Infection after vertebroplasty or kyphoplasty. A series of nine cases and review of literature

Application of Piezosurgery in Revision Surgery through Posterior Approach for Infection after Percutaneous Vertebral Augmentation: Technique Note with Case Series

OBJECTIVES

Pyogenic spondylitis after vertebral augmentation (PSVA) is a severe complication and even threatens the life of patients. How to deal with infectious bone cement is a big problem for surgeons. The application of piezosurgery has advantages in removal the infectious bone cement in limb bone and spinal laminectomy, but it is rarely used in PSVA. So, the present study aimed to introduce the application of piezosurgery in revision surgery for PSVA and report the preliminary radiological and clinical results.

METHODS

The data of nine patients with PSVA who had undergone revision surgery were retrospectively reviewed between May 2017 and January 2023 in our hospital. The technique of removal of infectious bone cement and lesion by piezosurgery and the reconstruction of the spinal stability were described, and the operation time and intraoperative blood loss were recorded. Postoperatively, radiographs and computed tomography scans were reviewed to evaluate the condition of bone cement removal, control of infection, and bone fusion. Oswestry disability index (ODI) and visual analog scale (VAS) were assessed pre- and postoperatively, and clinical outcomes were assessed using Odom's criteria.

RESULTS

All patients achieved satisfactory tainted bone cement cleaning and restoration of spinal alignment. The surgical time was 258.8 ± 63.2 (160-360) min, and the intraoperative blood loss was 613.3 ± 223.8 (300-900) mL. The VAS score decreased from 7.0 (6-8) points preoperatively to 2.4 (1-4) points postoperatively. The ODI index decreased from 71% (65%-80%) preoperatively to 20% (10%-30%) postoperatively. The patient's VAS and NDI scores after operation were significantly improved compared with those before surgery (p ≤ 0.05). Odom's outcomes were good for all patients in the last follow-up, and all patients reported satisfactory results.

CONCLUSIONS

Piezosurgery can effectively remove large blocks of infectious bone cement through a posterior approach while avoiding nerve and spinal cord damage. We cautiously suggest that a one-stage posterior approach using piezosurgery is an alternative option for surgical treatment of PSVA.

Spinal infection after vertebral augmentation: a covert complication with serious havoc

INTRODUCTION

Vertebral augmentation, including percutaneous vertebroplasty (PVP) or kyphoplasty (PKP), is the current least invasive surgical option and has been widely used to treat the painful osteoporotic vertebral compression fractures (OVCF). However, the postoperative infections could be life-threatening, even though they rarely occur. Our studies aim to clarify the causation and outcomes of spinal infections following augmentation and meanwhile to identify the risk factors.

METHODS

A retrospective study was conducted on patients with OVCF who underwent PVP or PKP, and were subsequently admitted to our institution with postoperative spinal infection between January 2010 and December 2022. A total of 33 patients were finally included.

RESULTS

The rate of spinal infection after augmentation in our single institute was 0.05% (2/3893). In addition to these 2 patients, the remaining 31 were referred from other hospitals. All 33 patients exhibited elevated inflammatory parameters, 14 patients presented with fever, and 9 patients experienced neurological deficits. Additionally, 29 patients had comorbidity and risk factors. Pathogens were identified in 26 patients, while only 7 patients were examined as culture negative. 27 patients underwent revision surgery and 6 patients only received conservative therapy. Anterior surgery was performed in 2 patients, while posterior surgery was performed in 20 patients. A combined anterior-posterior surgery was performed in 5 patients. At the final follow-up, 18 patients had unrestricted mobility, 10 patients required assistance from crutches or a walker for ambulation, 4 patients needed a wheelchair, and 1 patients died after revision surgery.

CONCLUSIONS

Spinal infection after vertebral augmentation is rare, but it cannot be ignored. Surgeons should make every effort to detect the potential preoperative spondylitis or discitis. Once postoperative spinal infection is confirmed, a prompt intravenous antibiotic therapy is warranted. If medication therapy fails, revision surgery involving debridement and spinal reconstruction should be considered.

Incidence and Risk Factors for Wound Revision after Surgical Treatment of Spinal Metastasis: A National Population-Based Study in South Korea

Wound complications are commonly seen after surgeries for metastatic spine tumors. While numerous studies have pinpointed various risk factors, there is ongoing debate. Therefore, this study aimed to verify various factors that are still under debate utilizing the comprehensive Korean National Health Insurance Service database. We identified and retrospectively reviewed a cohort of 3001 patients who underwent one of five surgical treatments (corpectomy, decompression and instrumentation, instrumentation only, decompression only, and vertebroplasty) for newly diagnosed spinal metastasis between 2009 and 2017. A Cox regression analysis was performed to determine the risk factors. A total of 197 cases (6.6%) of wound revision were found. Only the surgical method and Charlson comorbidity index were significantly different between the group that underwent wound revision and the group that did not. Regarding surgical methods, the adjusted hazard ratios for decompression only, corpectomy, instrumentation and decompression, and instrumentation only were 1.3, 2.2, 2.2, and 2.4, with these ratios being compared to the vertebroplasty group (p for trend = 0.02). In this regard, based on a sizable South Korean cohort, both surgical methods and medical comorbidity were found to be associated with the wound revision rate among spinal surgery patients for spinal metastasis.

Application of cement-augmented pedicle screws in elderly patients with spinal tuberculosis and severe osteoporosis: a preliminary study

OBJECTIVE

Surgical management of elderly patients with spinal tuberculosis and severe osteoporosis is challenging. Cement-augmented pedicle screws (CAPS) have been specifically designed for elderly patients with osteoporotic spines. Herein, we investigated the feasibility of CAPS applied in elderly patients with spinal tuberculosis and severe osteoporosis.

METHODS

We retrospectively analyzed data of patients with spinal tuberculosis and severe osteoporosis between January 2017 and January 2021. Surgical data, including surgical duration and intraoperative blood loss, were recorded. Radiological parameters, such as correction of regional kyphotic angle and screw loosening, were also evaluated. Additionally, visual analog scores (VAS) and Oswestry disability index (ODI) were used to evaluate back pain and functional recovery, respectively. Erythrocyte sedimentation (ESR) and C-reactive protein (CRP) concentrations were detected to assess tuberculosis activity. The presence of complications and fusion rate was also assessed.

RESULTS

A total of 15 patients were included in this study. The surgical duration was 263.0 ± 56.2 min, with an average blood loss of 378.7 ± 237.0 ml. The correction of regional kyphotic angle was 12.4° ± 15.0°, and it was well maintained until the final follow-up. The mean VAS decreased from 6.0 ± 1.2 points to 0.5 ± 0.6 points, and ODI reduced from 37.8% ± 7.6% to 8.3% ± 2.8% (P < 0.01). At the final follow-up, ESR and CRP levels were within normal range. Bony fusion occurred in all patients, with an average fusion duration of 8.8 ± 1.5 months. No cases of pedicle screw pullout, screw loosening, or pseudoarthrosis occurred. Tuberculosis recurrence and dissemination were not observed during the follow-ups.

CONCLUSIONS

CAPS fixation is an effective and safe technique to achieve solid fixation and favorable clinical outcomes in elderly patients with spinal tuberculosis and severe osteoporosis.

Posterior instrumentation for osteoporotic fractures in the thoracic or lumbar spine: Cement-augmented pedicle screws vs hybrid constructs

BACKGROUND

Cement-augmented pedicle screws (CPS) and hybrid construct (HC), consisting of pedicle screws and additional hooks, are common fixation methods for osteoporotic spine fracture. No study has compared surgical results of CPS and HC for treating osteoporotic spine fracture. The aim of the study was to compare surgical results using CPS or HC for osteoporotic fractures of the thoracic or lumbar spine.

METHODS

This retrospective cohort study included 84 patients who received surgical treatment with CPS (n = 43) or HC (n = 41) for osteoporotic spine fractures from January 2011 to December 2015, with a mean follow-up of 67 months. Sixty-five patients with neurological deficits received long posterior instrumentation, short posterior decompression, and posterolateral fusion. The 19 patients without neurologic deficits received long posterior instrumentation without posterior decompression and fusion. Radiographic, clinical, and neurologic outcomes were evaluated.

RESULTS

The HC group had significantly shorter operative times (231 vs 258 minutes), greater blood loss (497 vs 427 mL), better immediate postoperative kyphosis reduction (10.6° vs 9.1°), and greater final reduction loss (9.8° vs 7.1°) than the CPS group. In both groups, significant loss of the kyphotic angle was apparent during follow-up. Improved ambulation after surgery occurred in 51.2% and 58.5% of patients in the CPS and HC groups, respectively. Neurologic function after surgery improved 0.5 and 0.7 grades in the CPS and HC groups, respectively. Implants failed in 2.3% and 2.4% of patients in the CPS and HC groups, respectively. The incidence of cement leakage from screw augmentation was 38.9%.

CONCLUSION

The CPS and HC techniques for treating osteoporotic fractures of the thoracic or lumbar spine did not differ statistically in terms of improved radiologic and clinical outcomes, final neurologic and ambulatory function, or implant failure rates, making them equally comparable alternatives.

Investigation of preoperative asymptomatic bacteriuria as a risk factor for postvertebroplasty infection

BACKGROUND

Postvertebroplasty infection (PVI) is a catastrophic complication after vertebroplasty (VP). Although the urinary tract has been considered as a source of infectious pathogens, whether asymptomatic bacteriuria (ASB) is a risk factors for PVI remains unknown.

METHODS

This retrospective study included 716 patients (207 males; 509 females) treated with VP for osteoporotic vertebral fractures in a single medical center between May 2015 and December 2019. Clinical symptoms, urinalysis results, and culture data were collected preoperatively to identify patients with ASB. The primary outcome was PVI at the index level during follow-up. Demographic data and laboratory test results were compared between the PVI and non-PVI groups.

RESULTS

The mean age of the cohort was 78.6 ± 9.6 (range, 63-106). The prevalence of ASB was 14.1%, with female predominance (63.4%). The overall PVI rate was 1.26% (9/716). The PVI group had more patients with ASB (4/9, 44.4%) than did the non-PVI group (97/707, 13.7%) (p = 0.027). The rate of ASB treatment was similar between the PVI and non-PVI groups (25% vs. 23.7%, respectively). No case of PVI was caused by the urine culture pathogen. Multivariate analysis identified the following risk factors for PVI: ASB (odds ratio [OR], 5.61; 95% CI, 1.14-27.66; p = 0.034), smoking (OR, 16.26; 95% CI, 2.58-102.65; p = 0.003), and malignancy (OR 7.27; 95% CI, 1.31-40.31; p = 0.023).

CONCLUSION

ASB was not uncommon among patients admitted for VP and should be considered a marker of relatively poor host immunity. Preoperative ASB, a history of malignancy, and smoking were identified as significant risk factors for PVI.

No more tears from surgical site infections in interventional pain management

As the field of interventional pain management (IPM) grows, the risk of surgical site infections (SSIs) is increasing. SSI is defined as an infection of the incision or organ/space that occurs within one month after operation or three months after implantation. It is also common to find patients with suspected infection in an outpatient clinic. The most frequent IPM procedures are performed in the spine. Even though primary pyogenic spondylodiscitis via hematogenous spread is the most common type among spinal infections, secondary spinal infections from direct inoculation should be monitored after IPM procedures. Various preventive guidelines for SSI have been published. Cefazolin, followed by vancomycin, is the most commonly used surgical antibiotic prophylaxis in IPM. Diagnosis of SSI is confirmed by purulent discharge, isolation of causative organisms, pain/tenderness, swelling, redness, or heat, or diagnosis by a surgeon or attending physician. Inflammatory markers include traditional (C-reactive protein, erythrocyte sedimentation rate, and white blood cell count) and novel (procalcitonin, serum amyloid A, and presepsin) markers. Empirical antibiotic therapy is defined as the initial administration of antibiotics within at least 24 hours prior to the results of blood culture and antibiotic susceptibility testing. Definitive antibiotic therapy is initiated based on the above culture and testing. Combination antibiotic therapy for multidrug-resistant Gram-negative bacteria infections appears to be superior to monotherapy in mortality with the risk of increasing antibiotic resistance rates. The never-ending war between bacterial resistance and new antibiotics is continuing. This article reviews prevention, diagnosis, and treatment of infection in pain medicine.

Current status and challenges of percutaneous vertebroplasty (PVP)

A narrative review regarding percutaneous vertebroplasty (PVP) for osteoporotic vertebral fracture (OVF) is provided herein, addressing the epidemic of OVF in Japan, the latest response to the criticism of PVP for OVFs, the indications and potential risks of PVP for OVFs, and a future perspective for PVP. Each year in Japan, approximately 32,000 patients aged 55 years or older suffer from chronic low back pain for several months to several years due to a compression fracture. PVP is one of the surgical treatments for an OVF, and it is less invasive compared to the traditional open surgery. PVP is suitable for OVF patients who have difficulty walking as assessed by the modified Yokoyama's activities of daily living (ADL) scoring system, and for patients with Kummell's disease diagnosed by CT and MRI examinations. Serious adverse events related to PVP occur in 1.1-3.3% of the cases, but direct deaths from PVP are extremely rare at less than 1%. Recent studies demonstrated that OVF patients treated with PVP are less likely to die after the treatment than non-surgically treated patients, which conflicts with the Cochran reviews' conclusion not supporting PVP for OVFs. Novel robotic systems and procedure-support devices are being developed, providing a next step toward fully automated PVP procedures.

L4 Corpectomy: Surgical Approaches and Mitigating the Risk of Femoral Nerve Injuries

OBJECTIVE

Because of the challenging anatomic location, corpectomies are performed less often at the fourth lumbar vertebral body than at other levels. Our objective was to review the literature of L4 corpectomy and anterior column reconstruction.

METHODS

A literature search in the Medline/PubMed database was conducted following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines to identify all relevant cases and cases series describing corpectomies of the L4 vertebral body using "lumbar" AND "corpectomy" as search terms. We present an illustrative case to describe the technique.

RESULTS

We identified 18 articles with 30 patients who met the search criteria. Including our case illustration, the most common approach used was the lateral retroperitoneal approach (n = 17, 54.8%), of which 8 (26.7%) were performed via a transpsoas approach. Seven (23%) patients underwent corpectomy through a posterior approach, 4 (12.9%) through an anterior retroperitoneal approach, and 3 (10%) through combined anterior and lateral retroperitoneal. The overall complications rate was 19.3% including 1 case each of femoral nerve injury and iatrogenic lumbar nerve root injury.

CONCLUSIONS

Corpectomies of the L4 vertebral body are challenging. None of the various approaches described clearly demonstrates any superiority in mitigating the risk of neural complications. Decision making about which surgical approach to use should be based on patient-specific characteristics.

Why does patients’ discharge delay after vertebral augmentation? A factor analysis of 1,442 patients

Objective

Vertebral augmentation techniques are widely used to treat osteoporotic vertebral compression fractures (OVCFs). Superior analgesic effects and shortened bed rest time means patients recover quickly, but prolonged unscheduled hospitalization can increase medical expenses and the risk of bed rest complications. The aim of this study was to investigate the reasons for prolonged hospitalization after vertebral augmentation surgery and to determine the relative risk factors.

Methods

A single-center retrospective study was conducted to enroll patients with OVCFs and accepted vertebral augmentation surgery from January 2017 to December 2017. Clinical information was collected from the Hospital Information System (HIS). The criterion of delayed discharge was postoperative hospitalization more than 3 days. Telephone interviews and medical history evaluations were conducted to confirm the exact reason for retention. The risk factors were analyzed by multiple logistic regression.

Results

Overall, 1,442 patients were included, and 191 (13.2%) stayed in the hospital for more than 3 days postoperatively. The reasons for delayed discharge were psychological factors (37.2%), residual pain (32.5%), cardiopulmonary complications (15.7%), nonspecific symptoms (8.4%), incision abnormalities (2.6%), thrombosis (2.1%), and postanesthesia reactions (1.6%). The multiple logistic model was significant; age (OR 1.028; 95% CI 1.009–1.046), preoperative stay (OR 1.192; 95% CI 1.095–1.298), operation type (OR 1.494; 95% CI 1.019–2.189), and the number of surgical segments (OR 2.238; 95% CI 1.512–3.312) showed statistical significance. In contrast, gender (P > 0.1) and chronic comorbidities (P > 0.1) were not predictors in this model.

Conclusion

Overall, 13.2% of OVCF patients who underwent vertebral augmentation surgery were not discharged within 3 days postoperatively, and several predictors were found. Preoperative communication and comprehensive evaluations are calling for more attention; physicians should adopt an appropriate medical process to enhance rehabilitation in geriatric orthopedics.

Risk factors for tuberculous or nontuberculous spondylitis after percutaneous vertebroplasty or kyphoplasty in patients with osteoporotic vertebral compression fracture: A case-control study

Objectives

The contributing factors for spondylitis after percutaneous vertebroplasty (PVP) or percutaneous kyphoplasty (PKP) remain unclear. Here, we sought to investigate the factors affecting spondylitis occurrence after PVP/PKP. We also compared the clinical characteristics between patients with tuberculous spondylitis (TS) and nontuberculous spondylitis (NTS) following vertebral augmentation.

Methods

Literature searches (from January 1, 1982 to October 16, 2020) using MEDLINE, EMBASE, Google Scholar and Web of science databases were conducted to identify eligible studies according to predefined criteria. The local database was also retrospectively reviewed to include additional TS and NTS patients at our center.

Results

Thirty studies from the literature and 11 patients from our local institute were identified, yielding a total of 23 TS patients and 50 NTS patients for analysis. Compared with NTS group, patients in the TS group were more likely to have a history of trauma before PVP/PKP treatment. Univariate analyses of risk factors revealed pulmonary tuberculosis and diabetes were significant factors for TS after PVP/PKP. Analyzing NTS, we found obesity, a history of preoperative trauma, urinary tract infection, diabetes and multiple surgical segments (≥2) were significantly associated with its occurrence following PVP/PKP treatment. Multivariate logistic analyses showed a history of pulmonary tuberculosis and diabetes were independent risk factors for TS after PVP/PKP, while diabetes and the number of surgically treated segments independently influenced NTS development.

Conclusions

A history of pulmonary tuberculosis and diabetes were independent risk factors for TS. For NTS, diabetes and the number of surgically treated segments significantly influenced the occurrence of postoperative spinal infection. These data may be helpful for guiding risk stratification and preoperative prevention for patients, thereby reducing the incidence of vertebral osteomyelitis after PVP/PKP.

Beware of Brucella Spondylitis Following Vertebroplasty: An Unusual Case of Osteoporotic Vertebral Compression Fracture

There are two main types of infectious spondylitis reported in literature following kyphoplasty or vertebroplasty: tuberculous spondylitis and pyogenic spondylitis; no cases of Brucella spondylitis have been reported to date. We present a unique case of Brucella spondylitis with intraspinal abscess following vertebroplasty. The patient suffered from osteoporotic vertebral compression fracture (OVCF) of the L4 vertebra and received vertebroplasty; he ate mutton while traveling in the epidemic area a week before vertebroplasty. Two weeks after the procedure, the patient had recurrent low back pain and was finally diagnosed with Brucella spondylitis around the L4 vertebra four months later. This case report provides a warning that eating any undercooked food that may cause bacteremia—especially in orthopedic patients with joint or osseous abnormalities and especially those with intraosseous devices or injected substances.

Bilateral foot drop caused by T12 infectious spondylitis after vertebroplasty: a case report

The most common cause of foot drop is lumbar degenerative disc herniation, particularly at L4/5. We present a rare case of spinal cord injury accompanied by a thoracolumbar lesion that presented with bilateral foot drop. A 69-year-old male patient presented with sudden-onset severe bilateral leg pain and bilateral foot drop. Radiologic findings revealed T12 spondylitis compressing the conus medullaris. He had undergone vertebroplasty for a T12 compression fracture after a fall 6 months before. A physical examination showed bilateral foot drop, paresthesia of both L5 dermatomes, increased deep tendon reflex, and a positive Babinski sign. An acute bilateral L5 root lesion and a conus medullaris lesion were suspected based on electromyography. A surgical procedure was done for decompression and reconstruction. After the operation, bilateral lower extremity muscle strength recovered to a good grade from the trace grade, and the patient could walk without a cane. The current case is a very rare report of bilateral foot drop associated with T12 infectious spondylitis after vertebroplasty. It is essential to keep in mind that lesions of the thoracolumbar junction can cause atypical neurological symptoms. Furthermore, understanding the conus medullaris and nerve root anatomy at the T12-L1 level will be helpful for treating patients with atypical neurological symptoms.

Revision surgery after cement augmentation for osteoporotic vertebral fracture

INTRODUCTION

Cement augmentation has been proven to be a safe procedure for the treatment of osteoporotic vertebral fracture, and the overall result is encouraging. However, failures caused by different complications are not uncommon, and a few patients even need revision surgery. This retrospective study aimed to investigate the primary causes of revision surgery after cement augmentation for osteoporotic vertebral fracture and how to prevent them, and the second objective was to evaluate the clinical results of revision surgery.

HYPOTHESIS

The main hypothesis is that infection and neurological dysfunction are the prime causes of revision surgery after cement augmentation for osteoporotic vertebral fracture, and the second hypothesis is that revision surgery is effective to improve the quality of daily life.

MATERIALS AND METHODS

Twenty-one patients who underwent unplanned revision surgery after cement augmentation were retrospectively analyzed. The initial radiographic and medical records were reviewed to re-evaluate whether the initial diagnosis and surgical procedure were correct and suitable. The primary causes of revision surgery and the details were recorded. The visual analog scale (VAS) and Oswestry Disability Index (ODI) were used to evaluate the efficacy of the revision surgery, and patients with neurological dysfunction were evaluated with the American Spinal Injury Association (ASIA).

RESULTS

A total of 47.6% (10/21) of patients were misdiagnosed initially or had an incorrect indication for cement augmentation surgery, including 3 pre-existing spondylitis cases that were misdiagnosed as osteoporotic vertebral fracture and 7 cases of three column fractures that were treated with cement augmentation. The primary causes and details of the revision surgeries were as follows: 7 patients with infection underwent anterior and/or posterior debridement and fixation; 9 patients with progressive kyphosis underwent posterior osteotomy and fixation; and 5 patients with neurological dysfunction underwent posterior decompression and fixation. The mean follow-up time was 30.6±8.7 months, the VAS score decreased from 7.3±1.1 preoperatively to 2.3±0.3 (p<0.05) at the last follow-up, the ODI decreased from 61.1%±16.3% preoperatively to 20.6%±6.2% (p<0.05) at the last follow-up, and 5 patients with neurological dysfunction improved by at least one grade.

CONCLUSION

Infection, progressive kyphosis and neurological dysfunction are the primary causes of revision surgery after cement augmentation for osteoporotic vertebral fracture. Avoiding misdiagnosis and ensuring suitable indications might be the key points to decreasing unplanned revision surgery for cement augmentation for osteoporotic vertebral fracture. The quality of daily life and neurological function can be improved through revision surgery.

Simultaneous-onset infectious spondylitis with vertebral fracture mimicking an acute osteoporotic vertebral fracture erroneously treated with balloon kyphoplasty: illustrative case

BACKGROUND

Early balloon kyphoplasty (BKP) intervention for acute osteoporotic vertebral fracture (OVF) has been reported to be more effective than the conservative treatment. However, complications of early BKP intervention are still unknown.

OBSERVATIONS

A 71-year-old patient with OVF of L2 underwent BKP 2 weeks after symptom onset. Preoperative magnetic resonance imaging (MRI) and radiograph were compatible with new L2 OVF. Although computed tomography (CT) images revealed the atypical destruction of lower endplate of L2 as OVF, L2 BKP was planned. After BKP, his back pain improved dramatically. Two weeks after BKP, his lower back pain recurred. MRI and CT confirmed the diagnosis of infectious spondylitis with paravertebral abscess formation. With adequate antibiotic treatment and rehabilitation, he was symptom-free and completely ambulatory without signs of infection.

LESSONS

Signal changes on the fractured vertebral bodies during initial MRI and fractured vertebral instability on radiograph can mislead the surgeon to interpret the infection as a benign compression fracture. If the patients exhibit unusual destruction of the endplate on CT imaging, “simultaneous-onset” spondylitis with vertebral fracture should be included in the differential diagnosis. To determine the strategy for OVF, preoperative biopsy is recommended if simultaneous-onset spondylitis with vertebral fracture is suspected.

Debridement and corpectomy via single posterior approach to treat pyogenic spondylitis after vertebral augmentation

Background

Infection after vertebral augmentation (VA) often limits the daily activities of patients and even threatens their life. The operation may be one of the effective treatments if the patient suffers from intolerable severe pain, neurological deficits, and damage to spinal stability. This study aimed to investigate the clinical efficacy of the treatment of pyogenic spondylitis after vertebral augmentation (PSVA) with Single posterior debridement, vertebral body resection, and intervertebral bone graft fusion and internal fixation (sPVRIF).

Methods

The study was performed on 19 patients with PSVA who underwent VA at 4 hospitals in the region between January 2010 and July 2020. Nineteen patients were included. Among them, 16 patients underwent sPVRIF to treat the PSVA.

Results

A total of 2267 patients underwent VA at 4 hospitals in the region. Of the 19 patients with postoperative PSVA, suppurative spondylitis was misdiagnosed as an osteoporotic vertebral fracture(OVF) in 4 patients and they underwent VA. Besides osteoporosis, 18 patients had other comorbidities. The average interval between the first surgery and the diagnosis of PSVA was 96.4 days. Of the 19 patients, 16 received surgical treatment. The surgical time was 175.0±16.8 min, and the intraoperative blood loss was 465.6±166.0 mL. Pathogenic microorganisms were cultured in 12 patients.

Conclusion

PSVA is a severe complication that can even threaten the life of the patients. sPVRIF may be one of the effective treatments if the patient suffers from intolerable severe pain, neurological deficits, and damage to spinal stability.

A Smart Technique to Remove Ruptured Inflatable Bone Tamp From the Vertebral Body in Balloon Kyphoplasty

Accidental rupture of the inflatable bone tamp is a rare but possible complication during balloon kyphoplasty. We describe an easy and minimal invasive technique to remove this foreign body from fractured vertebra. A 62-year-old female patient with severe osteoporosis had a low energy trauma and sustained burst fracture of the 12th thoracic (Th12) vertebra. The inflated bone tamp was not possible to be fully deflated and during the maneuvers to withdraw the balloon, it was disassembled and trapped under the distal end of working cannula, remaining within the bone cavity formed by balloon. Since no standard recommendation for this complication exists in current literature, we faced the dilemma of either leaving ruptured bone tamp in situ or removing it with a more extensive approach. We decided to use an alternative minimal invasive technique and managed to remove it through the right pedicle using a small size straight pituitary rongeur forceps under biplane continuous image intensifier and neuromonitoring. Subsequently, balloon kyphoplasty (BK) was performed through the left cannula accompanied with pedicle screw fixation of the adjacent vertebrae. The patient was followed up to our outpatient department for one year without complications. This extremely rare complication during BK consists of a challenge for spine surgeons and interventional radiologists. The described technique is relatively easy, safe, minimal invasive, time-saving and avoids further complications related with trapping of foreign bodies within the vertebral body.

Spinal Epidural Hematoma After Percutaneous Kyphoplasty: Case Report and Literature Review

Objective

To present the case of a patient on long-term anticoagulants who developed acute spinal epidural hematoma (SEH) after percutaneous kyphoplasty (PKP) without signs of major cement extravasation to the spinal canal.

Methods

A 64-year-old woman with long-term oral antiplatelet drugs underwent the L1 PKP. Immediately after the operation, the back pain improved significantly without neurological deficit. However, 12 hours later, she developed progressive weakness of the bilateral lower limbs. No intraspinal cement leakage was obvious on the postoperative lumbar radiograph and computed tomography.

Results

An emergency MRI examination revealed a high signal aggregation in front of the spinal cord from T12 to L1, indicating spinal cord compression. The SEH was verified and removed during the laminectomy from T12-L1. Following the decompression surgery, the neurological deficit of the lower limbs improved. On follow-up after 6 months, the muscle strength of the bilateral lower limbs had returned to normal.

Conclusion

For the patient with long-term oral antiplatelet drugs or coagulation malfunction, the transpedicle approach or that via the costovertebral joint with a smaller abduction angle is recommended to reduce the risk of injury to the inner wall of the pedicle. For progressive aggravation of neurological dysfunction after surgery, SEH formation should be suspected despite the absence of intraspinal bone cement leakage. Secondary emergency decompression should be considered to avoid permanent damage to spinal cord nerve function caused by continuous compression.

Treating Vertebral Compression Fractures: Establishing the Appropriate Diagnosis, Preoperative Considerations, Treatment Techniques, Postoperative Follow-Up and General Guidelines for the Treatment of Patients With Symptomatic Vertebral Compression Fractures

Vertebral compression fractures (VCFs) result from either trauma or a pathologic process that weakens the bone by conditions such as osteoporosis or tumor. The incidence of VCFs has been rising over the last few decades in accordance with the aging population. These fractures can result in severe pain, physical limitation and disability, as well as increased morbidity and mortality. Patients with VCFs are optimally treated by accurate and early diagnosis and treatment. An effective method to treat these fractures is percutaneous vertebral augmentation, which is a set of minimally invasive procedures that stabilizes osseous fractures, provides immediate pain relief, and improves quality of life. Vertebral augmentation procedures include vertebroplasty, kyphoplasty, and vertebral augmentation with implants. Each of these techniques is described in general terms in this article. The ideal candidate for vertebral augmentation is a patient with a symptomatic fracture seen on cross-sectional imaging in which nonsurgical management has failed and has positive signs on physical examination with no absolute contraindication. This procedure should be done with the appropriate equipment and personnel in a facility designed for this purpose. After the procedure, the patient should undergo the appropriate follow-up to ensure optimal recovery. Additionally, it is essential that the patient receives appropriate therapy for the underlying disorder that predisposed them to the vertebral fracture.

Spinal implant-associated infections: a prospective multicentre cohort study

This study evaluated the clinical, laboratory, microbiological, radiological and treatment characteristics of patients with early-onset and late-onset spinal implant-associated infections. Patients diagnosed with spinal implant-associated infection between 2015-2019 were prospectively included and treated according to a standardised algorithm. Infections were classified as early-onset (≤6 weeks) and late-onset (>6 weeks). Among 250 patients, 152 (61%) had early-onset and 98 (39%) had late-onset infection. Local inflammatory signs was the most common manifestation in early-onset infections (84%), whereas late-onset infections presented mainly with persisting or increasing local pain (71%). Sonication fluid was more often positive than peri-implant tissue samples (90% vs. 79%; P = 0.016), particularly in late-onset infections (92% vs. 75%; P = 0.005). Predominant pathogens were coagulase-negative staphylococci, Staphylococcus aureus and Cutibacterium spp. Debridement and implant retention was the most common surgical approach in early-onset infections (85%), whereas partial or complete implant exchange was mainly performed in late-onset infections (62%). Of the 250 patients, 220 (88%) received biofilm-active antibiotics, and median treatment duration was 11.7 weeks. Moreover, 49 patients (20%) needed more than one revision for infection and six patients (2.4%) died during hospital stay. Concluding, most spinal implant-associated infections were acquired during surgery and presented within 6 weeks of surgery. Infections presented mainly with local inflammatory signs in early-onset and with persisting or increasing pain in late-onset infections. Sonication was the most sensitive microbiological method, particularly in late-onset infections. Debridement and implant retention was used in well-integrated implants without loosening, independent of the time of infection onset.

An unusual Staphylococcus saccharolyticus spondylodiscitis post kyphoplasty: a case report

Background

Staphylococcus saccharolyticus is a rarely encountered coagulase-negative, which grows slowly and its strictly anaerobic staphylococcus from the skin. It is usually considered a contaminant, but some rare reports have described deep-seated infections. Virulence factors remain poorly known, although, genomic analysis highlights pathogenic potential.

Case presentation

We report a case of Staphylococcus saccharolyticus spondylodiscitis that followed kyphoplasty, a procedure associated with a low rate but possible severe infectious complication (0.46%), and have reviewed the literature. This case specifically stresses the risk of healthcare-associated S. saccharolyticus infection in high-risk patients (those with a history of alcoholism and heavy smoking).

Conclusion

S. saccharolyticus infection is difficult to diagnose due to microbiological characteristics of this bacterium; it requires timely treatment, and improved infection control procedure should be encouraged for high-risk patients.

Outcome of spinal implant-associated infections treated with or without biofilm-active antibiotics: results from a 10-year cohort study

Purpose

Biofilm-active antibiotics are suggested to improve the outcome of implant-associated infections; however, their role in infections after spinal instrumentation is unclear. Therefore, we evaluated the outcome of patients with spinal implant-associated infections treated with and without biofilm-active antibiotics.

Methods

The probability of infection-free survival was estimated for treatment of spinal implant-associated infections with and without biofilm-active antibiotics using the Kaplan–Meier method; Cox proportional-hazards regression model was used to identify factors associated with treatment failure.

Results

Among 93 included patients, early-onset infection was diagnosed in 61 (66%) and late-onset in 32 infections (34%). Thirty patients (32%) were treated with biofilm-active antibiotic therapy and 63 (68%) without it. The infection-free survival after a median follow-up of 53.7 months (range, 8 days-9.4 years) was 67% (95% confidence interval [CI], 55–82%) after 1 year and 58% (95% CI 43–71%) after 2 years. The infection-free survival after 1 and 2 years was 94% (95% CI 85–99%) and 84% (95% CI 71–93%) for patients treated with biofilm-active antibiotics, respectively, and 57% (95% CI 39–80%) and 49% (95% CI 28–61%) for those treated without biofilm-active antibiotics, respectively (p = 0.009). Treatment with biofilm-active antibiotics (hazard ratio [HR], 0.23, 95% CI 0.07–0.77), infection with Staphylococcus auras (HR, 2.19, 95% CI 1.04–4.62) and polymicrobial infection (HR, 2.44, 95% CI 1.09–6.04) were significantly associated with treatment outcome. Severe pain was observed more often in patients without biofilm-active antibiotic therapy (49% vs. 18%, p = 0.027).

Conclusion

Treatment with biofilm-active antibiotics was associated with better treatment outcome and less postoperative pain intensity.

Electronic supplementary material

The online version of this article (10.1007/s15010-020-01435-2) contains supplementary material, which is available to authorized users.

Long Term Survival of Pathological Thoracolumbar Fractures Treated with Vertebroplasty: Analysis Using a Nationwide Insurance Claim Database

Background: There are still debates on the long-term outcome of treating pathological thoracolumbar fractures, including osteoporosis and oncologic problems, using vertebroplasty. Methods: We collected 8625 patients with pathological thoracolumbar fractures (ICD-9-CM codes 733.13 combined with 805.2 or 805.4) between the years of 2003 to 2013, from the two million random samples from the National Health Insurance Research Database in Taiwan. Survival analysis was conducted to estimate the mortality risks of different treatments, including vertebroplasty (n = 1389), conventional open surgery (n = 1219), or conservative treatment (n = 6017). A multivariable Cox proportional hazard model was constructed for adjustment of age, gender, comorbidities and complications. Results: Crude incidence rate of patients with pathological thoracolumbar fractures in Taiwan gradually increased year by year. Compared with conservative treatment, conventional open surgery and vertebroplasty seemed to improve long-term survival with adjusted hazard ratios (aHR) of 0.80 (95% confidence interval (CI) 0.70–0.93), and 0.87 (95% CI 0.77–0.99), respectively. The survival advantage of vertebroplasty appeared more evident for those aged over 75. However, we were unable to rule out confounding by indication. Conclusion: Although conventional open surgery would usually be the best choice for the treatment of patients with pathological thoracolumbar fractures, database information from current real-world practice appears to support vertebroplasty as a viable choice for elderly people over 75 years of age.

Risk factors of neurological deficit and pulmonary cement embolism after percutaneous vertebroplasty

Background

The risk factors, incidence, and clinical management of pulmonary cement embolism and neurological deficit during percutaneous vertebroplasty (PVP) were evaluated.

Methods

Three thousand one hundred and seventy-five patients with symptomatic osteoporotic vertebral compression fractures (OVCFs) treated with PVP were retrospectively reviewed in a single institution. Clinical parameters such as age, gender, number of fractures, and time from fracture to vertebroplasty were recorded at the time of surgery. Image and surgical parameters including the amount of cement, the vertebral level, uni- or bipedicle surgical approach, and leakage pattern were recorded.

Results

Type-C leakage, including paraspinal (25%), intradiscal (26%), and posterior (0.7%) leakage, was more common than type-B (11.4%) and type-S leaks (4.9%). Cement leakage into the spinal canal (type-C posterior) occurred in 26 patients (0.7%), and four patients needed surgical decompression. Three in nine patients with leakage into thoracic spine needed decompressive surgery, but only one of 17 patients into lumbar spine needed surgery (p < 0.01). Age, gender, number of fractures, and time from fracture to vertebroplasty were not risk factors of pulmonary cement embolism or neurological deficit. The risk factor of pulmonary cement embolism was higher volume of PMMA injected (p < 0.001) and risk factor of neurological deficit was type-C posterior cement leakage into thoracic spine. The incidence of pulmonary cement embolism was significantly high in the volume of PMMA injected (PMMA injection < 3.5 cc: 0%; 3.5–7.0 cc: 0.11%; > 7.0 cc: 0.9%; p < 0.01) which needed postoperative oxygen support.

Conclusions

Cement leakage is relatively common but mostly of no clinical significance. Percutaneous vertebroplasty in thoracic spine and high amount of PMMA injected should be treated with caution in clinical practice.

Adjacent Level Tuberculous Spondylodiscitis Leading to Proximal Junctional Kyphosis: Rare and Unusual Presentation

BACKGROUND

Vertebral osteomyelitis manifesting as a compression fracture misdiagnosed in the setting of steroid-induced or senile osteoporosis is very rare, although such patients are prone to infection or reactivation, as their immune system is exhausted. Spondylodiscitis occurring at adjacent levels following instrumented spinal fusion leading to pathologic fracture and proximal junctional failure, especially caused by tuberculosis, to our knowledge, has not been discussed in the literature.

METHODS

In case 1, a 61-year-old woman with osteoporotic T12 collapse was treated with corpectomy, anterior reconstruction, and posterior fixation from T9-L2. Initial biopsy and culture were normal. She presented 4 months later with compression fracture of T8; T8 corpectomy with anterior reconstruction and proximal extension of the construct was performed. In case 2, a 65-year-old woman with multiple comorbidities and osteoporotic L1 compression fracture was treated with L1 corpectomy, anterior reconstruction, and posterior instrumentation from T11-L3. She presented 4 months later with T10 vertebral body acute collapse; 2-stage anterior corpectomy and reconstruction was performed. In both cases, probing the affected vertebral body yielded pus. Pus and bone tissue samples sent for culture and histopathologic examination were positive for tuberculosis suggesting tuberculous spondylitis in both cases.

RESULTS

In both patients, tuberculous spondylodiscitis at the proximal adjacent level was diagnosed <1 year after the initial spinal surgery. Neither patient had a previous history of pulmonary or extrapulmonary tuberculosis. They were successfully treated with antituberculous therapy and proximal extension of the construct with anterior reconstruction.

CONCLUSIONS

Adjacent segment spondylodiscitis should be suspected and intraoperative biopsy must be considered for histopathologic and microbiologic examination to rule out subclinical infection in immunosuppressed patients with multiple comorbidities. Management should be individualized, considering the context of infection, causative organism, extent of bone destruction, and neurologic involvement.

Late-onset spondylodiscitis and psoas abscess, 5 years after percutaneous balloon kyphoplasty: a case report

Postoperative infection following percutaneous balloon kyphoplasty (PBK) is a rare complication and delayed onset infection is very rare. We report the case of a 62-year-old male, who developed spondylodiscitis and psoas abscess 5 years after two-level, L2 and L3 PBK. He was initially treated with abscess aspiration and long term antimicrobial treatment. Eventually, due to failure of conservative treatment he underwent anterior decompression, radical debridement of the infected tissue and non-instrumented fusion with strut graft, with excellent results.

Tuberculous spondylitis after percutaneous vertebroplasty: A case series of 9 cases

Background

Percutaneous vertebroplasty has become the treatment of choice for compression fractures. Although the incidence is low, infection after vertebroplasty is a serious complication. The pathogens most often responsible for infection are bacteria. Meanwhile, mycobacterium tuberculosis-induced infection is extremely rare. In this study, we reported our treatment experience with 9 cases of tuberculous spondylitis after vertebroplasty.

Methods

Between January 2001 and December 2015, 5749 patients underwent vertebroplasty or kyphoplasty in our department. Nine cases developed tuberculous spondylitis after vertebroplasty (0.16%). Data on clinical history, laboratory examinations, image, treatment and outcomes were examined.

Results

One male and 8 female patients with a mean age of 75.1 years developed tuberculous spondylitis after vertebroplasty. 5 patients had a history of pulmonary tuberculosis (TB). Revision surgeries were performed from 5 days to 1124 days after vertebroplasty. Seven patients underwent anterior debridement and fusion with or without posterior instrumentation, and 2 cases received posterior decompression and instrumentation only. After operation, the diagnosis of tuberculous spondylitis was confirmed by TB polymerase chain reaction (TB-PCR) or mycobacteria culture. Mean follow-up period after revision surgery was 36.8 months. At the end of follow-up, 1 patient with paraplegia had passed away, 2 needed a wheel chair, 4 required a walker and 2 were able to walk unassisted.

Conclusions

Vertebroplasty is a minimally invasive procedure but still retains some possibility of complications, including TB infection. Patients with a history of pulmonary TB or any elevation of infection parameters should be reviewed carefully to avoid infective complications.

Percutaneous Vertebral Body Augmentations: The State of Art

Osteoporotic compression fractures of the vertebral body can result in pain and long-term morbidity, including spinal deformity, with increased risk of mortality resulting from associated complications. Conservative management includes opioids and other analgesics, bed rest, and a back brace. For patients with severe and disabling pain, vertebral augmentation (vertebroplasty and kyphoplasty) is often considered, with these procedures endorsed by multiple professional societies, and provides immediate structural support, and stabilizes and reinforces the weakened bone structure. The purpose of this article is to review the vertebral biomechanics, indications and contraindications, and techniques of performing successful vertebral augmentation.

Extrapendicular Approach of Unilateral Percutaneous Vesselplasty for the Treatment of Kummell Disease

Background

Our purpose was to evaluate the efficacy of the extrapendicular approach for unilateral percutaneous vesselplasty in dealing with Kummell disease patients.

Methods

Twenty-seven patients undergoing vesselplasty at our institution were enrolled in the study. Vesselplasty was performed using percutaneous extrapendicular technique. Pain, restoration of vertebral body height, and cement leakage were evaluated in the process.

Results

Substantial pain relief was attained in all the patients. The visual analogue scale improved significantly from pre- to postoperation (P < .05), and remained unchanged at every follow-up. The anterior vertebral body heights were significantly corrected after operation (P < .05). No cement leakage was found.

Conclusion

This new technique of vesselplasty offers statistically significant benefits in Kummell disease patients. It also makes vesselplasty feasible, safe, and effective.

Polymerization kinetics stability, volumetric changes, apatite precipitation, strontium release and fatigue of novel bone composites for vertebroplasty

PURPOSE

The aim was to determine effects of diluent monomer and monocalcium phosphate monohydrate (MCPM) on polymerization kinetics and volumetric stability, apatite precipitation, strontium release and fatigue of novel dual-paste composites for vertebroplasty.

MATERIALS AND METHODS

Polypropylene (PPGDMA) or triethylene (TEGDMA) glycol dimethacrylates (25 wt%) diluents were combined with urethane dimethacrylate (70 wt%) and hydroxyethyl methacrylate (5 wt%). 70 wt% filler containing glass particles, glass fibers (20 wt%) and polylysine (5 wt%) was added. Benzoyl peroxide and MCPM (10 or 20 wt%) or N-tolyglycine glycidyl methacrylate and tristrontium phosphate (15 wt%) were included to give initiator or activator pastes. Commercial PMMA (Simplex) and bone composite (Cortoss) were used for comparison. ATR-FTIR was used to determine thermal activated polymerization kinetics of initiator pastes at 50-80°C. Paste stability, following storage at 4-37°C, was assessed visually or through mixed paste polymerization kinetics at 25°C. Polymerization shrinkage and heat generation were calculated from final monomer conversions. Subsequent expansion and surface apatite precipitation in simulated body fluid (SBF) were assessed gravimetrically and via SEM. Strontium release into water was assessed using ICP-MS. Biaxial flexural strength (BFS) and fatigue properties were determined at 37°C after 4 weeks in SBF.

RESULTS

Polymerization profiles all exhibited an inhibition time before polymerization as predicted by free radical polymerization mechanisms. Initiator paste inhibition times and maximum reaction rates were described well by Arrhenius plots. Plot extrapolation, however, underestimated lower temperature paste stability. Replacement of TEGDMA by PPGDMA, enhanced paste stability, final monomer conversion, water-sorption induced expansion and strontium release but reduced polymerization shrinkage and heat generation. Increasing MCPM level enhanced volume expansion, surface apatite precipitation and strontium release. Although the experimental composite flexural strengths were lower compared to those of commercially available Simplex, the extrapolated low load fatigue lives of all materials were comparable.

CONCLUSIONS

Increased inhibition times at high temperature give longer predicted shelf-life whilst stability of mixed paste inhibition times is important for consistent clinical application. Increased volumetric stability, strontium release and apatite formation should encourage bone integration. Replacing TEGDMA by PPGDMA and increasing MCPM could therefore increase suitability of the above novel bone composites for vertebroplasty. Long fatigue lives of the composites may also ensure long-term durability of the materials.

Surgical outcomes of infectious spondylitis after vertebroplasty, and comparisons between pyogenic and tuberculosis

Background

Infection after vertebroplasty (VP) is a rare but serious complication. Previous literatures showed most pathogens for infection after VP were bacteria; tuberculosis (TB) induced infection after VP was extremely rare. We reported our treatment experiences of cases with infectious spondylitis after VP, and compared the differences between developed pyogenic and TB spondylitis.

Methods

From January 2001 to December 2015, 5749 patients had undergone VP at our department were reviewed retrospectively. The causative organisms were obtained from tissue culture of revision surgery. Parameters including type of surgery, the interval between VP and revision surgery, neurologic status, and visual analog scale (VAS) of back pain were recorded. Laboratory data at the time of VP and revision surgery were collected. Charlson comorbidity index (CCI), preoperative bacteremia, urinary tract infection (UTI), pulmonary TB history were also analyzed.

Results

Eighteen patients were confirmed with developed infectious spondylitis after VP (0.32%, 18/5749). Two were male and 16 were female. The median age at VP was 73.4 years. Nine patients were TB and the other nine patients were pyogenic. The interval between VP and revision surgery ranged from 7 to 1140 days (mean 123.2 days). The most common type of revision surgery was anterior combined with posterior surgery. Seven patients developed neurologic deficit before revision surgery. Three patients died within 6 months after revision surgery, with a mortality of 16.7%. Finally, VAS of back pain was improved from 7.4 to 3.1. Seven patients could walk normally, the other 8 patients had some degree of disability. Both pyogenic and TB group had similar age, sex, and CCI distribution. The interval between VP and revision surgery was shorter in the patients with pyogenic organisms (75.9 vs 170.6 days). At revision surgery, WBC and CRP were prominently elevated in the pyogenic group. Five in the pyogenic group had UTI and bacteremia; five in TB group had a history of lung TB.

Conclusions

Infection spondylitis after VP required major surgery for salvage with a relevant part of residual disability. Before VP, any bacteremia/UTI or history of pulmonary TB should be reviewed rigorously; any elevation of infection parameters should be scrutinized strictly.

Postoperative Infection in Patients Undergoing Posterior Lumbosacral Spinal Surgery: A Pictorial Guide for Diagnosis and Early Treatment

Surgical site infections after posterior spinal surgery may lead to spondylodiscitis, pseudarthrosis, correction loss, adverse neurological sequelae, sepsis, and poor outcomes if not treated immediately. Infection rates vary depending on the type and extent of operative procedures, use of instrumentation, and patients' risk factors. Image evaluation is crucial for early diagnosis and should be complementary to clinical routes, laboratory survey, and treatment timing. Magnetic resonance imaging detects early inflammatory infiltration into the vertebrae and soft tissues, including hyperemic changes of edematous marrow, vertebral endplate, and abscess or phlegmon accumulation around the intervertebral disk, epidural, and paravertebral spaces. Aggressive surgical treatment can eradicate infection sources, obtain a stable wound closure, decrease morbidity, and restore spinal integrity. Organ/space infection is defined as any body parts opened to manipulate other than superficial/deep incision. Advanced magnetic resonance imaging evaluating abnormal fluid accumulation, heterogenous contrast enhancement of the endplate erosion due to cage/screw infection is categorized to inform a presumptive diagnosis for early implant salvage. However, patients' defense response, infection severity, bacteriology, treatment timing, spinal stability, and available medical and surgical options must be fully considered. Revision surgery is indicated for pseudarthrosis, implant loosening with correction loss, recalcitrant spondylodiscitis, and adjacent segment diseases for infection control.

Infection following percutaneous vertebral augmentation with polymethylmethacrylate

Although the incidence of infection following vertebroplasty or kyphoplasty is rare, postoperative infection and cement augmentation in preexistent spondylitis can cause life-threatening complications in frail patients with notable comorbidities. In such cases, urgent culture and biopsy and the long-term use of proper antibiotics are necessary.

PURPOSE

Infection following vertebral augmentation with polymethylmethacrylate (PMMA) is rare. We aimed to analyze 11 cases of pyogenic spondylitis and spondylodiscitis that occurred after vertebroplasty or kyphoplasty and to review similar cases in the literature.

METHODS

All cases of postoperative spinal infections in our institution between January 2005 and November 2016 that primarily underwent percutaneous vertebroplasty or kyphoplasty were retrospectively reviewed. Eleven patients (mean age 76.3 years) were included.

RESULTS

The incidence of infection following vertebroplasty/kyphoplasty was 0.36%. Postoperative infection occurred in 3 of 826 cases. All patients underwent combined surgical and antibiotic treatment because of neurologic deficit on the initial diagnosis of the infection or failure of prior medical treatment of the infection. The surgical procedure was thorough debridement of infected tissue and material including PMMA following anterior column reconstruction via anterior/posterior/combined approach in 10 patients and percutaneous pedicle screw fixation alone in 1 patient aged 96 years. The mean follow-up period was 21.1 months after the revision operation, excluding one patient who died 17 days after revision surgery. Ten patients recovered from infection.

CONCLUSIONS

Although the incidence of infection following vertebroplasty or kyphoplasty is rare, postoperative infection and cement augmentation in preexisting spondylitis can develop into a life-threatening complication in frail patients with notable comorbidities. In treating infected vertebroplasty and kyphoplasty, immediate culture and biopsy and the long-term use of proper antibiotics are critical. Prompt surgical treatment should be considered in case of significant neurologic deficit, severe instability due to infected fracture, and resistance to antibiotics.

Potential risks of using cement-augmented screws for spinal fusion in patients with low bone quality

BACKGROUND CONTEXT

Dramatic increases in the average life expectancy have led to increases in the variety of degenerative changes and deformities observed in the aging spine. The elderly population can present challenges for spine surgeons, not only because of increased comorbidities, but also because of the quality of their bones. Pedicle screws are the implants used most commonly in spinal surgery for fixation, but their efficacy depends directly on bone quality. Although polymethyl methacrylate (PMMA)-augmented screws represent an alternative for patients with osteoporotic vertebrae, their use has raised some concerns because of the possible association between cement leakages (CLs) and other morbidities.

PURPOSE

To analyze potential complications related to the use of cement-augmented screws for spinal fusion and to investigate the effectiveness of using these screws in the treatment of patients with low bone quality.

STUDY DESIGN

A retrospective single-center study.

PATIENT SAMPLE

This study included 313 consecutive patients who underwent spinal fusion using a total of 1,780 cement-augmented screws.

METHODS AND OUTCOME MEASURES

We analyzed potential complications related to the use of cement-augmented screws, including CL, vascular injury, infection, screw extraction problems, revision surgery, and instrument failure. There are no financial conflicts of interest to report.

RESULTS

A total of 1,043 vertebrae were instrumented. Cement leakage was observed in 650 vertebrae (62.3%). There were no major clinical complications related to CL, but two patients (0.6%) had radicular pain related to CL at the S1 foramina. Of the 13 patients (4.1%) who developed deep infections requiring surgical debridement, two with chronic infections had possible spondylitis that required instrument removal. All patients responded well to antibiotic therapy. Revision surgery was performed in 56 patients (17.9%), most of whom had long construction. A total of 180 screws were removed as a result of revision. There were no problems with screw extraction.

CONCLUSIONS

These results demonstrate the efficacy and safety of cement-augmented screws for the treatment of patients with low bone mineral density.

Surgical techniques and clinical evidence of vertebroplasty and kyphoplasty for osteoporotic vertebral fractures

Osteoporotic vertebral fracture is a disease condition with high morbidity and mortality, whose prevalence rises with mean increase in the life span. Conventional treatments for an osteoporotic vertebral fracture include bed rest, pain medication and brace implementation, but if the patient's pain is severe, cement augmentation procedures, including vertebroplasty and kyphoplasty, are performed. Vertebroplasty and kyphoplasty are relatively easy procedures that have been reported to be effective in controlling acute pain. But, the risk of complication and additional adjacent segment fracture and their superiority over conventional treatment remain debatable. Therefore, the authors have summarized the procedures, complications, and clinical evidence of vertebroplasty and kyphoplasty in this review.

Complications of percutaneous vertebroplasty: An analysis of 1100 procedures performed in 616 patients

Percutaneous vertebroplasty (PVP) is a minimally invasive procedure widely used for the treatment of pain due to vertebral fractures of different origins-osteoporotic, traumatic, or neoplastic. PVP is minimally invasive, but the complications are not rare; however, they are in most cases not significant clinically. The most frequent is cement leakage, which can occur onto veins, paravertebral soft tissue, into the intervertebral disk, or to the spinal canal, affecting foraminal area or epidural space. We analyzed results of treatment and complications of vertebroplasty performed with the use of polimethylomethylacrylate cement (PMMA) on 1100 vertebrae, with a special regard to the severity of complication and eventual clinical manifestation. One thousand one hundred PVP were analyzed, performed in 616 patients. There were 468 (76%) women and 148 men (24%), 24 to 94-year old, mean age 68 years. From 1100 procedures, 794 treated osteporotic and 137 fractures due to malignant disease, 69 PVP were made in traumatic fractures. One hundred patients had painful vertebral hemangiomas. Seven hundred twenty-six (66%) lesions were in thoracic, and 374 (34%) in lumbar area. Results of treatment were assessed using 10 cm Visual Analogue Scale (VAS) 12 hours after surgery, 7 days, 30 days, and then each 6 months, up to 3 years. Before surgery all patients had significant pain 7 to 10 in VAS scale, mean 8.9 cm. Twelve  hours after surgery 602 (97.7%) reported significant relief of pain, with mean VAS of 2,3 cm. Local complications occurred in 50% of osteoporotic, 34% of neoplastic, 16% of traumatic fractures, and 2% of vertebral hemangiomas. The most common was PMMA leakage into surrounding tissues-20%; paravertebral vein embolism-13%; intradiscal leakage-8%; and PMMA leakage into the spinal canal-0.8%. Results of treatment did not differ between patients with and without any complications. From 104 patients who had chest X-ray or CT study performed after surgery, pulmonary embolism was noted in 2 patients, but without any clinical symptoms. Only 1 patient-with PMMA leakage into the spinal canal required surgical decompression In conclusion, PVP is effective in decreasing the level of pain in compression vertebral fractures. Complications occur in almost half of the patients but in more than 95% of them do not produce any clinical symptoms.

Risk Assessment and Characterization of 30-Day Perioperative Myocardial Infarction Following Spine Surgery: A Retrospective Analysis of 1346 Consecutive Adult Patients

STUDY DESIGN

A retrospective review.

OBJECTIVE

The aim of the study was to perform a risk assessment of 30-day perioperative myocardial infarction (MI) for spine surgery patients.

SUMMARY OF BACKGROUND DATA

There is an increased emphasis to reduce complications and improve outcomes after spinal surgery. One of the more devastating perioperative complications of spinal surgery is MI.

METHODS

We evaluated all medical records of 1346 consecutive patients who underwent spinal surgery at a single institution from 2008 to 2010 for incidence of MI within 30 days of surgery and documented all demographic, preoperative, and operative variables. Associations between postoperative MI and individual risk factors were determined using logistic regression analysis. Patients were stratified into emergent and elective groups and a similar analysis was performed.

RESULTS

Overall, 22 patients (1.6%) had 30-day perioperative MI, 14 patients (1.2%) undergoing elective surgery, and 8 patients (4.2%) after emergent surgery (P = 0.047). Three (13.6%) patients experienced 30-day mortality and an additional 3 (13.6%) patients experienced mortality within 1 year. Multivariate logistic regression determined that age more than 65 years, atrial fibrillation, hypertension, prior MI, anticoagulant use, low albumin, length of stay more than 7 days, intraoperative transfusion, trauma etiology, baseline creatinine more than 1  mg/dL, and at least 2 levels of spinal fusion were predictive of postoperative MI. For patients undergoing emergent surgery, age more than 65 years was associated with an increased risk of postoperative MI. When stratified by elective surgery, we found that age more than 65, postoperative stay more than 7 days, intraoperative blood transfusion, baseline creatinine more than 1  mg/dL, and fusion of more than 1 level were associated with an increased risk of MI.

CONCLUSION

The present study demonstrates a low incidence of MI after elective surgery with a higher incidence after emergent spine surgery and identifies patient factors predictive of postoperative MI.

LEVEL OF EVIDENCE

3.

Tuberculous Spondylitis Following Kyphoplasty: A Case Report and Review of the Literature

Tuberculous spondylitis of the augmented vertebral column following percutaneous vertebroplasty or kyphoplasty has rarely been described. We report an unusual case of tuberculous spondylitis diagnosed after percutaneous kyphoplasty (PKP). A 61-year-old woman presented to our institution complaining of back pain following a fall 7 days before. Radiologic studies revealed an acute osteoporotic compression L1 fracture. The patient denied history of pulmonary tuberculosis (TB) and there were no signs of infection. The patient was discharged from hospital 4 days after undergoing L1 PKP with a dramatic improvement in her back pain. Two years later, the patient was readmitted with a 1 year history of recurrent back pain. Imaging examinations demonstrated long segmental bony destruction involving L1 vertebra with massive paravertebral abscess formation. The tentative diagnosis of tuberculous spondylitis was made, after a serum T-SPOT. The TB test was found to be positive. Anterior debridement, L1 corpectomy, decompression, and autologous rib graft interposition, and posterior T8-L4 instrumentation were performed. The histologic examination of the resected tissue results confirmed the diagnosis of spinal TB. Anti-TB medications were administered for 12 months and the patient recovered without sequelae. Spinal TB and osteoporotic vertebral compression fractures are similar clinically and radiologically. Spinal surgeons should consider this disease entity to avoid misdiagnosis or complications. Early surgical intervention and anti-TB treatment should be instituted as soon as the diagnosis of spinal TB after vertebral augmentation is made.

Neurosurgical approaches to spinal infections

Spinal infection is rare. Clinical suspicion is important in patients with nonmechanical neck and/or back pain to make the proper diagnosis in early disease. Before planning surgery, a thorough evaluation of the spinal stability, alignment, and deformity is necessary. Timing of surgery, side of approach, appropriate surgical technique, and spinal instruments used are crucial. Biomechanical preservation of the spinal column during and after the infection is a significant issue. Postoperative spine infection is another entity of which spinal surgeons should be aware of. Proper septic conditions with meticulous planning of surgery are essential for successful spine surgery and better outcome.

Risk factors of adjacent vertebral collapse after percutaneous vertebroplasty for osteoporotic vertebral fracture in postmenopausal women

BACKGROUND

Recently percutaneous vertebroplasty (PVP) was frequently performed for treatment of osteoporotic vertebral fractures (VFs). It is widely accepted that new compression fractures tend to occur adjacent to the vertebral bodies, typically within a month after PVP. To determine the risk factors among several potential predictors for de novo VFs following PVP in patients with osteoporosis.

METHODS

We retrospectively screened the clinical results of 88 patients who had been treated by PVP. Fifteen cases were excluded due to non-union. Of the remaining 73 patients, 19 (26.0%) later returned with pain due to a new vertebral compression fracture. One patient with a non-adjacent fracture and 2 patients with adjacent factures occurring 3 months later were excluded from the study. The 9 male patients were excluded to avoid gender bias. Ultimately, we divided the 61 remaining postmenopausal female patients (mean age: 78.9 years) into the collapse group (14 patients) who had experienced adjacent vertebral collapse after PVP and the non-collapse group (47 patients) who had not. Logistic regression analysis was performed to identify the risk factors for new VFs after PVP.

RESULTS

All 14 cases of adjacent VF occurred within the first month after surgery. The collapse group had significantly advanced age, higher urinary N-terminal cross-linking telopeptide of type I collagen, and lower lumbar and hip bone mineral density (BMD) scores as compared with the non-collapse group. The odds ratios for age, lumbar, total hip, femoral neck, and trochanteric BMD were 4.5, 8.2, 4.5, 7.2, and 9.6, respectively. Positive likelihood ratios suggested that age more than 85 years, lumbar BMD less than 0.700 [-2.6SD], total hip BMD less than 0.700 [-1.8SD], neck BMD less than 0.600 [-2.1], and trochanter BMD less than 0.600 conferred an elevated risk of adjacent VF.

CONCLUSIONS

Our study revealed that advanced age and decreased lumbar and hip BMD scores most strongly indicated a risk of adjacent VF following PVP.

Computer Simulation and Analysis on Flow Characteristics and Distribution Patterns of Polymethylmethacrylate in Lumbar Vertebral Body and Vertebral Pedicle

This study was designed to analyze the flow and distribution of polymethylmethacrylate (PMMA) in vertebral body through computer simulation. Cadaveric lumbar vertebrae were scanned through electron beam tomography (EBT). The data was imported into Mimics software to build computational model. Vertebral body center and junction of pedicle and vertebral body were chosen as injection points. Silicone oil with viscosity of 100,000 cSt matching with PMMA bone cement was chosen for injection. The flow and distribution of silicone oil were analyzed using Fluent software. In vertebral body, silicone oil formed a circle-like shape centered by injection point on transverse and longitudinal sections, finally forming a sphere-like shape as a whole. Silicone oil diffused along lateral and posterior walls forming a circle-like shape on transverse section centered by injection point in pedicle, eventually forming a sphere-like shape as a whole. This study demonstrated that silicone oil flowed and diffused into a circle-like shape centered by injection point and finally formed a sphere-like shape as a whole in both vertebral body and pedicle. The flow and distribution of silicon oil in computational model could simulate PMMA distribution in vertebral body. It may provide theoretical evidence to reduce PMMA leakage risk during percutaneous vertebroplasty.