Safety and Utility of Bilateral-contralateral Decompression for Adjacent Segment Stenosis After Lumbar Interbody Fusion Using Unilateral Biportal Endoscopy.

STUDY DESIGN

Retrospective case series study.

OBJECTIVE

To evaluate the safety and efficacy of bilateral-contralateral decompression using unilateral biportal endoscopy (UBE) for treating adjacent segment disease (ASD) after lumbar interbody fusion (LIF).

SUMMARY OF BACKGROUND DATA

ASD is a well-documented complication following LIF, often requiring additional surgical interventions. Traditional decompression techniques risk damaging the facet joints, potentially leading to further instability and degeneration. However, our bilateral-contralateral decompression using UBE focuses on minimizing facet joint resection and reducing the risk of postoperative instability.

METHODS

This study included 37 patients who underwent bilateral-contralateral UBE decompression for ASD following LIF at the L4-5 level between September 2020 and March 2022. Radiographic evaluations included measurements of vertebral range of motion (ROM), slip distance, disk height, lumbar lordosis, and facet joint preservation. Clinical assessments were performed using the visual analog scale (VAS) for back and leg pain and the Oswestry disability index (ODI).

RESULTS

The average final follow-up period was 14.5±1.9 mo. The average preoperative ROM was 3.0 degrees, which significantly increased to 4.8° at the final follow-up (P<0.05). Static structure and dynamic stability parameters, including the vertebral slip distance, lumbar lordosis, and disk height, showed no significant differences between the preoperative examination and 1-year postoperative follow-up. The facet joint preservation rate was 97.4±2.1% on average. Significant improvements in VAS scores for leg and back pain and ODI were observed. Despite improvement with conservative treatment in 7 patients with delayed instability, 2 patients required fusion surgery.

CONCLUSIONS

Bilateral-contralateral decompression through UBE has proven to be an effective and safe method for treating ASD following LIF. This technique is particularly suitable for patients requiring spinal stability maintenance. The high rates of facet joint preservation and low incidence of reoperation highlight this technique as a compelling alternative treatment for spinal stenosis.

LEVEL OF EVIDENCE

Level III.