Skeletal muscle-specific markers for paraspinal injury in full-endoscopic versus open microscopic lumbar spine...

Full-endoscopic lumbar surgery may minimize paraspinal muscle damage by avoiding extensive muscle dissection and retraction. However, objective biochemical comparisons of muscle injury between full-endoscopic and conventional open microscopic lumbar surgery remain limited. The purpose of this study was to compare postoperative changes in biochemical serum markers of skeletal muscle injury following open microscopic versus full-endoscopic lumbar decompression.

This prospective observational study included adult patients undergoing lumbar decompression surgery for degenerative lumbar disease. Patients were treated using either open microscopic or full-endoscopic surgery. Preoperative blood samples were obtained within 1 week before surgery, and postoperative samples were collected within 24 hours after surgery. Laboratory parameters included creatine phosphokinase, creatine kinase (CK)-MM, myoglobin, lactate dehydrogenase (LDH), LDH isoenzyme, aldolase, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, gamma-glutamyl transferase, and C-reactive protein. A numeric rating scale (NRS) back pain score was assessed preoperatively, immediately postoperatively (postoperative day 1), and at 3 months.

Two hundred four patients were included in the study: 148 underwent open microscopic surgery and 56 underwent full-endoscopic surgery. Postoperative increases in biochemical markers of skeletal muscle injury were significantly greater in the open surgery cohort than in the full-endoscopic cohort. In the open microscopic group, mean CK-MM increased from 100.4 (SD 72.5) U/L preoperatively to 138.4 (SD 78.9) U/L postoperatively, whereas in the full-endoscopic group it changed from 118.7 (SD 73.7) U/L to 109.3 (SD 51.4) U/L (p < 0.001 for between-group change). Similarly, mean myoglobin increased from 40.3 (SD 22.4) ng/ml to 112.3 (SD 78.6) ng/ml in the open microscopic group and from 38.8 (SD 22.2) ng/ml to 72.6 (SD 33.8) ng/ml in the full-endoscopic group (p < 0.001 for between-group change). Other laboratory markers did not demonstrate significant between-group differences after false discovery rate correction. The immediate postoperative NRS back pain score was significantly lower in the full-endoscopic group, whereas 3-month scores did not differ significantly between groups. A subgroup analysis of patients who underwent single-level surgery demonstrated consistent results.

Full-endoscopic lumbar decompression was associated with significantly smaller postoperative increases in CK-MM and myoglobin levels compared with open microscopic surgery, indicating reduced paraspinal muscle injury with the endoscopic approach. Consistent with these biochemical findings, immediate postoperative back pain was also significantly lower in the endoscopic group, further supporting the clinical relevance of reduced paraspinal muscle trauma.