Three-dimensional radiological classification of lumbar disc herniation in relation to surgical outcome

Abstract

Centrally located lumbar disc herniations have been reported to be of predictive value for poor post-operative clinical outcome. One hundred and fifty patients undergoing lumbar disc herniation surgery were prospectively included. Herniation-related parameters, including the grading of contours, were assessed from pre-operative computed tomography (CT) and magnetic resonance imaging (MRI) images using a new three-dimensional grading system. The radiological findings were compared with outcome parameters two years post-operatively (patient-assessed pain, function/health scores and evaluation by an independent observer). An intra- and inter-observer validation of the classification was performed in a subgroup of patients. High intra-observer and good inter-observer reliability for both CT and MRI was seen. In the study population, no relation between the distribution or size of the herniations and outcome at 2-year follow-up were found. The distribution and size of the lumbar disc herniations with the three-dimensional classification were not found to be of importance for the clinical outcome.

Fig. 1

a Transverse distribution. The transverse views of the spinal canal were equally divided into four sectors on each side of the midline. b Sagittal distribution. The sagittal plane of the spinal canal was divided into four sectors. c Longitudinal distribution. The longitudinal distribution of the disc herniations was estimated as being located cranial and/or equal and/or caudal to the level of the disc