- Email: [email protected]
The Incidence of C5 Palsy after Multilevel Cervical Decompression Procedures
Proceedings of the NASS 25th Annual Meeting / The Spine Journal 10 (2010) 1S–149S the two groups in back and leg pain at 1.5, 3, 6, 12, 24 months and ODI/ SF-36 scores at 6,12,24 months (pO0.2). CONCLUSIONS: The strengths of this comparative study are related to the strong consistencies between groups (homogenous patient population and selection, same surgeon and with the exception of BMP usage, identical surgical technique). The use of low dose BMP in MIS-TLIF does not seem to result in an increase incidence of radiculitis, but is associated with a greater incidence of potentially significant radiographic findings of HO and osteolysis. The impact of these radiographic findings on clinical outcome at 6, 12 and 24 months were not significant. FDA DEVICE/DRUG STATUS: Infuse: Investigational/Not approved. doi: 10.1016/j.spinee.2010.07.028
18. Pedicle Screws Adjacent to the Aorta: Is Prone CT Scan Helpful? Adam Wollowick, MD1, Beverly Thornhill, MD1, Terry Amaral, MD1, Etan Sugarman, MSIV2, Vishal Sarwahi, MD1; 1Montefiore Medical Center, Bronx, NY, USA; 2Albert Einstein College of Medicine, Bronx, NY, USA BACKGROUND CONTEXT: Pedicle screw fixation is becoming more common in spinal surgery. The rate of screw malposition varies but is generally felt to be around 10%. One of the dangers of malposition is the risk to the great vessels. CT scans, although considered to be the gold standard in assessing the location of pedicle screws, may be limited due to metallic artifact. PURPOSE: To determine if prone CT scan is helpful in assessing pedicle screws that are adjacent to the aorta. STUDY DESIGN/SETTING: Retrospective review of post-operative CT scans in patients treated with pedicle screw instrumentation for pediatric spinal deformity. The investigation was performed at an academic medical center in a major metropolitan area. PATIENT SAMPLE: 45 pediatric patients (18 years) with spinal deformity who were treated surgically with pedicle screw-based instrumentation. OUTCOME MEASURES: Proximity of screws to the aorta based upon supine and prone CT scans. METHODS: 45 patients had routine CT scans after spinal deformity surgery. In 6 of these patients, some screws were variably described as adjacent to the aorta, impinging upon the aorta, or contiguous with the aorta. CT scan in the prone position was repeated in these patients. In one patient where the screw was felt to compromise the lumen, a prone CT scan with contrast was performed. The aorta was studied with respect to changes in lumen size, pseudoaneurysm, and mobility. The distance of the aorta to the anterior border of vertebra was measured. CT scans in all the patients were independently reviewed by two radiologists, one spine surgeon and one vascular surgeon. RESULTS: Eight (8) screws showed close proximity to the aorta on supine CT. Two of these, in one patient, appeared embedded in the aorta. On prone CT scans, for 7 of the 8 screws, the aorta lumen and walls were clearly visualized and the aorta was noted to move away both qualitatively and quantitatively. These included the 2 screws that appeared embedded in the aorta. In one instance, the relationship was unchanged on supine and prone CT scans. The prone CT angiogram in the patient with questionable penetration provided better visualization of the aortic lumen. No screw was noted to violate the aortic lumen, encroach upon the aortic wall, or distort it. CONCLUSIONS: Use of the prone position during follow-up CT scan for evaluation of the relationship of pedicle screws to the aorta allows better visualization. When in doubt, the additional use of an arteriogram can define this relationship more clearly. CT scan done in the prone and supine positions with or without contrast allows better documentation of the pedicle screwaorta relationship. Mobility of the aorta on the CT scan at the questioned level indicates absence of tethering or scarring. Absence of pseudoaneurysm, stenosis, or intimal distortion on CT suggests absence of screw penetraion. This combined with mobility on prone CT scan can be useful when planning screw removal. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs. doi: 10.1016/j.spinee.2010.07.029
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19. Effect of Spinal Shortening on Motor-Evoked Potentials Causing Spinal Cord Injury and on Spinal Cord Blood Flow Hiteshkumar N. Modi, Seung-Woo Suh, MD, Jae-Young Hong, Jae-Hyuk Yang, MD; Scoliosis Research Institute, Department of Orthopedics, Korea University Guro Hospital, Seoul, Republic of Korea BACKGROUND CONTEXT: Animal study for spinal cord injury using spinal shortening is imperative to be helpful. PURPOSE: To study effect of spinal cord injury (SCI) on trans-cranial motor-evoked potential (Tc-MEP) and changes in the spinal cord blood flow (SCBF) on the LASER Doppler. STUDY DESIGN/SETTING: An animal experimental study. PATIENT SAMPLE: 10 farm-pigs. OUTCOME MEASURES: Neuromonitoring with Tc-MEP and SCBF with LASER Doppler. METHODS: Experiment was performed in 10 farm-pigs under general anesthesia. Neuromonitoring was done using Tc-MEP, and SCBF was measured using LASER Doppler flow meter. After dissection, pedicle screws were inserted in T10 and T13 level; which was followed by osteotomy and two level (T11-T12) corpectomy. A gradual staged (phase 1: without morphological change; phase 2: cord buckling; and phase 3: cord kinking) spinal shortening was performed, and simultaneously Tc-MEP and SCBF was monitored. After 30 minutes wake-up test was performed and animal was sacrificed and cord biopsy was obtained. RESULTS: During spinal shortening MEP signals were maintained in phase1 and phase2; however, during phase 3, all leads were lost suggesting complete SCI (32.263.6 mm). The average spinal shortening showing SCI (3562.7 mm) was similar to average vertebral body height of T11-12 (33.661.9 mm) (p50.115). However, when the distance of spinal shortening was compared with the average segmental height (27.761.3 mm) of spinal column (T1-L6), it showed a statistically significant difference (p! 0.0001). Considering into percentage of spinal column length, SCI was not occurred at the shortening of 5.1% length of spinal column (safe zone); however, SCI occurred at shortening of 6.3% length of spinal column (unsafe zone). On SCBF measurement, during phase 3 of shortening where it produced SCI, SCBF decreased by 43.1611.4% (p!0.0001). On wake-up test, we could not observe movements. Histopathology exhibited axonal cutting with ischemic and necrotic changes. CONCLUSIONS: Spinal shortening at TL level can be done safely with the shortening of average segmental height or 5.1% length of spinal column (T1L6); however, it creates SCI if shortening is of average vertebral body height at T11-T12 or 6.3% length of spinal column. Spinal shortening induced SCI model in pig will highlight its relation with spinal shortening amount in future. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs. doi: 10.1016/j.spinee.2010.07.030
20. The Incidence of C5 Palsy after Multilevel Cervical Decompression Procedures Ahmad Nassr, MD1, Jason C. Eck, DO, MS2, Ravi K. Ponnappan, MD3, Rami R. Zanoun, BS4, William F. Donaldson, III, MD4, James D. Kang, MD4; 1Mayo Clinic, Rochester, MN, USA; 2University of Massachusetts, Worcester, MA, USA; 3Thomas Jefferson University, Philadelphia, PA, USA; 4University of Pittsburgh, Pittsburgh, PA, USA BACKGROUND CONTEXT: Palsy of the C5 nerve is a well-known potential complication of cervical spine surgery with reported rates ranging from 0–30%. The exact etiology remains uncertain but has been attributed to iatrogenic nerve injury during surgery, tethering of the nerve root from shifting of the spinal cord, spinal cord ischemia, and reperfusion injury of the spinal cord. It is not currently known whether anterior, posterior or combined procedures are associated with increased rates of C5 palsy. PURPOSE: The purpose of this study was to review the incidence of C5 palsy in a large consecutive series of multilevel cervical spine decompression procedures.
All referenced figures and tables will be available at the Annual Meeting and will be included with the post-meeting online content.
10S
Proceedings of the NASS 25th Annual Meeting / The Spine Journal 10 (2010) 1S–149S
STUDY DESIGN/SETTING: Retrospective Analysis. PATIENT SAMPLE: 750 patients. METHODS: A retrospective analysis of 750 consecutive multilevel decompressive cervical spine surgeries performed by a single spine surgeon was conducted. We included patients undergoing multilevel anterior cervical corpectomy, anterior corpectomy followed by posterior fusion, posterior laminectomy and fusion and laminoplasty procedures for the treatment of cervical spinal stenosis. Patients were excluded if there was lack of adequate follow-up data, spinal cord injury preventing preoperative or postoperative motor testing, or if the decompressive surgery did not include the C5 level. Incidence of C5 palsy was determined and compared to determine if statistically significant differences existed among the various procedures, patient age and gender. Statistical analysis was performed using Chi-Squared analysis with significance defined as a p-value of less than 0.05. RESULTS: Of the 750 patients, 120 were eliminated based on the exclusion criteria. The 630 patients included in the analysis consisted of 292 females and 338 males. The mean age was 58 years (range, 19–87). The incidence of C5 palsy for the entire group was 42 of 630 (6.7%). The incidence of C5 palsy was highest in the laminectomy and fusion group (9.5%); followed by the anterior corpectomy-posterior fusion group (8.4%), anterior corpectomy alone group (5.1%), and finally the laminoplasty group (4.8%), although these differences did not reach statistical significance. The majority of cases were noted within one week of surgery, but delayed onset of up to 2 months was observed. Age at the time of surgery was not identified as a risk factor. Males were more likely to develop C5 palsy 8.6% versus females 4.5%, but this did not reach statistical significance (p50.056). Almost all patients recovered full strength in the affected extremities although recovery time was variable. CONCLUSIONS: The incidence of C5 palsy following cervical spine decompression was 6.7%. This is consistent with previously published studies and represents the largest series of patients to date. Based on these data there is no statistical difference in the incidence of C5 palsy based on the surgical procedure although a trend towards higher rates of palsy was observed in our laminectomy and fusion group and our anterior/posterior fusion group. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs. doi: 10.1016/j.spinee.2010.07.031
METHODS: With adherence to the Guide for the Care of Laboratory Animals, aortic occlusion was achieved in anesthetized NZ albino rabbits by using a 3F Fogerty catheter, introduced through femoral incision to the L2 level. Aortic occlusion was verified by disappearance of pulse oxymetry tracing. Increasing I.V. doses of minocycline were given (1, 2, 5, and 10 mg/ kg; n510–12 animals in each dose group) thirty minutes prior to aortic occlusion of 25 min. The modified motor Tarlov scoring (0- complete paraplegia to 3-normal movements on days 0 to 2) was correlated to histological injury in the different regions (L4 to L6) of the cord. A histopathological grading of the degree of hypoxic/ischemic damage (0- normal to 4- marked) of H&E stained sections was determined according to the degree of ventral horn disruption associated with other typical alterations. The number of intact motoneurons per 10 high power fields (HPF) was counted. TUNEL staining tested apoptotic neurons per 10 HPF. Statistical analysis was performed using Spearman Correlation, Kruskel-Wallis and Mann-Whitney tests. RESULTS: Spinal cord ischemia for 25 minutes resulted in high-grade paraplegia in the control group. Preoperative minocycline administration produced a dose-dependent, significant improvement in the post-ischemic neurological deficit (10 mg/kg; p!0.001). The severity of histopathological damage was inversely related to the neurological deficit scores, with a clear reduction after minocycline administration (p!0.003). The number of viable neurons increased significantly in the 10 mg/kg treated rabbits compared to controls. No statistical correlation or significance was found for TUNEL positive cells in minocycline treated rabbits compared to controls. Post-ischemic minocycline did not induce significant cord protection. CONCLUSIONS: Minocycline demonstrated dose-dependent neuroprotection against temporary ischemia to the spinal cord, with significant sparing of motoneurons. With the high safety profile of the drug, the functional recovery achieved with minocycline has the potential for clinical applicability. FDA DEVICE/DRUG STATUS: Minocycline: Not approved for this indication. doi: 10.1016/j.spinee.2010.07.032
Wednesday, October 6, 2010 2:05–3:05 PM Concurrent Session 1: Lumbar Motion Sparing
21. Spinal Cord Protection from Aortic Occlusion-Related Ischemia by Minocycline Yair Barzilay, MD, Jakov Fellig, MD, Benjamin Drenger, MD; HadassahHebrew University Medical Center, Jerusalem, Israel
22. ProdiscÒ-l Total Disc Replacement over Time: 5- to 8-Year Follow-up Rudolf Bertagnoli, MD, PhD; ProSpine, Straubing, Germany
BACKGROUND CONTEXT: Effective therapeutic methods to prevent paraplegia following transient ischemia to the spinal cord are still under investigation. As subsequent effects of spinal cord ischemia are similar in traumatic spinal injury and neoplastic cord compression, the role of minocycline, a 2nd-generation tetracycline, known to ameliorate secondary events of spinal cord injury, such as apoptosis and inflammation was examined. PURPOSE: The protective role of minocycline in attenuating the histopathological changes in the spinal cord following aortic occlusion-related ischemia in the rabbit was investigated. STUDY DESIGN/SETTING: PRCT PATIENT SAMPLE: 61 male New Zealand albino rabbits weighing 3.0 to 4.0 kg were allocated to control (10) and 5 study groups (51). The control group was exposed to 25 minutes of aortic occlusion at the level of L1-2. The study groups included preoperative I.V Minocycline administration, 30 minutes prior to the ischemic insult. 10 Rabbits were administered with 1 mg/kg Minocycline, 10 with 2 mg/kg, 9 with 5 mg/kg and 12 with 10 mg/kg. Another group of 10 rabbits were administered with 10 mg/kg of Minocycline 15 minutes following the termination of the ischemic insult. OUTCOME MEASURES: Clinical-Modified Tarlov score; Histopathological - grading from 0 to 4 based on hypoxic/ischemic damage; Viable neuron count; TUNEL staining for apoptosis.
BACKGROUND CONTEXT: Lumbar total disc replacement (TDR) is an alternative to spinal fusion surgery for the treatment of degenerative disc disease (DDD) between L3-S1. It is intended to address discogenic pain and has the potential benefit of preserving functional motion in vertebral bodies; TDR may thus reduce long-term subsequent degeneration at adjacent disc levels, although continuing study results are needed to quantify this statement. PURPOSE: The purpose of this study was to evaluate the five-to-eight year clinical results of the ProDiscÒ-L (Synthes Gmbh) TDR. STUDY DESIGN/SETTING: From 2000–2004, a prospective, controlled, consecutive case series was conducted. PATIENT SAMPLE: A total of 506 patients received lumbar arthroplasty utilizing the ProDiscÒ-L TDR. OUTCOME MEASURES: Patients were assessed pre-operatively and post-operatively at 3, 6, 12, 24 months, and yearly thereafter. METHODS: Evaluations included Oswestry Disability Index (ODI), Visual Analog Scales (VAS) for pain and satisfaction, and SF-36 patient selfassessments, physical and neurological exams, and radiographic evaluation RESULTS: The average age of patients was 45.8 years old; 51.2% were men and 48.8% women. Out of the 506 patients, 352 underwent singlelevel; 109 two-level; 40 three-level; 1 four-level; and 1 five-level surgery.
All referenced figures and tables will be available at the Annual Meeting and will be included with the post-meeting online content.
18. Pedicle Screws Adjacent to the Aorta: Is Prone CT Scan Helpful? Adam Wollowick, MD1, Beverly Thornhill, MD1, Terry Amaral, MD1, Etan Sugarman, MSIV2, Vishal Sarwahi, MD1; 1Montefiore Medical Center, Bronx, NY, USA; 2Albert Einstein College of Medicine, Bronx, NY, USA BACKGROUND CONTEXT: Pedicle screw fixation is becoming more common in spinal surgery. The rate of screw malposition varies but is generally felt to be around 10%. One of the dangers of malposition is the risk to the great vessels. CT scans, although considered to be the gold standard in assessing the location of pedicle screws, may be limited due to metallic artifact. PURPOSE: To determine if prone CT scan is helpful in assessing pedicle screws that are adjacent to the aorta. STUDY DESIGN/SETTING: Retrospective review of post-operative CT scans in patients treated with pedicle screw instrumentation for pediatric spinal deformity. The investigation was performed at an academic medical center in a major metropolitan area. PATIENT SAMPLE: 45 pediatric patients (18 years) with spinal deformity who were treated surgically with pedicle screw-based instrumentation. OUTCOME MEASURES: Proximity of screws to the aorta based upon supine and prone CT scans. METHODS: 45 patients had routine CT scans after spinal deformity surgery. In 6 of these patients, some screws were variably described as adjacent to the aorta, impinging upon the aorta, or contiguous with the aorta. CT scan in the prone position was repeated in these patients. In one patient where the screw was felt to compromise the lumen, a prone CT scan with contrast was performed. The aorta was studied with respect to changes in lumen size, pseudoaneurysm, and mobility. The distance of the aorta to the anterior border of vertebra was measured. CT scans in all the patients were independently reviewed by two radiologists, one spine surgeon and one vascular surgeon. RESULTS: Eight (8) screws showed close proximity to the aorta on supine CT. Two of these, in one patient, appeared embedded in the aorta. On prone CT scans, for 7 of the 8 screws, the aorta lumen and walls were clearly visualized and the aorta was noted to move away both qualitatively and quantitatively. These included the 2 screws that appeared embedded in the aorta. In one instance, the relationship was unchanged on supine and prone CT scans. The prone CT angiogram in the patient with questionable penetration provided better visualization of the aortic lumen. No screw was noted to violate the aortic lumen, encroach upon the aortic wall, or distort it. CONCLUSIONS: Use of the prone position during follow-up CT scan for evaluation of the relationship of pedicle screws to the aorta allows better visualization. When in doubt, the additional use of an arteriogram can define this relationship more clearly. CT scan done in the prone and supine positions with or without contrast allows better documentation of the pedicle screwaorta relationship. Mobility of the aorta on the CT scan at the questioned level indicates absence of tethering or scarring. Absence of pseudoaneurysm, stenosis, or intimal distortion on CT suggests absence of screw penetraion. This combined with mobility on prone CT scan can be useful when planning screw removal. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs. doi: 10.1016/j.spinee.2010.07.029
9S
19. Effect of Spinal Shortening on Motor-Evoked Potentials Causing Spinal Cord Injury and on Spinal Cord Blood Flow Hiteshkumar N. Modi, Seung-Woo Suh, MD, Jae-Young Hong, Jae-Hyuk Yang, MD; Scoliosis Research Institute, Department of Orthopedics, Korea University Guro Hospital, Seoul, Republic of Korea BACKGROUND CONTEXT: Animal study for spinal cord injury using spinal shortening is imperative to be helpful. PURPOSE: To study effect of spinal cord injury (SCI) on trans-cranial motor-evoked potential (Tc-MEP) and changes in the spinal cord blood flow (SCBF) on the LASER Doppler. STUDY DESIGN/SETTING: An animal experimental study. PATIENT SAMPLE: 10 farm-pigs. OUTCOME MEASURES: Neuromonitoring with Tc-MEP and SCBF with LASER Doppler. METHODS: Experiment was performed in 10 farm-pigs under general anesthesia. Neuromonitoring was done using Tc-MEP, and SCBF was measured using LASER Doppler flow meter. After dissection, pedicle screws were inserted in T10 and T13 level; which was followed by osteotomy and two level (T11-T12) corpectomy. A gradual staged (phase 1: without morphological change; phase 2: cord buckling; and phase 3: cord kinking) spinal shortening was performed, and simultaneously Tc-MEP and SCBF was monitored. After 30 minutes wake-up test was performed and animal was sacrificed and cord biopsy was obtained. RESULTS: During spinal shortening MEP signals were maintained in phase1 and phase2; however, during phase 3, all leads were lost suggesting complete SCI (32.263.6 mm). The average spinal shortening showing SCI (3562.7 mm) was similar to average vertebral body height of T11-12 (33.661.9 mm) (p50.115). However, when the distance of spinal shortening was compared with the average segmental height (27.761.3 mm) of spinal column (T1-L6), it showed a statistically significant difference (p! 0.0001). Considering into percentage of spinal column length, SCI was not occurred at the shortening of 5.1% length of spinal column (safe zone); however, SCI occurred at shortening of 6.3% length of spinal column (unsafe zone). On SCBF measurement, during phase 3 of shortening where it produced SCI, SCBF decreased by 43.1611.4% (p!0.0001). On wake-up test, we could not observe movements. Histopathology exhibited axonal cutting with ischemic and necrotic changes. CONCLUSIONS: Spinal shortening at TL level can be done safely with the shortening of average segmental height or 5.1% length of spinal column (T1L6); however, it creates SCI if shortening is of average vertebral body height at T11-T12 or 6.3% length of spinal column. Spinal shortening induced SCI model in pig will highlight its relation with spinal shortening amount in future. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs. doi: 10.1016/j.spinee.2010.07.030
20. The Incidence of C5 Palsy after Multilevel Cervical Decompression Procedures Ahmad Nassr, MD1, Jason C. Eck, DO, MS2, Ravi K. Ponnappan, MD3, Rami R. Zanoun, BS4, William F. Donaldson, III, MD4, James D. Kang, MD4; 1Mayo Clinic, Rochester, MN, USA; 2University of Massachusetts, Worcester, MA, USA; 3Thomas Jefferson University, Philadelphia, PA, USA; 4University of Pittsburgh, Pittsburgh, PA, USA BACKGROUND CONTEXT: Palsy of the C5 nerve is a well-known potential complication of cervical spine surgery with reported rates ranging from 0–30%. The exact etiology remains uncertain but has been attributed to iatrogenic nerve injury during surgery, tethering of the nerve root from shifting of the spinal cord, spinal cord ischemia, and reperfusion injury of the spinal cord. It is not currently known whether anterior, posterior or combined procedures are associated with increased rates of C5 palsy. PURPOSE: The purpose of this study was to review the incidence of C5 palsy in a large consecutive series of multilevel cervical spine decompression procedures.
All referenced figures and tables will be available at the Annual Meeting and will be included with the post-meeting online content.
10S
Proceedings of the NASS 25th Annual Meeting / The Spine Journal 10 (2010) 1S–149S
STUDY DESIGN/SETTING: Retrospective Analysis. PATIENT SAMPLE: 750 patients. METHODS: A retrospective analysis of 750 consecutive multilevel decompressive cervical spine surgeries performed by a single spine surgeon was conducted. We included patients undergoing multilevel anterior cervical corpectomy, anterior corpectomy followed by posterior fusion, posterior laminectomy and fusion and laminoplasty procedures for the treatment of cervical spinal stenosis. Patients were excluded if there was lack of adequate follow-up data, spinal cord injury preventing preoperative or postoperative motor testing, or if the decompressive surgery did not include the C5 level. Incidence of C5 palsy was determined and compared to determine if statistically significant differences existed among the various procedures, patient age and gender. Statistical analysis was performed using Chi-Squared analysis with significance defined as a p-value of less than 0.05. RESULTS: Of the 750 patients, 120 were eliminated based on the exclusion criteria. The 630 patients included in the analysis consisted of 292 females and 338 males. The mean age was 58 years (range, 19–87). The incidence of C5 palsy for the entire group was 42 of 630 (6.7%). The incidence of C5 palsy was highest in the laminectomy and fusion group (9.5%); followed by the anterior corpectomy-posterior fusion group (8.4%), anterior corpectomy alone group (5.1%), and finally the laminoplasty group (4.8%), although these differences did not reach statistical significance. The majority of cases were noted within one week of surgery, but delayed onset of up to 2 months was observed. Age at the time of surgery was not identified as a risk factor. Males were more likely to develop C5 palsy 8.6% versus females 4.5%, but this did not reach statistical significance (p50.056). Almost all patients recovered full strength in the affected extremities although recovery time was variable. CONCLUSIONS: The incidence of C5 palsy following cervical spine decompression was 6.7%. This is consistent with previously published studies and represents the largest series of patients to date. Based on these data there is no statistical difference in the incidence of C5 palsy based on the surgical procedure although a trend towards higher rates of palsy was observed in our laminectomy and fusion group and our anterior/posterior fusion group. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs. doi: 10.1016/j.spinee.2010.07.031
METHODS: With adherence to the Guide for the Care of Laboratory Animals, aortic occlusion was achieved in anesthetized NZ albino rabbits by using a 3F Fogerty catheter, introduced through femoral incision to the L2 level. Aortic occlusion was verified by disappearance of pulse oxymetry tracing. Increasing I.V. doses of minocycline were given (1, 2, 5, and 10 mg/ kg; n510–12 animals in each dose group) thirty minutes prior to aortic occlusion of 25 min. The modified motor Tarlov scoring (0- complete paraplegia to 3-normal movements on days 0 to 2) was correlated to histological injury in the different regions (L4 to L6) of the cord. A histopathological grading of the degree of hypoxic/ischemic damage (0- normal to 4- marked) of H&E stained sections was determined according to the degree of ventral horn disruption associated with other typical alterations. The number of intact motoneurons per 10 high power fields (HPF) was counted. TUNEL staining tested apoptotic neurons per 10 HPF. Statistical analysis was performed using Spearman Correlation, Kruskel-Wallis and Mann-Whitney tests. RESULTS: Spinal cord ischemia for 25 minutes resulted in high-grade paraplegia in the control group. Preoperative minocycline administration produced a dose-dependent, significant improvement in the post-ischemic neurological deficit (10 mg/kg; p!0.001). The severity of histopathological damage was inversely related to the neurological deficit scores, with a clear reduction after minocycline administration (p!0.003). The number of viable neurons increased significantly in the 10 mg/kg treated rabbits compared to controls. No statistical correlation or significance was found for TUNEL positive cells in minocycline treated rabbits compared to controls. Post-ischemic minocycline did not induce significant cord protection. CONCLUSIONS: Minocycline demonstrated dose-dependent neuroprotection against temporary ischemia to the spinal cord, with significant sparing of motoneurons. With the high safety profile of the drug, the functional recovery achieved with minocycline has the potential for clinical applicability. FDA DEVICE/DRUG STATUS: Minocycline: Not approved for this indication. doi: 10.1016/j.spinee.2010.07.032
Wednesday, October 6, 2010 2:05–3:05 PM Concurrent Session 1: Lumbar Motion Sparing
21. Spinal Cord Protection from Aortic Occlusion-Related Ischemia by Minocycline Yair Barzilay, MD, Jakov Fellig, MD, Benjamin Drenger, MD; HadassahHebrew University Medical Center, Jerusalem, Israel
22. ProdiscÒ-l Total Disc Replacement over Time: 5- to 8-Year Follow-up Rudolf Bertagnoli, MD, PhD; ProSpine, Straubing, Germany
BACKGROUND CONTEXT: Effective therapeutic methods to prevent paraplegia following transient ischemia to the spinal cord are still under investigation. As subsequent effects of spinal cord ischemia are similar in traumatic spinal injury and neoplastic cord compression, the role of minocycline, a 2nd-generation tetracycline, known to ameliorate secondary events of spinal cord injury, such as apoptosis and inflammation was examined. PURPOSE: The protective role of minocycline in attenuating the histopathological changes in the spinal cord following aortic occlusion-related ischemia in the rabbit was investigated. STUDY DESIGN/SETTING: PRCT PATIENT SAMPLE: 61 male New Zealand albino rabbits weighing 3.0 to 4.0 kg were allocated to control (10) and 5 study groups (51). The control group was exposed to 25 minutes of aortic occlusion at the level of L1-2. The study groups included preoperative I.V Minocycline administration, 30 minutes prior to the ischemic insult. 10 Rabbits were administered with 1 mg/kg Minocycline, 10 with 2 mg/kg, 9 with 5 mg/kg and 12 with 10 mg/kg. Another group of 10 rabbits were administered with 10 mg/kg of Minocycline 15 minutes following the termination of the ischemic insult. OUTCOME MEASURES: Clinical-Modified Tarlov score; Histopathological - grading from 0 to 4 based on hypoxic/ischemic damage; Viable neuron count; TUNEL staining for apoptosis.
BACKGROUND CONTEXT: Lumbar total disc replacement (TDR) is an alternative to spinal fusion surgery for the treatment of degenerative disc disease (DDD) between L3-S1. It is intended to address discogenic pain and has the potential benefit of preserving functional motion in vertebral bodies; TDR may thus reduce long-term subsequent degeneration at adjacent disc levels, although continuing study results are needed to quantify this statement. PURPOSE: The purpose of this study was to evaluate the five-to-eight year clinical results of the ProDiscÒ-L (Synthes Gmbh) TDR. STUDY DESIGN/SETTING: From 2000–2004, a prospective, controlled, consecutive case series was conducted. PATIENT SAMPLE: A total of 506 patients received lumbar arthroplasty utilizing the ProDiscÒ-L TDR. OUTCOME MEASURES: Patients were assessed pre-operatively and post-operatively at 3, 6, 12, 24 months, and yearly thereafter. METHODS: Evaluations included Oswestry Disability Index (ODI), Visual Analog Scales (VAS) for pain and satisfaction, and SF-36 patient selfassessments, physical and neurological exams, and radiographic evaluation RESULTS: The average age of patients was 45.8 years old; 51.2% were men and 48.8% women. Out of the 506 patients, 352 underwent singlelevel; 109 two-level; 40 three-level; 1 four-level; and 1 five-level surgery.
All referenced figures and tables will be available at the Annual Meeting and will be included with the post-meeting online content.