MRI based analysis of grade of spinal canal stenosis and grade of compression of nerve root by lumbar disc herniation as tools to predict probability to need surgical treatment

Abstract

Patients with a lumbar disc herniation (LDH) without high-grade neurological deficit (PWN) are usually treated non-operatively. If non-operative treatment is not successful, a postponed surgical treatment is performed. Postponed surgery is reported to show later improvement of pain and health-related quality of life and later return to work than early surgery. There are presently no objective parameters to predict if non-operative treatment may be successful in PWN, or if an early surgical treatment could be performed. To analyze if high-grade spinal canal stenosis lead to a higher rate of surgical treatment in PWN, we conducted a retrospective single-center cohort study and included PWN with acute onset of severe radicular pain (VAS ≥8). We excluded patients with workers’ compensation involvement, chronic pain syndrome, motor deficit <3/5, malignancy and history of prior spinal surgery. All patients were initially treated by the same standardized non-operative treatment. It was monitored if patients eventually choose an operative treatment or not. After a power analysis (aiming at >0.8), 1,053 consecutive patients (02.2008 to 12.2017) were identified by diagnostic code. One hundred and eight patients were enrolled in our investigation. Thirty-nine patients were treated non-operatively (Group 1), 69 were treated by operation (Group 2). Percent (%) spinal canal compromise based on cross-sectional area of LDH was 26.3% in Group 1, 33.7% in Group 2. The difference was significant (P<0.025). The investigated group of PWN had a significantly higher probability to need surgical treatment if they had a high-grade stenosis of the spinal canal. However, these results do not constitute a general indication for surgical treatment of PWN. The results of this study merely provide information for patients, and spine specialists, to be implemented in an individual decision-process that leads to a recommendation for type of treatment.