Vertebral augmentation in osteoporotic fractures

Restoring vertebral height in the treatment of multilevel vertebral compression fractures with vertebroplasty

Background

Osteoporosis (OP) is the fourth leading cause of disability in the elderly. The challenges presented by OP fractures are complex. Vertebral body fractures (VCF) are frequently encountered in osteoporotic patients. Due to the predominant age group of osteoporotic VCF along with co-morbidities, restoring the vertebral body height and the correction of kyphosis via minimally invasive methods are preferred. Vertebroplasty continues to be the most commonly employed method in this selection. The purpose of this study is to provide evidence for the combined employment of vertebroplasty with other minimally invasive techniques in the treatment of osteoporotic VCF. A retrospective analysis of patients treated for multilevel thoracolumbar osteoporotic VCF was performed. The patients were treated with percutaneous vertebroplasty (PVP), transforaminal lumbar interbody fusion supplemented by vertebroplasty (TLIF-VP) and minimally invasive transpedicular screw fixation supplemented by vertebroplasty (TP-VP). They were followed up for at least a year and VAS and ODI scores along with the degree of kyphotic correction and restoration of vertebral body height have been evaluated.

Results

Sixty patients with 132 levels of VCF treated were evaluated. PVP was superior in terms of shortened operative period, decreased blood loss, earlier ambulation and not requiring general anesthesia. Both TLIF-VP and TP-VP required general anesthesia, with longer operative period and increased blood loss, however it provided greater kyphotic correction. Restoration of vertebral body height was the highest in the PVP and TP-VP group. All patients benefited clinically from the interventions in regard to VAS pain and ODI scores.

Conclusions

VP continues to be the choice for minimally invasive correction of osteoporotic VCF. VP can be employed with other techniques as seen in this study in selected patients with sufficient symptomology. TLIF implantation allowed for discectomy and sufficient root decompression while transpedicular screw fixation allowed for greater correction especially in the chronic fractures.

Evaluation of biopsy results during vertebral augmentation in patients with a known history of malignancy

OBJECTIVES

To evaluate biopsy results during vertebral augmentation in vertebral compression fracture (VCF) patients with a known history of malignancy.

METHODS

An analysis of vertebral augmentation between 2012 and 2021 was performed retrospectively. Each level of VCF was biopsied, and all biopsies were sent for histopathological analyses. Imaging evaluation was performed in collaboration with an oncologist, a spine surgeon, and a radiologist. Patients were divided into two groups based on the preoperative imaging findings. Malignant VCF (MVCF) was presumed in group A, while osteoporotic VCF (OVCF) was presumed in group B.

RESULTS

One hundred and fifty-six VCF patients with a known history of malignancy were included. Group A included 91 patients with preoperative imaging findings suspicious for MVCF. And 73 patients were finally diagnosed as MVCF, with biopsy results confirming imaging findings. The incidence of MVCF was 46.8%. Group B included 65 patients with imaging evidence of OVCF. And all biopsy results were negative for malignancy. The sensitivity of imaging evaluation for finding MVCF was 100%, and the specificity was 78.3%.

CONCLUSION

A combination of X-ray, computed tomography (CT), and magnetic resonance imaging (MRI) is sufficient to distinguish MVCF from OVCF. Biopsy is not required to confirm the diagnosis during vertebral augmentation, if the imaging findings do not indicate MVCF in patients with a known history of malignancy. It is recommended to perform a biopsy in patients with preoperative imaging findings suspicious for MVCF.

KEY POINTS

• A combination of X-ray, CT, and MRI is sufficient to distinguish MVCF from OVCF. • Biopsy is not required in patients without imaging signs of MVCF. • Biopsy is recommended in patients with imaging findings suspicious for MVCF.

Sustained local ionic homeostatic imbalance caused by calcification modulates inflammation to trigger heterotopic ossification

Heterotopic ossification (HO) is a condition triggered by an injury leading to the formation of mature lamellar bone in extraskeletal soft tissues. Despite being a frequent complication of orthopedic and trauma surgery, brain and spinal injury, the etiology of HO is poorly understood. The aim of this study is to evaluate the hypothesis that a sustained local ionic homeostatic imbalance (SLIHI) created by mineral formation during tissue calcification modulates inflammation to trigger HO. This evaluation also considers the role SLIHI could play for the design of cell-free, drug-free osteoinductive bone graft substitutes. The evaluation contains five main sections. The first section defines relevant concepts in the context of HO and provides a summary of proposed causes of HO. The second section starts with a detailed analysis of the occurrence and involvement of calcification in HO. It is followed by an explanation of the causes of calcification and its consequences. This allows to speculate on the potential chemical modulators of inflammation and triggers of HO. The end of this second section is devoted to in vitro mineralization tests used to predict the ectopic potential of materials. The third section reviews the biological cascade of events occurring during pathological and material-induced HO, and attempts to propose a quantitative timeline of HO formation. The fourth section looks at potential ways to control HO formation, either acting on SLIHI or on inflammation. Chemical, physical, and drug-based approaches are considered. Finally, the evaluation finishes with a critical assessment of the definition of osteoinduction. STATEMENT OF SIGNIFICANCE: The ability to regenerate bone in a spatially controlled and reproducible manner is an essential prerequisite for the treatment of large bone defects. As such, understanding the mechanism leading to heterotopic ossification (HO), a condition triggered by an injury leading to the formation of mature lamellar bone in extraskeletal soft tissues, would be very useful. Unfortunately, the mechanism(s) behind HO is(are) poorly understood. The present study reviews the literature on HO and based on it, proposes that HO can be caused by a combination of inflammation and calcification. This mechanism helps to better understand current strategies to prevent and treat HO. It also shows new opportunities to improve the treatment of bone defects in orthopedic and dental procedures.

Direct and interactive influence of explanatory variables on properties of a calcium phosphate cement for vertebral body augmentation

We used the response surface methodology to investigate the direct and interactive effects of three explanatory variables on three properties of a calcium phosphate cement (CPC) for use in vertebroplasty (VP) and balloon kyphoplasty (BKP). The variables were poly(ethylene glycol) content of the cement liquid (PEG), powder-to-liquid ratio (PLR), and the amount of Na2HPO4 added to an aqueous solution of 4 wt/wt% poly(acrylic acid) (as the cement liquid) (SPC). The properties were injectability (I), final setting time (F), and 5-day compressive strength (UCS). We found that (1) there was an interactive effect between the variables on I and F but not on UCS; (2) the maximum I (98%) was obtained with PEG = 20 wt/wt% and PLR = 2 g mL(-1); (3) F = 15 min (the proposed optimum value for a CPC for use in VP and BKP) was obtained with PEG = 4 wt/wt% and PLR = 2.9 g mL(-1); and (4) the maximum UCS (39 MPa) was obtained with SPC = 0 and PLR = 3.5 g mL(-1).

Decompressed percutaneous vertebroplasty: a secured bone cement delivery procedure for vertebral augmentation in osteoporotic compression fractures

The purpose of this study was to assess the efficacy of a new assistive procedure for injecting cement in percutaneous vertebroplasty (PV). Percutaneous vertebroplasty is frequently used for treating patients with osteoporotic vertebral compression fractures. However, the leakage of bone cement during PV may lead to serious complications, such as spinal cord compression or pulmonary embolism. Herein we present a secure procedure designed to safely and effectively deliver the bone cement into the vertebral column.

MATERIALS AND METHODS

Thirty-five patients with a total of 50 levels of osteoporotic compression fracture were consecutively recruited for the study. During a routine PV operation, acrylic cement was injected with a simultaneous application of a continuous negative pressure to the contralateral side of the vertebral body. This negative pressure exerts a pulling force that attracts the bone cement to flow within the vertebral body.

RESULTS

With the proposed decompressed PV procedure, cross-filling of the vertebrographies was achieved for all 50 fracture levels, with no paravertebral venous plexus leakage. Three of the 50 levels (6%) exhibited contrast-medium leakage into the intradisc or cortical defect regions. After decompressed cement injection, excellent cross-filling of bone cement deposition was achieved in 38 of the 50 levels (76%; cement cross-filling region >75%), good cross-filling deposition was achieved in 7 levels (14%; cement cross-filling region >50%), deposition was poor in 3 levels (6%; cement cross-filling region <50%), and deposition failed in 2 levels (4%; fixed cement with no sign of cross-filling). Routine postoperative reviews revealed that six fracture levels (12%) had minimal cement leakage, with two leaking into the disc and four into paravertebral cortical defect regions.

CONCLUSIONS

Compared to the reported 20-88% cement leakage rate for the conventional PV procedure, the proposed decompressed PV procedure offers a more secure and effective way to perform cement injection, and reduces the likelihood of cement leakage.

Comparative hospital economics and patient presentation: vertebroplasty and kyphoplasty for the treatment of vertebral compression fracture

BACKGROUND AND PURPOSE

Previous studies evaluating vertebral augmentation procedure costs have not made detailed comparisons between vertebroplasty and kyphoplasty. Our study contrasts hospital costs for vertebroplasty versus kyphoplasty for the treatment of vertebral compression fractures in routine clinical practice in the United States.

MATERIALS AND METHODS

This retrospective cohort study analyzed 2007-2008 hospital discharge and billing records from the Premier Perspective data base. The primary outcome variable, differences in total hospital cost between vertebroplasty and kyphoplasty, was assessed by using analysis of covariance.

RESULTS

Three thousand six hundred seventeen patients received vertebroplasty (64% inpatient, 36% outpatient), and 8118 received kyphoplasty (54% inpatient, 46% outpatient). Approximately 75% were women, and most were white. Mean total unadjusted inpatient costs were $9837 for vertebroplasty versus $13 187 for kyphoplasty (P < .0001). Outpatient vertebroplasty costs were $3319 versus $8100 for kyphoplasty (P < .0001). Lower vertebroplasty costs were largely due to differences in hospital supply and OR. Mean vertebroplasty OR costs were $73.60 (anesthesia), $112.06 (recovery room), and $990.12 (surgery) versus $172.16 (anesthesia), $257.47 (recovery room), and $1,471.49 (surgery) with kyphoplasty. Adjustments for age, sex, admission status, and disease severity accentuated the differences. Mean adjusted inpatient costs were $11 386 for vertebroplasty versus $16 182 for kyphoplasty (P < .0001), and outpatient costs were $2997 for vertebroplasty versus $7010 for kyphoplasty (P < .0001). After adjustments for the same covariates, length-of-stay differences were no longer evident (P = .4945).

CONCLUSIONS

Performing vertebroplasty versus kyphoplasty reduces hospital costs by nearly $5000 for inpatient procedures and by more than $4000 for outpatient procedures.

The bioactivity and ion release of titanium-containing glass polyalkenoate cements for medical applications

The ion release profiles and bioactivity of a series of Ti containing glass polyalkenoate cements. Characterization revealed each material to be amorphous with a T(g) in the region of 650-660°C. The network connectivity decreased (1.83-1.35) with the addition of TiO(2) which was also evident with analysis by X-ray photoelectron spectroscopy. Ion release from cements were determined using atomic absorption spectroscopy for zinc (Zn(2+)), calcium (Ca(2+)), strontium (Sr(2+)), Silica (Si(4+)) and titanium (Ti(4+)). Ions such as Zn(2+) (0.1-2.0 mg/l), Ca(2+) (2.0-8.3 mg/l,) Sr(2+) (0.1-3.9 mg/l), and Si(4+) (14-90 mg/l) were tested over 1-30 days. No Ti(4+) release was detected. Simulated body fluid revealed a CaP surface layer on each cement while cell culture testing of cement liquid extracts with TW-Z (5 mol% TiO(2)) produced the highest cell viability (161%) after 30 days. Direct contact testing of discs resulted in a decrease in cell viability of the each cement tested.

Treatment of pathologic spinal fractures with combined radiofrequency ablation and balloon kyphoplasty

Background

In oncologic patients with metastatic spinal disease, the ideal treatment should be well tolerated, relieve the pain, and preserve or restore the neurological function.

The combination of fluoroscopic guided radiofrequency ablation (RFA) and kyphoplasty may fulfill these criteria.

Methods

We describe three pathological vertebral fractures treated with a combination of fluoroscopic guided RFA and kyphoplasty in one session: a 62-year-old man suffering from a painful L4 pathological fracture due to a plasmocytoma, a 68-year-old man with a T12 pathological fracture from metastatic hepatocellular carcinoma, and a 71-year-old man with a Th12 and L1 pathological fracture from multiple myeloma.

Results

The choice of patients was carried out according to the classification of Tomita. Visual analog score (VAS) and Oswestry disability index (ODI) were used for the evaluation of the functional outcomes. The treatment was successful in all patients and no complications were reported. The mean follow-up was 6 months. Marked pain relief and functional restoration was observed.

Conclusion

In our experience the treatment of pathologic spinal fractures with combined radiofrequency ablation and balloon kyphoplasty is safe and effective for immediate pain relief in painful spinal lesions in neurologically intact patients.