Vertebroplasty and Kyphoplasty
Compression fractures that are a result of osteoporosis are not benign. Besides the pain and disability that occur, morbidity and age-adjusted mortality rates are also higher in these patients. Specifically, there is as much as a 15% to 30% increase in mortality rate in patients with osteoporotic vertebral compression fractures (VCFs). A comparison of a prospective cohort of 9,575 women over the age of 65 years also confirmed an increased age-adjusted mortality rate, that increased with number of fractured levels, whether symptomatic or not. Each subsequent vertebral fracture also causes diminishing forced vital capacity. This seems to affect morbidity, since many of these patients eventually die as a result of pulmonary disease or cancer. Is this a cause or an effect? Certainly, many of these patients are debilitated with pulmonary disease and are steroid-dependent. This question may not be answered any time soon.
Until recently, VCFs have been treated mainly with bed rest, analgesics, braces, and variable modes of physical therapy. Operative intervention has been reserved for cases of neurologic compromise, which are exceedingly rare in these low-energy fractures. Poor bone quality usually necessitates long constructs, segmental fixation, anterior and posterior surgery, and polymethylmethacrylate (PMMA) augmentation. The massive undertaking of such surgical procedures is often not possible for medical reasons, or simply not desired by the patient. The advent of awareness of osteoporosis and early preventative regimens has helped to lessen fracture risk by as much as 50%. Nonetheless, despite maximal medical therapy, many fractures are still going to occur. What can be done for the elderly patient who has an acute or chronically painful VCF?
In 1984, the use of PMMA for the percutaneous treatment of vertebral hemangiomas was first described. Since then, a natural progression has occurred in the application of this technology to VCFs resulting from osteoporosis. Successful results have dominated the literature, with few complications noted. The complications that have occurred have typically been related to the common event of cement extrusion from the vertebral body through nutrient blood-vessel foramina that pierce the structural cortical shell. Despite a high rate of cement extrusion (30% to 73%), neurologic sequelae are uncommon, and thermal injury to the neural structures does not appear to occur. Pulmonary embolism of cement has rarely been reported, resulting in mortality.
Advantages of vertebroplasty include its relative simplicity, with the procedure often being performed under a local anesthetic. This allows conversation with the patient and a dynamic neurologic evaluation to help prevent cement extrusions. This minimally painful procedure can be done either unilaterally or bilaterally, as anatomy allows. There are several disadvantages of vertebroplasty, predominantly the result of high-pressure injection of a low-viscosity cement. This technique has the potential for cement extravasation and complications. Additionally, no attempt is made to reduce the vertebral deformity, so normal anatomy may or may not be restored with this technique.
Kyphoplasty is a relatively new procedure that has evolved from the technique of vertebroplasty. It was developed in 1997 and has gained popularity as an option for the treatment of osteoporotic VCFs. This technique involves the placement of inflatable bone tamps into the fractured vertebra, with subsequent expansion of these balloons to create a bone void and also to restore vertebral height. The premise of the procedure is that a more viscous bone cement is injected into the bone under low pressure, and a known volume of void is filled after variable height restoration. Few device-related complications have occurred in the first several years kyphoplasty has been used. Disadvantages of the procedure mainly relate to the relatively more complicated instruments and proper placement of the bone tamps. Instrumentation for kyphoplasty is also expensive, and this may be a consideration in the managed care arena.
Indications for percutaneous vertebral augmentation procedures are patient-dependent ( Table 1 ). The natural history of osteoporotic VCFs is symptomatic improvement, though a third of the patients will have chronic pain. Theoretically, increased kyphosis may also propagate adjacent compression fractures. If that holds true with further study, then acute intervention would be indicated in the presence of kyphosis. It is imperative that the treating physician fully evaluate the patient, including prefracture function and morbidity, and assess the risks of prolonged recumbency, narcotic medications, and braces. With these patient-specific factors in mind, several relative indications for vertebroplasty and kyphoplasty have been outlined in the literature. Acuity of treatment is truly dependent on the amount of pain, medical condition of the patient, and efficacy of nonsurgical treatments. Results have been excellent with both procedures, with few clinically significant complications. Kyphoplasty seems to show some promise in early studies with fewer complications, less frequent cement extrusion, and a similar efficacy to vertebroplasty ( Table 2 ).
Preoperative evaluation requires the patient to tolerate the prone position for 1 to 2 hours. General anesthesia is necessary for patients unable to lie prone or needing treatment to multiple levels, versus sedation and a local anesthetic for patients needing treatment to 1 or 2 levels. There should be no evidence of coagulopathy, and platelet inhibitors or anticoagulants should be stopped before the surgery to allow for normal clotting. Additional workup before either procedure should include standing anteroposterior and lateral radiographs, if possible, magnetic resonance imaging (MRI) with short tau inversion recovery (STIR) sequences, and occasionally bone scan and/or computed tomography (CT). Radiographs taken with the patient standing will often show more deformity or collapse than films done with the patient supine. This allows identification of some fractures that otherwise may not be easily visualized. Magnetic resonance imaging will show hypointensity or isointensity on the T1-weighted images, and a hyperintensity best seen on the STIR sequences (Fig. 1). This appearance is characteristic of an acute fracture, especially when a linear hyperintense zone underlies the depressed endplate. It is necessary to exclude malignant pathology, if possible. Computed tomography is helpful when patients are unable to tolerate MRI. Sagittal reconstructions will often show a vacuum phenomenon within the vertebral body, consistent with avascular necrosis or Kümmell's disease (Fig. 2). These latter fractures respond well to kyphoplasty or vertebroplasty. Bone scan is of limited value, however, and may be positive in only 20% of patients with height loss >15%; it is more often positive in fractures with height loss of >25%. Knowing the limitations of radiographic studies is necessary to determine the best evaluation of the patient while limiting the number of unnecessary tests.
(Enlarge Image)
(A) T1-weighted, (B) T2-weighted, and (C) short tau inversion recovery (STIR) images are shown. Without the STIR sequences, subtle changes may be missed. This STIRimage shows bony edema, with increased signal in endplate region.
(Enlarge Image)
(A) T1-weighted, (B) T2-weighted, and (C) short tau inversion recovery (STIR) images are shown. Without the STIR sequences, subtle changes may be missed. This STIRimage shows bony edema, with increased signal in endplate region.
(Enlarge Image)
(A) T1-weighted, (B) T2-weighted, and (C) short tau inversion recovery (STIR) images are shown. Without the STIR sequences, subtle changes may be missed. This STIRimage shows bony edema, with increased signal in endplate region.
(Enlarge Image)
This sequence of clinical images is shown for patient treated by vertebroplasty. Anteroposterior and lateral images are of some use but are limited due to bone density and overlying soft tissues. (A and B) Vacuum phenomenon is evident within vertebral body on radiographs. (C) Computed tomography confirms vacuum phenomenon and is consistent with diagnosis of Kümmell's disease. (D) T2-weighted magnetic resonance imaging shows fracture. (E) STIR image clearly shows vertebral enhancement consistent with bony edema and acute fracture.
(Enlarge Image)
This sequence of clinical images is shown for patient treated by vertebroplasty. Anteroposterior and lateral images are of some use but are limited due to bone density and overlying soft tissues. (A and B) Vacuum phenomenon is evident within vertebral body on radiographs. (C) Computed tomography confirms vacuum phenomenon and is consistent with diagnosis of Kümmell's disease. (D) T2-weighted magnetic resonance imaging shows fracture. (E) STIR image clearly shows vertebral enhancement consistent with bony edema and acute fracture.
(Enlarge Image)
This sequence of clinical images is shown for patient treated by vertebroplasty. Anteroposterior and lateral images are of some use but are limited due to bone density and overlying soft tissues. (A and B) Vacuum phenomenon is evident within vertebral body on radiographs. (C) Computed tomography confirms vacuum phenomenon and is consistent with diagnosis of Kümmell's disease. (D) T2-weighted magnetic resonance imaging shows fracture. (E) STIR image clearly shows vertebral enhancement consistent with bony edema and acute fracture.
(Enlarge Image)
This sequence of clinical images is shown for patient treated by vertebroplasty. Anteroposterior and lateral images are of some use but are limited due to bone density and overlying soft tissues. (A and B) Vacuum phenomenon is evident within vertebral body on radiographs. (C) Computed tomography confirms vacuum phenomenon and is consistent with diagnosis of Kümmell's disease. (D) T2-weighted magnetic resonance imaging shows fracture. (E) STIR image clearly shows vertebral enhancement consistent with bony edema and acute fracture.
(Enlarge Image)
This sequence of clinical images is shown for patient treated by vertebroplasty. Anteroposterior and lateral images are of some use but are limited due to bone density and overlying soft tissues. (A and B) Vacuum phenomenon is evident within vertebral body on radiographs. (C) Computed tomography confirms vacuum phenomenon and is consistent with diagnosis of Kümmell's disease. (D) T2-weighted magnetic resonance imaging shows fracture. (E) STIR image clearly shows vertebral enhancement consistent with bony edema and acute fracture.
After treatment by vertebroplasty or kyphoplasty, patients are allowed up after recovery from anesthesia or sedation. Symptomatic relief is usually significant within the first few days after the procedure. No procedure-specific limitations on patient activity are required after either procedure. Physical therapy is prescribed for patients with a significant muscular component to their pain after surgery, which is common in chronic fractures. Additionally, patients can be instructed regarding weight-bearing aerobic exercises for the prevention of further bone loss. Braces are not used.
Adjacent-level compression fractures deserve mention. Biomechanically, these procedures are augmenting a soft and fractured vertebral body. As a result of the use of PMMA, over-stiffening of segments may result in fracture of the untreated levels. This has been identified in as many as 10% of patients having these procedures. Not all of these fractures are symptomatic; however, the acute recurrence of pain after a pain-free postoperative interval should arouse suspicion of a new compression fracture. Treatment should proceed as for any acute fracture, though acute treatment with augmentation may be desirable to the patient after the results of the index procedure are realized. In my practice, this is especially problematic at the site of chronic fractures. When these fractures are left alone, the poor alignment increases the tendency for kyphosis and increases forces on the adjacent segments. Couple this with the increased stiffness of an augmented vertebral body after either of these procedures and there is a risk for subsequent adjacent-level fractures. Decreased volume of cement or use of more biologic materials may help reduce this tendency, but this problem needs to be monitored.
In summary, there are presently excellent options for the treatment of symptomatic VCFs in the osteoporotic patient. Recognition of the problem, patient education, and early pharmacologic treatment are preventive in many cases. Kyphoplasty and vertebroplasty are used in cases when other treatment fails, but allow for quick improvement of symptoms in most patients, with a minimum of complications. After augmentation of VCF, all patients should be re-evaluated to determine if they have been investigated for osteoporosis or if the present treatment regimen is adequate. New directions in treatment will include the use of hydroxyapatite cements and other osteoinductive agents for filling vertebral voids.
The print version of this article was originally certified for CME credit. For accreditation details, contact the publisher: Southern Medical Assocation, 35 Lakeshore Dr, Birmingham Alabama 35209, telephone: (205)945-1840.
In publishing this section in Southern Medical Journal, the Southern Medical Association recognizes educational needs of physicians in all specialties, especially those in primary care, for current information regarding the diagnosis and treatment of osteoporosis. In this section, authors may have included discussions about drug interventions, whether Food and Drug Administration approved or unapproved. Therefore, it is incumbent on physicians reading this section to be aware of these factors in interpreting the contents and evaluating recommendations. Moreover, views of authors do not necessarily reflect the opinions of the Southern Medical Association. Every effort has been made to encourage the author to disclose any commercial relationships or personal benefit that may be associated with this section. If the author disclosed a relationship, it is indicated below. This disclosure in no way implies that the information presented is biased or of lesser quality, but allows participants to make informed judgments regarding program content.
Ronald C. Hamdy, MD, FRCP, FACP
Grant/Research Support: Several pharmaceutical companies, including Merck, Procter &Gamble, Aventis, and Novartis
Consultant: Several pharmaceutical companies, including Merck, Procter &Gamble, Aventis, and Novartis
Speaker's Bureau: Several pharmaceutical companies, including Merck, Procter &Gamble, Aventis, and Novartis
Stock Shareholder: Several pharmaceutical companies, including Merck, Procter &Gamble, Aventis, and Novartis
Other Support: Several pharmaceutical companies, including Merck, Procter &Gamble, Aventis, and Novartis
Presented at the Fifth Annual Southern Medical Association Conference on Osteoporosis, Amelia Island, Fla, February 21-24, 2002.
Compression fractures that are a result of osteoporosis are not benign. Besides the pain and disability that occur, morbidity and age-adjusted mortality rates are also higher in these patients. Specifically, there is as much as a 15% to 30% increase in mortality rate in patients with osteoporotic vertebral compression fractures (VCFs). A comparison of a prospective cohort of 9,575 women over the age of 65 years also confirmed an increased age-adjusted mortality rate, that increased with number of fractured levels, whether symptomatic or not. Each subsequent vertebral fracture also causes diminishing forced vital capacity. This seems to affect morbidity, since many of these patients eventually die as a result of pulmonary disease or cancer. Is this a cause or an effect? Certainly, many of these patients are debilitated with pulmonary disease and are steroid-dependent. This question may not be answered any time soon.
Until recently, VCFs have been treated mainly with bed rest, analgesics, braces, and variable modes of physical therapy. Operative intervention has been reserved for cases of neurologic compromise, which are exceedingly rare in these low-energy fractures. Poor bone quality usually necessitates long constructs, segmental fixation, anterior and posterior surgery, and polymethylmethacrylate (PMMA) augmentation. The massive undertaking of such surgical procedures is often not possible for medical reasons, or simply not desired by the patient. The advent of awareness of osteoporosis and early preventative regimens has helped to lessen fracture risk by as much as 50%. Nonetheless, despite maximal medical therapy, many fractures are still going to occur. What can be done for the elderly patient who has an acute or chronically painful VCF?
In 1984, the use of PMMA for the percutaneous treatment of vertebral hemangiomas was first described. Since then, a natural progression has occurred in the application of this technology to VCFs resulting from osteoporosis. Successful results have dominated the literature, with few complications noted. The complications that have occurred have typically been related to the common event of cement extrusion from the vertebral body through nutrient blood-vessel foramina that pierce the structural cortical shell. Despite a high rate of cement extrusion (30% to 73%), neurologic sequelae are uncommon, and thermal injury to the neural structures does not appear to occur. Pulmonary embolism of cement has rarely been reported, resulting in mortality.
Advantages of vertebroplasty include its relative simplicity, with the procedure often being performed under a local anesthetic. This allows conversation with the patient and a dynamic neurologic evaluation to help prevent cement extrusions. This minimally painful procedure can be done either unilaterally or bilaterally, as anatomy allows. There are several disadvantages of vertebroplasty, predominantly the result of high-pressure injection of a low-viscosity cement. This technique has the potential for cement extravasation and complications. Additionally, no attempt is made to reduce the vertebral deformity, so normal anatomy may or may not be restored with this technique.
Kyphoplasty is a relatively new procedure that has evolved from the technique of vertebroplasty. It was developed in 1997 and has gained popularity as an option for the treatment of osteoporotic VCFs. This technique involves the placement of inflatable bone tamps into the fractured vertebra, with subsequent expansion of these balloons to create a bone void and also to restore vertebral height. The premise of the procedure is that a more viscous bone cement is injected into the bone under low pressure, and a known volume of void is filled after variable height restoration. Few device-related complications have occurred in the first several years kyphoplasty has been used. Disadvantages of the procedure mainly relate to the relatively more complicated instruments and proper placement of the bone tamps. Instrumentation for kyphoplasty is also expensive, and this may be a consideration in the managed care arena.
Indications for percutaneous vertebral augmentation procedures are patient-dependent ( Table 1 ). The natural history of osteoporotic VCFs is symptomatic improvement, though a third of the patients will have chronic pain. Theoretically, increased kyphosis may also propagate adjacent compression fractures. If that holds true with further study, then acute intervention would be indicated in the presence of kyphosis. It is imperative that the treating physician fully evaluate the patient, including prefracture function and morbidity, and assess the risks of prolonged recumbency, narcotic medications, and braces. With these patient-specific factors in mind, several relative indications for vertebroplasty and kyphoplasty have been outlined in the literature. Acuity of treatment is truly dependent on the amount of pain, medical condition of the patient, and efficacy of nonsurgical treatments. Results have been excellent with both procedures, with few clinically significant complications. Kyphoplasty seems to show some promise in early studies with fewer complications, less frequent cement extrusion, and a similar efficacy to vertebroplasty ( Table 2 ).
Preoperative evaluation requires the patient to tolerate the prone position for 1 to 2 hours. General anesthesia is necessary for patients unable to lie prone or needing treatment to multiple levels, versus sedation and a local anesthetic for patients needing treatment to 1 or 2 levels. There should be no evidence of coagulopathy, and platelet inhibitors or anticoagulants should be stopped before the surgery to allow for normal clotting. Additional workup before either procedure should include standing anteroposterior and lateral radiographs, if possible, magnetic resonance imaging (MRI) with short tau inversion recovery (STIR) sequences, and occasionally bone scan and/or computed tomography (CT). Radiographs taken with the patient standing will often show more deformity or collapse than films done with the patient supine. This allows identification of some fractures that otherwise may not be easily visualized. Magnetic resonance imaging will show hypointensity or isointensity on the T1-weighted images, and a hyperintensity best seen on the STIR sequences (Fig. 1). This appearance is characteristic of an acute fracture, especially when a linear hyperintense zone underlies the depressed endplate. It is necessary to exclude malignant pathology, if possible. Computed tomography is helpful when patients are unable to tolerate MRI. Sagittal reconstructions will often show a vacuum phenomenon within the vertebral body, consistent with avascular necrosis or Kümmell's disease (Fig. 2). These latter fractures respond well to kyphoplasty or vertebroplasty. Bone scan is of limited value, however, and may be positive in only 20% of patients with height loss >15%; it is more often positive in fractures with height loss of >25%. Knowing the limitations of radiographic studies is necessary to determine the best evaluation of the patient while limiting the number of unnecessary tests.
(Enlarge Image)
(A) T1-weighted, (B) T2-weighted, and (C) short tau inversion recovery (STIR) images are shown. Without the STIR sequences, subtle changes may be missed. This STIRimage shows bony edema, with increased signal in endplate region.
(Enlarge Image)
(A) T1-weighted, (B) T2-weighted, and (C) short tau inversion recovery (STIR) images are shown. Without the STIR sequences, subtle changes may be missed. This STIRimage shows bony edema, with increased signal in endplate region.
(Enlarge Image)
(A) T1-weighted, (B) T2-weighted, and (C) short tau inversion recovery (STIR) images are shown. Without the STIR sequences, subtle changes may be missed. This STIRimage shows bony edema, with increased signal in endplate region.
(Enlarge Image)
This sequence of clinical images is shown for patient treated by vertebroplasty. Anteroposterior and lateral images are of some use but are limited due to bone density and overlying soft tissues. (A and B) Vacuum phenomenon is evident within vertebral body on radiographs. (C) Computed tomography confirms vacuum phenomenon and is consistent with diagnosis of Kümmell's disease. (D) T2-weighted magnetic resonance imaging shows fracture. (E) STIR image clearly shows vertebral enhancement consistent with bony edema and acute fracture.
(Enlarge Image)
This sequence of clinical images is shown for patient treated by vertebroplasty. Anteroposterior and lateral images are of some use but are limited due to bone density and overlying soft tissues. (A and B) Vacuum phenomenon is evident within vertebral body on radiographs. (C) Computed tomography confirms vacuum phenomenon and is consistent with diagnosis of Kümmell's disease. (D) T2-weighted magnetic resonance imaging shows fracture. (E) STIR image clearly shows vertebral enhancement consistent with bony edema and acute fracture.
(Enlarge Image)
This sequence of clinical images is shown for patient treated by vertebroplasty. Anteroposterior and lateral images are of some use but are limited due to bone density and overlying soft tissues. (A and B) Vacuum phenomenon is evident within vertebral body on radiographs. (C) Computed tomography confirms vacuum phenomenon and is consistent with diagnosis of Kümmell's disease. (D) T2-weighted magnetic resonance imaging shows fracture. (E) STIR image clearly shows vertebral enhancement consistent with bony edema and acute fracture.
(Enlarge Image)
This sequence of clinical images is shown for patient treated by vertebroplasty. Anteroposterior and lateral images are of some use but are limited due to bone density and overlying soft tissues. (A and B) Vacuum phenomenon is evident within vertebral body on radiographs. (C) Computed tomography confirms vacuum phenomenon and is consistent with diagnosis of Kümmell's disease. (D) T2-weighted magnetic resonance imaging shows fracture. (E) STIR image clearly shows vertebral enhancement consistent with bony edema and acute fracture.
(Enlarge Image)
This sequence of clinical images is shown for patient treated by vertebroplasty. Anteroposterior and lateral images are of some use but are limited due to bone density and overlying soft tissues. (A and B) Vacuum phenomenon is evident within vertebral body on radiographs. (C) Computed tomography confirms vacuum phenomenon and is consistent with diagnosis of Kümmell's disease. (D) T2-weighted magnetic resonance imaging shows fracture. (E) STIR image clearly shows vertebral enhancement consistent with bony edema and acute fracture.
After treatment by vertebroplasty or kyphoplasty, patients are allowed up after recovery from anesthesia or sedation. Symptomatic relief is usually significant within the first few days after the procedure. No procedure-specific limitations on patient activity are required after either procedure. Physical therapy is prescribed for patients with a significant muscular component to their pain after surgery, which is common in chronic fractures. Additionally, patients can be instructed regarding weight-bearing aerobic exercises for the prevention of further bone loss. Braces are not used.
Adjacent-level compression fractures deserve mention. Biomechanically, these procedures are augmenting a soft and fractured vertebral body. As a result of the use of PMMA, over-stiffening of segments may result in fracture of the untreated levels. This has been identified in as many as 10% of patients having these procedures. Not all of these fractures are symptomatic; however, the acute recurrence of pain after a pain-free postoperative interval should arouse suspicion of a new compression fracture. Treatment should proceed as for any acute fracture, though acute treatment with augmentation may be desirable to the patient after the results of the index procedure are realized. In my practice, this is especially problematic at the site of chronic fractures. When these fractures are left alone, the poor alignment increases the tendency for kyphosis and increases forces on the adjacent segments. Couple this with the increased stiffness of an augmented vertebral body after either of these procedures and there is a risk for subsequent adjacent-level fractures. Decreased volume of cement or use of more biologic materials may help reduce this tendency, but this problem needs to be monitored.
In summary, there are presently excellent options for the treatment of symptomatic VCFs in the osteoporotic patient. Recognition of the problem, patient education, and early pharmacologic treatment are preventive in many cases. Kyphoplasty and vertebroplasty are used in cases when other treatment fails, but allow for quick improvement of symptoms in most patients, with a minimum of complications. After augmentation of VCF, all patients should be re-evaluated to determine if they have been investigated for osteoporosis or if the present treatment regimen is adequate. New directions in treatment will include the use of hydroxyapatite cements and other osteoinductive agents for filling vertebral voids.
The print version of this article was originally certified for CME credit. For accreditation details, contact the publisher: Southern Medical Assocation, 35 Lakeshore Dr, Birmingham Alabama 35209, telephone: (205)945-1840.
In publishing this section in Southern Medical Journal, the Southern Medical Association recognizes educational needs of physicians in all specialties, especially those in primary care, for current information regarding the diagnosis and treatment of osteoporosis. In this section, authors may have included discussions about drug interventions, whether Food and Drug Administration approved or unapproved. Therefore, it is incumbent on physicians reading this section to be aware of these factors in interpreting the contents and evaluating recommendations. Moreover, views of authors do not necessarily reflect the opinions of the Southern Medical Association. Every effort has been made to encourage the author to disclose any commercial relationships or personal benefit that may be associated with this section. If the author disclosed a relationship, it is indicated below. This disclosure in no way implies that the information presented is biased or of lesser quality, but allows participants to make informed judgments regarding program content.
Ronald C. Hamdy, MD, FRCP, FACP
Grant/Research Support: Several pharmaceutical companies, including Merck, Procter &Gamble, Aventis, and Novartis
Consultant: Several pharmaceutical companies, including Merck, Procter &Gamble, Aventis, and Novartis
Speaker's Bureau: Several pharmaceutical companies, including Merck, Procter &Gamble, Aventis, and Novartis
Stock Shareholder: Several pharmaceutical companies, including Merck, Procter &Gamble, Aventis, and Novartis
Other Support: Several pharmaceutical companies, including Merck, Procter &Gamble, Aventis, and Novartis
Presented at the Fifth Annual Southern Medical Association Conference on Osteoporosis, Amelia Island, Fla, February 21-24, 2002.