Institutional members access full text with Ovid®

Share this article on:

00007632-201204010-0001900007632_2012_37_e423_heo_vertebroplasty_7miscellaneous-article< 94_0_14_6 >Spine© 2012 Lippincott Williams & Wilkins, Inc.Volume 37(7)01 April 2012p E423–E429Therapeutic Efficacy of Vertebroplasty in Osteoporotic Vertebral Compression Fractures With Avascular Osteonecrosis: A Minimum 2-Year Follow-up Study[Clinical Case Series]Heo, Dong Hwa MD, PhD*; Choi, Jong Hun MD*; Kim, Moon Kyu MD, PhD†; Choi, Hyeun Chul MD, PhD*; Jeong, Je Hoon MD, PhD*; Chin, Dong Kyu MD, PhD‡; Cho, Yong Jun MD, PhD**Department of Neurosurgery, Spine Center, Hallym University Medical Center, Hallym University College of Medicine, Seoul, Korea†Department of Neurosurgery, Gangneung Asan Hospital, University of Ulsan College of Medicine, Gangneung, Korea‡Department of Neurosurgery, Spine and Spinal Cord Institute, Kangnam Severance Spine Hospital, Yonsei University College of Medicine, Seoul, Korea.Address correspondence and reprint requests to Jong Hun Choi, MD, Department of Neurosurgery, Kangnam Sacred Heart Hospital, College of Medicine, Hallym University, 948-1 Daerim-1 Dong, Yeongdeungpo-gu, Seoul, 150-950, Korea; E-mail: jonghun90@empal.comAcknowledgment date: March 22, 2011. First revision date: July 8, 2011. Acceptance date: August 25, 2011.The manuscript submitted does not contain information about medical device(s)/drug(s).No funds were received in support of this work. No benefits in any form have been or will be received from a commercial party related directly or indirectly to the subject of this manuscript.AbstractStudy Design. A retrospective review of clinical and radiological parameters.Objective. To assess for at least 2 years the radiological and clinical outcomes of patients who underwent polymethylmethacrylate (PMMA) vertebroplasty to treat osteoporotic vertebral compression fractures with avascular necrosis.Summary of Background Data. Recently, osteoporotic vertebral compression fractures with avascular osteonecrosis have been treated with percutaneous vertebroplasty. However, there have been no previous multiyear, clinical, and radiological studies of the results of vertebroplasty in the vertebral body with noninfected avascular osteonecrosis.Methods. Thirty patients were followed for at least 2 years after vertebroplasty. We retrospectively reviewed several parameters, including visual analogue scale score, Oswestry Disability Index, compression ratio, kyphotic angle, injection pattern of PMMA (interdigitation and solid mass), and morphological changes of the PMMA-cemented vertebral bodies.Results. The vertebral height and kyphotic angle were significantly corrected after vertebroplasty. However, the restored vertebral height recollapsed (P < 0.05), and the kyphotic angle became aggravated (P < 0.05) during the 2 years or longer of postoperative follow-up. Visual analogue scale and Oswestry Disability Index were significantly decreased at postoperative day 1. However, visual analogue scale and Oswestry Disability Index were significantly increased at 24 months postoperatively. There were 4 kinds of morphological changes of the injected PMMA-cemented vertebral body, including heterotopic ossification, fusion with the adjacent vertebral body, bone cement fragmentation and migration, and development of a radiolucent line around the PMMA mass in the vertebral body.Conclusion. After vertebroplasty, the compression and kyphosis of avascular necrotic vertebral bodies progressed continuously for 2 years or longer. Vertebroplasty may not provide sufficient stability. Therefore, we strongly recommend that strict observation and follow-up be used after vertebroplasty.Posttraumatic avascular osteonecrosis of a vertebral body occurring in a delayed fashion was first described by Kummell in 1895. Characteristic magnetic resonance imaging (MRI) findings of noninfected avascular osteonecrotic vertebral fractures show a collection of intravertebral fluid or the presence of conjunction with air.1,2 Avascular osteonecrosis, an intravertebral vacuum phenomenon, may be a relatively uncommon condition of osteoporotic compression fractures.3Recently, percutaneous vertebroplasty using polymethylmethacrylate (PMMA) has been attempted to repair compression fractures with avascular necrosis.1,3–7 Several studies have reported that vertebroplasty to treat an osteoporotic vertebral compression fracture with avascular necrosis is highly effective.1,3–7 However, these studies reported no long-term clinical and radiological results of vertebroplasty applied to a vertebral body with noninfected avascular osteonecrosis.The purpose of this study, therefore, was to assess for at least 2 years the radiological and clinical outcomes of patients who underwent PMMA vertebroplasty to treat osteoporotic vertebral compression fractures with avascular necrosis.MATERIALS AND METHODSThis study was designed as a retrospective review of clinical and radiological parameters. From January 2006 to October 2007, 86 patients who had osteoporotic compression fractures with avascular necrosis were treated by vertebroplasty with PMMA in 5 hospitals of our university medical center. Among these patients, we included only those who had a single-level osteoporotic vertebral compression fracture and were able to be followed for more than 2 years. We excluded the patients who had clinical histories of bone metabolic disorders or malignancies. A total of 30 levels in 30 patients were enrolled in our study. Before vertebroplasty, we performed x-ray films, measured bone mineral density, and performed MRI and radionuclide bone scanning to define acute osteoporotic compression fractures with avascular osteonecrosis in all enrolled patients.We performed a PMMA vertebroplasty after postural reduction of the compressed vertebral body.8 And, we used a transpedicular approach (bipedicular needle insertion) in 13 patients and an extrapedicular approach in 17 patients.We performed this investigation in accordance with our institutional guidelines, which comply with international laws and policies (Hallym University Institutional Review Board, #2009-48).Analysis of Radiological ParametersWe retrospectively reviewed preoperative radiological studies to evaluate the presence of avascular osteonecrosis in the vertebral body, which was defined as the collection of intravertebral fluid or the presence of conjunction with air, as seen via MRI. An MRI finding of intravertebral fluid was defined as an area of hypointensity on T1-weighted images and hyperintensity on T2-weighted images, and intravertebral air was defined as an area of hypointensity or a signal intensity void on T1- and T2-weighted images.2,9We reviewed radiological parameters, such as the compression ratio, kyphotic angle, injection patterns of PMMA cement, and morphological changes of the PMMA-cemented vertebral bodies.10We reviewed serial follow-up plain radiographs immediately after the vertebroplasty, and postoperatively at 12 months and 24 months or more (the final follow-up period). We analyzed the morphological changes of the PMMA-cemented vertebral bodies in the serial follow-up plain x-ray films. The anterior and posterior heights of the fractured vertebral body with avascular osteonecrosis were assessed to calculate the compression ratio (anterior/posterior height; anterior/posterior ratio) before and after the vertebroplasty.10 The kyphotic angle was measured using an angle between the lower end plate of the upper vertebral body and the lower end plate of the affected vertebral body. All our 5 institutes have used the same Picture Archiving and Communication System and its computer software (PiViewSTAR 5.0, INFINITT, Seoul, Korea) in the department of radiology. All heights and angles were measured using the same Picture Archiving and Communication System and its computer software.The degree of compression progression of the cemented vertebral bodies, which is the compression ratio difference between the immediate postvertebroplasty measurement and the follow-up period measurements (12 months postoperative, and the final follow-up period after the vertebroplasty), was calculated for all of the patients. The difference between compression ratios measured at 12 months after the vertebroplasty and at the final follow-up period was calculated as well. We compared each of the compression ratio differences.10Injection patterns of PMMA were classified as 2 types, solid mass with and without interdigitation. “Interdigitation” describes the pattern formed when PMMA is interspersed throughout the trabeculae, and “solid mass” describes the pattern seen when PMMA is lumped without interspersion.6,11 Polymethylmethacrylate-cemented vertebral bodies with osteonecrosis were classified into 2 groups as injection patterns of PMMA. Vertebral bodies that had solid masses with interdigitation patterns of injected PMMA cement were assigned to the “interdigitation group,” and vertebral bodies, which showed patterns of injected PMMA cement as only a solid mass without interdigitation, were assigned to the “solid mass group.” We compared the compression ratio differences between the 2 groups.Analysis of Clinical ParametersWe retrospectively reviewed the preoperative clinical parameters such as age, sex, bone mineral density, filler material (PMMA) volume, compliance with osteoporosis medications, visual analogue scale (VAS) score of the back, Oswestry Disability Index (ODI), and development of neurological symptoms. We checked the VAS score of the back preoperatively and postoperatively at 1 day, 12 months, and 24 months or more (the final follow-up period). We compared the preoperative VAS scores with the immediate postoperative scores and also compared the immediate postoperative VAS scores with the VAS score of 12 months postoperative and of the final follow-up period after vertebroplasty.10Statistical AnalysisWe used a nonparametric statistical analysis because of the small sample size. Statistical analysis was performed using the Fisher exact test, the Mann-Whitney U test, and the Wilcoxon rank sum test. P < 0.05 was considered statistically significant. SPSS 12.0 for Windows (SPSS, Chicago, IL) was used for the statistical analysis.RESULTSThe mean age of the patients was 70.73 ± 6.36 years (25 women and 5 men). The mean follow-up period was 25.13 ± 1.50 months (24–29 months).The treated levels were distributed from T10 to L3: 2 in T10, 2 in T11, 13 in T12, 12 in L1, and 1 in L3. The mean T score of the bone mineral density was −3.54 ± 0.64. The mean volume of the injected PMMA cement was 3.91 ± 0.82 mL (Table 1).TABLE 1. Characteristics of PatientsRecollapse of the Cemented Vertebral Body After VertebroplastyThe mean corrected kyphotic angle and restored compression ratio of fractured vertebrae before and after vertebroplasty were 5.00° ± 3.89° and 0.17 ± 0.13. Vertebral height and kyphotic angle were significantly corrected after vertebroplasty (P < 0.05). However, restored vertebral height was found to have recollapsed during the 2 years or more of postoperative follow-up. Twenty-six of 30 patients (86.7%) developed progression of the compression of the PMMA-augmented vertebral bodies after vertebroplasty. Progression of the compression of the cemented vertebral bodies was confirmed by serial follow-up plain x-ray films. The immediate postoperative mean compression ratio was 0.69 ± 0.10 and had decreased to 0.59 ± 0.10 at 1 year after the vertebroplasty. Furthermore, the mean postoperative compression ratio continued to decrease to 0.55 ± 0.11 at 2 years after the vertebroplasty (P < 0.05, Table 2).TABLE 2. Changes of Compression Ratio and Kyphotic Angle of Treated Vertebrae and Visual Analogue Scale ScoreAlso, the kyphotic angle was found to be aggravated during the 2 years or more of follow-up. The immediate postoperative mean kyphotic angle was 8.54° ± 4.50° and had increased to 11.77° ± 4.79° at 1 year after the vertebroplasty. The postoperative mean kyphotic angle continued to increase to 13.62 ± 5.66° at 2 years after the vertebroplasty (P < 0.05, Table 2).There were 12 patients in the interdigitation group and 18 patients in the solid mass group. We compared the mean differences of compression ratios of cemented vertebral bodies and mean kyphotic angles between the “interdigitation group” and the “solid mass group.” The mean difference between the compression ratios taken immediately postoperative and during the final follow-up period was 0.08 ± 0.08 in the interdigitation group and 0.19 ± 0.08 in the solid mass group. The mean difference in compression ratios of the solid mass group was significantly higher than that of the interdigitation group (P < 0.05, Table 3). The mean difference in measurements of the kyphotic angle taken immediately postoperative and during the final follow-up period was 2.54° ± 3.57° in the interdigitation group and 6.77° ± 3.10° in the solid mass group. The mean difference of the kyphotic angle of the solid mass group was significantly higher than that of the interdigitation group (P < 0.05, Table 3).TABLE 3. Relationship Between Injection Patterns of Polymethylmethacrylate and Recollapse of Treated VertebraeOnly 14 of the 30 patients (46.7%) had maintained strict, regular, good compliance with their osteoporosis medications after the vertebroplasty. However, 11 of these 14 patients (78.6%) with good compliance with their osteoporosis medications still showed progression of the compression of the augmented vertebrae (P > 0.05).Postoperative Morphological Changes of the Cemented Vertebral BodyFifteen of 30 patients (50.0%) showed 20 cases of morphological changes of PMMA-cemented vertebral bodies during the follow-up period, and 15 patients (50.0%) did not. There were 4 kinds of morphological changes observed in the injected PMMA-cemented vertebral body including heterotopic ossification, fusion with the adjacent vertebral body, bone cement fragmentation and migration, and development of a radiolucent line around the PMMA mass in the vertebral body (Table 1, Figures 1 and 2).Figure 1. Lateral radiographs of an 83-year-old woman with an L1 compression fracture. A, Preoperative lateral radiograph showing L1 compression fracture with air cleft. B, Immediate postoperative lateral x-ray showing well-deposited polymethylmethacrylate cement and reexpansion of compressed vertebral body. C, 24 months after the vertebroplasty, heterotopic ossification and bone fusion developed in the vertebral body (arrow).Figure 2. Lateral plain films of a 65-year-old woman with a T12 compression fracture. A, Preoperative lateral radiograph shows a T12 compression fracture with air cleft. B, Immediate postoperative lateral plain x-ray shows good expansion of the vertebral body after vertebroplasty with postural reduction. C, 6 months after the vertebroplasty, recollapse has occurred and a radiolucent line has developed around the polymethylmethacrylate solid mass (arrow). D, 25 months after the vertebroplasty, lateral plain x-ray shows that augmented vertebrae have experienced further recollapse.There were 10 cases of heterotopic ossification formation, 2 cases of fusion with the adjacent vertebral body, 3 cases of bone cement fragmentation and migration, and 5 cases of development of a radiolucent line in the vertebral body.Clinical OutcomesThe mean preoperative VAS score was 8.83 ± 0.75, and, on postoperative day 1, it was 1.93 ± 0.83, indicating that the mean VAS score decreased significantly after the initial operation (P < 0.05, Table 2). VAS scores measured during the postoperative follow-up showed that the mean VAS scores were 2.37 ± 1.33 at 12 months postoperative and 3.00 ± 1.64 at the final follow-up appointment (more than 24 months postoperative; Table 2). The mean VAS score at 24 months postoperative was significantly higher than the mean VAS score at day 1 after the vertebroplasty (P < 0.05, Table 2). The mean ODI was 78.9 ± 7.8 preoperatively, 28.6 ± 7.3 at postoperative day 1, 33.3 ± 6.3 at 12 months postoperative, and 37.4 ± 6.9 at final follow-up appointment. Although the mean ODI was significantly decreased after the vertebroplasty, the mean ODI continued to increase at 2 years after the vertebroplasty (P ≤ 0.05, Table 2).Only 1 patient presented with a symptom of neurological compromise, which was weakness in both legs due to neural canal encroachment by recollapse of the cemented vertebral body (Figure 3). We performed emergent decompression and fusion operations to remedy this problem. Postoperatively, weakness of both legs improved completely.Figure 3. Radiological studies of a 71-year-old man with an L1 compression fracture. A, Immediate postoperative lateral plain X-ray shows good expansion of the vertebral body after vertebroplasty with postural reduction. B, 2 months after the vertebroplasty, the patient presented with weakness in both legs. A magnetic resonance image shows that the recollapsed cemented L1 vertebral body has compressed the thecal sac (arrow).DISCUSSIONAugmentation with PMMA cement for avascular osteonecrosis, as previously reported, may be effective for early relief of back pain and restoration of height of the compressed vertebral body.3–7 We agree that vertebroplasty or cement augmentation kyphoplasty appear to be good treatments for intervertebral pseudoarthrosis at the immediate postoperative state and during the early follow-up period (within 1 year). In our study, most of the enrolled patients presented with marked pain relief and good restoration of the compressed vertebral body during the immediate postvertebroplasty state. However, recollapse of the augmented vertebral body and kyphosis progressed continuously during the 2 years or longer of follow-up after vertebroplasty (Figures 1 and 2). As recollapse and kyphosis were aggravated, patients again complained of back pain. One patient, in particular, suffered neural canal encroachment that occurred with concomitant recollapse of the cemented L1 vertebrae just 2 months after vertebroplasty (Figure 3) . We performed decompression and fusion operations to help this patient.The injected PMMA mass may interfere with the healing process of osteonecrosis and fracture rather than providing stabilization.9,12 Exothermal and toxic effects of PMMA may injure the surrounding bone structure directly. Furthermore, PMMA is not a bioactive filler material and, as such, cannot be replaced by new bone formation. Therefore, the interposition of fibrous tissues between PMMA and bone may occur. Fibrotic wall formation around a PMMA mass may induce micromotion and future instability.9,12,13 These phenomena may induce recollapse of the cemented vertebral body. Thermal necrosis and outer fibrotic wall formation, the latter of which is more severe when PMMA forms as a solid lump rather than as a contiguous bone interdigitation, may aggravate the process of osteonecrosis and result in recollapse after PVP. In our study, the recollapse of vertebral bodies with a solid-mass PMMA injection pattern without interdigitation occurred more severely than in patients with PMMA solid masses with interdigitation. Furthermore, in 5 patients, a radiolucent line developed around the PMMA solid mass (Figure 2). This radiolucent line may be a lesion of thermal necrosis and outer fibrotic wall formation. All patients who presented with a radiolucent line around the PMMA solid mass developed recollapse of augmented vertebrae.The interdigitation injection pattern of PMMA and normal trabecular filling with cement have prevented recollapse of augmented vertebral bodies and aggravation of kyphosis. However, in our experience, it is difficult to perform normal trabecular bone filling with PMMA during vertebroplasty. This is because at the beginning of injection with cement, PMMA was usually filled into the osteonecrotic cavity rather than the trabecular portion, and PMMA cement may easily leak into the anterior prevertebral area, intervertebral disc, and posterior epidural space after filling PMMA into the osteonecrotic cavity. The osteonecrotic cavity may connect to the anterior prevertebral area, intervertebral disc, and posterior epidural space. We think trabecular filling with PMMA with interdigitation must be attempted during vertebroplasty. Sometimes, we can see the intravertebral vacuum cleft (radiolucent area) in the fluoroscopic view during vertebroplasty. We made an effort to place the needle tip in the portion without vacuum cleft (osteonecrotic cavity). We carefully observed whether or not interdigitation was performed after a small amount of cement was injected. If an interdigitation pattern was not seen, we slightly advanced the portion of the needle tip. After performing interdigitation of PMMA, the needle was repositioned in the osteonecrotic cavity, and we injected PMMA cement into the osteonecrotic cavity.In the follow-up period, heterotopic ossifications or heterotopic ossification and fusion with the adjacent vertebrae occurred at some PMMA-augmented vertebrae (Figure 1). We suggest that heterotopic ossification may be the result of a restabilization response. Vertebroplasty may not provide enough strength and stability in cases of compressed vertebrae with avascular necrosis. Therefore, heterotopic ossification with or without fusion may occur (Figure 1).Fragmentation and migration of the injected PMMA mass developed in 3 cases. Fragmentation of the injected PMMA cement and heterotopic ossification occurred with concomitant recollapse of the vertebrae, possibly related to the fact that vertebroplasty is not sufficient to support the compressed vertebral body with osteonecrosis. In light of phenomena such as heterotopic ossification, recollapse of augmented vertebrae, and fragmentation of injected PMMA cement, we suggested that osteoporotic vertebral compression fractures with osteonecrosis are a different pathologic condition compared with fractures without osteonecrosis, and our results should not be generalized to all vertebral compression fractures. Recently, bioactive filler materials such as calcium phosphate (CaP) have been used in vertebroplasty. Previously, CaP cement, had been used during vertebroplasty in osteoporotic vertebral compression fractures with osteonecrosis.14 However, CaP-augmented vertebral bodies were compressed, and heterotopic ossification developed and increased.14 Therefore, we did not recommend augmentation with CaP cement in compression fractures with osteonecrosis.In recent times, if patients presented with severe kyphotic change or compressed vertebral body indenting the spinal thecal sac, we have performed fusion surgeries via anterior or posterior approach regardless of the compromised neurological symptoms. However, if patients had severe comorbidity and a significant history of illness such as cardiopulmonary disease, stroke, or cancer, we have performed vertebroplasty. Also, we have emphasized and encouraged the patients to take osteoporosis medication during the follow-up period.In this study, there were several limitations. We did not have a control group that underwent conservative treatments. Therefore, the results of our study cannot be generalized to all osteoporotic compression fractures with osteonecrosis. Also, we were only able to follow a total of 30 patients. To better estabilish the clinical and radioloigcal outcomes of this procedure, more patients should be studied over an extended follow-up period. Randomized case control trials should also be evaluated.CONCLUSIONAccording to our results, in cases of osteoporotic vertebral compression fractures with osteonecrosis that manifests as an intravertebral vacuum phenomenon, pseudoarthrosis, or intravertebral fluid collection, percutaneous vertebroplasty may not effectively provide enough stability or maintain stabilization for an extended period of time. After vertebroplasty, the compression and kyphosis of avascular necrotic vertebral bodies progressed continuously during the 2 years or longer of patient follow-up.Therefore, we strongly recommend rigorous observation and extended follow-up for patients who have undergone osteoporotic vertebral compression fractures with noninfected avascular osteonecrosis after vertebroplasty. Furthermore, if any symptoms of neurological compromise appear after vertebroplasty, optimal surgical intervention should be performed.Key Points After vertebroplasty, the compression and kyphosis of avascular necrotic vertebral bodies progressed continuously during the 2 years or longer of patient follow-up. Visual analogue scale score and ODI were significantly decreased at postoperative day 1. However, VAS and ODI were significantly increased at 24 months postoperatively. There were 4 kinds of morphological changes observed in the injected PMMA-cemented vertebral body including heterotopic ossification, fusion with the adjacent vertebral body, bone cement fragmentation and migration, and development of a radiolucent line around the PMMA mass in the vertebral body. We strongly recommended rigorous observation and extended follow-up for patients who have undergone osteoporotic vertebral compression fractures with noninfected avascular osteonecrosis after vertebroplasty.References1. Libicher M, Appelt A, Berger I, et al. The intravertebral vacuum phenomenon as specific sign of osteonecrosis in vertebral compression fractures: results from a radiological and histological study. Eur Radiol 2007;17:2248–52. [CrossRef] [Full Text] [Medline Link] [Context Link]2. Yu CW, Hsu CY, Shih TT, et al. Vertebral osteonecrosis: MR imaging findings and related changes on adjacent levels. AJNR Am J Neuroradiol 2007;28:42–7. [Medline Link] [Context Link]3. Kim D, Lee S, Jang JS, et al. Intravertebral vacuum phenomenon in osteoporotic compression fracture: report of 67 cases with quantitative evaluation of intravertebral instability. J Neurosurg 2004;100:24–31. [CrossRef] [Medline Link] [Context Link]4. Becker S, Tuschel A, Chavanne A, et al. Balloon kyphoplasty for vertebra plana with or without osteonecrosis. J Orthop Surg 2008;16:14–9. [Medline Link]5. Jang J, Kim D, Lee S. Efficacy of percutaneous vertebroplasty in the treatment of intravertebral pseudarthrosis associated with noninfected avascular necrosis of the vertebral body. Spine 2003;28:1588–92. [CrossRef] [Full Text] [Medline Link]6. Lane JI, Maus TP, Wald JT, et al. Intravertebral clefts opacified during vertebroplasty: pathogenesis, technical implications, and prognostic significance. AJNR Am J Neuroradiol 2002;23:1642–6. [Medline Link] [Context Link]7. Wiggins MC, Sehizadeh M, Pilgram TK, et al. Importance of intravertebral fracture clefts in vertebroplasty outcome. AJR Am J Roentgenol 2007;188:634–40. [CrossRef] [Medline Link] [Context Link]8. Chin DK, Kim YS, Cho YE, et al. Efficacy of postural reduction in osteoporotic vertebral compression fractures followed by percutaneous vertebroplasty. Neurosurgery 2006;58:695–700. [CrossRef] [Full Text] [Medline Link] [Context Link]9. Heo DH, Chin DK, Yoon YS, et al. Recollapse of previous vertebral compression fracture after percutaneous vertebroplasty. Osteoporos Int 2009;20:473–80. [CrossRef] [Full Text] [Medline Link] [Context Link]10. Heo DH, Cho YJ, Sheen SH, et al. Morphological changes of injected calcium phosphate cement in osteoporotic compressed vertebral bodies. Osteoporos Int 2009;20:2063–70. [CrossRef] [Full Text] [Medline Link] [Context Link]11. Han I, Chin D, Kuh S, et al. Magnetic resonance imaging findings of subsequent fractures after vertebroplasty. Neurosurgery 2009;64:740–4. [CrossRef] [Full Text] [Medline Link] [Context Link]12. Lewis G. Properties of acrylic bone cement: state of the art review. J Biomed Mater Res 1997;38:155–82. [CrossRef] [Medline Link] [Context Link]13. Huang KY, Yan JJ, Lin RM. Histopathologic findings of retrieved specimens of vertebroplasty with polymethylmethacrylate cement: case control study. Spine 2005;30:E585–8. [CrossRef] [Full Text] [Medline Link] [Context Link]14. Heo DH, Cho SM, Cho YJ, et al. Heterotopic ossifications after vertebroplasty using calcium phosphate in osteoporotic vertebral compression fractures: report of 2 cases. World Neurosurg 2010;73:207–9. [Context Link]avascular osteonecrosis; osteoporosis; spinal fracture; vertebroplastyovid.com:/bib/ovftdb/00007632-201204010-0001900003626_2007_17_2248_libicher_intravertebral_|00007632-201204010-00019#xpointer(id(R1-19))|11065213||ovftdb|00042643-200709000-00005SL00003626200717224811065213P72[CrossRef]10.1007%2Fs00330-007-0684-0ovid.com:/bib/ovftdb/00007632-201204010-0001900003626_2007_17_2248_libicher_intravertebral_|00007632-201204010-00019#xpointer(id(R1-19))|11065404||ovftdb|00042643-200709000-00005SL00003626200717224811065404P72[Full Text]00042643-200709000-00005ovid.com:/bib/ovftdb/00007632-201204010-0001900003626_2007_17_2248_libicher_intravertebral_|00007632-201204010-00019#xpointer(id(R1-19))|11065405||ovftdb|00042643-200709000-00005SL00003626200717224811065405P72[Medline Link]17522865ovid.com:/bib/ovftdb/00007632-201204010-0001900000388_2007_28_42_yu_osteonecrosis_|00007632-201204010-00019#xpointer(id(R2-19))|11065405||ovftdb|SL000003882007284211065405P73[Medline Link]17213422ovid.com:/bib/ovftdb/00007632-201204010-0001900005088_2004_100_24_kim_intravertebral_|00007632-201204010-00019#xpointer(id(R3-19))|11065213||ovftdb|SL0000508820041002411065213P74[CrossRef]10.3171%2Fspi.2004.100.1.0024ovid.com:/bib/ovftdb/00007632-201204010-0001900005088_2004_100_24_kim_intravertebral_|00007632-201204010-00019#xpointer(id(R3-19))|11065405||ovftdb|SL0000508820041002411065405P74[Medline Link]14748570ovid.com:/bib/ovftdb/00007632-201204010-0001900042374_2008_16_14_becker_osteonecrosis_|00007632-201204010-00019#xpointer(id(R4-19))|11065405||ovftdb|SL000423742008161411065405P75[Medline Link]18453651ovid.com:/bib/ovftdb/00007632-201204010-0001900007632_2003_28_1588_jang_vertebroplasty_|00007632-201204010-00019#xpointer(id(R5-19))|11065213||ovftdb|00007632-200307150-00021SL00007632200328158811065213P76[CrossRef]10.1097%2F01.BRS.0000076824.61074.06ovid.com:/bib/ovftdb/00007632-201204010-0001900007632_2003_28_1588_jang_vertebroplasty_|00007632-201204010-00019#xpointer(id(R5-19))|11065404||ovftdb|00007632-200307150-00021SL00007632200328158811065404P76[Full Text]00007632-200307150-00021ovid.com:/bib/ovftdb/00007632-201204010-0001900007632_2003_28_1588_jang_vertebroplasty_|00007632-201204010-00019#xpointer(id(R5-19))|11065405||ovftdb|00007632-200307150-00021SL00007632200328158811065405P76[Medline Link]12865850ovid.com:/bib/ovftdb/00007632-201204010-0001900000388_2002_23_1642_lane_intravertebral_|00007632-201204010-00019#xpointer(id(R6-19))|11065405||ovftdb|SL00000388200223164211065405P77[Medline Link]12427615ovid.com:/bib/ovftdb/00007632-201204010-0001900000386_2007_188_634_wiggins_intravertebral_|00007632-201204010-00019#xpointer(id(R7-19))|11065213||ovftdb|SL00000386200718863411065213P78[CrossRef]10.2214%2FAJR.06.0542ovid.com:/bib/ovftdb/00007632-201204010-0001900000386_2007_188_634_wiggins_intravertebral_|00007632-201204010-00019#xpointer(id(R7-19))|11065405||ovftdb|SL00000386200718863411065405P78[Medline Link]17312047ovid.com:/bib/ovftdb/00007632-201204010-0001900006123_2006_58_695_chin_vertebroplasty_|00007632-201204010-00019#xpointer(id(R8-19))|11065213||ovftdb|00006123-200604000-00012SL0000612320065869511065213P79[CrossRef]10.1227%2F01.NEU.0000204313.36531.79ovid.com:/bib/ovftdb/00007632-201204010-0001900006123_2006_58_695_chin_vertebroplasty_|00007632-201204010-00019#xpointer(id(R8-19))|11065404||ovftdb|00006123-200604000-00012SL0000612320065869511065404P79[Full Text]00006123-200604000-00012ovid.com:/bib/ovftdb/00007632-201204010-0001900006123_2006_58_695_chin_vertebroplasty_|00007632-201204010-00019#xpointer(id(R8-19))|11065405||ovftdb|00006123-200604000-00012SL0000612320065869511065405P79[Medline Link]16575333ovid.com:/bib/ovftdb/00007632-201204010-0001900002501_2009_20_473_heo_vertebroplasty_|00007632-201204010-00019#xpointer(id(R9-19))|11065213||ovftdb|00002501-200903000-00015SL0000250120092047311065213P80[CrossRef]10.1007%2Fs00198-008-0682-3ovid.com:/bib/ovftdb/00007632-201204010-0001900002501_2009_20_473_heo_vertebroplasty_|00007632-201204010-00019#xpointer(id(R9-19))|11065404||ovftdb|00002501-200903000-00015SL0000250120092047311065404P80[Full Text]00002501-200903000-00015ovid.com:/bib/ovftdb/00007632-201204010-0001900002501_2009_20_473_heo_vertebroplasty_|00007632-201204010-00019#xpointer(id(R9-19))|11065405||ovftdb|00002501-200903000-00015SL0000250120092047311065405P80[Medline Link]18636218ovid.com:/bib/ovftdb/00007632-201204010-0001900002501_2009_20_2063_heo_morphological_|00007632-201204010-00019#xpointer(id(R10-19))|11065213||ovftdb|00002501-200912000-00010SL00002501200920206311065213P81[CrossRef]10.1007%2Fs00198-009-0911-4ovid.com:/bib/ovftdb/00007632-201204010-0001900002501_2009_20_2063_heo_morphological_|00007632-201204010-00019#xpointer(id(R10-19))|11065404||ovftdb|00002501-200912000-00010SL00002501200920206311065404P81[Full Text]00002501-200912000-00010ovid.com:/bib/ovftdb/00007632-201204010-0001900002501_2009_20_2063_heo_morphological_|00007632-201204010-00019#xpointer(id(R10-19))|11065405||ovftdb|00002501-200912000-00010SL00002501200920206311065405P81[Medline Link]19300891ovid.com:/bib/ovftdb/00007632-201204010-0001900006123_2009_64_740_han_vertebroplasty_|00007632-201204010-00019#xpointer(id(R11-19))|11065213||ovftdb|00006123-200904000-00025SL0000612320096474011065213P82[CrossRef]10.1227%2F01.NEU.0000339120.41053.F1ovid.com:/bib/ovftdb/00007632-201204010-0001900006123_2009_64_740_han_vertebroplasty_|00007632-201204010-00019#xpointer(id(R11-19))|11065404||ovftdb|00006123-200904000-00025SL0000612320096474011065404P82[Full Text]00006123-200904000-00025ovid.com:/bib/ovftdb/00007632-201204010-0001900006123_2009_64_740_han_vertebroplasty_|00007632-201204010-00019#xpointer(id(R11-19))|11065405||ovftdb|00006123-200904000-00025SL0000612320096474011065405P82[Medline Link]19349832ovid.com:/bib/ovftdb/00007632-201204010-0001900004620_1997_38_155_lewis_properties_|00007632-201204010-00019#xpointer(id(R12-19))|11065213||ovftdb|SL0000462019973815511065213P83[CrossRef]10.1002%2F%28SICI%291097-4636%28199722%2938%3A2%3C155%3A%3AAID-JBM10%3E3.0.CO%3B2-Covid.com:/bib/ovftdb/00007632-201204010-0001900004620_1997_38_155_lewis_properties_|00007632-201204010-00019#xpointer(id(R12-19))|11065405||ovftdb|SL0000462019973815511065405P83[Medline Link]9178743ovid.com:/bib/ovftdb/00007632-201204010-0001900007632_2005_30_e585_huang_polymethylmethacrylate_|00007632-201204010-00019#xpointer(id(R13-19))|11065213||ovftdb|00007632-200510010-00027SL00007632200530e58511065213P84[CrossRef]10.1097%2F01.brs.0000182226.56498.55ovid.com:/bib/ovftdb/00007632-201204010-0001900007632_2005_30_e585_huang_polymethylmethacrylate_|00007632-201204010-00019#xpointer(id(R13-19))|11065404||ovftdb|00007632-200510010-00027SL00007632200530e58511065404P84[Full Text]00007632-200510010-00027ovid.com:/bib/ovftdb/00007632-201204010-0001900007632_2005_30_e585_huang_polymethylmethacrylate_|00007632-201204010-00019#xpointer(id(R13-19))|11065405||ovftdb|00007632-200510010-00027SL00007632200530e58511065405P84[Medline Link]16205333Recently, osteoporotic vertebral compression fractures with avascular osteonecrosis have been treated with percutaneous vertebroplasty. However, there have been no previous multiyear, clinical, and radiological studies of the results of vertebroplasty in the vertebral body with noninfected avascular osteonecrosis. In the light of our results, vertebroplasty may not eff ectively provide enough stability or maintain stabilization for an extended time.Therapeutic Efficacy of Vertebroplasty in Osteoporotic Vertebral Compression Fractures With Avascular Osteonecrosis: A Minimum 2-Year Follow-up StudyHeo, Dong Hwa MD, PhD; Choi, Jong Hun MD; Kim, Moon Kyu MD, PhD; Choi, Hyeun Chul MD, PhD; Jeong, Je Hoon MD, PhD; Chin, Dong Kyu MD, PhD; Cho, Yong Jun MD, PhDClinical Case Series737