Object: The objective of this study was to evaluate the invasiveness of microendoscopic discectomy (MED) in comparison with microscopic discectomy (MD) by measuring serum levels of creatine phosphokinase (CPK)-MM and lactate dehydrogenase (LDH)-5, and by comparing visual analog scale (VAS) scores of postoperative pain.
Methods: This study included a group of 15 patients who underwent surgery using MED and 15 patients who underwent surgery using MD, both for single-level unilateral herniated nucleus pulposus. The CPK-MM and LDH-5 levels were measured at admission and after 1, 3, and 5 days postoperatively. Pain assessment was recorded using scores raging from 0 to 10 on a subjective VAS at admission and at 1, 3, and 5 days postoperatively.
Results: The mean CPK-MM levels were lower for the MED group than for the MD group at both 3 (576.1 +/- 286.3 IU/L compared with 968.1 +/- 377.8 IU/L) and 5 days (348.1 +/- 231.0 IU/L compared with 721.7 +/- 463.2) postoperatively (p < 0.05). The mean VAS scores for postoperative back pain were lower in the MED group than in the MD group, both at 1 (3.3 +/- 2.3 compared with 5.8 +/- 1.5) and 5 days (1.9 +/- 1.1 compared with 3.6 +/- 1.1) postoperatively (p < 0.01).
Conclusions: The MED procedure is less invasive than MD, and causes less muscle damage and less back pain.