Work

Endoscopic Spine Surgery for Adjacent Segment Disease After Lumbar Fusion: Indications, Outcomes, and a Proposed Treatment Algorithm

Year: 2026

Type: review

Abstract: Spinal fusion alters segmental biomechanics and redistributes mechanical load to the levels above and below the arthrodesis, which may accelerate degeneration at those levels. When such degeneration becomes symptomatic, producing new-onset back pain, radiculopathy, or neurological deficit, the condition is termed adjacent segment disease (ASD). ASD is a recognized cause of late postoperative morbidity and revision surgery after lumbar fusion, with cumulative estimates of approximately 16.5% at 5 years and 22-36% at 10 years. Conventional management has centered on neural decompression combined with extension of the existing fusion construct. Although effective, revision fusion carries greater operative complexity, increased blood loss, prolonged recovery, and higher complication rates than the index procedure, and lengthening the construct transfers stress to newly adjacent levels. Endoscopic spine surgery has emerged as a less invasive alternative that permits targeted neural decompression through small working corridors while preserving the paraspinal musculature and posterior stabilizing structures. This narrative review examines the evolving role of endoscopic techniques in ASD after lumbar fusion and compares them with conventional revision fusion in terms of indications, outcomes, and limitations. The transforaminal, interlaminar, and unilateral biportal endoscopic approaches are described, together with the technical challenges imposed by reduced disc height, epidural scarring, and distorted anatomy in previously operated segments. Reported series demonstrate significant improvements in pain and function, favorable perioperative profiles, and low complication rates, with clinical efficacy comparable to open revision surgery in controlled comparisons. A pragmatic treatment algorithm is proposed that stratifies patients by symptom pattern, imaging-defined pathology, and segmental stability. Endoscopic decompression appears most appropriate for stable segments with focal neural compression, after assessing segmental translation and angulation on flexion-extension radiographs; significant instability or deformity remains an indication for fusion-based revision. The available evidence is dominated by retrospective series, and randomized comparative trials are lacking.

Source: Orthopedic Research and Reviews

DOI: 10.2147/orr.s654805