Aria Nouri1, Lindsay Tetreault, Juan J Zamorano, Kristian Dalzell, Aileen M Davis, David Mikulis, Albert Yee, Michael G Fehlings. 1. *Division of Neurosurgery and Spine Program, Toronto Western Hospital, Toronto, Ontario, Canada †Toronto Western Research Institute, University Health Network, Toronto, Ontario, Canada ‡Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada §Christchurch Public Hospital & Burwood Spinal Unit, Christchurch, New Zealand ¶Division of Health Care and Outcomes Research, Toronto Western Research Institute, Toronto, Ontario, Canada ‖Toronto Western Hospital, University Health Network Toronto, Toronto, Ontario, Canada **Institute of Health Policy, Management and Evaluation and Institute of Medical Science and Graduate Department of Rehabilitation Science, University of Toronto, Toronto, Ontario, Canada ††Division of Brain Imaging & Behaviour Systems, Toronto Western Hospital, Toronto, Ontario, Canada; and ‡‡Division of Orthopaedic Surgery, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada.
Abstract
STUDY DESIGN: Ambispective, retrospective cohort study from prospectively collected data. SUMMARY OF BACKGROUND DATA: Cervical spondylotic myelopathy is the commonest cause of spinal cord impairment in the elderly population worldwide. Although magnetic resonance imaging (MRI) is the primary imaging modality for confirming the diagnosis, its role in predicting surgical outcome remains unclear. METHODS: Two hundred seventy-eight patients with 1 or more clinical signs of myelopathy were enrolled; and they underwent decompression surgery. Complete baseline clinical and MRI data were available for 102 patients. MRI parameters measured included presence/absence of signal change on T1 and T2, T2 signal quantitative factors, and anatomical measurements. A dichotomized postoperative modified Japanese Orthopedic Association (mJOA) score at 6 months was used to characterize patients with mild myelopathy (≥16) and those with substantial residual neurological impairment (<16). Univariate analysis assessed the relationship between baseline parameters and outcome. Multivariate logistic regression was conducted after a conceptual division of variables into 3 groups: T1 signal analysis, T2 signal analysis, and anatomical measurements. RESULTS: Baseline mJOA (P<0.001; odds ratio [OR]=1.644, 95% confidence interval [95% CI]: 1.326-2.037), maximum canal compromise (MCC) (P=0.0322; OR=0.965, 95% CI: 0.934-0.997), T2 hyperintensity region of interest area (P=0.0422; OR=0.67; 95% CI: 0.456-0.986), and sagittal extent (P=0.026; OR=0.673; 95% CI: 0.475-0.954) were significantly associated with outcome univariately. The final model was comprised of T1 hypointensity (P=0.029; OR=0.242; CI: 0.068-0.866), MCC (P=0.005; OR=0.940; CI: 0.90-0.982) and baseline mJOA (P<0.001; OR=1.743; CI: 1.353-2.245), yielding an area under the receiver operating characteristic curve (AUC) of 0.845. CONCLUSION: Baseline mJOA is a strong predictor of postsurgical outcome in cervical spondylotic myelopathy at 6 months. However, a model inclusive of MCC and T1 hypointensity assessment provides superior predictive capacity. This suggests that MRI analysis has a significant role in predicting surgical outcome. LEVEL OF EVIDENCE: 3.
STUDY DESIGN: Ambispective, retrospective cohort study from prospectively collected data. SUMMARY OF BACKGROUND DATA: Cervical spondylotic myelopathy is the commonest cause of spinal cord impairment in the elderly population worldwide. Although magnetic resonance imaging (MRI) is the primary imaging modality for confirming the diagnosis, its role in predicting surgical outcome remains unclear. METHODS: Two hundred seventy-eight patients with 1 or more clinical signs of myelopathy were enrolled; and they underwent decompression surgery. Complete baseline clinical and MRI data were available for 102 patients. MRI parameters measured included presence/absence of signal change on T1 and T2, T2 signal quantitative factors, and anatomical measurements. A dichotomized postoperative modified Japanese Orthopedic Association (mJOA) score at 6 months was used to characterize patients with mild myelopathy (≥16) and those with substantial residual neurological impairment (<16). Univariate analysis assessed the relationship between baseline parameters and outcome. Multivariate logistic regression was conducted after a conceptual division of variables into 3 groups: T1 signal analysis, T2 signal analysis, and anatomical measurements. RESULTS: Baseline mJOA (P<0.001; odds ratio [OR]=1.644, 95% confidence interval [95% CI]: 1.326-2.037), maximum canal compromise (MCC) (P=0.0322; OR=0.965, 95% CI: 0.934-0.997), T2 hyperintensity region of interest area (P=0.0422; OR=0.67; 95% CI: 0.456-0.986), and sagittal extent (P=0.026; OR=0.673; 95% CI: 0.475-0.954) were significantly associated with outcome univariately. The final model was comprised of T1 hypointensity (P=0.029; OR=0.242; CI: 0.068-0.866), MCC (P=0.005; OR=0.940; CI: 0.90-0.982) and baseline mJOA (P<0.001; OR=1.743; CI: 1.353-2.245), yielding an area under the receiver operating characteristic curve (AUC) of 0.845. CONCLUSION: Baseline mJOA is a strong predictor of postsurgical outcome in cervical spondylotic myelopathy at 6 months. However, a model inclusive of MCC and T1 hypointensity assessment provides superior predictive capacity. This suggests that MRI analysis has a significant role in predicting surgical outcome. LEVEL OF EVIDENCE: 3.
Authors: A R Martin; B De Leener; J Cohen-Adad; D W Cadotte; S Kalsi-Ryan; S F Lange; L Tetreault; A Nouri; A Crawley; D J Mikulis; H Ginsberg; M G Fehlings Journal: AJNR Am J Neuroradiol Date: 2017-04-20 Impact factor: 3.825
Authors: A R Martin; B De Leener; J Cohen-Adad; D W Cadotte; S Kalsi-Ryan; S F Lange; L Tetreault; A Nouri; A Crawley; D J Mikulis; H Ginsberg; M G Fehlings Journal: AJNR Am J Neuroradiol Date: 2017-04-20 Impact factor: 3.825
Authors: Michael G Fehlings; Lindsay A Tetreault; K Daniel Riew; James W Middleton; Bizhan Aarabi; Paul M Arnold; Darrel S Brodke; Anthony S Burns; Simon Carette; Robert Chen; Kazuhiro Chiba; Joseph R Dettori; Julio C Furlan; James S Harrop; Langston T Holly; Sukhvinder Kalsi-Ryan; Mark Kotter; Brian K Kwon; Allan R Martin; James Milligan; Hiroaki Nakashima; Narihito Nagoshi; John Rhee; Anoushka Singh; Andrea C Skelly; Sumeet Sodhi; Jefferson R Wilson; Albert Yee; Jeffrey C Wang Journal: Global Spine J Date: 2017-09-05