- Email: [email protected]
Correlation of Preoperative Depression and Somatic Perception Scales with Postoperative Disability and Quality of Life after Lumbar Discectomy
16S
Proceedings of the NASS 25th Annual Meeting / The Spine Journal 10 (2010) 1S–149S
demographic data, Glasgow Coma Scores (GCS), Injury Severity Score (ISS), ASIA score, Charlson CoMorbiditiy Index (CCI), mechanism of injury, administration of methylprednisolone (NASCIS II, III), time from injury to surgery, and surgical approach were evaluated. Multivariate regression analysis was done to identify factors predictive of the one-year SF-36 Physical Composite Summary Score (SF-36 PCS). RESULTS: There were 280 patients (78 females, 202 males) who met inclusion criteria and had adequate follow-up, 31% were smokers. The mean age at injury was 41.4617.4 years and the mean body mass index was 25.364.6 kg/m2. The most common injury mechanism was MVA (38%) followed by a fall (37%) and sports injury (15%). Half of the patients had an ASIA E injury (49%), followed by ASIA A (28%), ASIA D (9%), ASIA B (8%) and ASIA C (6%). The mean admission ISS was 10.9610.8, mean CCI was 0.961.5, mean GCS was 14.362.2. Methylprednisolone was administered in 32% of patients. The majority of patients were stabilized posteriorly (76%) with 9% treated anteriorly and combined anterior-posterior in 16%. The mean time from injury to surgery was 60.0655.4 hours. Factors predictive of the SF-36 PCS at one year were the ASIA Grade and the CCI. CONCLUSIONS: One-Year SF-36 PCS scores are dependent on ASIA score and the presence of comorbid conditions. This study does not support the contention that timing of surgical decompression and stabilization alter long term clinical outcomes. The findings of this study may be different if neurological outcome or complication rates were the clinical outcomes of interest. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs. doi: 10.1016/j.spinee.2010.07.045
34. Quantifying MRI in Spinal Cord Injury to Predict Neurological Recovery Rajeshwar N. Srivastava, MD; King Georges Medical College, CSM Medical University, Lucknow, India BACKGROUND CONTEXT: Diagnostic imaging, particularly Magnetic Resonance Imaging (MRI), plays a crucial role in evaluating and detecting spinal trauma. Subtle bone marrow, soft-tissue, and spinal cord abnormalities, which may not be apparent on other imaging modalities, can be readily detected on MRI. Early detection often leads to prompt accurate diagnosis and expeditious management, in many cases avoiding unnecessary procedures. PURPOSE: MRI as a prognostic indicator in spinal trauma. STUDY DESIGN/SETTING: Prospective. PATIENT SAMPLE: Sixty two patients of spinal trauma needing admission formed the study group. OUTCOME MEASURES: Abnormal spinal cord patterns in terms of cord edema/non hemorrhagic contusion, hemorrhagic contusion, cord compression and epidural hematoma. The findings were quantified by measuring the length and girth of segment involved. METHODS: We performed this prospective study from august 2006 to July 2007, on sixty two patients of acute spinal trauma. All patients underwent MRI examination. Prior to MRI, detailed neurological and functional status of the patient were recorded. We evaluated the various traumatic findings by quantifying MRI. MRI findings were correlated with clinical findings at admission & discharge according to ASIA sensory and motor scores & ASIA impairment scale. RESULTS: 1. Sizable focus of haemorrhage involving O1 cm of the cord was present in 32% of cases with 95% confidence limit of 20.94–45.34%. 2. Severe cord compressionO75% was present in 34% of patients with 95% CL of 22.33–47.01%. 3. Epidural hematoma was present in 5% of cases. 4. Cord oedema/non haemorrhagic contusions involving!3 cm of cord was present in 24.56% of patient with 95% confidence limit of 14.13–37.76% 5. Cord oedema/contusions involvingO3 cm of cord was present in 49.12% of patients with 95% confidence limit of 35.63–62.71%. On bivariate analysis a) There was a definitive correlation of cord edema involving!3 cm of cord &
O3 cm of cord with sensory outcome. Chances of non improvement were more in patients with cord edema involving O3 cm of cord (p!.05). In patients with cord edema involving O3 cm of cord, chances of sensory improvement was 5.75 times lesser than in patients with cord edema involving !3 cm of cord (odds ratio55.75 (95% CI: 0.95, 36), Fisher’s exact p50.0427 (p!.05). b) Presence of sizable focus of haemorrhage in cord (O1 cm) was most strongly associated with the poor outcome (odds ratio 6.97 and p5.0047). The risk of retaining a complete cord injury at the time of follow up for patients who initially had evidence of significant haemorrhage in cord was more than 6 folds with patients without initial haemorrhage(Odds ratio - \6.97 and p50.0047). c) It was noted that the patients in which epidural hematoma was present, no improvement was seen, however, by statistical analysis it was proved that epidural hematomas was not a risk factor and it is not related with the outcome (odds ratio - 0.5 and p50.22). d) Presence of severe cord compression O75% was a risk factor for poor outcome (odds ratio - 4.90 and p50.0143). On multiple logistic regression/multivariate analysis, a. Sizable focus of hemorrhage O1 cm was most consistently associated with poor outcome (odds ratio -6.73 and p50.32) b. In the patients with severe cord compression O75% the risk of poor outcome was more (odds ratio 4.3 and p50.149) however was not statistically significant. c. Presence of cord oedema/ non haemorrhagic contusion was not associated with poor outcome (odds ratio 0.25 and p50.178). CONCLUSIONS: In our study we found out that T2 fr FSE sagittal images are best images for the evaluation of spinal trauma. For evaluation of cord hemorrhage best images were gradient recalled echo (GRE). Presence of sizable focus of haemorrhage in cord (O1 cm) was most strongly associated with the poor outcome. Chances of non improvement were more in patients with cord edema involving O3 cm of cord. Cord compression of O75% was a risk factor with poor outcome. Epidural hematoma was not a risk factor and did not influence outcome. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs. doi: 10.1016/j.spinee.2010.07.046
35. Correlation of Preoperative Depression and Somatic Perception Scales with Postoperative Disability and Quality of Life after Lumbar Discectomy Scott L. Parker, MD1, Kaisorn L. Chaichana, MD1, Debraj Mukherjee, MD, MPH1, Owoicho Adogwa, MPH2, Joseph Cheng, MD2, Matthew McGirt, MD2; 1The Johns Hopkins University, Baltimore, MD, USA; 2Vanderbilt University, Nashville, TN, USA BACKGROUND CONTEXT: Not all patients will benefit from lumbar discectomy. Patients with certain psychological predispositions may be especially vulnerable to poor outcomes. PURPOSE: Determine the role that pre-op depression and somatic anxiety have on long-term back/leg pain, disability, quality of life for patients undergoing single-level lumbar discectomy. STUDY DESIGN/SETTING: Prospective cohort study. PATIENT SAMPLE: Patients undergoing discectomy for single-level herniated lumbar disc. OUTCOME MEASURES: BPVAS, LPVAS, SF-36, ODI, Zung selfrating depression scale, modified somatic perception questionnaire. METHODS: 67 adults undergoing discectomy for single-level herniated lumbar disc underwent quantitative measurement of leg/back pain(VAS),quality of life(SF-36),and disease-specific disability (ODI) pre-operatively, at 6 weeks,3,6,and 12 months after surgery. Degree of pre-op depression and somatization assessed using Zung Self-Rating Depression Scale and modified somatic perception questionnaire (MSPQ). Multivariate regression analyses assessed associations between Zung and MSPQ scores with achievement of minimum clinical important difference (MCID) in each outcome measure by 12 months post-op.
All referenced figures and tables will be available at the Annual Meeting and will be included with the post-meeting online content.
Proceedings of the NASS 25th Annual Meeting / The Spine Journal 10 (2010) 1S–149S RESULTS: All patients completed 12-month follow-up. Overall, a significant improvement in VAS-leg, VAS-back, ODI, and SF-36 PCS was observed by 6 weeks after surgery. Improvements in all outcomes were maintained throughout 12 months. Increasing pre-op depression (Zung score) was associated with a decreased likelihood of achieving MCID in disability (p 5 0.006) and quality of life (p 5 0.04) but not associated with leg (p 5 0.96) or back pain (p 5 0.85) by 12 months, Table 1, Figure 1. Increasing preoperative somatic anxiety (MSPQ score) associated with decreased likelihood of achieving MCID in disability (p 5 0.002) and quality of life (p 5 0.03) but was not associated with leg (p 5 0.64) or back pain (p 5 0.77) by 12 months, Table 2, Figure 2. CONCLUSIONS: Zung and MSPQ are valuable tools at risk stratifying patients who may not experience clinically relevant improvement in disability and quality of life after discectomy. Efforts to address these confounding and underlying contributors of depression and heightened somatic anxiety may improve overall outcomes after lumbar discectomy. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
17S
BDI, increased AA SPL, and increased lateral AA height. On MRI, these three patients had intact OC joint capsules and disrupted CC ligaments. These patients were found to be ASIA D according to medical record documentation. CONCLUSIONS: On the basis of imaging and neurological status, two distinct patterns of injury were identified: isolated AA injuries (Type I) and combined OC and AA injuries (Type II). All of the patients had disrupted CC ligaments and therefore the CC ligament integrity did not correspond to joint diastasis. The integrity of the OC joint capsule was the only factor that differentiated the two subsets of patients. Figures 1 and 2 demonstrate a type II injury with a disrupted OC capsule and disrupted CC ligaments. Figures 3 and 4 illustrate a type I injury with an intact OC anterior OC joint capsule and disrupted CC ligament complex. Type II injuries have worse neurological status compared to type I injuries due to horizontal and vertical instability in the former. In conclusion, the OC joint capsules may be an important stabilizer of the OC joint. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
doi: 10.1016/j.spinee.2010.07.047 doi: 10.1016/j.spinee.2010.07.050
Wednesday, October 6, 2010 5:15–6:15 PM Focused Paper Presentations 1: Trauma 36. Classification of Craniocervical Dissociative Injuries Based on CT and MRI Kristen E. Radcliff, MD1, Joseph Hong, DO1, Charles Reitman, MD2, D. Greg Anderson, MD1, Alan Hilibrand, MD1, Todd Albert, MD1, Alex Vaccaro, MD, PhD1; 1Rothman Institute/Thomas Jefferson University Department of Orthopedic Surgery, Philadelphia, PA, USA; 2Baylor College of Medicine, Houston, TX, USA BACKGROUND CONTEXT: Craniocervical dissociative injuries are rare, devastating injuries. Previous classifications focus on radiographic displacement or midline structures. PURPOSE: The purpose of this study was to determine and classify occipitocervical dissociative injuries based on CT and MRI characteristics. STUDY DESIGN/SETTING: Retrospective Analysis of Prospectively Collected Data. PATIENT SAMPLE: Patients evaluated between 2000 and 2009 at Thomas Jefferson Hospital and the Delaware Valley Regional Spinal Cord Injury Center was searched. Inclusion criteria were acute, traumatic distractive injury of the OC or atlantoaxial joints. Exclusion criteria include patients with a traumatic, postsurgical, infectious, neoplastic, rheumatic, degenerative, or congenital instability. OUTCOME MEASURES: Clinical and radiographic outcome measures were assessed. METHODS: After approval by the IRB, medical records were evaluated for diagnosis, neurological exam at presentation and discharge, associated injuries, operative details. CT and MRI were evaluated for diastasis of the OC and atlantoaxial (AA) joints, basion dental interval (BDI), AA spinolaminar line and integrity of the craniocervical (CC) ligaments and OC joint capsules. RESULTS: Seven patients were identified with craniocervical dissociative Injuries. CT evaluation revealed that four patients presented abnormal OC joint diastasis, abnormal large BDIs, abnormal AA spinolaminar line (SPL), and increased lateral AA height. MRI evaluation of these patients revealed disrupted CC ligament complex and OC joint capsules. Three patients were ASIA A and one was ASIA B neurological status according to orthopedic spine, neurosurgery, and rehabilitation attending examination. Three patients were found to have normal OC joint height, increased
37. A Spinal Cord Pressure-Displacement Model of Posterior Wall Burst Fracture Peter F. Jarzem, MD, Jerod Hines, MD, Mahdi Bassi, MD; McGill University Health Centre, Montreal, QC, Canada BACKGROUND CONTEXT: Spinal Trauma can injure the spinal cord through two mechanisms 1) direct injury from displaced bone/disc at the time of injury/impact and 2) residual pressure on the spinal cord from ongoing spinal canal compromise. This paper describes a model of traumatic residual SC compression. PURPOSE: To determine amount of compression required to cause pressure elevation in spinal cord in an animal cadaver model. STUDY DESIGN/SETTING: We used a novel plunger device connected to a pressure transducer via intravenous solution tubing to measure pressures within the spinal canal. The dural sac was injected with radio-opaque dye and a portable fluoroscopy unit was utilized to verify amount of cord compression. PATIENT SAMPLE: All porcine specimens. METHODS: 6 Porcine spinal sections: 6 thoracic, and 6 lumbar were harvested from 30 kg pigs. Myelographic dye was then injected in the subarachnoid space. A plunger with a sensing probe was then advanced through the vertebral body in the spinal canal through a previously prepared hole. AP and lateral fluoroscopic images were obtained to determine the extent of canal compromise. The plunger was advanced in 0.25 mm increments at a rate of on 0.25 mm/2 min. Pressure was measured at each increment. Pressure versus displacement curves were then determined. RESULTS: Initial cord compromise does not lead to significant pressure elevation. After an initial low pressure plateau, pressure rises rapidly to high levels that can cause cord damage. This elevation in cord pressure occurs when 60% of the canal has been compromised and rises abruptly with little further canal transgression. CONCLUSIONS: These pressure displacement relationships demonstrate that the spinal canal can initially sustain 60% reductions in canal volume before having abrupt and dangerous spinal cord pressure elevations. Further work needs to be done to determine if stress relaxation will occur (and reduce cord pressure) and to determine if the same pressure displacement relationships exist in live animal models and human cadaver specimens. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs. doi: 10.1016/j.spinee.2010.07.051
All referenced figures and tables will be available at the Annual Meeting and will be included with the post-meeting online content.
Proceedings of the NASS 25th Annual Meeting / The Spine Journal 10 (2010) 1S–149S
demographic data, Glasgow Coma Scores (GCS), Injury Severity Score (ISS), ASIA score, Charlson CoMorbiditiy Index (CCI), mechanism of injury, administration of methylprednisolone (NASCIS II, III), time from injury to surgery, and surgical approach were evaluated. Multivariate regression analysis was done to identify factors predictive of the one-year SF-36 Physical Composite Summary Score (SF-36 PCS). RESULTS: There were 280 patients (78 females, 202 males) who met inclusion criteria and had adequate follow-up, 31% were smokers. The mean age at injury was 41.4617.4 years and the mean body mass index was 25.364.6 kg/m2. The most common injury mechanism was MVA (38%) followed by a fall (37%) and sports injury (15%). Half of the patients had an ASIA E injury (49%), followed by ASIA A (28%), ASIA D (9%), ASIA B (8%) and ASIA C (6%). The mean admission ISS was 10.9610.8, mean CCI was 0.961.5, mean GCS was 14.362.2. Methylprednisolone was administered in 32% of patients. The majority of patients were stabilized posteriorly (76%) with 9% treated anteriorly and combined anterior-posterior in 16%. The mean time from injury to surgery was 60.0655.4 hours. Factors predictive of the SF-36 PCS at one year were the ASIA Grade and the CCI. CONCLUSIONS: One-Year SF-36 PCS scores are dependent on ASIA score and the presence of comorbid conditions. This study does not support the contention that timing of surgical decompression and stabilization alter long term clinical outcomes. The findings of this study may be different if neurological outcome or complication rates were the clinical outcomes of interest. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs. doi: 10.1016/j.spinee.2010.07.045
34. Quantifying MRI in Spinal Cord Injury to Predict Neurological Recovery Rajeshwar N. Srivastava, MD; King Georges Medical College, CSM Medical University, Lucknow, India BACKGROUND CONTEXT: Diagnostic imaging, particularly Magnetic Resonance Imaging (MRI), plays a crucial role in evaluating and detecting spinal trauma. Subtle bone marrow, soft-tissue, and spinal cord abnormalities, which may not be apparent on other imaging modalities, can be readily detected on MRI. Early detection often leads to prompt accurate diagnosis and expeditious management, in many cases avoiding unnecessary procedures. PURPOSE: MRI as a prognostic indicator in spinal trauma. STUDY DESIGN/SETTING: Prospective. PATIENT SAMPLE: Sixty two patients of spinal trauma needing admission formed the study group. OUTCOME MEASURES: Abnormal spinal cord patterns in terms of cord edema/non hemorrhagic contusion, hemorrhagic contusion, cord compression and epidural hematoma. The findings were quantified by measuring the length and girth of segment involved. METHODS: We performed this prospective study from august 2006 to July 2007, on sixty two patients of acute spinal trauma. All patients underwent MRI examination. Prior to MRI, detailed neurological and functional status of the patient were recorded. We evaluated the various traumatic findings by quantifying MRI. MRI findings were correlated with clinical findings at admission & discharge according to ASIA sensory and motor scores & ASIA impairment scale. RESULTS: 1. Sizable focus of haemorrhage involving O1 cm of the cord was present in 32% of cases with 95% confidence limit of 20.94–45.34%. 2. Severe cord compressionO75% was present in 34% of patients with 95% CL of 22.33–47.01%. 3. Epidural hematoma was present in 5% of cases. 4. Cord oedema/non haemorrhagic contusions involving!3 cm of cord was present in 24.56% of patient with 95% confidence limit of 14.13–37.76% 5. Cord oedema/contusions involvingO3 cm of cord was present in 49.12% of patients with 95% confidence limit of 35.63–62.71%. On bivariate analysis a) There was a definitive correlation of cord edema involving!3 cm of cord &
O3 cm of cord with sensory outcome. Chances of non improvement were more in patients with cord edema involving O3 cm of cord (p!.05). In patients with cord edema involving O3 cm of cord, chances of sensory improvement was 5.75 times lesser than in patients with cord edema involving !3 cm of cord (odds ratio55.75 (95% CI: 0.95, 36), Fisher’s exact p50.0427 (p!.05). b) Presence of sizable focus of haemorrhage in cord (O1 cm) was most strongly associated with the poor outcome (odds ratio 6.97 and p5.0047). The risk of retaining a complete cord injury at the time of follow up for patients who initially had evidence of significant haemorrhage in cord was more than 6 folds with patients without initial haemorrhage(Odds ratio - \6.97 and p50.0047). c) It was noted that the patients in which epidural hematoma was present, no improvement was seen, however, by statistical analysis it was proved that epidural hematomas was not a risk factor and it is not related with the outcome (odds ratio - 0.5 and p50.22). d) Presence of severe cord compression O75% was a risk factor for poor outcome (odds ratio - 4.90 and p50.0143). On multiple logistic regression/multivariate analysis, a. Sizable focus of hemorrhage O1 cm was most consistently associated with poor outcome (odds ratio -6.73 and p50.32) b. In the patients with severe cord compression O75% the risk of poor outcome was more (odds ratio 4.3 and p50.149) however was not statistically significant. c. Presence of cord oedema/ non haemorrhagic contusion was not associated with poor outcome (odds ratio 0.25 and p50.178). CONCLUSIONS: In our study we found out that T2 fr FSE sagittal images are best images for the evaluation of spinal trauma. For evaluation of cord hemorrhage best images were gradient recalled echo (GRE). Presence of sizable focus of haemorrhage in cord (O1 cm) was most strongly associated with the poor outcome. Chances of non improvement were more in patients with cord edema involving O3 cm of cord. Cord compression of O75% was a risk factor with poor outcome. Epidural hematoma was not a risk factor and did not influence outcome. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs. doi: 10.1016/j.spinee.2010.07.046
35. Correlation of Preoperative Depression and Somatic Perception Scales with Postoperative Disability and Quality of Life after Lumbar Discectomy Scott L. Parker, MD1, Kaisorn L. Chaichana, MD1, Debraj Mukherjee, MD, MPH1, Owoicho Adogwa, MPH2, Joseph Cheng, MD2, Matthew McGirt, MD2; 1The Johns Hopkins University, Baltimore, MD, USA; 2Vanderbilt University, Nashville, TN, USA BACKGROUND CONTEXT: Not all patients will benefit from lumbar discectomy. Patients with certain psychological predispositions may be especially vulnerable to poor outcomes. PURPOSE: Determine the role that pre-op depression and somatic anxiety have on long-term back/leg pain, disability, quality of life for patients undergoing single-level lumbar discectomy. STUDY DESIGN/SETTING: Prospective cohort study. PATIENT SAMPLE: Patients undergoing discectomy for single-level herniated lumbar disc. OUTCOME MEASURES: BPVAS, LPVAS, SF-36, ODI, Zung selfrating depression scale, modified somatic perception questionnaire. METHODS: 67 adults undergoing discectomy for single-level herniated lumbar disc underwent quantitative measurement of leg/back pain(VAS),quality of life(SF-36),and disease-specific disability (ODI) pre-operatively, at 6 weeks,3,6,and 12 months after surgery. Degree of pre-op depression and somatization assessed using Zung Self-Rating Depression Scale and modified somatic perception questionnaire (MSPQ). Multivariate regression analyses assessed associations between Zung and MSPQ scores with achievement of minimum clinical important difference (MCID) in each outcome measure by 12 months post-op.
All referenced figures and tables will be available at the Annual Meeting and will be included with the post-meeting online content.
Proceedings of the NASS 25th Annual Meeting / The Spine Journal 10 (2010) 1S–149S RESULTS: All patients completed 12-month follow-up. Overall, a significant improvement in VAS-leg, VAS-back, ODI, and SF-36 PCS was observed by 6 weeks after surgery. Improvements in all outcomes were maintained throughout 12 months. Increasing pre-op depression (Zung score) was associated with a decreased likelihood of achieving MCID in disability (p 5 0.006) and quality of life (p 5 0.04) but not associated with leg (p 5 0.96) or back pain (p 5 0.85) by 12 months, Table 1, Figure 1. Increasing preoperative somatic anxiety (MSPQ score) associated with decreased likelihood of achieving MCID in disability (p 5 0.002) and quality of life (p 5 0.03) but was not associated with leg (p 5 0.64) or back pain (p 5 0.77) by 12 months, Table 2, Figure 2. CONCLUSIONS: Zung and MSPQ are valuable tools at risk stratifying patients who may not experience clinically relevant improvement in disability and quality of life after discectomy. Efforts to address these confounding and underlying contributors of depression and heightened somatic anxiety may improve overall outcomes after lumbar discectomy. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
17S
BDI, increased AA SPL, and increased lateral AA height. On MRI, these three patients had intact OC joint capsules and disrupted CC ligaments. These patients were found to be ASIA D according to medical record documentation. CONCLUSIONS: On the basis of imaging and neurological status, two distinct patterns of injury were identified: isolated AA injuries (Type I) and combined OC and AA injuries (Type II). All of the patients had disrupted CC ligaments and therefore the CC ligament integrity did not correspond to joint diastasis. The integrity of the OC joint capsule was the only factor that differentiated the two subsets of patients. Figures 1 and 2 demonstrate a type II injury with a disrupted OC capsule and disrupted CC ligaments. Figures 3 and 4 illustrate a type I injury with an intact OC anterior OC joint capsule and disrupted CC ligament complex. Type II injuries have worse neurological status compared to type I injuries due to horizontal and vertical instability in the former. In conclusion, the OC joint capsules may be an important stabilizer of the OC joint. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.
doi: 10.1016/j.spinee.2010.07.047 doi: 10.1016/j.spinee.2010.07.050
Wednesday, October 6, 2010 5:15–6:15 PM Focused Paper Presentations 1: Trauma 36. Classification of Craniocervical Dissociative Injuries Based on CT and MRI Kristen E. Radcliff, MD1, Joseph Hong, DO1, Charles Reitman, MD2, D. Greg Anderson, MD1, Alan Hilibrand, MD1, Todd Albert, MD1, Alex Vaccaro, MD, PhD1; 1Rothman Institute/Thomas Jefferson University Department of Orthopedic Surgery, Philadelphia, PA, USA; 2Baylor College of Medicine, Houston, TX, USA BACKGROUND CONTEXT: Craniocervical dissociative injuries are rare, devastating injuries. Previous classifications focus on radiographic displacement or midline structures. PURPOSE: The purpose of this study was to determine and classify occipitocervical dissociative injuries based on CT and MRI characteristics. STUDY DESIGN/SETTING: Retrospective Analysis of Prospectively Collected Data. PATIENT SAMPLE: Patients evaluated between 2000 and 2009 at Thomas Jefferson Hospital and the Delaware Valley Regional Spinal Cord Injury Center was searched. Inclusion criteria were acute, traumatic distractive injury of the OC or atlantoaxial joints. Exclusion criteria include patients with a traumatic, postsurgical, infectious, neoplastic, rheumatic, degenerative, or congenital instability. OUTCOME MEASURES: Clinical and radiographic outcome measures were assessed. METHODS: After approval by the IRB, medical records were evaluated for diagnosis, neurological exam at presentation and discharge, associated injuries, operative details. CT and MRI were evaluated for diastasis of the OC and atlantoaxial (AA) joints, basion dental interval (BDI), AA spinolaminar line and integrity of the craniocervical (CC) ligaments and OC joint capsules. RESULTS: Seven patients were identified with craniocervical dissociative Injuries. CT evaluation revealed that four patients presented abnormal OC joint diastasis, abnormal large BDIs, abnormal AA spinolaminar line (SPL), and increased lateral AA height. MRI evaluation of these patients revealed disrupted CC ligament complex and OC joint capsules. Three patients were ASIA A and one was ASIA B neurological status according to orthopedic spine, neurosurgery, and rehabilitation attending examination. Three patients were found to have normal OC joint height, increased
37. A Spinal Cord Pressure-Displacement Model of Posterior Wall Burst Fracture Peter F. Jarzem, MD, Jerod Hines, MD, Mahdi Bassi, MD; McGill University Health Centre, Montreal, QC, Canada BACKGROUND CONTEXT: Spinal Trauma can injure the spinal cord through two mechanisms 1) direct injury from displaced bone/disc at the time of injury/impact and 2) residual pressure on the spinal cord from ongoing spinal canal compromise. This paper describes a model of traumatic residual SC compression. PURPOSE: To determine amount of compression required to cause pressure elevation in spinal cord in an animal cadaver model. STUDY DESIGN/SETTING: We used a novel plunger device connected to a pressure transducer via intravenous solution tubing to measure pressures within the spinal canal. The dural sac was injected with radio-opaque dye and a portable fluoroscopy unit was utilized to verify amount of cord compression. PATIENT SAMPLE: All porcine specimens. METHODS: 6 Porcine spinal sections: 6 thoracic, and 6 lumbar were harvested from 30 kg pigs. Myelographic dye was then injected in the subarachnoid space. A plunger with a sensing probe was then advanced through the vertebral body in the spinal canal through a previously prepared hole. AP and lateral fluoroscopic images were obtained to determine the extent of canal compromise. The plunger was advanced in 0.25 mm increments at a rate of on 0.25 mm/2 min. Pressure was measured at each increment. Pressure versus displacement curves were then determined. RESULTS: Initial cord compromise does not lead to significant pressure elevation. After an initial low pressure plateau, pressure rises rapidly to high levels that can cause cord damage. This elevation in cord pressure occurs when 60% of the canal has been compromised and rises abruptly with little further canal transgression. CONCLUSIONS: These pressure displacement relationships demonstrate that the spinal canal can initially sustain 60% reductions in canal volume before having abrupt and dangerous spinal cord pressure elevations. Further work needs to be done to determine if stress relaxation will occur (and reduce cord pressure) and to determine if the same pressure displacement relationships exist in live animal models and human cadaver specimens. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs. doi: 10.1016/j.spinee.2010.07.051
All referenced figures and tables will be available at the Annual Meeting and will be included with the post-meeting online content.