The Influence of the Degree of Lumbar Disc Degeneration on MRI and the Amount of Removed Disc on Clinical Outcomes / 대한척추외과학회지

ABSTRACT

STUDY DESIGN: The influence of lumbar disc degeneration, the space-occupying ratio on MRI and the amount of removed disc on the clinical outcomes of an open discectomy were analyzed retrospectively. OBJECTIVES: This study analyzed the pre and post-operative factors associated with the clinical outcome of an open discectomy. SUMMARY OF LITERATURE REVIEW Much controversy still exists regarding the factors that influence the clinical outcome following an open discectomy. MATERIALS AND METHODS: Out of 207 patients who had been treated with an open discectomy for a lumber disc herniation, between April 1997 and December 2003, 161 patients who underwent MRI with the same apparatus, with at least 6 months of follow-up, were analyzed. The study group was composed of 111 men and 50 women, with a mean age at the time of surgery of 33.1 years old. The mean follow-up period was 42 months. The degree of disc degeneration was classified according to the Thompson's classification, and the extent of the discectomy was measured by the volume. The postoperative outcomes were judged using Nayer's classification. RESULTS: The highest frequency of disc herniation occurred at the L4-5 level, with being of the subligamentous extrusion type. The disc degeneration observed on MRI had a high statistical correlation with age (p0.05). Clinically, 123 cases were more than fair, and 4 cases underwent reoperation due to recurrence. The clinical outcome, sex, age and space-occupying ratio were of little statistical value (p>0.05). Statistically, the greater the amount of disc removed, the better the clinical outcome (p<0.05). Those with disc degeneration classified as grade 3 from the MRI had unsatisfactory clinical outcomes (p<0.05). CONCLUSIONS: Those with disc degeneration classified as grade 3 from the MRI had unsatisfactory clinical outcomes. The greater the amount of disc removed the more satisfactory the clinical outcomes. No statistical relationships were found between the space-occupying ratio and the clinical outcome.