Modified Percutaneous Endoscopic Interlaminar Discectomy through the Near-spinous Process Approach for L4/5 Disc Herniation: A Retrospective Clinical Study

Abstract

Objective: Compared with traditional open surgery, percutaneous endoscopic lumbar discectomy (PELD) has the advantages of less trauma, faster recovery, and less postoperative pain, so it has been widely used in the field of spinal surgery. However, it still has the defect of intraoperative fluoroscopy occurrences, complications, and even the risk of damage to the spinal cord and nerve. This study aims to compare the clinical efficacy of modified percutaneous endoscopic interlaminar discectomy (MPEID) with percutaneous endoscopic transforaminal discectomy (PETD) in treating L4/5 lumbar disc herniation (LDH) and to evaluate the effectiveness and safety of MPEID.

Methods: Thirty-four L4/5 LDH patients treated at the Second Affiliated Hospital of Nanchang University from June 2020 to June 2021 were studied retrospectively. Seventeen underwent MPEID and seventeen PETD. Variables analyzed included demographics, operative duration, intraoperative fluoroscopy occurrences, and surgical outcomes. Effectiveness was evaluated using the visual analogue scale (VAS), Oswestry disability index (ODI), and modified MacNab criteria. Lumbar Magnetic Resonance Imaging (MRI) was used to assess radiological outcomes. A paired t-test was performed to compare intragroup pre- and postoperative clinical data, VAS, and ODI scores.

Results: The average operative time in PETD group was 91.65 ± 14.04 min, and the average operative time in MPEID group was 65.41 ± 12.61 min (p < 0.001). In PETD group, the fluoroscopy occurrences averaged 9.71 ± 1.05 times, with fluoroscopy occurrences averaging 6.47 ± 1.00 times (p < 0.001) in MPEID group. At 12 months follow-up, the clinical effect showed significant improvement in both two groups. The MPEID group showed a decrease in average VAS-back score from 5.41 ± 2.18 to 1.76 ± 1.09 (p < 0.001) and VAS-leg score from 6.53 ± 1.66 to 0.82 ± 0.64 (p < 0.001). The ODI scores decreased from 51.35 ± 10.65 to 11.71 ± 2.91 (p < 0.001). In the PETD group, the VAS-back score decreased from 4.94 ± 1.98 to 2.06 ± 1.25 (p < 0.001), VAS-leg score from 7.12 ± 1.73 to 1.12 ± 0.60 (p < 0.001), and ODI scores from 48.00 ± 11.62 to 12.24 ± 2.56 (p < 0.001). According to the modified MacNab criteria, MPEID had 15 excellent and two good results; PETD had 12 excellent and 5 good (p = 0.23). No nerve root injuries, dural tears, or significant complications were reported.

Conclusion: MPEID and PETD effectively treat L4/5 LDH, with MPEID showing shorter operative times and fewer fluoroscopies. Furthermore, the MPEID group can provide excellent clinical efficacy as the PETD group in the short term.

Keywords: L4/5 Lumbar disc herniation; Percutaneous endoscopic interlaminar discectomy; Percutaneous endoscopic lumbar discectomy; Percutaneous endoscopic transforaminal discectomy.

FIGURE 1

PETD intraoperative fluoroscopy and preoperative and postoperative. MRI (A–E) Intraoperative radiographs. (F and G) Preoperative MRI, H and I: MRI 3 months after surgery.

FIGURE 2

Schematic diagram of the MPEID spinal endoscopy technique for L4/5 disc herniation. (A and B) Interlaminar space with and without a postural cushion on X‐ray. (C) An 18‐G needle was inserted from the lower end of the L5 spinous process to the most lateral edge of the L4 lamina on the affected side. (D) The sequential tract dilatation was performed. (E) The working channel was moved in the direction of the black arrow, using the inclined baffle to protect the nerve and to enlarge the operable space under the operating scope.

FIGURE 3

MPEID intraoperative fluoroscopy and preoperative and postoperative MRI. (A–E) Intraoperative radiographs, (F and G) Preoperative MRI, H and I: MRI 3 months after surgery.

FIGURE 4

Clinical efficacy evaluation. (A) Compared to PETD group, the MPEID group showed a significant decrease in operative time. (B) Compared to PETD group, the MPEID group showed a significant decrease in fluoroscopy times. (C) In the PETD group, there was a significant decrease in VAS‐back, VAS‐leg, and ODI scores at postoperative day 1, 3 months, and 12 months. (D) In the MPEID group, there was a significant decrease in VAS‐back, VAS‐leg, and ODI scores at postoperative day 1, 3 months, and 12 months. *p < 0.05; **p < 0.01; ***p < 0.001.

FIGURE 5

Diagram of the safety of the procedure. (A and B) Interlaminar space of L4/5 laminae interval space was widen and the angle between the L4/5 plate gap and the intervertebral disc was reduced. (C) A safe zone was created within the intervertebral space with the herniated disc's displacement of the nerve root.