- Email: [email protected]
4:47 Percutaneous vertebroplasty and kyphoplasty for painful vertebral body fractures in cancer patients
Proceedings of the NASS 17th Annual Meeting / The Spine Journal 2 (2002) 47S–128S Summary of findings: Although it was difficult to assess a prognosis based on any single parameter, the total score obtained for each patient could be correlated with the prognosis (p.0001). It was found that 86.1% of patients who scored under 8 points survived for less than 6 months, whereas 91.3% of patients who scored above 12 points survived more than 1 year. In the group scoring between 9 and 11 points, 70.7% of patients survived for more than 6 months. There were significant differences in the survival of the three groups scoring from 0 to 8, from 9 to 11 and from 12 to 15 points, respectively. These three grades of the criteria were postulated: 0 to 8 points predicts less than 6 months, 9 to 11 predicts more than 6 months and 12 to 15 predicts more than 1 year. The accuracy of the criteria for predicted prognosis in forecasting the period of survival was 81.2%. There was no significant difference between the patients who had died after surgery and those who died without surgical intervention. Furthermore, this assessment was valuable in predicting prognosis for different lesions that were classified by the Surgical Classification. Relationship between findings and existing knowledge: Our prior system is a simple, clinical and practical assessment. Therefore, we tried to revise it, keeping the advantage of it. As a result, this revised scoring system was more valuable in predicting prognosis than the previous one. Furthermore, the revised version could be applied to the patients without surgical intervention. Therefore, the revised version was more appropriate for indicating treatment modalities for a metastatic spine tumor. Overall significance of findings: The accuracy of criteria in the revision for predicted prognosis was 81.2%. An excisional procedure is indicated in patients with a total score of 12 or more and in the subgroup of patients with a score between 9 and 11 points whose lesions are located at sites that allow for aggressive removal. A palliative operation or conservative treatment is indicated for patients who score under 8 points. Disclosures: No disclosures. Conflict of interest: No conflicts.
PII: S1529-9430(02)00389-3
75S
0.992/0.873 and 0.988/0.749, respectively. Because the model is based on the mechanics of burst fracture, it is not predictive of wedge fracture risk.
Fig. 1. Histogram of VBN values for all fracture cases. There is a clear distinction between the VBN burst fracture prediction values for the intact and the burst fracture group. The model is based on the mechanics of burst fracture and hence is not predictive of wedge fracture risk. Relationship between findings and existing knowledge: Previous biomechanical analyses of metastatic spinal stability have not modeled the mechanism of burst fracture, thus limiting their predictive ability. Retrospective radiographic studies have shown tumor size and pedicle involvement to increase the risk of fracture in the metastatic spine. However, such methods based on the maximum cross-sectional area of the tumor have not yielded good specificity or clear threshold values as compared with the three-dimensional quantifications used in this study. Overall significance of findings: The VBN model exhibited excellent (100%) predictive ability for burst fractures in metastatically involved vertebrae providing useful clinical information for prophylactic decision making. Although more extensive prospective study is needed, these retrospective study results support the wider implementation of biomechanically based fracture risk prediction tools for use in clinically assessing patients with skeletal metastases. Disclosures: No disclosures. Conflict of interest: No conflict. PII: S1529-9430(02)00322-4
4:41 Metastatic burst fracture risk prediction Sandra Roth, MSc1, Payam Mousavi1, Henry Ahn, MD1, Joel Finkelstein, MD, FRCSC1, Edward Chow, MBBS, MSc, FRCPC1, Cari Whyne, PhD1; 1 Sunnybrook and Women’s College Health Sciences Centre, Toronto, ON, Canada Purpose of study: The clinical validity and utility of three biomechanically based predictive models for burst fracture risk in metastatically involved vertebrae were assessed. This study determines the ability of these models to accurately predict vertebral stability and yield clear clinical threshold values for burst fracture risk. Methods used: Digital computed tomography scan images of lytic thoracic and lumbar spinal metastases were categorized as burst fractured, wedge fractured or intact. Stability was analyzed using three predictive models of vertebral load carrying capacity: 1) VBN (maximum radial vertebral bulge under load), 2) VHN (maximum axial vertebral displacement under load), and 3) TS, (percentage volume of tumor). VBN and VHN were previously developed from an experimentally validated finite element model reflecting the biphasic mechanism of burst fracture while incorporating semiautomated estimates of tumor volume, bone mineral density, disc quality and pedicle involvement. Receiver-operator curves (ROC) and Hosmer-Lemeshow tests (HLT) were used to determine goodness of fit. Summary of findings: Lytic metastases were identified in 72 patients, yielding a total of 92 vertebrae (maximum 2 per patient): 21 were fractured (23%, 4 wedge,17 burst) and 71 were intact (77%). Burst fracture prediction using VBN was found to have a specificity, sensitivity and confidence interval of 1 (ROC and HLT) at a threshold of 5.22 (Fig. 1). Burst fracture prediction using VHN and TS were also strong with ROC/HLT values of
4:47 Percutaneous vertebroplasty and kyphoplasty for painful vertebral body fractures in cancer patients Daryl R. Fourney, MD, FRCSC1, Donald F. Schomer, MD1, Remi Nader, MD1, Jennifer Fourney-Chlan, PhD1, Ziya L. Gokaslan, MD, FACS1; 1The University of Texas M. D., Anderson Cancer Center, Houston, TX Purpose of study: Minimally invasive vertebroplasty—which involves the percutaneous injection of polymethylmethacrylate bone cement into a vertebral body—was developed in France in the 1980s. The indication for treatment is the management of pain, likely caused by structural instability of the vertebral body. Percutaneous balloon kyphoplasty, a recent modification of vertebroplasty, involves inflation of a balloon into the collapsed vertebral body to restore height and reduce kyphotic deformity, prior to stabilization with bone cement. The current North American experience with both procedures is largely limited to the treatment of benign osteoporotic compression fractures. The objective of this study was to assess the safety and efficacy of vertebroplasty and kyphoplasty in the treatment of painful vertebral body fractures in cancer patients. Methods used: We reviewed a consecutive group of patients undergoing vertebroplasty and kyphoplasty at out institution between October 2000 and February 2002. Five patients treated for benign osteoporotic compression fractures were excluded. Ninety-seven procedures (65 vertebroplasties and 32 kyphoplasties) were performed in 56 patients during 58 treatment sessions. Mean age was 62 years (range, 30–81 yr) and mean duration of symptoms was 5.3 months. Indications for treatment were intractable spinal pain from osteolytic disease and instability secondary to metastases (35
76S
Proceedings of the NASS 17th Annual Meeting / The Spine Journal 2 (2002) 47S–128S
patients) or myeloma (21 patients). Symptomatic levels were identified by correlating the clinical data with MRI and radiographic findings. Summary of findings: Patients noted marked or complete pain relief after 51 procedures (88%), and no change after 3 procedures (5%); data were incomplete in four patients (7%). No patient was worse after treatment. Reductions in visual analog pain scores remained significant up to 1 year (p.02, Wilcoxon signed-rank test). After a mean follow-up of 4.3 months, only one patient had died; mean survival, as determined by Kaplan-Meier analysis, was 12.9 months. There were no deaths or complications related to the procedures. One patient was readmitted to hospital 15 days after kyphoplasty for an exacerbation of preexisting congestive heart failure. A patient with metastatic esthesioneuroblastoma developed sudden paraplegia 13 days after an L1 vertebroplasty secondary to spinal cord compression caused by a progressive T8 epidural metastasis. Relationship between findings and existing knowledge: The efficacy of vertebroplasty in the present report is similar to the two comparable European series [1,2]. A lack of complications related to bone cement leakage may reflect the use of relatively smaller injection volumes. To the authors’ knowledge, kyphoplasty in the setting of cancer has not been previously reported. Overall significance of findings: Percutaneous vertebroplasty and kyphoplasty provided significant pain relief in a high percentage of patients that appears to be durable over time. Precise indications for each of these techniques are evolving; however, they are safe and feasible in well-selected patients with refractory spinal pain resulting from myeloma bone disease or metastases. Disclosures: Device or drug: vertebroplasty. Status: approved. Device or drug: kyphoplasty. Status: approved. Conflict of interest: No conflicts. PII: S1529-9430(02)00323-6
Friday, November 1, 2001 4:29–5:12 pm Concurrent Session 4B: Lumbar Fusion—Bone and Blood Allograft Risks
in 44 patients (62%). There was no statistically significant difference in the number of CS units transfused intraoperatively between the patients who required postoperative TXF and those who did not. The charge associated with AB totaled $361 per unit. CS charges totaled $951 per case, regardless of the number of units transfused. In the group requiring postoperative TXF, all 25 units of AB were used totaling $9,025 in charges. In this group CS was used in 11 cases, totaling $10,461 in charges. However, 5 of these patients did not receive any CS TXF ($4,755 in charges). In the group not requiring a postoperative TXF, 62 units of AB had been predonated, with charges totaling $22,382. CS was used in 60 of these patients with a total charge of $57,060. However, 22 patients did not receive any CS TXF ($29,922 in charges). The total charge for AB and CS for all 79 cases was $98,928. The total cost for AB not used and CS without subsequent return was $48,059. Relationship between findings and existing knowledge: Previous reports have varied greatly in their recommendations regarding the use of intraoperative blood salvage and replacement. Likewise, multiple factors have been identified as predictors of postoperative blood TXF. Overall significance of findings: Based on our study, it appears that postoperative TXF may be more likely required in males, patients over 55 years, patients who are shorter stature and in patients with a preoperative hematocrit less than 35. If these criteria could have been applied to our sample of patients preoperatively, we may have saved $22,382 in charges associated in unnecessary predonations of AB. The charge for two units of AB ($722) is still less than the charge for CS ($951), which raises the question of which should be the preferred method of insuring the availability of blood for TXF. Considering our entire cohort, a total savings of $89,903 in charges could have been realized if we would have been able to predict preoperatively which patients would not require/receive their predonated AB. In summary, our study has demonstrated that a selective approach to blood predonation and intraoperative salvage can result in substantial savings in charges associated with single-level posterolateral spinal fusions. Disclosures: No disclosures. Conflict of interest: No conflicts.
PII: S1529-9430(02)00324-8
4:29 Cost–benefit analysis of blood replacement in single-level posterior spinal fusion Chad Rutter, DO1, Aleksandar Curcin, MD, MBA1, Mark Rosenthal, MD2; 1 Baltimore, MD, USA; 2North American Spine Society, Baltimore, MD, USA
4:35 Trends in recalls of musculoskeletal tissue allografts: analysis of Food and Drug Administration recall data Jeffrey Wang, MD1, Randal Mills, PhD2, Michael Roberts, MA2, Dayna Buskirk, DC3; 1University of California, Los Angeles, Los Angeles, CA, USA; 2Regeneration Technologies, Alachua, FL, USA; 3Regeneration Technologies, Inc., Alachua, FL, USA
Purpose of study: This study was undertaken to review our experience with single-level posterior instrumented lumbar fusions in an effort to identify which patients would require blood transfusion (TXF) and to determine the cost effectiveness of using autologous blood predonation (AB) and intraoperative blood salvage (CS). Methods used: Data were collected by means of retrospective chart review. Clinical data included demographics and comorbidities, pre- and postoperative HCT, duration of procedure, EBL, CS collection, number of AB units collected preoperatively, number and source of perioperative units of blood transfused. Financial data included charges for AB (Red Cross plus hospital processing) and hospital charges for CS. Summary of findings: Seventy-nine patients were included. The major difference between patients was the type of concurrent procedure carried out during the surgical setting. Forty procedures were at L4–L5, 23 at L5–S1, 14 at L3–L4 and 2 at L2–L3. Concurrent procedures, in addition to the fusion, were undertaken in 71 cases (90%). AB was used in 53 patients, and CS was used in 71 cases. Sixty-five patients (82%) did not receive postoperative TXF, and females were less likely to require a postoperative TXF (p.026). Thirteen patients (18%) received a postoperative TXF with older age, shorter height and lower preoperative hematocrit being more likely to require a TXF (p.001). Overall CS blood was transfused intraoperatively
Purpose of study: This poster provides an analysis of data collected and disseminated by the US Food and Drug Administration (FDA) concerning recalls of musculoskeletal tissue allografts and includes a discussion of the implications for patient safety. Methods used: The FDA collects and publishes information concerning recalls of regulated products, including musculoskeletal tissue allografts, on a weekly basis. For each recall, data are provided concerning the specific products involved in the recall, the “recalling” firm or manufacturer, the reasons for the recall, the volume of products and the geographic distribution of the recalled products. All FDA reports from 1994 through 2001 were reviewed to identify those recalls that involved musculoskeletal tissue. The reasons for recall, numbers of grafts recalled, trends over time and implications for patient safety were analyzed. Summary of findings: From 1994 through 2001, a total of 15,338 musculoskeletal tissue allografts were recalled in the United States. The most common reasons for recall include “improper donor evaluation” (10,929 grafts; 71.3%), and/or presence of positive serology results (3,140 grafts; 20.5%), results (976 grafts; 6.4%). Analysis of trends over time show that improper donor screening and testing, mishandling of positive serology results and other human errors continue to occur quite commonly (to date, 1,235 musculoskeletal tissue grafts have been reported as recalled in 2001).
PII: S1529-9430(02)00389-3
75S
0.992/0.873 and 0.988/0.749, respectively. Because the model is based on the mechanics of burst fracture, it is not predictive of wedge fracture risk.
Fig. 1. Histogram of VBN values for all fracture cases. There is a clear distinction between the VBN burst fracture prediction values for the intact and the burst fracture group. The model is based on the mechanics of burst fracture and hence is not predictive of wedge fracture risk. Relationship between findings and existing knowledge: Previous biomechanical analyses of metastatic spinal stability have not modeled the mechanism of burst fracture, thus limiting their predictive ability. Retrospective radiographic studies have shown tumor size and pedicle involvement to increase the risk of fracture in the metastatic spine. However, such methods based on the maximum cross-sectional area of the tumor have not yielded good specificity or clear threshold values as compared with the three-dimensional quantifications used in this study. Overall significance of findings: The VBN model exhibited excellent (100%) predictive ability for burst fractures in metastatically involved vertebrae providing useful clinical information for prophylactic decision making. Although more extensive prospective study is needed, these retrospective study results support the wider implementation of biomechanically based fracture risk prediction tools for use in clinically assessing patients with skeletal metastases. Disclosures: No disclosures. Conflict of interest: No conflict. PII: S1529-9430(02)00322-4
4:41 Metastatic burst fracture risk prediction Sandra Roth, MSc1, Payam Mousavi1, Henry Ahn, MD1, Joel Finkelstein, MD, FRCSC1, Edward Chow, MBBS, MSc, FRCPC1, Cari Whyne, PhD1; 1 Sunnybrook and Women’s College Health Sciences Centre, Toronto, ON, Canada Purpose of study: The clinical validity and utility of three biomechanically based predictive models for burst fracture risk in metastatically involved vertebrae were assessed. This study determines the ability of these models to accurately predict vertebral stability and yield clear clinical threshold values for burst fracture risk. Methods used: Digital computed tomography scan images of lytic thoracic and lumbar spinal metastases were categorized as burst fractured, wedge fractured or intact. Stability was analyzed using three predictive models of vertebral load carrying capacity: 1) VBN (maximum radial vertebral bulge under load), 2) VHN (maximum axial vertebral displacement under load), and 3) TS, (percentage volume of tumor). VBN and VHN were previously developed from an experimentally validated finite element model reflecting the biphasic mechanism of burst fracture while incorporating semiautomated estimates of tumor volume, bone mineral density, disc quality and pedicle involvement. Receiver-operator curves (ROC) and Hosmer-Lemeshow tests (HLT) were used to determine goodness of fit. Summary of findings: Lytic metastases were identified in 72 patients, yielding a total of 92 vertebrae (maximum 2 per patient): 21 were fractured (23%, 4 wedge,17 burst) and 71 were intact (77%). Burst fracture prediction using VBN was found to have a specificity, sensitivity and confidence interval of 1 (ROC and HLT) at a threshold of 5.22 (Fig. 1). Burst fracture prediction using VHN and TS were also strong with ROC/HLT values of
4:47 Percutaneous vertebroplasty and kyphoplasty for painful vertebral body fractures in cancer patients Daryl R. Fourney, MD, FRCSC1, Donald F. Schomer, MD1, Remi Nader, MD1, Jennifer Fourney-Chlan, PhD1, Ziya L. Gokaslan, MD, FACS1; 1The University of Texas M. D., Anderson Cancer Center, Houston, TX Purpose of study: Minimally invasive vertebroplasty—which involves the percutaneous injection of polymethylmethacrylate bone cement into a vertebral body—was developed in France in the 1980s. The indication for treatment is the management of pain, likely caused by structural instability of the vertebral body. Percutaneous balloon kyphoplasty, a recent modification of vertebroplasty, involves inflation of a balloon into the collapsed vertebral body to restore height and reduce kyphotic deformity, prior to stabilization with bone cement. The current North American experience with both procedures is largely limited to the treatment of benign osteoporotic compression fractures. The objective of this study was to assess the safety and efficacy of vertebroplasty and kyphoplasty in the treatment of painful vertebral body fractures in cancer patients. Methods used: We reviewed a consecutive group of patients undergoing vertebroplasty and kyphoplasty at out institution between October 2000 and February 2002. Five patients treated for benign osteoporotic compression fractures were excluded. Ninety-seven procedures (65 vertebroplasties and 32 kyphoplasties) were performed in 56 patients during 58 treatment sessions. Mean age was 62 years (range, 30–81 yr) and mean duration of symptoms was 5.3 months. Indications for treatment were intractable spinal pain from osteolytic disease and instability secondary to metastases (35
76S
Proceedings of the NASS 17th Annual Meeting / The Spine Journal 2 (2002) 47S–128S
patients) or myeloma (21 patients). Symptomatic levels were identified by correlating the clinical data with MRI and radiographic findings. Summary of findings: Patients noted marked or complete pain relief after 51 procedures (88%), and no change after 3 procedures (5%); data were incomplete in four patients (7%). No patient was worse after treatment. Reductions in visual analog pain scores remained significant up to 1 year (p.02, Wilcoxon signed-rank test). After a mean follow-up of 4.3 months, only one patient had died; mean survival, as determined by Kaplan-Meier analysis, was 12.9 months. There were no deaths or complications related to the procedures. One patient was readmitted to hospital 15 days after kyphoplasty for an exacerbation of preexisting congestive heart failure. A patient with metastatic esthesioneuroblastoma developed sudden paraplegia 13 days after an L1 vertebroplasty secondary to spinal cord compression caused by a progressive T8 epidural metastasis. Relationship between findings and existing knowledge: The efficacy of vertebroplasty in the present report is similar to the two comparable European series [1,2]. A lack of complications related to bone cement leakage may reflect the use of relatively smaller injection volumes. To the authors’ knowledge, kyphoplasty in the setting of cancer has not been previously reported. Overall significance of findings: Percutaneous vertebroplasty and kyphoplasty provided significant pain relief in a high percentage of patients that appears to be durable over time. Precise indications for each of these techniques are evolving; however, they are safe and feasible in well-selected patients with refractory spinal pain resulting from myeloma bone disease or metastases. Disclosures: Device or drug: vertebroplasty. Status: approved. Device or drug: kyphoplasty. Status: approved. Conflict of interest: No conflicts. PII: S1529-9430(02)00323-6
Friday, November 1, 2001 4:29–5:12 pm Concurrent Session 4B: Lumbar Fusion—Bone and Blood Allograft Risks
in 44 patients (62%). There was no statistically significant difference in the number of CS units transfused intraoperatively between the patients who required postoperative TXF and those who did not. The charge associated with AB totaled $361 per unit. CS charges totaled $951 per case, regardless of the number of units transfused. In the group requiring postoperative TXF, all 25 units of AB were used totaling $9,025 in charges. In this group CS was used in 11 cases, totaling $10,461 in charges. However, 5 of these patients did not receive any CS TXF ($4,755 in charges). In the group not requiring a postoperative TXF, 62 units of AB had been predonated, with charges totaling $22,382. CS was used in 60 of these patients with a total charge of $57,060. However, 22 patients did not receive any CS TXF ($29,922 in charges). The total charge for AB and CS for all 79 cases was $98,928. The total cost for AB not used and CS without subsequent return was $48,059. Relationship between findings and existing knowledge: Previous reports have varied greatly in their recommendations regarding the use of intraoperative blood salvage and replacement. Likewise, multiple factors have been identified as predictors of postoperative blood TXF. Overall significance of findings: Based on our study, it appears that postoperative TXF may be more likely required in males, patients over 55 years, patients who are shorter stature and in patients with a preoperative hematocrit less than 35. If these criteria could have been applied to our sample of patients preoperatively, we may have saved $22,382 in charges associated in unnecessary predonations of AB. The charge for two units of AB ($722) is still less than the charge for CS ($951), which raises the question of which should be the preferred method of insuring the availability of blood for TXF. Considering our entire cohort, a total savings of $89,903 in charges could have been realized if we would have been able to predict preoperatively which patients would not require/receive their predonated AB. In summary, our study has demonstrated that a selective approach to blood predonation and intraoperative salvage can result in substantial savings in charges associated with single-level posterolateral spinal fusions. Disclosures: No disclosures. Conflict of interest: No conflicts.
PII: S1529-9430(02)00324-8
4:29 Cost–benefit analysis of blood replacement in single-level posterior spinal fusion Chad Rutter, DO1, Aleksandar Curcin, MD, MBA1, Mark Rosenthal, MD2; 1 Baltimore, MD, USA; 2North American Spine Society, Baltimore, MD, USA
4:35 Trends in recalls of musculoskeletal tissue allografts: analysis of Food and Drug Administration recall data Jeffrey Wang, MD1, Randal Mills, PhD2, Michael Roberts, MA2, Dayna Buskirk, DC3; 1University of California, Los Angeles, Los Angeles, CA, USA; 2Regeneration Technologies, Alachua, FL, USA; 3Regeneration Technologies, Inc., Alachua, FL, USA
Purpose of study: This study was undertaken to review our experience with single-level posterior instrumented lumbar fusions in an effort to identify which patients would require blood transfusion (TXF) and to determine the cost effectiveness of using autologous blood predonation (AB) and intraoperative blood salvage (CS). Methods used: Data were collected by means of retrospective chart review. Clinical data included demographics and comorbidities, pre- and postoperative HCT, duration of procedure, EBL, CS collection, number of AB units collected preoperatively, number and source of perioperative units of blood transfused. Financial data included charges for AB (Red Cross plus hospital processing) and hospital charges for CS. Summary of findings: Seventy-nine patients were included. The major difference between patients was the type of concurrent procedure carried out during the surgical setting. Forty procedures were at L4–L5, 23 at L5–S1, 14 at L3–L4 and 2 at L2–L3. Concurrent procedures, in addition to the fusion, were undertaken in 71 cases (90%). AB was used in 53 patients, and CS was used in 71 cases. Sixty-five patients (82%) did not receive postoperative TXF, and females were less likely to require a postoperative TXF (p.026). Thirteen patients (18%) received a postoperative TXF with older age, shorter height and lower preoperative hematocrit being more likely to require a TXF (p.001). Overall CS blood was transfused intraoperatively
Purpose of study: This poster provides an analysis of data collected and disseminated by the US Food and Drug Administration (FDA) concerning recalls of musculoskeletal tissue allografts and includes a discussion of the implications for patient safety. Methods used: The FDA collects and publishes information concerning recalls of regulated products, including musculoskeletal tissue allografts, on a weekly basis. For each recall, data are provided concerning the specific products involved in the recall, the “recalling” firm or manufacturer, the reasons for the recall, the volume of products and the geographic distribution of the recalled products. All FDA reports from 1994 through 2001 were reviewed to identify those recalls that involved musculoskeletal tissue. The reasons for recall, numbers of grafts recalled, trends over time and implications for patient safety were analyzed. Summary of findings: From 1994 through 2001, a total of 15,338 musculoskeletal tissue allografts were recalled in the United States. The most common reasons for recall include “improper donor evaluation” (10,929 grafts; 71.3%), and/or presence of positive serology results (3,140 grafts; 20.5%), results (976 grafts; 6.4%). Analysis of trends over time show that improper donor screening and testing, mishandling of positive serology results and other human errors continue to occur quite commonly (to date, 1,235 musculoskeletal tissue grafts have been reported as recalled in 2001).