Kyphoplasty Procedures Research Articles

Percutaneous Balloon Kyphoplasty in Treatment of Painful Osteoporotic Occult Vertebral Fracture: A Retrospective Study of 89 Cases.

BackgroundThe definition of a vertebral fracture is usually based on the presence of a deformation of the vertebral body and this can be misleading in the presence of a fracture without radiologic collapse with the definition of occult osteoporotic vertebral fractures (OOVFs). STIR sequence of MRI images showing hyperintensity signal was the most confirmative screening examination used to determine the presence of painful OOVFs. To date, clinical management of OOVFs has been rarely discussed.Material/MethodsBetween 2011 and 2013, 89 patients suffering from painful OOVFs underwent 142 percutaneous balloon kyphoplasty (PKP) procedures. Outcome data (mean variation of anterior and middle vertebral body height, visual analog scale [VAS] scores, Oswestry Disability Index [ODI] scores, and SF-36 scores) were recorded preoperatively, postoperatively, and at 1 month, 6 months, and 2 year after treatment, to evaluate the results.ResultsWe successfully treated 89 patients (142 vertebral bodies) with PKP. Cement leakages were observed in 12 (8.45%) treated vertebral bodies and there were 5 new adjacent vertebral fractures during the follow-up period. The mean variation of anterior and middle vertebral body height changed from 96.5±3.4% preoperatively to 97.2±2.5% postoperatively (p>0.05) and from 96.3±2.8% preoperatively to 97.9±3.1% postoperatively (p>0.05), respectively. The mean VAS scores were reduced significantly from pre-surgery to post-surgery (8.3±1.2 to 2.9±0.7; p<0.05), as was the ODI score (76.4±12.5 to 26.7±5.6; p<0.05). The SF-36 scores, including Bodily Pain (BF), Vitality (VT), Physical Function (PF), and Social Functioning (SF), all showed notable improvement (P<0.05). These variations were maintained during the 2-year follow-up period.ConclusionsPKP is a safe and effective method in the treatment of painful OOVFs.

Osteointegration and Resorption of Intravertebral and Extravertebral Calcium Phosphate Cement.

Eleven patients with painful osteoporotic vertebral fractures who underwent kyphoplasty using calcium phosphate (CaP) cement were followed up for 1 week, 1, 2, and 3 years in a monocentric, nonrandomized, noncontrolled retrospective trial. This study investigates long-term radiomorphologic features of intraosseous CaP cement implants and of extraosseous CaP cement leakages for up to 3 years after implantation by kyphoplasty. Kyphoplasty is frequently used for the treatment of painful osteoporotic fractures. Of the materials available, CaP is frequently used as a filling material. Resorption of this material is frequently observed, although clinical outcome is comparable with other cements. Kyphoplasty utilizing CaP cement was performed in 11 patients with painful osteoporotic vertebral fractures. All patients received a pharmacological antiosteoporosis treatment consisting of calcium, vitamin D, and a standard dose of oral bisphosphonates. Radiomorphologic measurements, pain, and mobility were assessed. Intraosseous and extraosseous CaP cement volumes decreased significantly over 3 years. However, vertebral stability as determined by a constant vertebral body height and the sagittal index was not impaired. Pain improved significantly 2 years after implantation and the mobility scores 1 year after kyphoplasty at least until the third year. Intravertebral CaP cement implants are resorbed slowly over time without jeopardizing stability and clinical outcomes most likely because of a slowly progressing osseous replacement. Extraosseous CaP cement material because of leakages during the kyphoplasty procedure is almost completely resorbed as early as 2 years after the leakage occurred. Therefore, CaP cement is an important alternative to PMMA-based cement materials utilized for kyphoplasty of osteoporotic vertebral fractures.

Effect of an Outer Sleeve on an Inflatable Balloon Tamp in Terms of Height Restoration Under Simulated Physiological Load.

An in vitro biomechanical study. The aim of this study was to determine the effect of an optional sleeve on height restoration and compare it with the fracture reduction achieved by a commercially available inflatable bone tamp under simulated physiological load (110 N). Loss of reduction after bone tamp deflation before cement injection still remains a concern. The optional sleeve surrounds the bone tamp to help maintain height during the kyphoplasty procedure while filling the created cavity with bone cement on the contralateral side. Eighteen osteoporotic vertebral bodies (VBs) (T11-L4) were alternately assigned to 1 of the 2 treatment groups: group A: KYPHON (Kyphon Inc.) and group B: AFFIRM with sleeve (Globus Medical Inc.). The VBs were compressed axially at a rate of 5 mm/min until compressed to 40% of the initial anterior height. The fractured VBs then underwent kyphoplasty with cement augmentation while still maintaining load (110 N). The augmented VBs were then recompressed and anterior VB height (mm) and wedge angle (degrees) were measured initially after mechanically creating an anterior wedge fracture, and after repairing the compression fracture. The effect of kyphoplasty on vertebral height, kyphotic angle, cement volumes, and inflation pressures were compared between the treatment groups. Failure load (N) data were compared between intact and repaired VBs. Average percentage of lost VB height restored in group A was 30%, compared with 56% for group B. The mean changes in wedge angle were similar to those of vertebral height measurements. No significant difference in mean inflation pressures (group A: 175±37 psi; group B: 160±36 psi) were found between the 2 groups. Average percentage increase in failure load was 241% and 212% in groups A and B, respectively. Some height restoration was observed using the commercially available bone tamp in fractured VBs under simulated physiological load. The use of an outer sleeve significantly enhanced height restoration compared with the inflatable bone tamp alone.

Effect of Bone Cement Volume Fraction on Adjacent Vertebral Fractures After Unilateral Percutaneous Kyphoplasty.

A retrospective study. Complications of the bone cement used in vertebroplasty and kyphoplasty procedures have received increasingly more attention, especially for bone cement volume. The aim of the study was to retrospectively assess the relationship between bone cement volume fraction and adjacent vertebral fracture (AVF) after unilateral percutaneous kyphoplasty (PKP). Between 2006 and 2011, 495 patients with single-level osteoporotic vertebral compression fracture (OVCF) were surgically treated by unilateral PKP and had completed 12-month follow-up in our hospital. According to the new OVCF, they were divided into 3 groups: AVF group, non-AVF group, and normal group (who were not new OVCF). On the basis of the value of the plain radiography, the cement volume fraction for the vertebral body was calculated, and cement leakage, bone mineral density, visual analog scale, and Cobb angle of preoperative and postoperative were analyzed. During the follow-up, 110 (22.2%) patients had new OVCF, and others were normal (n=385). Fifty-two cases were AVF and 58 were non-AVF. The cement volume fraction of AVF group, non-AVF group, and normal group were 32.5%±5.5%, 27.3%±1.8%, and 27.1%±2.6%, respectively. The 95% confidence interval of volume fraction were (31.0, 34.1), (26.8, 27.7), and (26.9, 28.5), respectively. The AVF group showed higher cement volume fraction in 3 groups (P<0.05), and there were no significant difference between non-AVF and normal group (P>0.05). There were 19 (36.5%) patients with cement leakage in AVF group, 12 (20.7%) in non-AVF group, and 68 (17.7%) in normal group. The AVF group showed higher cement leakage (P<0.05). Compared with AVF group and normal group, non-AVF group had lower bone mineral density in preoperation. All groups reported significantly improved visual analog scale scores and Cobb angle on the day of surgery. However, there were no significant difference between the 3 groups. Unilateral PKP is an effective and safe procedure for patients with OVCF. However, cement volume should be determined in terms of the vertebral body fraction to obtain a favorable outcome. The risk of AVF and cement leakage will increase obviously with the cement volume fraction increased. We recommend that a bone cement volume fraction of about one fourth is suitable for unilateral PKP.

Trends in Inpatient Vertebroplasty and Kyphoplasty Volume in the United States, 2005-2011: Assessing the Impact of Randomized Controlled Trials.

Retrospective analysis of the Nationwide Inpatient Sample, 2005-2011. To identify trends in procedural volume and rates in the time period surrounding publication of randomized controlled trials (RCTs) that examined the utility of vertebroplasty and kyphoplasty. Vertebroplasty and kyphoplasty are frequently performed for vertebral compression fractures. Several RCTs have been published with conflicting outcomes regarding pain and quality of life compared with nonsurgical management and sham procedures. Four RCTs with discordant results were published in 2009. The Nationwide Inpatient Sample provided longitudinal, retrospective data on United States' inpatients between 2005 and 2011. Inclusion was determined by a principal or secondary International Classification of Diseases, Ninth Revision, Clinical Modification code of 81.65 (percutaneous vertebroplasty) or 81.66 (percutaneous vertebral augmentation; "kyphoplasty"). No diagnoses were excluded. Years were stratified as "pre" (2005-2008) and "post" (2010-2011) in relation to the 4 RCTs published in 2009. Patient, hospital, and admission characteristics were compared using Pearson χ test. The estimated annual inpatient procedures performed decreased from 54,833 to 39,832 in the pre and post periods, respectively. The procedural rate for fractures decreased from 20.1% to 14.7% (P<0.0001). Patient and hospital demographics did not change considerably between the time periods. In the post period, weekend admissions increased (34.2% vs. 12.4%, P<0.0001), elective admissions decreased (21.4% vs. 40.0%, P<0.0001), routine discharge decreased (33.0% vs. 52.1%, P<0.0001), and encounters with ≥3 Elixhauser comorbidities increased (54.5% vs. 39.1%, P<0.0001). The absolute rate of inpatient vertebroplasty and kyphoplasty procedures for fractures decreased 5% in the period (2010-2011) following the publication of 4 RCTs in 2009. The proportion of elective admissions and routine discharges decreased, possibly indicating a population with greater disease severity. Although our analysis cannot demonstrate a cause-and-effect relationship, the decreased inpatient volume and procedural rates surrounding the publication of sentinel negative RCTs is clearly observed.

A Case Report for a Mortality Following Kyphoplasty: Suggested Method of Prevention

Study design: A case report and review of literature. Objective: To discuss the implementation of a bilateral cannula venting technique to prevent perioperative mortality and morbidity related to kyphoplasty. Summary of background data: Several authors have suggested various recommendations for techniques to lower complications related to kyphoplasty, such as specific cement types, consistencies, volumes, and intravertebral pressures. However, there are few commentaries regarding venting during kyphoplasty as a method to reduce complications, such as embolism. Methods: A 69-year-old male suffered acute cardiac decompensation and arrest during a kyphoplasty procedure, ultimately resulting in his death. Results: Autopsy report from the coroner’s office revealed the cause of death as a pulmonary fat and bone marrow embolism. In response to this event, the attending physician and his partners began venting during the kyphoplasty procedure, using a bilateral cannula technique. Conclusion: The bilateral venting modification has been adopted as the standard of practice with the senior author and his local colleagues. Since implementing this technique, the group of surgeons has successfully performed over 1000 kyphoplasty surgeries without any resulting in perioperative mortality or morbidity.

A Longitudinal Cohort Investigation of the Development of Symptomatic Adjacent Level Compression Fractures Following Balloonassisted Kyphoplasty in a Series of 726 Patients

Background: Balloon-assisted kyphoplasty (BAK) is a well-accepted treatment for symptomatic vertebral compression fractures (VCF) secondary to osteoporosis. Some have raised a concern of an increased incidence of adjacent fractures due to alterations in spine biomechanics after cement augmentation. The incidence of subsequent VCFs following BAK is poorly understood. The aim of this study was to investigate the timing, location, and incidence of new VCFs following BAK and to identify risk factors associated specifically with the occurrence of new adjacent level fractures. Objectives: The study was performed to determine the incidence of symptomatic subsequent adjacent and remote level compression fractures in a cohort of patients undergoing BAK. Study Design: Longitudinal cohort investigation at an academic medical center and a central referral center for VCFs. Setting: A consecutive single surgeon series of 726 patients with osteoporotic compression fractures. Methods: A prospectively collected cohort of 726 patients who underwent BAK between 2001 and 2014 for osteoporotic VCFs was evaluated. Seventy-seven patients were identified who underwent a second BAK for a new compression fracture and were include in the present series. The indication for BAK treatment was pain unresponsive to non-surgical management for all cases. Variables were recorded for each patient, including the time between index and subsequent fracture, fracture level, and number of initial fractures as well as with tobacco use, body mass index (BMI), and chronic steroid use. Results: Seventy-seven of 726 patients (10.6%) underwent a second BAK procedure on average 350 days following the initial procedure (range 21 to 2,691 days). Third and fourth procedures were less common, treated in 11 and 3 patients, respectively. Forty-eight of 77 patients (62%) suffered a fracture at a level immediately adjacent to the index level at mean time of 256 days. Remote level fractures were treated at a mean time of 489 days, but no statistical difference was noted. There was no statistically significant difference between tobacco use, BMI, and chronic steroid use between patients suffering from remote and adjacent level VCFs. Limitations: This was not a population based study, and the true incidence of subsequent fractures after BAK might be underestimated by this analysis. Conclusions: Symptomatic compression fractures after BAK are relatively uncommon and may occur long after the initial kyphoplasty procedure. Only half of subsequent fractures occur immediately adjacent to the initially treated level; the others occur remotely. Patients with a single symptomatic thoracic or lumbar fracture suffered from remote and adjacent level fractures equally. In contrast, all patients who suffered both a thoracic and lumbar fracture at the same time had a second fracture at an adjacent level. Specific risk factors for remote versus adjacent level fractures could not be determined. Key words: Balloon kyphoplasty, cement augmentation, osteoporosis, vertebral compression fracture, adjacent level fracture, vertebroplasty

Analysis of vertebral augmentation practice patterns: a 2016 update

ObjectiveTo evaluate procedure utilization patterns for vertebroplasty and kyphoplasty in the US Medicare population from 2004 to 2014.MethodsThe analysis was performed using the Centers for Medicare and Medicaid Services database...

Transforaminal Endoscopic Solution to a Kyphoplasty Complication: Technical Note

Kyphoplasty is a minimally invasive spine surgical procedure performed to stabilize and treat the pain caused by a spine compression fracture. Complications are rare with kyphoplasty and include cement extrusion into the vertebral canal leading to spinal cord or nerve root compression. Herein, the authors present a case of a 72-year-old woman who presented with symptoms of a right L2 radiculopathy after a kyphoplasty procedure. Computed tomography imaging showed leakage of the kyphoplasty cement into the neural foramen above and medial to the right L2 pedicle. A transforaminal endoscopic surgical approach was used to remove the cement and decompress the L2 nerve. The patient's postoperative clinical course was uneventful. Clinicians should be aware that for the treatment of complications to vertebroplasty and kyphoplasty procedures, minimally invasive transforaminal endoscopic surgery is one option to avoid the destabilizing effects of laminectomy and facetectomy.

Outcome of Kyphoplasty in Vertebral Compression Fractures for Multiple Myeloma

Introduction The principle symptoms in multiple myeloma result from bone destruction, especially the spine. Kyphoplasty is a new technique that involves the introduction of inflatable bone tamps (IBT) into the vertebral body. The purpose of the IBT is to restore the vertebral body back toward its original height, while creating a cavity that can be filled with highly viscous bone cement. The aim was to evaluate clinical and radiological outcome of kyphoplasty in the treatment of osteolytic vertebral compression fractures resulting from multiple myeloma. Material and Methods 10 (Ten) patients underwent consecutive kyphoplasty procedures in 13 vertebrae for osteolytic vertebral compression fractures resulting from multiple myeloma. Cement leakage and any complications were recorded. Early objective analysis was made by comparing preoperative and latest VAS and ODI scores. Height restoration was estimated by measuring vertebral height on lateral radiographs. Results The mean age of patients was 62years, mean duration of symptoms was 8 months, and mean follow-up was 7.4 (range 6–12) months. There were no major complications related directly to use of this technique. On average, 40% of height lost at the time of fracture was restored. Asymptomatic cement leakage occurred at one level in one patient. Significant improvement in VAS and ODI scores were observed. Conclusion Kyphoplasty was efficacious in the treatment of osteolytic vertebral compression fractures resulting from multiple myeloma. Kyphoplasty is associated with early clinical improvement of pain and function as well as some restoration of vertebral body height.

Eye lens dosimetry in anesthesiology: a prospective study.

The eye lens is one of the most sensitive organs for radiation injury and exposure might lead to radiation induced cataract. Eye lens dosimetry in anesthesiology has been published in few clinical trials and an active debate about the causality of radiation induced cataract is still ongoing. Recently, the International Commission on Radiological Protection (ICRP) recommended a reduction in the annual dose limit for occupational exposure for the lens of the eye from 150 to 20mSv, averaged over a period of 5years, with the dose in a single year not exceeding 50mSv. This prospective study investigated eye lens dosimetry in anesthesiology practice during a routine year of professional activity. The radiation exposure measured represented the exposure in a normal working schedule of a random anesthesiologist during 1month and this cumulative eye lens dose was extrapolated to 1year. Next, eye lens doses were measured in anesthesiology during neuro-embolisation procedures, radiofrequency ablations or vertebroplasty/kyphoplasty procedures. The eye lens doses are measured in terms of the dose equivalent H p(3) with the Eye-D dosimeter (Radcard, Poland) close to the right eye (on the temple). In 16 anesthesiologists, the estimated annual eye lens doses range from a minimum of 0.4mSv to a maximum of 3.5mSv with an average dose of 1.33mSv. Next, eye lens doses were measured for nine neuro-embolisation procedures, ten radiofrequency ablations and six vertebroplasty/kyphoplasty procedures. Average eye lens doses of 77±76µSv for neuro-embolisations, 38±34µSv for cardiac ablations and 40±44µSv for vertebro-/kyphoplasty procedures were recorded. The maximum doses were respectively 264, 97 and 122µSv. This study demonstrated that the estimated annual eye lens dose is well below the revised ICRP's limit of 20mSv/year. However, we demonstrated high maximum and average doses during neuro-embolisation, cardiac ablation and vertebro-/kyphoplasty procedures. With radiation induced cataract being explained as a possible stochastic effect, without a threshold dose, anesthesiologists who regularly work in a radiological environment should remain vigilant and maintain radiation safety standards at all times. This includes adequately protective equipment (protection shields, apron, thyroid shield and leaded eye wear), keeping distance, routine monitoring and appropriate education.

Clinical evaluation of percutaneous kyphoplasty in the treatment of osteolytic and osteoblastic metastatic vertebral lesions

Percutaneous vertebral augmentation (Percutaneous vertebroplasty, PVP and Percutaeous kyphoplasty, PKP) for the treatment of metastatic spinal lesions has been considered as a preferred alternative to relieve pain and rebuild spinal stabilization relying on minimally invasive procedure. However, there have been few reports on clinical outcomes of percutaneous kyphoplasty in the treatment of osteolytic and osteoblastic metastatic vertebral fracture. We report our experience for 81 kyphoplasty procedures performed in 45 patients with thoracic and lumbar vertebral lesions caused by metastases. 4 out of the 45 patients were withdrawn at 1-year follow-up. 41 patients demonstrated good clinical result. The osteoblastic group performed a better pain relief in visual analog scale (VAS) score after the treatment than the osteoclastic group 3 days, 1 month, 3 months and 1 year after the KP. And the Oswestry Disability Index (ODI) scores of the osteoblastic group is lower than that of the osteoclastic group just in 3 days after the KP. And there were no significant difference between the two groups of ODI scores 1 month, 3 month and 1 year after the KP. And there were no statistical differences of the radiographic parameters including VB height variation and local kyphosis angle (LKA) between the two groups. Kyphoplasty results in an effective, minimally invasive procedure for the stabilization of thoracic and lumbar metastatic vertebral lesions, including both osteoblastic and osteoclastic types, which achieves statistically significant pain relief, function improvement, preventing further local kyphotic deformity, and VB height.

Vertebral Augmentation After Recent Randomized Controlled Trials: A New Rise in Kyphoplasty Volumes

PurposeIn 2009, the results of two randomized controlled trials refuting the effectiveness of vertebroplasty compared with sham procedures were published in a leading journal. The purpose of the present study was to evaluate the impact of these randomized trials on subsequent volume and utilization rates of vertebral augmentation (VA) in the United States. MethodsUsing nationwide Medicare Part B databases, Current Procedural Terminology, version 4, codes for thoracic and lumbar vertebroplasty and kyphoplasty were studied from 2006 to 2013 (codes 22520 to 22525). The total volumes of procedures were determined and utilization rates were calculated. Volumes and rates by provider specialty were also studied. ResultsThe total volume of VA procedures peaked in 2008 at 101,807 and thereafter fell steadily to 80,940 in 2013. The utilization rates per 100,000 beneficiaries also showed a similar trend. Radiologists performed the largest number of VA procedures in 2013 (33,618 procedures [42%]), followed by orthopedic surgeons (19,886 procedures [25%]). After 2009, vertebroplasty volumes decreased sharply. Kyphoplasty volumes increased in 2011, after an initial decrease in 2010. The divergent trend in the volumes of the two procedures persisted through 2013. ConclusionsAfter the publication of the two trials’ results in 2009, vertebroplasty volumes and rates decreased sharply. However, there is an emerging trend toward performing more kyphoplasty procedures, mitigating the decrease in total volume of VA procedures. Radiologists have the strongest role in performing these procedures among all medical specialties.

Cardiac Perforation Caused by Cement Embolus After Total Hip Replacement

A 77-year-old woman was transferred to our hospital with persistent chest pain. She had no previous history of coronary heart disease. Two months earlier, she had undergone a complication-free hip replacement surgery with a cemented prosthesis. On admission, she was nearly asymptomatic, but because of elevated cardiac troponin and ST-segment elevation in the inferior and lateral leads, a coronary angiography was performed, which showed normal coronary arteries. However, fluoroscopy revealed a thin, opaque structure apparently overlying the heart. After 2 hours of observation, signs and symptoms of pericarditis were noted, and shortly thereafter, worsening ensued with progression to cardiac tamponade. After percutaneous evacuation of 250 mL blood from the pericardial cavity, her clinical condition normalized. A computed tomography scan was performed …

Biomechanical aspects of vertebral augmentation

With increasing age, bone mass decreases and the structure of the cancellous bone in the vertebral body changes. Especially in osteoporotic patients, but also with metastases in the vertebral body, this leads to decreased strength and, thus, to an increased risk of vertebral fractures. It is expected that this problem will increase significantly because of demographic developments. To treat or to prevent such vertebral fractures, different augmentation techniques have been developed. They can mainly be divided into vertebroplasty or kyphoplasty procedures. The goal of this paper is to summarize biomechanical aspects of these augmentations procedures and to present some alternative methods. With vertebroplasty, the loss of bone mass is balanced by injecting bone cement which improves the failure strength of the affected vertebral body. With kyphoplasty, cavities are created and these are filled with bone cement. Disadvantages of vertebroplasty are uncontrollable cement extrusion and increased fracture risk in the adjacent vertebral bodies. With balloon kyphoplasty, the adjacent cancellous bone is compacted during dilation and, thus, does not allow good integration with the remaining trabeculae. In addition, this method is associated with an increased risk of fracture in the adjacent vertebrae. To counter these disadvantages, a number of new types of cement and alternative augmentation methods are being developed, with which the vertebral body may be filled or distracted. The efficacy of these new methods should be tested in appropriate experimental biomechanical studies before they are used in patients.

Outcome of percutaneous balloon kyphoplasty in vertebral compression fractures.

Background:Incidence of vertebral compression fractures (VCFs) is increasing due to increase in human life expectancy and prevalence of osteoporosis. Vertebroplasty had been traditional treatment for pain, but it neither attempts to restore vertebral body height nor eliminates spinal deformity and is associated with a high rate of cement leakage. Balloon kyphoplasty involves introduction of inflatable balloon into the fractured body of vertebra for elevation of the end-plates prior to fixation of the fracture with bone cement. This study evaluates short term functional and radiological outcomes of balloon kyphoplasty. The secondary aim is to explore short-term complications of the procedure.Materials and Methods:A retrospective study of 199 kyphoplasty procedures in 135 patients from March 2009 to March 2012 were evaluated with short form-36 (SF-36) score, visual analogue scale (VAS), detailed neurological and radiological evaluations. The mean followup was 18 months (range 12–20 months). Statistical analysis including paired sample t-test was done with statistical package for social sciences.Results:Statistically significant improvements in SF-36 (from 34.29 to 48.53, an improvement of 14.24, standard deviation (SD) - 20.08 P < 0.0001), VAS (drop of 4.49, from 6.74 to 2.24, SD - 1.44, P < 0.0001), percentage restoration of lost vertebral height (from 30.62% to 16.19%, improvement of 14.43%, SD - 15.37, P < 0.0001) and kyphotic angle correction (from 17.41° to 10.59°, improvement of 6.82, SD - 7.26°, P < 0.0001) were noted postoperatively. Six patients had cement embolism, 65 had cement leak and three had adjacent level fracture which required repeat kyphoplasty later. One patient with history of ischemic heart disease had cardiac arrest during the procedure. No patients had neurological deterioration in the followup period.Conclusions:Kyphoplasty is a safe and effective treatment for VCFs. It improves physical function, reduces pain and corrects kyphotic deformity.

TH-AB-201-07: Reducing Fluoroscopy Operator Dose by Placing Lead Aprons On the Patient: Does It Live Up to the Hype?

Purpose: Staff radiation exposure during interventional fluoroscopy procedures is an ongoing concern. Recent studies tout reduced radiation exposure to fluoroscopy operators through the use of lead-equivalent shielding placed on the surface of the patient, claiming dose reductions of up to 75%. We sought to validate this claim when lead-equivalent shielding is wrapped around the patient's lower abdomen and upper legs during kyphoplasty. Methods: An anthropomorphic torso phantom was placed on the interventional table. The X-ray tube, detector, and table height were adjusted by a musculoskeletal radiologist who routinely performs kyphoplasty procedures. Air kerma rate (AKR) was measured using a survey meter appropriate for low-energy scattered X-rays (Unfors RaySafe) with different combinations of shielding placed on the phantom and/or in front of the survey meter. Shielding placed in front of the survey meter simulated the protective effect of an operator's own lead apron. Measurements were made at various angles and distances around the phantom; fluoroscopic acquisition parameters were constant for all measurements. Results: 1) Wrapped shielding on the phantom reduced AKR at the meter over a very limited angle — when the wrapped shielding was directly between the phantom and the survey meter (87% AKR reduction).2) No statistically significant difference in AKR was observed when the wrapped shielding was not directly between the phantom and the survey meter (p=0.97) .3) Shielding placed in front of the survey meter, representing protection of an operator's apron, reduced measured AKR by over 90% at all angles.4) Wrapped shielding did not provide additional dose savings when shielding was also placed in front of the survey meter. Conclusion: The use of wrapped shielding would not further reduce radiation exposure to an operator who is wearing a lead apron. Claims that wrapped shielding reduces staff dose may be vastly overstating the benefit to fluoroscopy operators.

Comparative study of cement leakage and related influencing factors: vertebroplasty versus kyphoplasty

Objective To test the differences of cement leakage rate, the distribution and reasons of leakage between vertebroplasty and kyphoplasty technique on vertebral body specimens. Methods Forty vertebral body specimens were made into compression fracture model for further test: 20 of them were treated with vertebroplasty(group A),and the rest 20 specimens were proceeded to kyphoplasty procedure (group B). After surgical treatment, cement leakage and the distribution of cement were identified with reference of CT scan and recorded. Statistical softwares were employed to analyze the data, and differences was regarded as statistically significant when P<0.05. Results Eight cases(40%)of cement leakage were observed in 20 specimens of group A and 3 cases(15%)in group B respectively.χ2 test was used for the comparison of leakage rate, and it was found there was no statistically significant difference(P> 0.05). But it could show a trend:the rate of leakage after kyphoplasty was lower. Conclusion Using a kyphoplasty technique can gain lower leakage rate and higher safety than vertebroplasty. Special attentions should be paid to the pressure of balloon and the distribution of bone cement during surgical procedure. The application of high viscosity bone cement can prevent the leakage of cement effectively. Key words: Vertebroplasty; Kyphoplasty; Bone cement leakage

Vertebral fracture assessment: Current research status and application in patients with kyphoplasty

Imaging of the spine is of paramount importance for the recognition of osteoporotic vertebral fractures (VFs), and standard radiography (SR) of the spine is the suggested diagnostic method but is not routinely used because of the cost and radiation exposure considerations. VF assessment (VFA) is an efficient, low radiation method for identifying VFs at the time of bone mineral density (BMD) measurement. Prediction models used to indicate the need for VFA may have little predictive power in subspecialty referral populations such as rheumatologic patients or patients who underwent kyphoplasty. Rheumatologic patients are frequently at increased risk for VFs, and VFA should be performed on an individual basis, also taking in account the guidelines for the general population. Kyphoplasty is a new minimal invasive procedure for the treatment of VFs and is being performed with increasing frequency. Following kyphoplasty, there may be a risk of new VFs in adjacent vertebrae. The assessment and follow-up of patients who underwent kyphoplasty requires repetitive X-ray imaging with the known limitations of SR. Thus, VFA may facilitate the evaluation of VFs in these patients because most of the kyphoplasty patients would fulfill the criteria. In a pilot study, we measured the BMD and performed VFA in 28 patients treated with kyphoplasty. Ratios of anterior to posterior (A/P) and middle to posterior (M/P) height were measured, and Genant's method was used to classify vertebrae accordingly. Intraobserver and interobserver reliability for A/P, M/P and the Genant's method were determined. Only 1 patient did not meet the criteria for VFA. Of the 364 available vertebrae, 295 could be analyzed. Most missing data (concerning 69 vertebrae) occurred in the upper thoracic region. Three of the 69 non-eligible vertebrae were lumbar vertebrae with cement leakage from the kyphoplasty procedure. In our hands, VFA was highly reproducible, demonstrating very good agreement in terms of intraobserver and interobserver reliability. Agreement was very good on the vertebral level, "vertebrae with kyphoplasty" level and "2 above and 1 below the kyphoplasty vertebrae" level. The application of Genant's method to these patients also resulted in perfect agreement. We believe that the potential value of VFA in patients treated with kyphoplasty requires further evaluation, particularly comparing VFA with SR and performing a longitudinal follow-up. More research will help to adopt care processes that determine which patients require VFA and how often VFA should be performed, while also considering the impact of this technique on the cost of healthcare organizations.

Prone position in balloon kyphoplasty leads to no secondary vertebral compression fractures in osteoporotic spine - a MRI study.

Purpose: Vertebral compression fractures are the most common fractures in the elderly. Long lasting pain and deformity is responsible for consecutive impairment with markedly reduced life quality, increased morbidity and mortality. The beneficial effects of balloon kyphoplasty are verified in many studies. Subsequent fracture risk is not finally clarified, cement related risks and deformity related risks are discussed. There is less knowledge about the risk of bone marrow edema and new fractures during balloon kyphoplasty procedure. The goal of this study is to examine, if prone position during kyphoplasty is an independent risk factor for new fractures in the osteoporotic spine. Methods: Consecutive MRI study of 20 patients with fresh, non-traumatic thoracolumbar vertebral compression fractures and balloon kyphoplasty treatment. MRI Scans of the thoracolumbar spine were obtained after surgery, before patients have been mobilized. Specific MRI changes like new bone marrow edema, signal intensity changes in adjacent and remote segments and new fractures were assessed by specialized neuro-radiologist. Results: 20 MR images were examined within 48 hours after balloon kyphoplasty procedure. 85% did not show bone marrow edema extent changes after kyphoplasty. We found minor increase of bone marrow edema within the augmented vertebral body in 3 cases. We did not find any new bone marrow edema and no new fractures in adjacent and remote segments after balloon kyphoplasty treatment.Conclusion: Prone position leads to no new bone marrow edema and no new fractures in the osteoporotic spine. Accordingly, prone position has no risk for adjacent level fractures in osteoporotic spines.