Comparison of the Clinical and Radiological Outcomes of Full-Endoscopic Laminotomy and Conventional Subtotal Laminectomy for Lumbar Spinal Stenosis: A Randomized Controlled Trial

Abstract

Study design: Randomized controlled trial.

Objective: The primary objective of this study was to compare the short-term clinical and radiological outcomes of full-endoscopic lumbar laminotomy (FEL) with those of subtotal lumbar laminectomy (STL) for lumbar spinal stenosis (LSS).

Methods: In this prospective randomized trial a total of 52 patients were enrolled from May 2016 to September 2021 after providing written informed consent. The authors investigated 45 patients who were followed up for more than 6 months.

Results: There were significant improvements in visual analogue scale (VAS) and Oswestry Disability Index (ODI) scores after the operation in both groups. The FEL group tended to have significantly shorter hospital stay. Interestingly, a statistically significant increase in postoperative lumbar lordosis and segmental angle was observed in the FEL group and both groups, respectively. Spondylolisthesis was exacerbated or newly developed in five of the 21 patients (24%) in the STL group. In contrast, improvement in spondylolisthesis was observed in two of the 24 patients (8%) in the FEL group. There were no complications that resulted in fatal sequelae and no significant difference in the complication rate.

Conclusions: The clinical results of FEL were similar to those of STL. In addition, the results of FEL were superior to those of STL in terms of a decrease in the postoperative length of stay and radiologic instability, such as iatrogenic spondylolisthesis. The results of this study indicate that FEL is a comparable surgical method to STL for LSS.

Keywords: decompression; endoscopy; full-endoscopy; laminectomy; spinal stenosis; spine; spondylolisthesis.

Figure 1.

Enrollment to follow-up flow diagram.

Figure 2.

Clinical status assessment. Graph showing preoperative and postoperative mean VAS back scores (A), VAS leg scores (B), and ODI scores (C) for both the STL (black) and FEL (gray) groups. Footnotes* Wilcoxon signed-rank test was used. ** Significant difference, P-value < .005. STL, subtotal laminectomy; FEL, full-endoscopic laminotomy; VAS, visual analogue scale; ODI, Oswestry Disability Index

Figure 3.

Radiologic status assessment. Graph showing preoperative and postoperative mean LL (left), and SL (right) for both the STL (black) and FEL (gray) groups. Footnotes* Wilcoxon signed-rank test was used** Significant difference, p-value < 0.005.STL, subtotal laminectomy; FEL, full-endoscopic laminotomy; LL, Lumbar lordosis; SL, Segmental lordosis

Figure 4.

One patient (serial number 3, subtotal laminectomy [STL] group) had no preoperative spondylolisthesis but grade I spondylolisthesis is newly observed after surgery (From the left, preoperative, postoperative, 6 months, 1 year, 5 years later. In a separate, visual analogue scale [VAS] back and leg, Oswestry Disability Index [ODI] improved from 6, 7, 52 to 0, 0, 4, respectively at the last follow-up).

Figure 5.

In one case (serial number 27, full-endoscopic laminotomy [FEL] group), spondylolisthesis was present before surgery, but slight improvement in spondylolisthesis is observed on serial follow-up images after surgery. (From the left, preoperative, postoperative, 3 months, 17 months later. In a separate, visual analogue scale [VAS] back, leg, and Oswestry Disability Index [ODI] improved from 2, 8, 52 to 3, 3, 14, respectively at the last follow-up).

Figure 6.

A patient (serial number 20, full-endoscopic laminotomy [FEL] group) underwent FEL for the left leg radiating pain in 2016, which improved; however, he had to undergo fusion surgery after diagnosis of right foraminal disc extrusion with newly developed right leg radiating pain after 17 months. (A: preoperative magnetic resonance imaging, B: 17 months later, C: postoperative radiographs).