Dural sac cross-sectional area and morphological grade show significant associations with patient-rated outcome of surgery for lumbar central spinal stenosis

• Published in: European spine journal 2017-10, Vol.26 (10), p.2552-2564
• Main Authors: Mannion, A. F., Fekete, T. F., Pacifico, D., O’Riordan, D., Nauer, S., von Büren, M., Schizas, C.
• Format: Article
• Language: English
• Subjects: Bone surgery; Cerebrospinal fluid; Decompression; Dura Mater - diagnostic imaging; Dura Mater - pathology; Geriatrics; Humans; Lumbar Vertebrae - diagnostic imaging; Lumbar Vertebrae - surgery; Magnetic Resonance Imaging; Medicine; Medicine & Public Health; Morphology; Neurosurgery; NMR; Nuclear magnetic resonance; Original Article; Patients; Retrospective Studies; Spinal stenosis; Spinal Stenosis - diagnostic imaging; Spinal Stenosis - epidemiology; Spinal Stenosis - physiopathology; Spinal Stenosis - surgery; Spine (lumbar); Surgery; Surgical Orthopedics; Treatment Outcome
• ISSN: 0940-6719; 1432-0932
• DOI: 10.1007/s00586-017-5280-7

Purpose Lumbar central spinal stenosis (LSS) is one of the most common reasons for spine surgery in the elderly patient. Magnetic resonance imaging (MRI) represents the gold standard for the assessment of LSS and can be used to obtain quantitative measures of the dural sac cross-sectional area (DCSA) or qualitative measures (morphological grades A–D) of the rootlet/cerebrospinal fluid ratio. This study investigated the intercorrelation between these two MRI evaluation methods and explored their respective relationships with the patient baseline clinical status and outcome 12 months after surgery. Methods This was a retrospective analysis of prospectively collected data from 157 patients (88 male, 69 female; age 72 ± 7 years) who were undergoing first-time surgery for LSS. Patients with foraminal or isolated lateral stenosis were excluded. The Core Outcome Measures Index (COMI) was completed before and 12 months after surgery. Preoperative T2 axial MRIs were blinded and independently evaluated for DCSA and morphological grade. Spearman rank correlation coefficients described the relationship between the two MRI measures of stenosis severity and between each of these and the COMI baseline and change-scores (pre to 12 months’ postop). Multiple logistic regression analysis (controlling for baseline COMI, age, gender, number of operated levels, health insurance status) was used to analyse the influence of stenosis severity on the achievement of the minimum clinically important change (MCIC) score for COMI and on global treatment outcome (GTO). Results There was a correlation of ρ  = −0.69 ( p   0.85). However, logistic regression revealed significant ( p