Vertebroplasty and Kyphoplasty in the Treatment of Malignant Vertebral Fractures

Interventional Radiology in the Management of Metastases and Bone Tumors

Interventional Radiology (IR) has experienced an exponential growth in recent years. Technological advances of the last decades have made it possible to use new treatments on a larger scale, with good results in terms of safety and effectiveness. In musculoskeletal field, painful bone metastases are the most common target of IR palliative treatments; however, in selected cases of bone metastases, IR may play a curative role, also in combination with other techniques (surgery, radiation and oncology therapies, etc.). Primary malignant bone tumors are extremely rare compared with secondary bone lesions: osteosarcoma, Ewing sarcoma, and chondrosarcoma are the most common; however, the role of interventional radiology in this fiels is marginal. In this review, the main techniques used in interventional radiology were examined, and advantages and limitations illustrated. Techniques of ablation (Radiofrequency, Microwaves, Cryoablation as also magnetic resonance imaging-guided high-intensity focused ultrasound), embolization, and Cementoplasty will be described. The techniques of ablation work by destruction of pathological tissue by thermal energy (by an increase of temperature up to 90 °C with the exception of the Cryoablation that works by freezing the tissue up to -40 °C). Embolization creates an ischemic necrosis by the occlusion of the arterial vessels that feed the tumor. Finally, cementoplasty has the aim of strengthening bone segment weakened by the growth of pathological tissue through the injection of cement. The results of the treatments performed so far were also assessed and presented focused the attention on the management of bone metastasis.

Role of Bone Biopsy During Kyphoplasty in the Setting of Known Cancer: A Case Report

STUDY DESIGN

Case report.

OBJECTIVE

The aim of this study was to emphasize the utility of routine biopsy during kyphoplasty and to report on a unique case of a patient with known history of prostate cancer found to have a new metastatic cancer.

SUMMARY OF BACKGROUND DATA

Vertebral compression fractures (VCFs) may cause debilitating pain with nearly one-third of them leading to chronic pain resulting in a tremendous impact on quality of life in patients. Kyphoplasty has been established as an effective means of surgical treatment. However, routine biopsy during kyphoplasty is presently not the standard of care under the presumption that most VCFs are caused by osteoporosis. The role of biopsy in the setting of known malignancy with multiple other risk factors for VCFs is not well understood.

METHODS

We report on a case of a 73-year-old male with known prostate cancer presenting with persistent unremitting low back pain failing conservative management. Patient develops multiple VCFs in the course of 6 months and is treated with multiple kyphoplasties. Routine biopsy at each level is negative until the last kyphoplasty results positive for malignancy. Surprisingly, the pathology is positive for malignancy other than the patient's known prostate cancer.

RESULTS

Pathology results prompt oncology workup on the patient which reveals multiple metastases and a new diagnosis of adenocarcinoma of possible upper gastrointestinal origin. In addition, patient's known prostate cancer is also noted to be active. Patient is subsequently started on chemotherapy.

CONCLUSION

We highlight the utility of routine biopsy during kyphoplasty especially in patients with known history of malignancy. We emphasize that presumptions about the etiology of a VCF are difficult to make with multiple risk factors and that routine biopsy prevents incorrect presumptions such as in this case.Level of Evidence: 5.

Use of O-arm with neuronavigation in percutaneous vertebroplasty reduces the surgeon's exposure to intraoperative radiation

INTRODUCTION

Percutaneous vertebroplasty is commonly used to treat spinal fractures. The authors compare radiation exposure as potential risk for the surgical team during vertebroplasty guided by O-arm combined with neuronavigation versus vertebroplasty guided by C-arm fluoroscopy.

MATERIAL AND METHODS

The clinical material consisted of a group of 29 patients (44 vertebrae) with fractures of the thoracolumbar spine treated with percutaneous vertebroplasty guided by O-arm with neuronavigation. In this new method, the operating room staff leaves the operating room for the duration of the 3D scan of the appropriate spine section using the O-arm. In the next stage, the needle of the vertebroplasty system is introduced using only neuronavigation without the need for a radiological view. Finally, the cement injection was made under O-arm fluoroscopic control. The comparison group consisted of a group of 35 patients (40 vertebrae) treated with the classical method using C-arm fluoroscopy. The two methods were compared in terms of the average dose of emitted ionizing radiation through the device (O-arm vs. C-arm) to which surgeons are exposed during percutaneous vertebroplasty.

RESULTS

As a result of vertebroplasty procedures guided by neuronavigation, a statistically significant difference between the values of mean dose of radiation emitted by O-arm and C-arm systems was noted. The O-arm emitted 912 cGy/cm² vs. 1722 cGy/cm² emitted by the C-arm during fluoroscopically assisted procedures and 601.28 cGy/cm² vs. 1506.86 cGy/cm² per vertebrae.

CONCLUSIONS

During vertebroplasty with the O-arm combined with neuronavigation the radiation dose is significantly lower as compared with the C-arm used for fluoroscopic guidance, minimizing the potential risk of radiation exposure to surgeons.

Long-term outcome of treatment of vertebral body hemangiomas with direct ethanol injection and short-segment stabilization

BACKGROUND

Vertebral body hemangiomas with myelopathy are difficult to manage.

OBJECTIVE

The objective of this study was to evaluate the role of intraoperative ethanol embolization, surgical decompression, and instrumented short-segment fusion in vertebral hemangioma (VH) with myelopathy and long-term outcome (>24 months).

CLINICAL MATERIALS AND METHODS

This prospective study included symptomatic VH with cord compression with myelopathy. Pathologic fractures and deformity or multilevel pathologies were excluded from the study. Surgery consisted of intraoperative bilateral pedicular absolute alcohol (<1% hydrated ethyl alcohol) injection, laminectomy, and cord decompression at the level of pathology followed by a short-segment instrumented fusion using pedicle screws.

RESULTS

The study included 33 patients (mean 26.9±13.2, range: 10-68 years, 18 females). The clinical features of the study were myelopathy in all patients (5 paraplegic), sphincter involvement (13), and mid back or lower back pain (7). The preoperative American Spinal Injury Association (ASIA) scores were A (7), B (11), C (6), D (8), and E (1). Majority of the patients had single vertebral involvement (30) and three patients had multiple-level involvement. Six patients underwent surgery earlier (one underwent alcohol embolization). The mean surgical time was 124±39 minutes, and the average blood loss was 274±80 cc. The mean amount of absolute alcohol injected was 14.6±5.7 cc (two patients required 20 and 25 cc). Immediate embolization was achieved in all patients, allowing laminectomy and easy removal of soft-tissue hemangioma. Post surgery, one patient had transient deterioration, and the condition of the rest of the patients improved (sphincters improved in nine patients) at a follow-up ranging 28-103 months (mean 47.6±22.3). Follow-up ASIA scores were E (26), D (4), B (2), and C (1). All patients showed evidence of bone sclerosis and relief of cord compression on follow-up imaging.

CONCLUSIONS

This is the largest study in literature showing excellent improvement, low reoperation rates after ethanol embolization, and short-segment fixation.

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.

Fracture care using percutaneously applied titanium mesh cages (OsseoFix®) for unstable osteoporotic thoracolumbar burst fractures is able to reduce cement-associated complications--results after 12 months

Background

Despite the known demographic shift with expected doubled rate of vertebral body fractures by the year 2050, a standardized treatment concept for traumatic and osteoporotic incomplete burst fracture of the truncal spine does not exist. This study aims to determine whether minimally invasive fracture care for incomplete osteoporotic thoracolumbar burst fractures using intravertebral expandable titanium mesh cages is a suitable procedure and may provide improved safety in terms of cement-associated complications in comparison to kyphoplasty procedure.

Methods

In 2011/2012, 15 patients (10 women, 5 men; mean age 77) with 15 incomplete osteoporotic thoracolumbar burst fractures (T10 to L4) were stabilized using intravertebral expandable titanium mesh cages (OsseoFix®) as part of a prospective study. X-ray, MRI and bone density measurements (DXA) were performed preinterventionally. The clinical and radiological results were evaluated preoperatively, postoperatively and after 12 months according to the visual analogue scale (VAS), the Oswestry Disability Index (ODI), X-ray (Beck Index, Cobb angle) and CT analyses. Wilcoxon rank sum test, sign test and Fischer’s exact test were used for statistical evaluation.

Results

A significant reduction in pain intensity (VAS) from preoperative 8.0 to 1.6 after 12 months and significant improvement in activity level (ODI) from preoperative 79.0 to 30.5 % after 12 months were revealed. Radiologically, the mean kyphotic angle according to Cobb showed significant improvements from preoperative 9.1° to 8.0° after 12 months. A vertebral body subsidence was revealed in only one case (6.7 %). No changes in the position of the posterior wall were revealed. No cement leakage or perioperative complications were seen.

Conclusion

As a safe and effective procedure, the use of intravertebral expandable titanium mesh cages presents a valuable alternative to usual intravertebral stabilization procedures for incomplete osteoporotic burst fractures and bears the potential to reduce cement-associated complications.

Trial registration

German Clinical Trials Register (DKRS) DRKS00008833.

Augmentation of failed human vertebrae with critical un-contained lytic defect restores their structural competence under functional loading: An experimental study

BACKGROUND

Lytic spinal lesions reduce vertebral strength and may result in their fracture. Vertebral augmentation is employed clinically to provide mechanical stability and pain relief for vertebrae with lytic lesions. However, little is known about its efficacy in strengthening fractured vertebrae containing lytic metastasis.

METHODS

Eighteen unembalmed human lumbar vertebrae, having simulated uncontained lytic defects and tested to failure in a prior study, were augmented using a transpedicular approach and re-tested to failure using a wedge fracture model. Axial and moment based strength and stiffness parameters were used to quantify the effect of augmentation on the structural response of the failed vertebrae. Effects of cement volume, bone mineral density and vertebral geometry on the change in structural response were investigated.

FINDINGS

Augmentation increased the failed lytic vertebral strength [compression: 85% (P<0.001), flexion: 80% (P<0.001), anterior-posterior shear: 95%, P<0.001)] and stiffness [(40% (P<0.05), 53% (P<0.05), 45% (P<0.05)]. Cement volume correlated with the compressive strength (r(2)=0.47, P<0.05) and anterior-posterior shear strength (r(2)=0.52, P<0.05) and stiffness (r(2)=0.45, P<0.05). Neither the geometry of the failed vertebrae nor its pre-fracture bone mineral density correlated with the volume of cement.

INTERPRETATION

Vertebral augmentation is effective in bolstering the failed lytic vertebrae compressive and axial structural competence, showing strength estimates up to 50-90% of historical values of osteoporotic vertebrae without lytic defects. This modest increase suggests that lytic vertebrae undergo a high degree of structural damage at failure, with strength only partially restored by vertebral augmentation. The positive effect of cement volume is self-limiting due to extravasation.

Results of kyphoplasty in the minimally invasive treatment of vertebral metastasis

OBJECTIVE: To evaluate the clinical and radiological outcome of minimally invasive surgical treatment of vertebral metastases using the technique of kyphoplasty. METHODS: This was a prospective observational study of patients with the diagnosis of spinal metastasis who underwent minimally invasive surgical treatment by filling the vertebral body with balloon kyphoplasty technique. Clinical evaluation included patient age at surgery, diagnosis of the tumor, biopsy results, data of the surgical procedure performed, visual pain scale (VAS) and complications related to surgery. Radiological evaluation involved the study of radiographic procedures in the anteroposterior and lateral incidences, with the analysis of vertebral body kyphosis and the occurrence of extravasation of cement. RESULTS: 22 patients with spinal metastases who were treated by balloon kyphoplasty, 8 (36%) males and 14 (64%) females were studied. The average age was 56.05 years and the mean follow-up was 8.5 months. The mean preoperative VAS was 8.73, 1.73 in the initial postoperative period, and 1.92 in the late postoperative period. CONCLUSION: Kyphoplasty proved to be a safe and effective technique for symptomatic treatment of vertebral metastases.

Treatment of vertebral pathological fractures by percutaneous vertebroplasty

OBJECTIVE: To evaluate a consecutive series of patients undergoing vertebroplasty for pain control, according to results and complications in the short and medium follow-up. METHODS: Retrospective analysis of medical records of 26 patients undergoing vertebroplasty from January 2007 to December 2010. Patients were evaluated by the questionnaire of assessment of low back pain (Oswestry Index) and the visual analog pain scale (VAS) on the day before surgery, on the second day and 12 months after the procedure. RESULTS: Significant improvement of pain symptoms within 48 hours after surgery was reported in 22 patients (91.6%), two patients (8.32%) showed moderate improvement. Of the 22 patients with significant pain relief, 21 (95.4%) maintained the benefit and one (4.6%) had intense pain (new fracture in the body of L1) at a mean follow up of 12 months. Regarding the Oswestry Index, preoperative average was 52.9%. On the second day and 12 months after surgery this average was 23.6% and 24.5%, respectively; good results according to this index. Two patients were excluded from the study due to incomplete medical records. CONCLUSION: Despite the small sample size and short follow-up, the results of vertebroplasty were effective for the relief of pain symptoms and were safe as regards the risks of complications.

Utility of routine biopsy at vertebroplasty in the management of vertebral compression fractures: a tertiary center experience

OBJECT

The authors assess the utility of routine biopsy at vertebroplasty for vertebral compression fracture (VCF) as a tool in the early detection of malignancy in presumed benign VCF.

METHODS

A prospective observational study was conducted on a cohort of consecutive patients undergoing vertebroplasty over a 5-year period between April 2006 and March 2011 at the Royal London Hospital. Polymethylmethacrylate cement injection was used in every procedure. Intraoperative vertebral body biopsy was performed routinely at every level of VCF. Pain visual analog scale (VAS) scores, Oswestry Disability Index (ODI) scores, analgesic usage, and complications were recorded preoperatively and at 1 day, 1 week, 1 month, 6 months, and 1 year postoperatively.

RESULTS

A total of 202 levels were augmented in 147 patients. The most common levels augmented were T-12 (17%), L-1 (18%), and L-4 (10%). Analysis of 184 routine vertebral biopsies in 135 patients revealed that in 86 patients with presumed osteoporosis and no prior cancer diagnosis, 4 (4.7%) had a malignant VCF. In 20 known cancer patients presumed to be in remission, 2 (10%) had a malignant VCF. Routine vertebral biopsy returned an overall cancer diagnosis rate of 5.5% (6 of 109) when combining the 2 groups (patients with no prior history of cancer or cancer thought to be in remission). In these 6 patients, history, examination, laboratory tests, and preprocedure imaging all failed to suggest malignancy diagnosed at routine biopsy. Significant reductions in pain VAS and ODI scores were evident at Day 1 and were sustained at up to 1 year postoperatively (p < 0.001). They were not dependent on the level of fracture (T3-10, T11-L2, or L3-S1) (p > 0.05), number of levels treated (single level, 2 levels, or > 2 levels) (p > 0.05), or etiology of VCF (p > 0.05). The complication rate was 6% (9 of 147). There were 5 deaths, none of which were directly related to surgery.

CONCLUSIONS

Routine vertebral biopsy performed at vertebroplasty may demonstrate cancer-related VCFs in unsuspected patients with no previous cancer diagnosis or active malignancy in patients previously thought to be in remission. This early diagnosis of cancer or relapsed disease will play an important role in expediting patients' subsequent cancer management. In cases of multiple-level VCF, the authors advocate biopsy at each level to maximize the diagnostic yield from the specimens and to avoid missing a malignancy at a single level.

Kyphoplasty in osteoporotic vertebral compression fractures--guidelines and technical considerations

Osteoporotic vertebral compression fractures are a menace to the elderly generation causing diminished quality of life due to pain and deformity. At first, conservative treatment still is the method of choice. In case of resulting deformity, sintering and persistent pain vertebral cement augmentation techniques today are widely used. Open correction of resulting deformity by different types of osteotomies addresses sagittal balance, but has comparably high morbidity.

Besides conventional vertebral cement augmentation techniques balloon kyphoplasty has become a popular tool to address painful thoracic and lumbar compression fractures. It showed improved pain reduction and lower complication rates compared to standard vertebroplasty. Interestingly the results of two placebo-controlled vertebroplasty studies question the value of cement augmentation, if compared to a sham operation. Even though there exists now favourable data for kyphoplasty from one randomised controlled trial, the absence of a sham group leaves the placebo effect unaddressed. Technically kyphoplasty can be performed with a transpedicular or extrapedicular access. Polymethyl methacrylate (PMMA)-cement should be favoured, since calcium phosphate cement showed inferior biomechanical properties and less effect on pain reduction especially in less stable burst fractures. Common complications of kyphoplasty are cement leakage and adjacent segment fractures. Rare complications are toxic PMMA-monomer reactions, cement embolisation, and infection.

Percutaneous vertebroplasty in vertebral compression fractures of benign or malignant origin: a prospective study of 1188 patients with follow-up of 12 months

BACKGROUND

Vertebral body fractures are a source of high costs for the health care system and will continue to be one as the population ages. Cost-effective treatment is thus all the more important. In this study, we evaluated patients' quality of life during the first 12 months after they had undergone percutaneous vertebroplasty for vertebral body fractures which were refractory to conservative treatment. Our analysis took the causes of the fractures into account.

METHODS

Pain, mobility, and need for analgesics were assessed prospectively on verbal rating scales one day before and one day after vertebroplasty, as well as over a follow-up period of up to 12 months. The same examiner interviewed each patient at all time points to obtain this information.

RESULTS

1188 patients underwent vertebroplasty for 1980 vertebral body fractures; the most common etiology was osteoporosis (75%). There was statistically relevant improvement in all three of the variables studied from the day before the procedure to the last follow-up, regardless of the cause of fracture (p<0.01). Most of the clinical benefit was already evident on the day after the procedure. Patients with fractures due to osteoporosis experienced further statistically relevant improvement by 6 months after treatment.

CONCLUSION

Percutaneous vertebroplasty immediately relieves the pain of vertebral body fractures, improves patients' mobility, and lowers their consumption of analgesics. There can be further clinical improvement up to 6 months after the procedure, particularly in patients with fractures due to osteoporosis. As osteoporosis is the most common cause of vertebral body fractures, this patient group is important not just clinically, but economically as well.

Percutaneous vertebroplasty in the management of vertebral osteoporotic fractures. Short-term, mid-term and long-term follow-up of 285 patients

OBJECTIVES

To evaluate the short-term, mid-term and long-term follow-up of 285 patients who had undergone percutaneous vertebroplasty (PVP) for osteoporotic vertebral compression fracture (VCF) in our department from 2003 to 2006, and, particularly, to analyse our data on the safety and the usefulness of PVP for durable pain reduction, mobility improvement and the need for analgesic drugs.

MATERIALS AND METHODS

Follow-up analysis was made through a questionnaire completed by the patients before and after PVP (1 week, 1 year and 3 years). The results are reported by subdivision of patients into groups (by gender, age and number of treated vertebrae), with special reference to pain management, drug administration and quality of life.

RESULTS

All patients (285) were followed up for 1 week, 186 for 12 months, and 68 patients were followed up for 3 years. One week after PVP all patients reported normal ambulation (with or without pain), and more than 95% were able to perform activities of daily living (ADL) either without pain or with mild pain. There was no difference in pain relief between the genders after 1 week's follow up, but after 3 years better analgesia results were observed in women. There was no statistically significant difference in the visual analogue scale (VAS) values before PVP between age groups (P = 0.7) and gender (P = 0.4); Patients younger than 75 years had better outcomes than did older ones (>75 years) at 1 week and 1 year follow up. Patients also reported significant reduction in drug therapy for pain.

CONCLUSIONS

PVP is a safe and useful procedure for the treatment of vertebral osteoporotic fractures. It produces enduring pain reduction, improves patients' mobility and decreases the need for analgesic drugs.

An improved metric for quantifying the stiffnesses of intact human vertebrae

Accurately quantifying the compressive stiffnesses of whole human vertebrae is important in the development of new treatment regimes for fractures due to osteoporosis or metastatic involvement. Two methods are commonly used to quantify compressive stiffnesses of whole vertebrae: first, the maximum slope of the force-deformation curve over a 0.2 per cent strain window; second, the slope of the best-fit line to the load-deflection curve over a specified loading range. Because the whole bone load-displacement response is non-linear, these two measurement systems yield different stiffness values for the same set of experimental data. Thus, the goal of this study was to develop and validate a standard method for deriving the whole bone stiffnesses of human vertebrae. Data from uniaxial compression tests on isolated human thoracic vertebrae (N=30 from 24 donors; T7-T10; age, 84 +/- 10, seven male, and 17 female) were analysed using the two aforementioned stiffness measurement techniques. A sensitivity analysis was also conducted whereby stiffness values were calculated for strain windows ranging from 0.05 per cent to 10 per cent. The results showed that the whole vertebra stiffness was sensitive to the calculation method. Using strain window approaches, the calculated stiffness was erratic at small strain ranges (less than 0.75 per cent), but it began to stabilize at 1 per cent strain. Comparing the historical measurement techniques versus the new standard, it was found that the 1 per cent and 0.2 per cent strain window techniques were well correlated (R2 = 0.91; p < 0.01); however, compared with the 1 per cent strain window method, the 0.2 per cent technique consistently overestimated stiffness and had five times the sensitivity to small changes in strain window magnitude. In conclusion, it is recommended that the 1 per cent strain window technique is adopted as a new standard for measuring the whole bone compressive stiffnesses of human vertebrae based on this method's superior level of accuracy and repeatability when compared with current techniques. The adoption of such a standard in the biomechanics field is important because it allows for inter-study comparisons of new orthopaedic treatments, such as vertebroplasty products.

Vertebroplasty and kyphoplasty for spinal metastases

PURPOSE OF REVIEW

Pathologic fractures of the spine are extremely painful and cause significant disability and morbidity in patients suffering from metastatic cancer. Often, these patients are not candidates for open surgical procedures and cannot address mechanical instability and radiation therapy can take weeks to become effective. Minimally invasive surgical techniques have been developed over the past several years, offering a simple and effective way of managing painful pathologic fractures.

RECENT FINDINGS

Vertebroplasty and kyphoplasty offer patients a minimally invasive, percutaneous procedure that dramatically reduces pain related to pathologic spinal fractures almost immediately with very low complication rates. Visual analog scale pain scores, narcotic usage and quality of life scales (SF-36) have all been shown to improve in a durable fashion for over 1 year. Also, these procedures can be performed before, after or concurrently with most radiation and chemotherapy protocols.

SUMMARY

We recommend vertebroplasty or kyphoplasty in properly selected patients with painful pathologic fractures as early as possible. Newer biomaterials, which are softer than currently used cement, may offer better protection from adjacent level fracturing and lower complication rates.

Balloon kyphoplasty in the treatment of metastatic disease of the spine: a 2-year prospective evaluation

There is currently little data on the longer term efficacy and safety of balloon kyphoplasty (BKP) in patients with metastatic vertebral compression fractures (VCFs). To prospectively assess the long-term efficacy and safety of BKP in treating thoracic and lumbar spinal metastatic fractures that result in pain or instability. Sixty-five patients (37 men, mean age: 66 years) underwent 99 BKP procedures. Patient-related outcomes of pain visual analogue scale (VAS) and Oswestry Disability Index were assessed pre- and post-operatively and after 3, 6, 12 and 24 months. Correction of vertebral height and kyphotic deformity were assessed by radiographic measurements. Mean pain VAS and Oswestry Disability Index significantly improved from pre- to post-treatment (P < 0.0001), this improvement being sustained up to 24-month follow up. A gain in height restoration and a reduction of the post-operative kyphotic angle were seen post-operatively and at 3 months although these radiographic outcomes returned to pre-operative levels at 12 months. BKP was associated with a rate of cement leakage and incidence vertebral fracture of 12 and 8%, respectively. No symptomatic cement leaks or serious adverse events were seen during the 24 months of follow up. BKP is a minimally invasive procedure that provides immediate and long-term pain relief and improvement in functional ability in selected patients with metastatic VCFs. The procedure appears to have good long-term safety.

Molecular mechanisms and treatment of bone metastasis

The metastasis of cancer cells to bone alters bone architecture and mineral homeostasis. As described by the 'seed and soil' hypothesis, bone represents a fertile ground for cancer cells to flourish. A 'vicious cycle' of reciprocal bone-cancer cellular signals occurs with osteolytic (bone-resorbing) metastases, and a similar mechanism likely modulates osteoblastic (bone-forming) metastatic lesions as well. The development of targeted therapies either to block initial cancer cell chemotaxis, invasion and adhesion or to break the 'vicious cycle' is dependent on a more complete understanding of bone metastases. Although bisphosphonates delay progression of skeletal metastases, it is clear that more-effective therapies are needed. Cancer-associated bone morbidity remains a major public health problem, and to improve therapy and prevention it is important to understand the pathophysiology of the effects of cancer on bone. This review details scientific advances in this area.

Complications and safety aspects of kyphoplasty for osteoporotic vertebral fractures: a prospective follow-up study in 102 consecutive patients

Background

Kyphoplasty represents an established minimal-invasive method for correction and augmentation of osteoporotic vertebral fractures. Reliable data on perioperative and postoperative complications are lacking in the literature. The present study was designed to evaluate the incidence and patterns of perioperative complications in order to determine the safety of this procedure for patients undergoing kyphoplasty.

Patients and Methods

We prospectively enrolled 102 consecutive patients (82 women and 20 men; mean age 69) with 135 operatively treated fractured vertebrae who underwent a kyphoplasty between January 2004 to June 2006. Clinical and radiological follow-up was performed for up 6 months after surgery.

Results

Preoperative pain levels, as determined by the visual analogous scale (VAS) were 7.5 +/- 1.3. Postoperative pain levels were significantly reduced at day 1 after surgery (VAS 2.3 +/- 2.2) and at 6-month follow-up (VAS 1.4 +/- 0.9). Fresh vertebral fractures at adjacent levels were detected radiographically in 8 patients within 6 months. Two patients had a loss of reduction with subsequent sintering of the operated vertebrae and secondary spinal stenosis. Accidental cement extravasation was detected in 7 patients in the intraoperative radiographs. One patient developed a postoperative infected spondylitis at the operated level, which was treated by anterior corporectomy and 360 degrees fusion. Another patient developed a superficial wound infection which required surgical revision. Postoperative bleeding resulting in a subcutaneous haematoma evacuation was seen in one patient.

Conclusion

The data from the present study imply that percutaneous kyphoplasty can be associated with severe intra- and postoperative complications. This minimal-invasive surgical procedure should therefore be performed exclusively by spine surgeons who have the capability of managing perioperative complications.

Vertebroplasty and Kyphoplasty

Percutaneous vertebroplasty and kyphoplasty provide minimally invasive options for the management of osteoporotic and osteolytic vertebral compression fractures. These techniques provide substantial pain relief and support without requiring long periods of recumbency, and have an acceptable complication rate. Vertebral augmentation techniques such as vertebroplasty and kyphoplasty provide pain relief and improvement in quality of life in the highly selected patient. Complications can be avoided with careful surgical technique, and good outcomes can be achieved with proper patient selection.

Percutaneous vertebroplasty in painful schmorl nodes

The Schmorl node represents displacement of intervertebral disc tissue into the vertebral body. Both Schmorl nodes and degenerative disc disease are common in the human spine. We performed a retrospective study, for the period from January 2003 to February 2005, evaluating 23 patients affected by painful Schmorl nodes, who underwent in our department percutaneous transpedicular injection of polymethylmethacrylate (vertebroplasty) in order to solve their back pain not responsive to medical and physical management. Eighteen patients reported improvement of the back pain and no one reported a worsening of symptoms. Improvement was swift and persistent in reducing symptoms. Painful Schmorl nodes, refractory to medical or physical therapy, should be considered as a new indication within those vertebral lesions adequately treatable utilizing Vertebroplasty procedure.