An algorithm for selection of full endoscopic approach for symptomatic nerve root decompression.

Area of Science:

• Neurosurgery
• Orthopedic Surgery
• Minimally Invasive Spine Surgery

Background:

• Lumbar compressive radiculopathy presents challenges for endoscopic decompression.
• Selecting between Transforaminal (TF) and Interlaminar (IL) endoscopic approaches lacks clear guidelines, leading to potential complications.
• A novel surgical nomenclature and algorithm are proposed to standardize approach selection.

Purpose of the Study:

• To introduce and validate the FAPDIS (Facet angle, Anterior pathology, Posterior pathology, Dorsal, Inferior, and Superior migration) algorithm for selecting endoscopic decompression approaches.
• To establish a reliable method for describing nerve root compression in lumbar radiculopathy.
• To improve the selection process for TF or IL endoscopic surgery.

Main Methods:

• Retrospective analysis of 396 patients undergoing TF or IL full endoscopic spine surgery.
• Classification of MRI findings using the FAPDIS algorithm.
• Evaluation of inter-observer agreement for approach selection and FAPDIS factors.
• Pre- and post-operative assessment of Visual Analog Scale (VAS) and Oswestry Disability Index (ODI) scores at 6 months.

Main Results:

• High inter-observer agreement for TF (0.873) and IL (0.882) approach selection.
• FAPDIS factors, particularly P3 and P4 pathology, showed minor disagreement, while others correlated well.
• Significant reduction in VAS scores (9 to 1) and ODI scores (89 to 12) post-surgery (p < 0.001).

Conclusions:

• The FAPDIS nomenclature and algorithm provide a reliable tool for selecting endoscopic surgical approaches.
• This systematic approach aids in achieving adequate decompression with minimized perioperative complications.
• The algorithm facilitates precise description of nerve root compression for optimal surgical planning.