Clinical application of a new three-dimensional radiological classification of lumbar disc herniations

The results after lumbar discectomy are usually satisfactory. However, there is a group of patients with less favorable result. The predictive factors affecting the result are not fully understood. In this paper a new radiological classification for lumbar disc herniations has been used in order to study the predictive value of the type and location of the herniation for the postoperative result. 142 patients operated with standard lumbar discectomy were included in the study. The preoperative CT-scans were used to classify the disc herniations in the transverse, sagittal and longitudinal directions and the size of the herniations were calculated. At a mean of 7.7 years postoperatively a patient administrated questionnaire was used to compare the clinical results to the radiological findings. A significantly smaller size of the lumbar disc herniation was found with increasing age, which could reflect the increased degeneration of the disc. Patients with a wide transverse distribution of the herniation seem to have a less favorable postoperative outcome in terms of higher rate of repeat surgery (p = 0.056). No other correlations were found.