty of this population and the mitigated postoperative outcomes associated with MIS oncological procedures.

Robot and working tube-assisted invasion-controlled surgery for spinal metastases

Objective

This study aims to highlight the use of robots in surgery and that of tube-assisted minimally invasive surgery for spinal metastases, as well as elaborate on the concept of invasion-controlled surgery (ICS).

Summary of background

Many patients with spinal metastasis cancer cannot afford serious complications when undergoing traditional open surgery because of their poor physical condition. Robots and minimally invasive technology have been introduced into the field of spine surgery and they have shown significant advantages.

Methods

Six patients who underwent robot and working tube-assisted ICS for spinal metastases. Relevant demographic, medical, surgical, and postoperative data were collected from medical records and analyzed.

Results

Mean operative time was 3.8 h and the mean length of the surgical incision was 4.9 cm. The mean estimated blood loss was 400 ml. The mean bedtime and hospital length of stay were 3.2 days and 6.5 days, respectively. No obvious complications were reported during treatment. The mean accuracy of screw placement was 98%. The mean time for further system treatment after surgery was 5.8 days. All patients experienced significant pain relief. The mean preoperative visual analog scale (VAS) was 7.83 points. The mean VAS at 1 day, 1 week, and 1 month after surgery were 2.83, 1.83, and 1.17 points, respectively. Frankel grade was improved in five of six patients. One patient preoperatively with Frankel grade D was the same postoperatively.

Conclusion

The concept of ICS is suitable for patients with spinal metastases. Robot and working tube-assisted ICS for spinal metastases is one of the safest and most effective treatment methods.

How do vertebroplasty and kyphoplasty affect the quality of life of patients with multiple myeloma spinal metastasis?

BACKGROUND

Metastatic spinal lesions are diseases that impair the quality of life and require early diagnosis and treatment. The count of spinal metastasis patients rises day by day. Increased life expectancy has increased the incidence of cancer, making metastases more observable. The aim of our study was to investigate how the quality of life is affected in the patient group with vertebral fracture due to spinal metastases of multiple myeloma and undergoing vertebroplasty and kyphoplasty.

MATERIALS AND METHODS

Forty-two patients with fracture due to spinal metastasis and adequate follow-up between the years of 2011 and 2018 were included in the study. Patients were listed according to their primary malignancy and metastases. The effect of vertebroplasty and kyphoplasty was investigated by evaluating preoperative and postoperative VAS and Oswestry Disability Index scores. All patients' radiographic kyphosis angle, compression ratio and wedging index were calculated before operation and after operation.

RESULTS

A total of 76 vertebrae were operated in 42 patients. Significant differences were found in the comparison of preoperative and postoperative quality of life according to VAS and Oswestry Disability Index scores in the patients undergoing vertebroplasty, kyphoplasty or both procedures after spinal metastases (VAS; p = 0.0001, ODI; p = 0.002/0.0001). There were statistically significant differences in preoperative local kyphosis angle, compression ratio and wedging index and post-op local kyphosis angle, compression ratio and wedging index (p = 0.001).

CONCLUSION

Vertebroplasty and kyphoplasty, minimally invasive procedures performed after spinal metastases, improve the quality of life of the patients.

Use of Cement-Augmented Percutaneous Pedicular Screws in the Management of Multifocal Tumoral Spinal Fractures

STUDY DESIGN

Retrospective case series observational study.

PURPOSE

Cancer patients are often aged and are further weakened by their illness and treatments. Our goal was to evaluate the efficiency and safety of using minimally invasive techniques to operate on spinal fractures in these patients.

OVERVIEW OF LITERATURE

Vertebroplasty is now considered to be a safe technique that allows a significant reduction of the pain induced by a spinal tumoral fracture. However, few papers describe the kyphosis reduction that can be achieved by combining percutaneous fixation and anterior vertebral reconstruction.

METHODS

We studied 35 patients seen between December 2013 and October 2016 who had at least one pathological spinal fracture and multiple vertebral metastases. The population's mean age was 67 years, and no patients included had preoperative neurological deficits. The patients underwent a minimally invasive surgery consisting of a percutaneous pedicular fixation with cement-enhanced screws and anterior reconstruction comprising kyphoplasty when possible or corpectomy in cases of excessive damage to the vertebral body. Back pain, traumatic local and regional kyphosis, and Beck's Index were collected pre- and postoperatively, and at 3-, 6-, and 12-month follow-ups.

RESULTS

Mean follow-up time was 13.4 months. Significant reductions in back pain (p<0.001) and local (p<0.001) and regional kyphosis (p=0.006) were found at the 6-month follow-up (alpha risk level <0.05). Beck's Index was also significantly increased, indicating good restoration of the anterior vertebral height. By the final follow-up, no screws had fallen/pulled out. There were no infectious or neurological complications.

CONCLUSIONS

Percutaneous cement-enhanced fixation for pathological fractures has proven a safe and efficient technique in our experience, enabling weak patients to rapidly become ambulatory again without complications. Further follow-up of the patients is necessary to assess the long-term effects of this technique and the continued quality of life of our patients.

Bioactive pedicle screws prepared by chemical and heat treatments improved biocompatibility and bone-bonding ability in canine lumbar spines

Background

Titanium (Ti)-6Al-4V alloy, which is widely used in spinal instrumentation with a pedicle screw (PS) system. However, significant clinical problems, including loosening and back-out of PSs, persist. During the last decade, a novel technology that produces bioactive Ti from chemical and heat treatments has been reported that induces the spontaneous formation of a hydroxyapatite (HA) layer on the surface of Ti materials. The purpose of this study was to study the effect of bioactivation of Ti-6Al-4V PSs on the ability of HA formation in vitro and its biocompatibility and bone-bonding ability in vivo.

Methods

Ti-6V-4Al alloy PSs were prepared and bioactivated by NaOH-CaCl₂-heat-water treatments. The HA-forming ability of bioactive PSs in simulated body fluid (SBF) was evaluated by field emission scanning electron microscopy (FE-SEM) and energy dispersive X-ray analysis (EDX). Six 11-month-old female beagle dogs were used for the in vivo study. Bioactive and control (without bioactivation) PSs were left and right randomly placed from L1 to L6. One and three months after surgery, lumbar spines were removed for biomechanical and histological analyses.

Results

In vitro: The surface analysis of bioactive PSs by FE-SEM and EDX showed substantial HA deposits over the entire surface. In vivo: The mean extraction torque was significantly higher for bioactive PSs compared to controls PSs (P<0.01); there was no significant difference in pull-out strength between control and bioactive PSs. Histologically, the contact area between bone tissue and screw surface showed no significant trend to be greater in bioactive PSs compared to control PSs (P = 0.06).

Conclusions

Bioactive PSs prepared by chemical and heat treatments formed layers of HA on the surface of screws in vitro that improved biocompatibility and bonding ability with bone in vivo. Bioactive PSs may reduce screw loosening to overcome the obstacles confronted in spinal instrumentation surgery.

Comparison of the effects of minimally invasive percutaneous pedicle screws osteosynthesis and open surgery on repairing the pain, inflammation and recovery of thoracolumbar vertebra fracture

We compared the clinical effects of minimally invasive percutaneous pedicle screws osteosynthesis (MIPPSO) and open surgery on the repair of thoracolumbar vertebra fracture. Seventy patients, who suffered from thoracolumbar vertebra fracture and received treatment at our hospital, were selected and randomly divided into either the minimally invasive percutaneous pedicle screws osteosynthesis group (MIPPSO group) and the traditional open pedicle screws osteosynthesis group (TOPSO group) with 35 cases in each group. The perioperative parameters including length of incision, duration of operation, bleeding during operation, length of hospital stay, the changes of pre-operative and post-operative VAS pain scores, inflammatory indexes including serum C-reactive protein (CRP) and creatine kinase (CK), and imaging indexes including Cobb's angle and anterior margin height of vertebral body of both groups were compared. The length of incision, duration of operation, bleeding volume during operation and length of hospital stay in the MIPPSO group were significantly lower than those in the TOPSO group (P<0.05). Both minimally invasive surgery and traditional surgery effectively alleviated the pain (P<0.05), which was more significant in MIPPSO group (P<0.05). The post-operative inflammatory indexes, CRP and CK levels, of both groups were higher compared to the pre-operation (P<0.05), which was more significant in TOPSO group (P<0.05). The differences of imaging indexes, including Cobb's angle and anterior margin height of injured vertebra, were statistically significant between pre-operation and post-operation for each group (P<0.05); however, there were no statistically significant differences between two groups at either pre-operation or post-operation (P>0.05). The effect of minimally invasive percutaneous pedicle screws osteosynthesis is similar to the traditional open surgery, however, the MIPPSO technique has the advantages of small trauma, less bleeding, short duration of operation, rapid post-operative recovery, light pain, less economic cost, and better aesthetic effect and is therefore worthy of clinical promotion.

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

Objective

We evaluated the validity of bone cement-augmented percutaneous screw fixation for treating malignant spinal metastases.

Methods

Between 2011 and 2015, 14 patients (eight men and six women) who underwent bone cement-augmented percutaneous screw fixation for malignant spinal metastases were enrolled in this study. Their life expectancy was considered to be more than one month and less than one year, based on the revised Tokuhashi scoring system. Clinical findings including the back pain scale score, functional outcome, procedure related complications, and survival were assessed preoperatively, postoperatively, and then six months after the procedure.

Results

Twelve of the patients (86%) survived up to six months after the procedure. Three required mini-open decompressive laminectomy for severe epidural compression. Bone cement-augmented percutaneous screw fixation was performed one level above, one level below, and at the pathologic level itself. The mean operation time was 60 minutes (45–180) and blood loss was less than 100 mL. Prior to surgery, the mean pain score on the visual analogue scale was 8.8, while one month after the procedure, it had reduced to 3.0; this improvement was maintained until the six-month assessment in the surviving patients. All patients were able to sit within the first two days after surgery, and no patient experienced neurological deterioration at the one-month follow up after the surgery. No patient experienced screw loosening during the six months of follow-up. Asymptomatic cement leakage into the epidural space was observed in two patients, but no major complications were observed.

Conclusion

For selected patients with malignant spinal metastases, bone cement-augmented percutaneous screw fixation can provide significant pain relief and improve quality of life.

Minimally invasive spinal surgery for the management of symptomatic spinal metastasis

INTRODUCTION

Symptomatic metastatic spinal disease is on the increase. Minimally invasive spinal surgery has been associated with a lower complication profile when compared to traditional open methods; however there is paucity of literature evaluating the place of percutaneous pedicle screw fixation (PPSF) in the management of spinal metastases. The purpose of the study is to assess the efficacy of Minimally Invasive Spine Surgery (MISS) using PPSF with or without mini-decompression in the management of symptomatic spinal metastases.

MATERIAL AND METHODS

This is a single institution prospective study of 51 consecutive patients with metastatic spinal disease treated with PPSF. Patients presenting with pathological compression fractures and mechanical instability had PPSF, and those with radiological and/or clinical metastatic spinal cord compression (MSCC) underwent an additional mini-decompression. Data collected included patient demographics, Karnofsky's performance status (KPS), pain scores and neurology. Other data included number and location of involved levels, number of instrumented levels, blood loss, accuracy of screw placement and complications.

RESULTS

Of the 51 patients, 49 could be successfully treated with MISS (26 females and 23 males). 26 patients (55%) required a mini-decompression. 27 patients (55%) had improvement in KPS by at least 10 points (p < 0.0005). Only 2 patients (4%) had a worsening of KPS, due to other coexisting problems. Six of the 13 patients improved their neurology by one Frankel grade following surgery and 95% reported improvement in pain. Mean blood loss was 92mls for the fixation only group and 222mls for those requiring mini-decompression, with no other differences between these two surgical groups. Screw positioning was excellent in 91%, with 98% having uncompromised bony hold. Only two patients required revision surgery for aseptic loosening.

CONCLUSION

MISS using PPSF is a safe and reproducible technique that maintains or improves functional outcome in the vast majority of patients presenting with spinal metastases.

When Less Is More: The indications for MIS Techniques and Separation Surgery in Metastatic Spine Disease

STUDY DESIGN

Systematic review.

OBJECTIVE

The aim of this study was to review the techniques, indications, and outcomes of minimally invasive surgery (MIS) and separation surgery with subsequent radiosurgery in the treatment of patients with metastatic spine disease.

SUMMARY OF BACKGROUND DATA

The utilization of MIS techniques in patients with spine metastases is a growing area within spinal oncology. Separation surgery represents a novel paradigm where radiosurgery provides long-term control after tumor is surgically separated from the neural elements.

METHODS

PubMed, Embase, and CINAHL databases were systematically queried for literature reporting MIS techniques or separation surgery in patients with metastatic spine disease. PRISMA guidelines were followed.

RESULTS

Of the initial 983 articles found, 29 met inclusion criteria. Twenty-five articles discussed MIS techniques and were grouped according to the primary objective: percutaneous stabilization (8), tubular retractors (4), mini-open approach (8), and thoracoscopy/endoscopy (5). The remaining 4 studies reported separation surgery. Indications were similar across all studies and included patients with instability, refractory pain, or neurologic compromise. Intraoperative variables, outcomes, and complications were similar in MIS studies compared to traditional approaches, and some MIS studies showed a statistically significant improvement in outcomes. Studies of mini-open techniques had the strongest evidence for superiority.

CONCLUSIONS

Low-quality evidence currently exists for MIS techniques and separation surgery in the treatment of metastatic spine disease. Given the early promising results, the next iteration of research should include higher-quality studies with sufficient power, and will be able to provide higher-level evidence on the outcomes of MIS approaches and separation surgery.

LEVEL OF EVIDENCE

N/A.

Characteristics of Patients Who Survived < 3 Months or > 2 Years After Surgery for Spinal Metastases: Can We Avoid Inappropriate Patient Selection?

PURPOSE

Survival after metastatic cancer has improved at the cost of increased presentation with metastatic spinal disease. For patients with pathologic spinal fractures and/or spinal cord compression, surgical intervention may relieve pain and improve quality of life. Surgery is generally considered to be inappropriate if anticipated survival is < 3 months. The aim of this international multicenter study was to analyze data from patients who died within 3 months or 2 years after surgery, to identify preoperative factors associated with poor or good survival, and to avoid inappropriate selection of patients for surgery in the future.

PATIENTS AND METHODS

A total of 1,266 patients underwent surgery for impending pathologic fractures and/or neurologic deficits and were prospectively observed. Data collected included tumor characteristics, preoperative fitness (American Society of Anesthesiologists advisory [ASA]), neurologic status (Frankel scale), performance (Karnofsky performance score [KPS]), and quality of life (EuroQol five-dimensions questionnaire [EQ-5D]). Outcomes were survival at 3 months and 2 years postsurgery. Univariable and multivariable logistic regression analyses were used to find preoperative factors associated with short-term and long-term survival.

RESULTS

In univariable analysis, age, emergency surgery, KPS, EQ-5D, ASA, Frankel, and Tokuhashi/Tomita scores were significantly associated with short survival. In multivariable analysis, KPS and age were significantly associated with short survival (odds ratio [OR], 1.36; 95% CI, 1.15 to 1.62; and OR, 1.14; 95% CI, 1.02 to 1.27, respectively). Associated with longer survival in univariable analysis were age, number of levels included in surgery, KPS, EQ-5D, Frankel, and Tokuhashi/Tomita scores. In multivariable analysis, the number of levels included in surgery (OR, 1.21; 95% CI, 1.06 to 1.38) and primary tumor type were significantly associated with longer survival.

CONCLUSION

Poor performance status at presentation is the strongest indicator of poor short-term survival, whereas low disease load and favorable tumor histology are associated with longer-term survival.

Complications After Percutaneous Pedicle Screw Fixation for the Treatment of Unstable Spinal Metastases

BACKGROUND

Complications after surgical stabilization for the treatment of unstable spinal metastases are common. Less invasive surgical (LIS) procedures are potentially associated with a lower risk of complications; however, little is known regarding the complications after LIS procedures for the treatment of spinal metastases. Our primary objective was to determine the characteristics and rate of complications after percutaneous pedicle screw fixation (PPSF) for the treatment of mechanically unstable spinal metastases. The secondary objective was to identify factors associated with the occurrence of complications and survival.

METHODS

A retrospective multicenter cohort study of patients who underwent PPSF between 2009 and 2014 for the treatment of unstable spinal metastases was performed. Patient data pertaining to demographics, diagnosis, treatment, neurologic function, complications, and survival were collected.

RESULTS

A total of 101 patients were identified, 45 men (45 %) and 56 women (55 %) with a mean age of 60.3 ± 11.2 years. The median operating time was 122 (range 57-325) minutes with a median blood loss of 100 ml (based on 41 subjects). Eighty-eight patients (87 %) ambulated within the first 3 days after surgery. An overall median survival of 11.0 (range 0-70) months was observed, with 79 % of the patients alive at 3 months after treatment. Eighteen patients experienced a total of 30 complications; nonsurgical complications were the most commonly encountered. Prolonged operating time was independently associated with an increased risk of complications.

CONCLUSIONS

A complication rate of 18 % was found after PPSF for unstable spinal metastases. Potential advantages of less invasive treatment are limited blood loss and high early ambulation rate.