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P116. Adipose stem cells can be induced towards the nucleus pulposus phenotype
166S
Proceedings of the NASS 20th Annual Meeting / The Spine Journal 5 (2005) 1S–189S
CONFLICT OF INTEREST: No conflicts. doi: 10.1016/j.spinee.2005.05.328 P114. Efficacy of delayed magnesium administration on spinal cord injury in the rat Alex Mohit, MD, PhD1, Jiejang Zhou, MD2, Diana Wiseman, MD2, Andrew Dailey, MD3; 1University of Washington, Seattle, WA, USA; 2 University of Washington, WA, USA; 3University of Washington/ Harborview Medical Center, Seattle, WA, USA BACKGROUND CONTEXT: High dose methylprednisolone is commonly administered in the setting of non-penetrating spinal cord injury. However, questionable clinical gains from its administration along with its known side effects have led to concerns regarding its routine use. Magnesium is a well known neuroprotective agent in experimental brain injury and spinal cord ischemia. It prevents glutamate toxicity by N-methyl-Daspartate receptor blockage in neural structures. PURPOSE: To study the efficacy of intravenous magnesium sulfate in reduction of secondary injury after non-penetrating spinal cord injury in a rat model. STUDY DESIGN/SETTING: Laboratory study in an animal model for spinal cord injury. PATIENT SAMPLE: None. OUTCOME MEASURES: BBB behavioral motor score. METHODS: Using the New York University (NYU) weight impactor model for spinal cord injury, we produced lesions within spinal cords of anesthetized Sprauge-Dwaley rats after thoracic laminectomy. The animals were then observed using a behavioral motor scoring system (BBB). The animals were graded from 0 (no movement) to 21 (normal movement) weekly for a period of 4 weeks. Animals received either saline, methylprednisolone, magnesium alone or magnesium and methylprednisolone 10 minutes after injury. After 4 weeks, we analyzed the sections of spinal cords from these animals by luxol fast blue for myelin and H&E. RESULTS: Comparison between animals that received magnesium and control animals, revealed a 40% improvement in BBB scoring at 4 weeks. Histologic analysis revealed remarkable loss of myelin staining in control animals for up to 10mm form the impact site. The animals that received magnesium had dramatically less myelin loss. Furthermore, administration of magnesium up to 8 hours after injury produced the same BBB scores as animals that received it 10 minutes after injury. Administration of magnesium at 12 and 24 hours after injury produced similar BBB scores as control animals. CONCLUSIONS: These results, although preliminary, suggest that intravenous administration of magnesium has a protective effect against secondary injury in the rat spinal cord. This is evidenced by improved clinical performance of these animals at 4 weeks and preservation of myelin on spinal cord sections. DISCLOSURES: FDA device/drug: Magnesium Sulfate. status: Not approved for this indication. CONFLICT OF INTEREST: No conflicts.
STUDY DESIGN/SETTING: Retrospective review of 79 patients with multilevel DDD/IDD causing disabling low back pain for at least 12 months before receiving two level TDR with the Charite´ artificial disc prosthesis. PATIENT SAMPLE: A series of 79 patients since 1996 having had two level TDR performed by a single surgeon. One patient declined study entry. The average follow-up was 29 months (12–72). In 69 cases L4–5/L5-S1 TDR was preformed, in 8 cases L3–4/L4–5, and in 1 case L3–4/L5-S1. Seven patients received a fusion at an adjacent level. OUTCOME MEASURES: Back and leg VAS, Oswestry Disability Index (ODI), and Roland-Morris Disability Questionnaire (R-MD). METHODS: Outcome measures were collected preoperatively and postoperatively at 3, 6, 12, and 24 months, and annually thereafter. All patients completed preoperative and end point outcome measures; some did not complete all of their postoperative outcome measures. Operative time, blood loss, complications, and length of hospital stay were documented. Patient compensation status and postoperative return to work was documented. RESULTS: When comparing preoperative and end point assessments there was a 77.9% improvement in back VAS, an 85.7% improvement in leg VAS, a 35 point (68.1%) improvement in ODI, and a 12.4 point (71.9%) improvement in R-MD. As some postoperative outcome measures were not completed subgroups with complete data were analyzed. Fifty patients completed a 12 month assessment. There was a 79.7% improvement in back VAS, an 89.7% in leg VAS, a 36.0 point (70.4%) improvement in ODI, and an 11.8 point (74.7%) improvement in R-MD. Thirty-four patients completed the 24 month data. There was an 80.6% improvement in back VAS, a 91.6% in leg VAS, a 43.1 point (78.0%) improvement in ODI, and a 13.6 point (77.5%) improvment in R-MD. Nine patients had prior surgery. When compared with those with no prior surgery, no statistical difference was detected. There was a trend to suggest that the ODI and back VAS scores of the patients with previous surgery improved more quickly in the early stages. Fourteen patients were involved in compensation claims at the time of surgery. Their results were compared with those patients without compensation claims. The numbers were too small to be statistically significant, but there was a trend suggesting recovery was delayed in the compensation group. However, at 24 months there was no difference in the outcome scores. In the patient sample, 87% of patients returned to work. The average hospital stay was 5.4 days. The average operative time was 85 minutes. The average blood loss was 130mls. No major intra-operative complications were documented. One neurological complication was documented. Two revision procedures were preformed. No prosthetic failure occurred. CONCLUSIONS: Two level TDR in the lumbar spine for treatment of multilevel DDD/IDD is a viable option and will become part of the armamentarium of spine surgeons and possibly the treatment of choice. The postoperative improvements in outcome measures are significant and sustained. Prior surgery and compensation does not preclude a good result. DISCLOSURES: FDA device/drug: Charite´ disc prosthesis. Status: Not approved for this indication. CONFLICT OF INTEREST: Author (MS) Consultant: DePuy Spine.; Author (MS) Other: Participates on DePuy Spine’s disc developement team. doi: 10.1016/j.spinee.2005.05.330
doi: 10.1016/j.spinee.2005.05.329
P115. Two level lumbar disc replacement: retrospective study of 79 patients with minimum follow-up period of one year Matthew Scott-Young, MBBS, FRACS, FAORTHOA; Pacific Private Clinic, Southport, Queensland, Australia BACKGROUND CONTEXT: Surgical management of low back pain secondary to multilevel degenerative disc disease and internal disc disruption (DDD/IDD) remains controversial. There is little published evidence as to the success of two level total disc replacement (TDR). PURPOSE: To assess two level TDR as a treatment option for multilevel DDD/IDD, report the postoperative return to work rate, and assess the results of compensation patients and patients with prior surgery.
P116. Adipose stem cells can be induced towards the nucleus pulposus phenotype Marco N. Helder1, Behrouz Zandieh Doulabi, PhD2, Roel J.W. Hoogendoorn, MD1, John K. Fraser, PhD3, Paul I.J.M. Wuisman, MD, PhD1; 1VU University Medical Center, Amsterdam, Netherlands; 2Academic Center of Dentistry–Vrije Universiteit, Amsterdam, Netherlands; 3MacroPore Biosurgery Inc., San Diego, CA, USA BACKGROUND CONTEXT: Treatment of degenerative disc disease (DDD) with multipotent adult cells has the potential for regeneration of the nucleus pulposus (NP). Human adipose contains stem cell-like cells (ASC), however, it is not known if ASC can differentiate towards the NP cell phenotype.
Proceedings of the NASS 20th Annual Meeting / The Spine Journal 5 (2005) 1S–189S PURPOSE: We hypothesize that co-culture of NP cells with ASC will generate a microenvironment in which the NP differentiation capacity of ASC will be exhibited. STUDY DESIGN/SETTING: This was tested in a transwell setting using co-cultures of ASCs and NP cells in micromass and/or monolayer. PATIENT SAMPLE: NP- and ASC cells were obtained from the same scoliosis patients. OUTCOME MEASURES: real-time PCR was performed to quantify the relative expression levels of the markers runx-2, CDMP-2, and aggrecan. METHODS: NP cells were isolated according to Gan et al. (Clin Orthop Rel Res 411, p. 315, 2003), ASCs according to Zuk et al. (Tissue Eng 7, p. 211, 2001). Cells were cultured in DMEM/F12⫹10% FCS. Co-cultures (passage 1 cells) were performed in 4 groups in transwells: (1) NP and ASC monolayer; (2) NP monolayer, ASC micromass; (3) NP micromass, ASC monolayer; and (4) NP and ASC monolayers at opposite sites of the transwell filter. After 11 days of culture, total RNA was isolated, and real-time PCR was performed to quantify the relative expression levels of cbfa1/runx-2, CDMP-2, and aggrecan (normalized to the 18S gene). RESULTS: We found that in both groups 1 and 2, the NP monolayers induced relatively high expressions in ASC for runx-2 (15.32 and 37.03 arbitrary units (a.u.), respectively) and CDMP-2 (17.5 resp. 232.3 a.u.), but no expression of aggrecan mRNA. However, both in group 3 (ASC monolayer with NP micromass culture) as well as in group 4 (ASC and NP monolayers on opposite sides of the transwell filter) only slightly elevated levels of runx-2 (2.3 and 4.9 a.u.) and CDMP-2 (5.5 and 1.6 a.u) were observed, but now also aggrecan mRNA expression could be demonstrated 1.7 a.u and 2.3 a.u). CONCLUSIONS: Our data indicate that NP cell monolayers induce early chondrogenic differentiation in ASC (relatively high runx-2 / CDMP-2, undetectable aggrecan). By contrast, when NP cells are cultured under micromass conditions or when close contacts between ASC and NP cells exist, induction progresses to later differentiation phases (lowered runx2 / CDMP-2, upregulation of aggrecan). We conclude that in an appropriate microenvironment, as present in the nucleus, ASC can differentiate towards a NP-like phenotype and hence may enhance regeneration of DDD. DISCLOSURES: No disclosures. CONFLICT OF INTEREST: No conflicts.
167S
STUDY DESIGN/SETTING: Methodological study. PATIENT SAMPLE: Thirty-five lateral radiographs of thoracolumbar (18 thoracic and 17 lumbar) osteoporotic compression fractures were randomly selected. Patient group was composed of 28 female and 7 male and the mean age was 63 (55–75) years. All patients had bone mineral densities indicating osteoporosis. OUTCOME MEASURES: Kyphotic deformity was measured by using four different techniques: 1) Measuring the angle between the superior and the inferior end plates of the fractured vertebral body (FVB), 2) Measuring the angle between the inferior end plate of the vertebral body just above the fracture and the inferior end plate of the FVB, 3) Measuring the angle between the inferior end plate of the vertebra above and the superior end plate of the vertebra below the FVB, 4) Measuring the angle between the superior end plate of the vertebral body above and the inferior end plate of the vertebral body below. Three different heights (anterior, mid and posterior) of vertebral body were measured to determine the vertebral body height (VBH). METHODS: Measurements were done on two occasions with 3 weeks interval by three spine surgeons. The observers were blinded as to the dates of the radiographs and the identities of the patients. Between the measuring sessions, the radiographs were cleaned completely of all marks with soft alcohol pads. All measurements were done by using the same goniometer and marking implement. The intra- and inter-observer limits of agreement of the techniques was calculated by using Bland-Altman Method. RESULTS: The mean intra-observer agreement intervals of measurement techniques ranged from ⫾7.1 degrees to ⫾9.3 degrees for kyphosis angle and from ⫾4.5mm to ⫾6.6mm for VBH measurement techniques. The mean interobserver agreement interval for kyphosis angle ranged from ⫾8.2 degrees to ⫾11.1 degrees and between ⫾4.5mm to ⫾6.5mm for vertebral body height measurements. CONCLUSIONS: This study revealed that although the intra and interobserver agreement intervals were similar for all techniques, they were still higher than the generally accepted 5 degrees of measurement error. These high intervals for measurement errors should be taken into account when interpreting the results of correction in sagittal plane deformities of OVCF patients after surgical procedures such as vertebral augmentation techniques. DISCLOSURES: No disclosures. CONFLICT OF INTEREST: No conflicts.
doi: 10.1016/j.spinee.2005.05.331 doi: 10.1016/j.spinee.2005.05.332 P117. Radiographic measurement of the sagittal plane deformity: evaluation of intrinsic error Murat Pekmezci1, Ahmet Alanay1*, Emre Acaroglu1, Muharrem Yazici1, Oguz Karaeminogullari, MD2, Akin Cil, MD1, A.C.M. Pijnenburg, MD3, Yasemin Genc, PhD3, Adil Surat, MD1; 1Hacettepe University Faculty of Medicine, Ankara, Turkey; 2Baskent University, Ankara, Turkey; 3 Diaknessenhuis, Utrecht, Netherlands BACKGROUND CONTEXT: Measuring the sagittal plane deformity is important in terms of evaluation of the severity of the osteoporotic vertebral compression fractures, the treatment method and its outcome. There is still debate on the efficacy of vertebral augmentation techniques in correction of sagittal plane deformity which is secondary to the non-uniform analysis of sagittal plane deformity and the lack of reliability of the different methods used in the published studies. Cobb method has been shown to be the most reliable technique with a reasonable measurement error to determine the kyphosis in fresh fractures of young patients. However, measurement errors may be higher for elderly patients as it may be difficult to determine the landmarks due to osteopenia and the degenerative changes. There is not yet any published study on the agreement intervals of the methods currently used to evaluate sagittal plane malalignment in elderly patients. PURPOSE: The purpose of this study was to determine the measurement error of commonly used techniques, first when the same observer and then when different observers measured the same radiographs to determine the severity of kyphotic deformity.
P118. Surgical technique and clinical outcome of posterolateral endoscopic surgery for pyogenic spondylodiscitis in patients with serious comorbid conditions Manabu Ito1, Kuniyoshi Abumi2, Yoshihisa Kotani1, Ken Kadoya2, Masahiko Takahata1, Hideki Sudo3, Akio Minami1; 1Hokkaido University Sapporo, Sapporo, Japan; 2Hokkaido University, Sapporo, Hokkaido, Japan; 3Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido, Japan BACKGROUND CONTEXT: The number of spinal infections has been increasing, probably due to an increase of immunosuppressed patients who have comorbid medical problems. Many patients with spinal infections are resistant to initial antibiotics treatment because of their serious medical problems. Moreover, major spinal surgery often results in post-surgical complications. PURPOSE: The purpose of this study is to report a new surgical technique and clinical results of posterolateral spinal endoscopic surgery for pyogenic spondylodiscitis in patients with multiple comorbidities. STUDY DESIGN/SETTING: A retrospective clinical study. PATIENT SAMPLE: Fifteen consecutive patients were involved. There were 10 male and 5 female patients. Their ages ranged from 15 to 74 years. The levels of infection were T9/10 in one patient, L1/2 in two, L2/3 in one, L3/4 in six, L4/5 in two, and L5/S in three. Most patients had comorbid medical problems. Previous physicians had treated all the patients with antibiotics and bed rest. The interval between the onset of spinal infection and their referral to our institution ranged from 3 weeks to 104 weeks.
Proceedings of the NASS 20th Annual Meeting / The Spine Journal 5 (2005) 1S–189S
CONFLICT OF INTEREST: No conflicts. doi: 10.1016/j.spinee.2005.05.328 P114. Efficacy of delayed magnesium administration on spinal cord injury in the rat Alex Mohit, MD, PhD1, Jiejang Zhou, MD2, Diana Wiseman, MD2, Andrew Dailey, MD3; 1University of Washington, Seattle, WA, USA; 2 University of Washington, WA, USA; 3University of Washington/ Harborview Medical Center, Seattle, WA, USA BACKGROUND CONTEXT: High dose methylprednisolone is commonly administered in the setting of non-penetrating spinal cord injury. However, questionable clinical gains from its administration along with its known side effects have led to concerns regarding its routine use. Magnesium is a well known neuroprotective agent in experimental brain injury and spinal cord ischemia. It prevents glutamate toxicity by N-methyl-Daspartate receptor blockage in neural structures. PURPOSE: To study the efficacy of intravenous magnesium sulfate in reduction of secondary injury after non-penetrating spinal cord injury in a rat model. STUDY DESIGN/SETTING: Laboratory study in an animal model for spinal cord injury. PATIENT SAMPLE: None. OUTCOME MEASURES: BBB behavioral motor score. METHODS: Using the New York University (NYU) weight impactor model for spinal cord injury, we produced lesions within spinal cords of anesthetized Sprauge-Dwaley rats after thoracic laminectomy. The animals were then observed using a behavioral motor scoring system (BBB). The animals were graded from 0 (no movement) to 21 (normal movement) weekly for a period of 4 weeks. Animals received either saline, methylprednisolone, magnesium alone or magnesium and methylprednisolone 10 minutes after injury. After 4 weeks, we analyzed the sections of spinal cords from these animals by luxol fast blue for myelin and H&E. RESULTS: Comparison between animals that received magnesium and control animals, revealed a 40% improvement in BBB scoring at 4 weeks. Histologic analysis revealed remarkable loss of myelin staining in control animals for up to 10mm form the impact site. The animals that received magnesium had dramatically less myelin loss. Furthermore, administration of magnesium up to 8 hours after injury produced the same BBB scores as animals that received it 10 minutes after injury. Administration of magnesium at 12 and 24 hours after injury produced similar BBB scores as control animals. CONCLUSIONS: These results, although preliminary, suggest that intravenous administration of magnesium has a protective effect against secondary injury in the rat spinal cord. This is evidenced by improved clinical performance of these animals at 4 weeks and preservation of myelin on spinal cord sections. DISCLOSURES: FDA device/drug: Magnesium Sulfate. status: Not approved for this indication. CONFLICT OF INTEREST: No conflicts.
STUDY DESIGN/SETTING: Retrospective review of 79 patients with multilevel DDD/IDD causing disabling low back pain for at least 12 months before receiving two level TDR with the Charite´ artificial disc prosthesis. PATIENT SAMPLE: A series of 79 patients since 1996 having had two level TDR performed by a single surgeon. One patient declined study entry. The average follow-up was 29 months (12–72). In 69 cases L4–5/L5-S1 TDR was preformed, in 8 cases L3–4/L4–5, and in 1 case L3–4/L5-S1. Seven patients received a fusion at an adjacent level. OUTCOME MEASURES: Back and leg VAS, Oswestry Disability Index (ODI), and Roland-Morris Disability Questionnaire (R-MD). METHODS: Outcome measures were collected preoperatively and postoperatively at 3, 6, 12, and 24 months, and annually thereafter. All patients completed preoperative and end point outcome measures; some did not complete all of their postoperative outcome measures. Operative time, blood loss, complications, and length of hospital stay were documented. Patient compensation status and postoperative return to work was documented. RESULTS: When comparing preoperative and end point assessments there was a 77.9% improvement in back VAS, an 85.7% improvement in leg VAS, a 35 point (68.1%) improvement in ODI, and a 12.4 point (71.9%) improvement in R-MD. As some postoperative outcome measures were not completed subgroups with complete data were analyzed. Fifty patients completed a 12 month assessment. There was a 79.7% improvement in back VAS, an 89.7% in leg VAS, a 36.0 point (70.4%) improvement in ODI, and an 11.8 point (74.7%) improvement in R-MD. Thirty-four patients completed the 24 month data. There was an 80.6% improvement in back VAS, a 91.6% in leg VAS, a 43.1 point (78.0%) improvement in ODI, and a 13.6 point (77.5%) improvment in R-MD. Nine patients had prior surgery. When compared with those with no prior surgery, no statistical difference was detected. There was a trend to suggest that the ODI and back VAS scores of the patients with previous surgery improved more quickly in the early stages. Fourteen patients were involved in compensation claims at the time of surgery. Their results were compared with those patients without compensation claims. The numbers were too small to be statistically significant, but there was a trend suggesting recovery was delayed in the compensation group. However, at 24 months there was no difference in the outcome scores. In the patient sample, 87% of patients returned to work. The average hospital stay was 5.4 days. The average operative time was 85 minutes. The average blood loss was 130mls. No major intra-operative complications were documented. One neurological complication was documented. Two revision procedures were preformed. No prosthetic failure occurred. CONCLUSIONS: Two level TDR in the lumbar spine for treatment of multilevel DDD/IDD is a viable option and will become part of the armamentarium of spine surgeons and possibly the treatment of choice. The postoperative improvements in outcome measures are significant and sustained. Prior surgery and compensation does not preclude a good result. DISCLOSURES: FDA device/drug: Charite´ disc prosthesis. Status: Not approved for this indication. CONFLICT OF INTEREST: Author (MS) Consultant: DePuy Spine.; Author (MS) Other: Participates on DePuy Spine’s disc developement team. doi: 10.1016/j.spinee.2005.05.330
doi: 10.1016/j.spinee.2005.05.329
P115. Two level lumbar disc replacement: retrospective study of 79 patients with minimum follow-up period of one year Matthew Scott-Young, MBBS, FRACS, FAORTHOA; Pacific Private Clinic, Southport, Queensland, Australia BACKGROUND CONTEXT: Surgical management of low back pain secondary to multilevel degenerative disc disease and internal disc disruption (DDD/IDD) remains controversial. There is little published evidence as to the success of two level total disc replacement (TDR). PURPOSE: To assess two level TDR as a treatment option for multilevel DDD/IDD, report the postoperative return to work rate, and assess the results of compensation patients and patients with prior surgery.
P116. Adipose stem cells can be induced towards the nucleus pulposus phenotype Marco N. Helder1, Behrouz Zandieh Doulabi, PhD2, Roel J.W. Hoogendoorn, MD1, John K. Fraser, PhD3, Paul I.J.M. Wuisman, MD, PhD1; 1VU University Medical Center, Amsterdam, Netherlands; 2Academic Center of Dentistry–Vrije Universiteit, Amsterdam, Netherlands; 3MacroPore Biosurgery Inc., San Diego, CA, USA BACKGROUND CONTEXT: Treatment of degenerative disc disease (DDD) with multipotent adult cells has the potential for regeneration of the nucleus pulposus (NP). Human adipose contains stem cell-like cells (ASC), however, it is not known if ASC can differentiate towards the NP cell phenotype.
Proceedings of the NASS 20th Annual Meeting / The Spine Journal 5 (2005) 1S–189S PURPOSE: We hypothesize that co-culture of NP cells with ASC will generate a microenvironment in which the NP differentiation capacity of ASC will be exhibited. STUDY DESIGN/SETTING: This was tested in a transwell setting using co-cultures of ASCs and NP cells in micromass and/or monolayer. PATIENT SAMPLE: NP- and ASC cells were obtained from the same scoliosis patients. OUTCOME MEASURES: real-time PCR was performed to quantify the relative expression levels of the markers runx-2, CDMP-2, and aggrecan. METHODS: NP cells were isolated according to Gan et al. (Clin Orthop Rel Res 411, p. 315, 2003), ASCs according to Zuk et al. (Tissue Eng 7, p. 211, 2001). Cells were cultured in DMEM/F12⫹10% FCS. Co-cultures (passage 1 cells) were performed in 4 groups in transwells: (1) NP and ASC monolayer; (2) NP monolayer, ASC micromass; (3) NP micromass, ASC monolayer; and (4) NP and ASC monolayers at opposite sites of the transwell filter. After 11 days of culture, total RNA was isolated, and real-time PCR was performed to quantify the relative expression levels of cbfa1/runx-2, CDMP-2, and aggrecan (normalized to the 18S gene). RESULTS: We found that in both groups 1 and 2, the NP monolayers induced relatively high expressions in ASC for runx-2 (15.32 and 37.03 arbitrary units (a.u.), respectively) and CDMP-2 (17.5 resp. 232.3 a.u.), but no expression of aggrecan mRNA. However, both in group 3 (ASC monolayer with NP micromass culture) as well as in group 4 (ASC and NP monolayers on opposite sides of the transwell filter) only slightly elevated levels of runx-2 (2.3 and 4.9 a.u.) and CDMP-2 (5.5 and 1.6 a.u) were observed, but now also aggrecan mRNA expression could be demonstrated 1.7 a.u and 2.3 a.u). CONCLUSIONS: Our data indicate that NP cell monolayers induce early chondrogenic differentiation in ASC (relatively high runx-2 / CDMP-2, undetectable aggrecan). By contrast, when NP cells are cultured under micromass conditions or when close contacts between ASC and NP cells exist, induction progresses to later differentiation phases (lowered runx2 / CDMP-2, upregulation of aggrecan). We conclude that in an appropriate microenvironment, as present in the nucleus, ASC can differentiate towards a NP-like phenotype and hence may enhance regeneration of DDD. DISCLOSURES: No disclosures. CONFLICT OF INTEREST: No conflicts.
167S
STUDY DESIGN/SETTING: Methodological study. PATIENT SAMPLE: Thirty-five lateral radiographs of thoracolumbar (18 thoracic and 17 lumbar) osteoporotic compression fractures were randomly selected. Patient group was composed of 28 female and 7 male and the mean age was 63 (55–75) years. All patients had bone mineral densities indicating osteoporosis. OUTCOME MEASURES: Kyphotic deformity was measured by using four different techniques: 1) Measuring the angle between the superior and the inferior end plates of the fractured vertebral body (FVB), 2) Measuring the angle between the inferior end plate of the vertebral body just above the fracture and the inferior end plate of the FVB, 3) Measuring the angle between the inferior end plate of the vertebra above and the superior end plate of the vertebra below the FVB, 4) Measuring the angle between the superior end plate of the vertebral body above and the inferior end plate of the vertebral body below. Three different heights (anterior, mid and posterior) of vertebral body were measured to determine the vertebral body height (VBH). METHODS: Measurements were done on two occasions with 3 weeks interval by three spine surgeons. The observers were blinded as to the dates of the radiographs and the identities of the patients. Between the measuring sessions, the radiographs were cleaned completely of all marks with soft alcohol pads. All measurements were done by using the same goniometer and marking implement. The intra- and inter-observer limits of agreement of the techniques was calculated by using Bland-Altman Method. RESULTS: The mean intra-observer agreement intervals of measurement techniques ranged from ⫾7.1 degrees to ⫾9.3 degrees for kyphosis angle and from ⫾4.5mm to ⫾6.6mm for VBH measurement techniques. The mean interobserver agreement interval for kyphosis angle ranged from ⫾8.2 degrees to ⫾11.1 degrees and between ⫾4.5mm to ⫾6.5mm for vertebral body height measurements. CONCLUSIONS: This study revealed that although the intra and interobserver agreement intervals were similar for all techniques, they were still higher than the generally accepted 5 degrees of measurement error. These high intervals for measurement errors should be taken into account when interpreting the results of correction in sagittal plane deformities of OVCF patients after surgical procedures such as vertebral augmentation techniques. DISCLOSURES: No disclosures. CONFLICT OF INTEREST: No conflicts.
doi: 10.1016/j.spinee.2005.05.331 doi: 10.1016/j.spinee.2005.05.332 P117. Radiographic measurement of the sagittal plane deformity: evaluation of intrinsic error Murat Pekmezci1, Ahmet Alanay1*, Emre Acaroglu1, Muharrem Yazici1, Oguz Karaeminogullari, MD2, Akin Cil, MD1, A.C.M. Pijnenburg, MD3, Yasemin Genc, PhD3, Adil Surat, MD1; 1Hacettepe University Faculty of Medicine, Ankara, Turkey; 2Baskent University, Ankara, Turkey; 3 Diaknessenhuis, Utrecht, Netherlands BACKGROUND CONTEXT: Measuring the sagittal plane deformity is important in terms of evaluation of the severity of the osteoporotic vertebral compression fractures, the treatment method and its outcome. There is still debate on the efficacy of vertebral augmentation techniques in correction of sagittal plane deformity which is secondary to the non-uniform analysis of sagittal plane deformity and the lack of reliability of the different methods used in the published studies. Cobb method has been shown to be the most reliable technique with a reasonable measurement error to determine the kyphosis in fresh fractures of young patients. However, measurement errors may be higher for elderly patients as it may be difficult to determine the landmarks due to osteopenia and the degenerative changes. There is not yet any published study on the agreement intervals of the methods currently used to evaluate sagittal plane malalignment in elderly patients. PURPOSE: The purpose of this study was to determine the measurement error of commonly used techniques, first when the same observer and then when different observers measured the same radiographs to determine the severity of kyphotic deformity.
P118. Surgical technique and clinical outcome of posterolateral endoscopic surgery for pyogenic spondylodiscitis in patients with serious comorbid conditions Manabu Ito1, Kuniyoshi Abumi2, Yoshihisa Kotani1, Ken Kadoya2, Masahiko Takahata1, Hideki Sudo3, Akio Minami1; 1Hokkaido University Sapporo, Sapporo, Japan; 2Hokkaido University, Sapporo, Hokkaido, Japan; 3Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido, Japan BACKGROUND CONTEXT: The number of spinal infections has been increasing, probably due to an increase of immunosuppressed patients who have comorbid medical problems. Many patients with spinal infections are resistant to initial antibiotics treatment because of their serious medical problems. Moreover, major spinal surgery often results in post-surgical complications. PURPOSE: The purpose of this study is to report a new surgical technique and clinical results of posterolateral spinal endoscopic surgery for pyogenic spondylodiscitis in patients with multiple comorbidities. STUDY DESIGN/SETTING: A retrospective clinical study. PATIENT SAMPLE: Fifteen consecutive patients were involved. There were 10 male and 5 female patients. Their ages ranged from 15 to 74 years. The levels of infection were T9/10 in one patient, L1/2 in two, L2/3 in one, L3/4 in six, L4/5 in two, and L5/S in three. Most patients had comorbid medical problems. Previous physicians had treated all the patients with antibiotics and bed rest. The interval between the onset of spinal infection and their referral to our institution ranged from 3 weeks to 104 weeks.