- Email: [email protected]
Friday, September 28, 2018 4:05 PM–5:05 PM abstracts: cervical myelopathy and deformity
The Spine Journal 18 (2018) S70 S128 PATIENT SAMPLE: A total of 153 CD patients enrolled between 2013 and 2015. OUTCOME MEASURES: Radiographic analysis. METHODS: Cervical deformity pts undergoing surgery from 2013 to 2015 were enrolled in a prospective, multicenter database. Radiographs were reviewed by 12 individuals in a consensus method to identify severe sagittal CD. Radiographic parameters correlating with HRQL were introduced in a 2-step cluster analysis (combination of hierarchical cluster and K-mean cluster) to identify patterns of sagittal deformity. Comparison of lateral and difference lateral-extension between clusters were analyzed using an ANOVA in a post-hoc analysis. RESULTS: After review, 83 pts (54.2%) were identified as severe CD, 51 (33.3%) as nonsever CD and 19 (12.4%) remained unclassified due to lack of agreement. Among the 83 severe CD, eight were due to coronal deformity of the cervical spine, leaving 75 patients having severe cervical deformity due to sagittal malalignment and utilized for the study. Mean age 64, BMI 29, 66% female. Significant correlations were seen between focal alignment or flexibility of max kyphosis, CL and TS-CL flexibility (r=0.27, 0.31, −0.36). Cluster analysis revealed three distinct groups based on alignment and flexibility. Group 1 (46.2%) patients (“flatneck with lack of compensation” pattern) were classified with a large TS-CL mismatch (57.2 vs. 28.1 vs. 41.0 p<.001) despite flexibility in the CL (C2-C7 lateralto-extension: −15.5 vs. −9.9 vs. 2.7 p<.001). Group 2 (30.8%) patients (“focal deformity” pattern) had focal kyphosis between two adjacent levels (−14.4 vs. −18.3 vs. −5.5 p<.001), but no large regional cervical kyphosis under the setting of a low T1S. Group 3 (23.1%) patients (“cervico-thoracic” pattern) had a very large T1S (39.1 vs. 21.5 vs. 54 p<.001) with a compensatory hyperlordosis of the cervical spine (−18.2 vs. −6.6 vs. 13 p<.001) but no reserve of extension left (TS-CL lateral-to-extension: 22.3 vs. 12.1 vs. −0.2 p<.001). Comparison of thoracolumbar alignment reveal no significant difference in PT, PI-LL, SVA and TPA (all p>.2) but a significantly smaller TK for group 2 (−55.5 vs. −37.7 vs. −69.8 p<.001). CONCLUSIONS: A total of three different patterns of deformity have been identified within this cohort – lack of compensation, focal deformity, cervico-thoracic deformity. One key element to understand the difference between these groups was the alignment in extension, critical for cervical deformity understanding. This information is a first step in developing a classification system that can guide surgical treatment for cervical deformity and fusion level. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs. https://doi.org/10.1016/j.spinee.2018.06.521
257. Development of a modified cervical deformity frailty index: a streamlined clinical tool for preoperative risk stratification Peter G. Passias, MD1, Frank A. Segreto, BS2, Cole Bortz, BA3, Renaud Lafage, MSc4, Virginie Lafage, PhD4, Justin S. Smith, MD, PhD5, Breton Line, BS6, Han Jo Kim, MD4, Robert K. Eastlack, MD7, D. Kojo Hamilton, MD8, Themistocles S. Protopsaltis, MD9, Richard A. Hostin Jr., MD10, Eric O. Klineberg, MD11, Douglas C. Burton, MD12, Robert A. Hart, MD13, Frank J. Schwab, MD4, Shay Bess, MD14, Christopher I. Shaffrey, MD15, Christopher P. Ames, MD16; International Spine Study Group 17; 1 NY Spine Institute, NYU Langone Health, New York, NY, USA; 2 NYU Langone Medical Center, Orthopaedic Hospital, Manhattan, NY, USA; 3 New York, NY, USA; 4 Hospital for Special Surgery, New York, NY, USA; 5 UVA Health System, Charlottesville, VA, USA; 6 Denver International Spine Center, Denver, CO, USA; 7 Scripps Clinic, San Diego, CA, USA; 8 University of Pittsburgh School of Medicine, Pittsburgh, PA, USA; 9 Department of Orthopaedic Surgery, NYU Langone Orthopaedic Hospital, NYU Langone Health, New York, NY, USA; 10 Southwest Scoliosis Institute, Plano, TX, USA; 11 UC, Davis School of Medicine, Sacramento, CA, USA; 12 University of Kansas Medical Center, Kansas City, KS, USA; 13 Swedish Neuroscience Institute, Seattle, WA, USA; 14 Denver, CO, USA; 15 University of Virginia, Charlottesville, VA, USA;
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University of California, San Francisco, San Francisco, CA, USA; Brighton, CO, USA
BACKGROUND CONTEXT: To improve preoperative risk stratification for surgical cervical deformity (CD) patients, Miller et al developed a CD frailty index (CD-FI) incorporating 40 physiciandocumented and patient-reported factors. While novel, the CD-FI is cumbersome to use in a clinical setting due to the large number of factors needed to calculate the score. To increase clinical utility, a simpler, modified CD-FI (mCD-FI) is necessary. PURPOSE: To develop a simplified frailty index for CD patients. STUDY DESIGN/SETTING: Retrospective review of prospective, multicenter CD database. PATIENT SAMPLE: A total of 121 CD patients (61±11 years, 60%F). OUTCOME MEASURES: Length of stay (LOS), health-related quality of life questionnaires: NDI, EQ-5D, NRS Neck Pain. METHODS: Cervical deformity patients (C2–C7 Cobb>10°, CL>10°, cSVA>4cm, or CBVA>25°)>18 years with available preop CD-FI component factors. Pearson bivariate correlation assessed relationships between component deficits of the CD-FI and overall CD-FI score. The top 19 deficits contributing to overall CD-FI score were included in multiple stepwise regression models. Deficits derived from the model with the largest R2were recorded as binary variables, and the mean score of all deficits calculated, resulting in a mCD-FI ranging from 0 to 1. Patients were stratified using published cutoffs: not frail (NF, <0.3), frail (0.3–0.5), severely frail (SF, >0.5). Means comparison tests established correlations between frailty category and clinical outcomes. Significance was set P<.05. RESULTS: A total of 121 CD patients were included (61±11 years, 60%F, BMI: 29.2±7.8kg/m2). The final multiple stepwise regression model identified the following combination of factors as responsible for 86% of the variation in CD-FI score: lung disease (β=0.033), BMI <18.5 or >30 (β=0.015), diabetes (β=0.040), depression (β=0.020), liver disease (β= −1.101), rheumatoid arthritis (β=0.058), venous disease (β=0.099), unsteady gait (β=0.022), bladder incontinence (β=0.031), bowel incontinence (β=0.044), leg weakness (β=0.040), >3 comorbidities (β=0.151), anxiety (β=0.098), difficulty sleeping >6 hours (β=0.056), and inability to walk (β=0.043). From these 15 deficits the overall population's mCD-FI was calculated: 0.31±0.14. Breakdown of patients by mCD-FI category: NF: 47.9%, frail: 46.3%, SF: 5.8%. As compared to NF and frail patients, SF patients had the longest inpatient hospital stays (2.5 and 1.7 times longer, respectively, P=.042), as well as greater baseline neck pain (NRS neck 1.3 and 1.1 times higher, P=.033), inferior NDI scores (1.6 and 1.2 times greater, P<.001) and inferior EQ-5D outcomes (1.2 and 1.1 times lower, P<.001). Compared to NF, frail patients had higher odds of superficial infection (OR:1.1 [1.001–1.2]), and SF patients had significantly increased odds of mortality (OR:10.4 [1.2–90.6]). CONCLUSIONS: In this modified cervical deformity frailty index, greater levels of patient frailty were correlated with inferior clinical outcomes, longer hospital length of stay, increased neck pain, and decreased health-related quality of life. Additionally, frail patients were at greater risk for infection, and severely frail patients had significantly greater odds of mortality. The relatively few number of deficits needed to calculate the present frailty score gives this modified cervical deformity frailty index increased clinical utility. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs. https://doi.org/10.1016/j.spinee.2018.06.522
258. The C5-T3 angle: a novel parameter of the cervicothoracic junction Sang-Hun Lee, MD, PhD1, Micheal Raad, MD2, Brian J. Neuman, MD3, Munish C. Gupta, MD4, Hamid Hassanzadeh, MD5, Virginie Lafage, PhD6, Peter G. Passias, MD7, Themistocles S. Protopsaltis, MD8, D. Kojo Hamilton, MD9, Justin S. Smith, MD, PhD10, Christopher I. Shaffrey, MD11, Eric O. Klineberg, MD12, Jeffrey L. Gum, MD13, Shay Bess, MD14,
Refer to onsite annual meeting presentations and postmeeting proceedings for possible referenced figures and tables. Authors are responsible for accurately reporting disclosure and FDA device/drug status at time of abstract submission.
S128
The Spine Journal 18 (2018) S70 S128 15
16
Richard A. Hostin Jr., MD , Christopher P. Ames, MD , Khaled M. Kebaish, MD3; International Spine Study Group 17; 1 Johns Hopkins University, Department of Orthopedic surgery, Baltimore, MD, USA; 2 Johns Hopkins, Baltimore, MD, USA; 3 Baltimore, MD, USA; 4 Washington University School of Medicine, St. Louis, MO, USA; 5 University of Virginia, Department of Orthopedic Surgery, Charlottesville, VA, USA; 6 Hospital for Special Surgery, New York, NY, USA; 7 NY Spine Institute, NYU Langone Health, New York, NY, USA; 8 Department of Orthopaedic Surgery, NYU Langone Orthopaedic Hospital, NYU Langone Health, New York, NY, USA; 9 University of Pittsburgh School of Medicine, Pittsburgh, PA, USA; 10 UVA Health System, Charlottesville, VA, USA; 11 University of Virginia, Charlottesville, VA, USA; 12 UC, Davis School of Medicine, Sacramento, CA, USA; 13 Norton Leatherman Spine Center, Louisville, KY, USA; 14 Denver, CO, USA; 15 Southwest Scoliosis Institute, Plano, TX, USA; 16 University of California, San Francisco, San Francisco, CA, USA; 17 Brighton, CO, USA BACKGROUND CONTEXT: Unlike the thoracolumbar junction (TLJ) angle which is well-defined as T10 – L2, there is no consensus on how to define the CTJ angle. The CTJ consists of mobile lower cervical and rigid upper thoracic spinal segments, giving it unique anatomical and biomechanical characteristics. To our knowledge, this is the first study attempting to define a new parameter for assessing the cervicothoracic junction. PURPOSE: Attempting to define a new parameter for assessing the cervicothoracic junction. STUDY DESIGN/SETTING: Retrospective analysis of a prospective database. PATIENT SAMPLE: Adult spinal deformity patients operated on between the years 2008 and 2016 were included in the analysis. We excluded patients with history of cervical spinal fusion or an upper instrumented vertebra higher than T5. OUTCOME MEASURES: The criteria for an ideal CTJ angle would be: constant, significantly correlated with sagittal parameters, and involving maximum number of levels. METHODS: This is a retrospective analysis of a prospective surgical database. ASD patients operated on between the years 2008 and 2016 were included in the analysis. We excluded patients with history of cervical spinal fusion or an upper-most instrumented vertebra higher than T5. The criteria for an ideal CTJ angle would be: longitudinally constant, crosssectionally correlates with other parameters and involves the maximum number of levels. A combination of 12 angles between C5 and T4 were analyzed. The variation in each angle's value over time (preoperative, 6 weeks and 2 years) was assessed using ANOVA. Pearson correlation analysis was performed between the most constant candidate parameters and: demographic data, preoperative sagittal spinopelvic parameters and the amount of correction at 2 years. RESULTS: A total of 427 patients (mean age 59.9, 74% women) met our inclusion criteria and were included in the analysis. Seven of 12 CTJ angles; C5-T1, C5-T2, C5-T3, C6-T1, C6-T2, C7-T1 and C7-T2 were constant between preoperative, PO6W and PO2Y measurements (p>.05). All the seven candidate angles showed significant correlation with age and preoperative sagittal angles including pelvic tilt (PT), lumbar lordosis (LL; L1–S1), TLJ angle (T10–L2), thoracic kyphosis (TK, T4–T12), cervical lordosis (CL; C2–C7), pelvic incidence (PI) minus LL, T1 slope (TS) minus CL, T1 pelvic angle (T1PA), sagittal vertical axis (SVA) C2-7 and C7-S1 (p<.01). The candidate CTJ angles were not affected by PI, amount of correction of PT, LL, TL and TK, PI minus LL at PO2Y. However, the amount of correction involving cervical spine parameters (CL, TS minus CL, SVA C2–C7 and SVA C7–S1) showed significant correlations with the CTJ angles (mostly p<.01). CONCLUSIONS: Based on the present study, the C5-T3 angle is the ideal parameter to assess the CTJ, given its constant value over time, involvement of maximal number of segments as well as an appropriate correlation with other major spinal sagittal parameters. Further studies assessing its implications on clinical outcomes may be warranted.
FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs. https://doi.org/10.1016/j.spinee.2018.06.523
259. The influence of cervical spondylolisthesis on clinical presentation and surgical outcome in patients with degenerative cervical myelopathy: analysis of a global cohort Aria Nouri, MD, MSc1, So Kato, MD2, Michael W. Robinson, MD, PhD3, Juan C. Mejia Munne, MD1, George Yang1, William Jeong1, Rani Nasser, MD4, Joseph S. Cheng, MD, MS5, Michael G. Fehlings, MD, PhD, FRCSC6; 1 Cincinnati, OH, USA; 2 The University of Tokyo Hospital, Bunkyo-ku, Tokyo, Japan; 3 University of Cincinnati Medical Center, Cincinnati, OH, USA; 4 Montefiore Medical Center, Department of Neurosurgery, Spine Research Group, Bronx, NY, USA; 5 University of Cincinnati College of Medicine, Cincinnati, OH, USA; 6 Toronto Western Hospital, Toronto, ON, Canada BACKGROUND CONTEXT: Cervical spondylolisthesis (CS) presents in ∼12% of patients with degenerative cervical myelopathy (DCM). However, its impact on clinical presentation and surgical outcome have not been welldescribed. Using a prospective and multicenter cohort, we compare patients with and without CS on MRI undergoing surgical treatment for DCM. PURPOSE: To determine the influence of cervical spondylolisthesis in patients with DCM. STUDY DESIGN/SETTING: Retrospective review of prospectively collected data from multiple global sites. PATIENT SAMPLE: A total of 458 patients with MRIs and clinical data. OUTCOME MEASURES: The modified Japanese Orthopedic Association score (mJOA), Nurick grade, SF-36 Mental and Physical Component Scores, and the Neck Disability Index. METHODS: A total of 458 MRIs from the AOSpine North America and International Studies were reviewed. Patient demographics and baseline neurological and functional status were also obtained. CS was identified using T2 MRI. Patients with DCM were divided into two cohorts, those with CS and those without. Patient demographics, neurological and functional status at baseline and outcome at 2-year follow-up were compared using independent t-tests, chi square tests, Fischer exact tests, and multivariate analysis. RESULTS: In comparison to the nonspondylolisthesis cohort (n=404), CS patients (n=54) were on average 8.8 years older (p<.0001), presented with worse baseline neurological and function status (mJOA, p=.008; Nurick, p=.008; SF-36-PCS, p=.01), more commonly presented with ligamentum flavum enlargement (81.5% vs. 53.5%, p<.0001), were less commonly from Asia (p=.0002), and tended to have more levels of compression (p=.052) and lower prevalence rates of OPLL (p=.098). There was no difference in sagittal alignment between the groups (p=.94). The surgical approach varied between cohorts (p=.0002), with posterior approaches more commonly performed with CS (61.1% vs. 37.4%). CS patients also had more operated levels (4.28±1.43 vs. 3.61±1.19, p=.0002), and tended to undergo longer operations (196.58±89.20 minutes vs. 177.20±75.57 minutes, p=.087). The mean improvement of neurological function was lower with CS [mJOA (1.51±3.56 vs. 2.77±2.72, p=.003); Nurick (−0.78 ±1.42 vs. −1.45±1.45, p=.002)], and CS was an independent predictor of worse mJOA recovery ratio at 2-years (B=−0.190, p<.0001). CONCLUSIONS: CS patients are older and present with worse neurological and functional impairment. Furthermore, they receive surgery on more levels and more commonly from the posterior. CS may indicate a more advanced state of DCM pathology and is more likely to result in a suboptimal surgical outcome. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs. https://doi.org/10.1016/j.spinee.2018.06.524
Refer to onsite annual meeting presentations and postmeeting proceedings for possible referenced figures and tables. Authors are responsible for accurately reporting disclosure and FDA device/drug status at time of abstract submission.
257. Development of a modified cervical deformity frailty index: a streamlined clinical tool for preoperative risk stratification Peter G. Passias, MD1, Frank A. Segreto, BS2, Cole Bortz, BA3, Renaud Lafage, MSc4, Virginie Lafage, PhD4, Justin S. Smith, MD, PhD5, Breton Line, BS6, Han Jo Kim, MD4, Robert K. Eastlack, MD7, D. Kojo Hamilton, MD8, Themistocles S. Protopsaltis, MD9, Richard A. Hostin Jr., MD10, Eric O. Klineberg, MD11, Douglas C. Burton, MD12, Robert A. Hart, MD13, Frank J. Schwab, MD4, Shay Bess, MD14, Christopher I. Shaffrey, MD15, Christopher P. Ames, MD16; International Spine Study Group 17; 1 NY Spine Institute, NYU Langone Health, New York, NY, USA; 2 NYU Langone Medical Center, Orthopaedic Hospital, Manhattan, NY, USA; 3 New York, NY, USA; 4 Hospital for Special Surgery, New York, NY, USA; 5 UVA Health System, Charlottesville, VA, USA; 6 Denver International Spine Center, Denver, CO, USA; 7 Scripps Clinic, San Diego, CA, USA; 8 University of Pittsburgh School of Medicine, Pittsburgh, PA, USA; 9 Department of Orthopaedic Surgery, NYU Langone Orthopaedic Hospital, NYU Langone Health, New York, NY, USA; 10 Southwest Scoliosis Institute, Plano, TX, USA; 11 UC, Davis School of Medicine, Sacramento, CA, USA; 12 University of Kansas Medical Center, Kansas City, KS, USA; 13 Swedish Neuroscience Institute, Seattle, WA, USA; 14 Denver, CO, USA; 15 University of Virginia, Charlottesville, VA, USA;
16 17
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University of California, San Francisco, San Francisco, CA, USA; Brighton, CO, USA
BACKGROUND CONTEXT: To improve preoperative risk stratification for surgical cervical deformity (CD) patients, Miller et al developed a CD frailty index (CD-FI) incorporating 40 physiciandocumented and patient-reported factors. While novel, the CD-FI is cumbersome to use in a clinical setting due to the large number of factors needed to calculate the score. To increase clinical utility, a simpler, modified CD-FI (mCD-FI) is necessary. PURPOSE: To develop a simplified frailty index for CD patients. STUDY DESIGN/SETTING: Retrospective review of prospective, multicenter CD database. PATIENT SAMPLE: A total of 121 CD patients (61±11 years, 60%F). OUTCOME MEASURES: Length of stay (LOS), health-related quality of life questionnaires: NDI, EQ-5D, NRS Neck Pain. METHODS: Cervical deformity patients (C2–C7 Cobb>10°, CL>10°, cSVA>4cm, or CBVA>25°)>18 years with available preop CD-FI component factors. Pearson bivariate correlation assessed relationships between component deficits of the CD-FI and overall CD-FI score. The top 19 deficits contributing to overall CD-FI score were included in multiple stepwise regression models. Deficits derived from the model with the largest R2were recorded as binary variables, and the mean score of all deficits calculated, resulting in a mCD-FI ranging from 0 to 1. Patients were stratified using published cutoffs: not frail (NF, <0.3), frail (0.3–0.5), severely frail (SF, >0.5). Means comparison tests established correlations between frailty category and clinical outcomes. Significance was set P<.05. RESULTS: A total of 121 CD patients were included (61±11 years, 60%F, BMI: 29.2±7.8kg/m2). The final multiple stepwise regression model identified the following combination of factors as responsible for 86% of the variation in CD-FI score: lung disease (β=0.033), BMI <18.5 or >30 (β=0.015), diabetes (β=0.040), depression (β=0.020), liver disease (β= −1.101), rheumatoid arthritis (β=0.058), venous disease (β=0.099), unsteady gait (β=0.022), bladder incontinence (β=0.031), bowel incontinence (β=0.044), leg weakness (β=0.040), >3 comorbidities (β=0.151), anxiety (β=0.098), difficulty sleeping >6 hours (β=0.056), and inability to walk (β=0.043). From these 15 deficits the overall population's mCD-FI was calculated: 0.31±0.14. Breakdown of patients by mCD-FI category: NF: 47.9%, frail: 46.3%, SF: 5.8%. As compared to NF and frail patients, SF patients had the longest inpatient hospital stays (2.5 and 1.7 times longer, respectively, P=.042), as well as greater baseline neck pain (NRS neck 1.3 and 1.1 times higher, P=.033), inferior NDI scores (1.6 and 1.2 times greater, P<.001) and inferior EQ-5D outcomes (1.2 and 1.1 times lower, P<.001). Compared to NF, frail patients had higher odds of superficial infection (OR:1.1 [1.001–1.2]), and SF patients had significantly increased odds of mortality (OR:10.4 [1.2–90.6]). CONCLUSIONS: In this modified cervical deformity frailty index, greater levels of patient frailty were correlated with inferior clinical outcomes, longer hospital length of stay, increased neck pain, and decreased health-related quality of life. Additionally, frail patients were at greater risk for infection, and severely frail patients had significantly greater odds of mortality. The relatively few number of deficits needed to calculate the present frailty score gives this modified cervical deformity frailty index increased clinical utility. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs. https://doi.org/10.1016/j.spinee.2018.06.522
258. The C5-T3 angle: a novel parameter of the cervicothoracic junction Sang-Hun Lee, MD, PhD1, Micheal Raad, MD2, Brian J. Neuman, MD3, Munish C. Gupta, MD4, Hamid Hassanzadeh, MD5, Virginie Lafage, PhD6, Peter G. Passias, MD7, Themistocles S. Protopsaltis, MD8, D. Kojo Hamilton, MD9, Justin S. Smith, MD, PhD10, Christopher I. Shaffrey, MD11, Eric O. Klineberg, MD12, Jeffrey L. Gum, MD13, Shay Bess, MD14,
Refer to onsite annual meeting presentations and postmeeting proceedings for possible referenced figures and tables. Authors are responsible for accurately reporting disclosure and FDA device/drug status at time of abstract submission.
S128
The Spine Journal 18 (2018) S70 S128 15
16
Richard A. Hostin Jr., MD , Christopher P. Ames, MD , Khaled M. Kebaish, MD3; International Spine Study Group 17; 1 Johns Hopkins University, Department of Orthopedic surgery, Baltimore, MD, USA; 2 Johns Hopkins, Baltimore, MD, USA; 3 Baltimore, MD, USA; 4 Washington University School of Medicine, St. Louis, MO, USA; 5 University of Virginia, Department of Orthopedic Surgery, Charlottesville, VA, USA; 6 Hospital for Special Surgery, New York, NY, USA; 7 NY Spine Institute, NYU Langone Health, New York, NY, USA; 8 Department of Orthopaedic Surgery, NYU Langone Orthopaedic Hospital, NYU Langone Health, New York, NY, USA; 9 University of Pittsburgh School of Medicine, Pittsburgh, PA, USA; 10 UVA Health System, Charlottesville, VA, USA; 11 University of Virginia, Charlottesville, VA, USA; 12 UC, Davis School of Medicine, Sacramento, CA, USA; 13 Norton Leatherman Spine Center, Louisville, KY, USA; 14 Denver, CO, USA; 15 Southwest Scoliosis Institute, Plano, TX, USA; 16 University of California, San Francisco, San Francisco, CA, USA; 17 Brighton, CO, USA BACKGROUND CONTEXT: Unlike the thoracolumbar junction (TLJ) angle which is well-defined as T10 – L2, there is no consensus on how to define the CTJ angle. The CTJ consists of mobile lower cervical and rigid upper thoracic spinal segments, giving it unique anatomical and biomechanical characteristics. To our knowledge, this is the first study attempting to define a new parameter for assessing the cervicothoracic junction. PURPOSE: Attempting to define a new parameter for assessing the cervicothoracic junction. STUDY DESIGN/SETTING: Retrospective analysis of a prospective database. PATIENT SAMPLE: Adult spinal deformity patients operated on between the years 2008 and 2016 were included in the analysis. We excluded patients with history of cervical spinal fusion or an upper instrumented vertebra higher than T5. OUTCOME MEASURES: The criteria for an ideal CTJ angle would be: constant, significantly correlated with sagittal parameters, and involving maximum number of levels. METHODS: This is a retrospective analysis of a prospective surgical database. ASD patients operated on between the years 2008 and 2016 were included in the analysis. We excluded patients with history of cervical spinal fusion or an upper-most instrumented vertebra higher than T5. The criteria for an ideal CTJ angle would be: longitudinally constant, crosssectionally correlates with other parameters and involves the maximum number of levels. A combination of 12 angles between C5 and T4 were analyzed. The variation in each angle's value over time (preoperative, 6 weeks and 2 years) was assessed using ANOVA. Pearson correlation analysis was performed between the most constant candidate parameters and: demographic data, preoperative sagittal spinopelvic parameters and the amount of correction at 2 years. RESULTS: A total of 427 patients (mean age 59.9, 74% women) met our inclusion criteria and were included in the analysis. Seven of 12 CTJ angles; C5-T1, C5-T2, C5-T3, C6-T1, C6-T2, C7-T1 and C7-T2 were constant between preoperative, PO6W and PO2Y measurements (p>.05). All the seven candidate angles showed significant correlation with age and preoperative sagittal angles including pelvic tilt (PT), lumbar lordosis (LL; L1–S1), TLJ angle (T10–L2), thoracic kyphosis (TK, T4–T12), cervical lordosis (CL; C2–C7), pelvic incidence (PI) minus LL, T1 slope (TS) minus CL, T1 pelvic angle (T1PA), sagittal vertical axis (SVA) C2-7 and C7-S1 (p<.01). The candidate CTJ angles were not affected by PI, amount of correction of PT, LL, TL and TK, PI minus LL at PO2Y. However, the amount of correction involving cervical spine parameters (CL, TS minus CL, SVA C2–C7 and SVA C7–S1) showed significant correlations with the CTJ angles (mostly p<.01). CONCLUSIONS: Based on the present study, the C5-T3 angle is the ideal parameter to assess the CTJ, given its constant value over time, involvement of maximal number of segments as well as an appropriate correlation with other major spinal sagittal parameters. Further studies assessing its implications on clinical outcomes may be warranted.
FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs. https://doi.org/10.1016/j.spinee.2018.06.523
259. The influence of cervical spondylolisthesis on clinical presentation and surgical outcome in patients with degenerative cervical myelopathy: analysis of a global cohort Aria Nouri, MD, MSc1, So Kato, MD2, Michael W. Robinson, MD, PhD3, Juan C. Mejia Munne, MD1, George Yang1, William Jeong1, Rani Nasser, MD4, Joseph S. Cheng, MD, MS5, Michael G. Fehlings, MD, PhD, FRCSC6; 1 Cincinnati, OH, USA; 2 The University of Tokyo Hospital, Bunkyo-ku, Tokyo, Japan; 3 University of Cincinnati Medical Center, Cincinnati, OH, USA; 4 Montefiore Medical Center, Department of Neurosurgery, Spine Research Group, Bronx, NY, USA; 5 University of Cincinnati College of Medicine, Cincinnati, OH, USA; 6 Toronto Western Hospital, Toronto, ON, Canada BACKGROUND CONTEXT: Cervical spondylolisthesis (CS) presents in ∼12% of patients with degenerative cervical myelopathy (DCM). However, its impact on clinical presentation and surgical outcome have not been welldescribed. Using a prospective and multicenter cohort, we compare patients with and without CS on MRI undergoing surgical treatment for DCM. PURPOSE: To determine the influence of cervical spondylolisthesis in patients with DCM. STUDY DESIGN/SETTING: Retrospective review of prospectively collected data from multiple global sites. PATIENT SAMPLE: A total of 458 patients with MRIs and clinical data. OUTCOME MEASURES: The modified Japanese Orthopedic Association score (mJOA), Nurick grade, SF-36 Mental and Physical Component Scores, and the Neck Disability Index. METHODS: A total of 458 MRIs from the AOSpine North America and International Studies were reviewed. Patient demographics and baseline neurological and functional status were also obtained. CS was identified using T2 MRI. Patients with DCM were divided into two cohorts, those with CS and those without. Patient demographics, neurological and functional status at baseline and outcome at 2-year follow-up were compared using independent t-tests, chi square tests, Fischer exact tests, and multivariate analysis. RESULTS: In comparison to the nonspondylolisthesis cohort (n=404), CS patients (n=54) were on average 8.8 years older (p<.0001), presented with worse baseline neurological and function status (mJOA, p=.008; Nurick, p=.008; SF-36-PCS, p=.01), more commonly presented with ligamentum flavum enlargement (81.5% vs. 53.5%, p<.0001), were less commonly from Asia (p=.0002), and tended to have more levels of compression (p=.052) and lower prevalence rates of OPLL (p=.098). There was no difference in sagittal alignment between the groups (p=.94). The surgical approach varied between cohorts (p=.0002), with posterior approaches more commonly performed with CS (61.1% vs. 37.4%). CS patients also had more operated levels (4.28±1.43 vs. 3.61±1.19, p=.0002), and tended to undergo longer operations (196.58±89.20 minutes vs. 177.20±75.57 minutes, p=.087). The mean improvement of neurological function was lower with CS [mJOA (1.51±3.56 vs. 2.77±2.72, p=.003); Nurick (−0.78 ±1.42 vs. −1.45±1.45, p=.002)], and CS was an independent predictor of worse mJOA recovery ratio at 2-years (B=−0.190, p<.0001). CONCLUSIONS: CS patients are older and present with worse neurological and functional impairment. Furthermore, they receive surgery on more levels and more commonly from the posterior. CS may indicate a more advanced state of DCM pathology and is more likely to result in a suboptimal surgical outcome. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs. https://doi.org/10.1016/j.spinee.2018.06.524
Refer to onsite annual meeting presentations and postmeeting proceedings for possible referenced figures and tables. Authors are responsible for accurately reporting disclosure and FDA device/drug status at time of abstract submission.