The protection of superior articular process in percutaneous transforaminal endoscopic discectomy should decreases the risk of adjacent segment diseases biomechanically

•Biomechanical deterioration was considered primary triggers of adjacent segment disease (ASD).•Our published literature proved that a larger grades of facetectomy may increase the risk low back pain, a common symptom of ASD, So we can hypothesise that which may increase ASD risk biomechanically.•Our computational results indicated, in most body positions, biomechanical indicators deteriorated in the half facetectomy model.•In PTED, on the basis of achieving the surgical purpose, superior articular process should be protected to decreases the risk of ASD biomechanically. Facetectomy is a useful procedure in percutaneous transforaminal endoscopic discectomy (PTED) for the enlargement of surgical field and operative space and for the decompression of existing nerve roots for patients who suffer foraminal stenosis. Biomechanical deterioration can initially trigger the adjacent segment disease (ASD), and our previous literature proved that a large grade of facetectomy can increase the risk of biomechanical deterioration and resulting low back pain. However, no study has discussed whether different grades of facetectomy influence the risk of ASD. A validated osteoligamentous lumbosacral finite element model and corresponding PTED models with quarter and half facetectomy were constructed in our previous study. Biomechanical indicators were computed and recorded to evaluate the risk of ASD. Obvious differences between the intact model and the quarter facetectomy model had no basis. Nevertheless, in most body positions, most of the above indicators deteriorated in the half facetectomy model. On the basis of achieving the surgical purpose in PTED, the superior articular process should be protected to decrease the risk of ASD biomechanically.