BACKGROUND: Adjacent segment disease after lumbar fusion is a notable clinical problem that may require revision surgery. However, the extension of fusion requires greater surgical invasiveness and results in reduced spinal mobility, particularly in elderly patients. Transforaminal full-endoscopic lumbar foraminotomy (TF-FELF) under local anesthesia may be a less invasive alternative for foraminal stenosis occurring at adjacent segments after lumbar fusion. This study evaluated the clinical and radiological outcomes of TF-FELF under local anesthesia for foraminal stenosis in adjacent segments after lumbar fusion. METHODS: This retrospective study included 15 patients who underwent TF-FELF under local anesthesia for bony foraminal stenosis at the adjacent level after lumbar fusion between July 2016 and June 2025. Variables evaluated included demographic characteristics, operative time, duration of follow-up, complications, and additional surgeries. Foraminal area was measured on sagittal computed tomography images preoperatively and on the first postoperative day. Clinical outcomes were assessed using the modified MacNab criteria. RESULTS: < 0.001). According to the modified MacNab criteria, outcomes were excellent in 10 cases, good in 4 cases, and fair in 1 case, with an overall improvement rate of 93.3%. CONCLUSIONS: TF-FELF under local anesthesia for adjacent segment foraminal stenosis after lumbar fusion resulted in significant expansion of the foraminal area and favorable clinical outcomes and was performed safely as a minimally invasive procedure. This technique may be a useful treatment option that preserves spinal mobility in elderly patients after lumbar fusion. CLINICAL RELEVANCE: TF-FELF under local anesthesia may provide a minimally invasive treatment option for adjacent-segment foraminal stenosis after lumbar fusion, particularly in elderly patients without clear instability.
Watanabe et al. (2026) studied this question.