Aims
Annular fibrosus suture (AFS) selection criteria remain inconsistent regarding anatomical and biological factors, and operative boundaries remain undefined despite established associations between annular injury and postoperative recurrence risk, recognition of surgical repair as a critical recurrence-reduction strategy, and advances in suture instrumentation that have enhanced feasibility and precision. This study aimed to delineate operative boundaries by analyzing failure patterns across multidimensional anatomical and biological parameters.
Methods
A retrospective cohort study was conducted of patients undergoing full-endoscopic discectomy with attempted annular fibrosus suture. Patients were stratified by defect width, Pfirrmann grade, calcification or ossification status, bone mineral density (osteoporosis), segmental stability, and suture margin width (distance from defect edge). A composite outcome encompassing technical and clinical failure was defined, and multivariable logistic regression was performed to identify independent risk factors.
Results
Soft disc herniation without calcification or ossification constituted a favorable substrate for suture repair. Mild-to-moderate disc degeneration indicated preserved biomechanical integrity and was associated with minimal failure risk, whereas advanced degeneration markedly increased technical difficulty. Substantial defect width emerged as a critical safety boundary, with rates of suture tearing and technical failure rising sharply when anatomical deficiency exceeded acceptable thresholds. Severe osteoporosis, potential segmental instability, and insufficient suture margin were identified as additional independent risk factors compromising annular repair security.
Conclusions
This study defines operative boundaries by tissue substrate quality and anatomical geometry. It provides a binary risk framework for preoperative selection, supporting safe zones of soft herniations and mild-to-moderate degeneration while highlighting adverse effects of large defects, osteoporosis, instability, and calcified or ossified lesions.