L4-L5 anatomy classification system for lateral lumbar interbody fusion

Area of Science:

• Spinal Surgery
• Orthopedic Research
• Neurosurgery

Background:

• Lateral lumbar interbody fusion (LLIF) offers advantages like minimal tissue damage and improved fusion outcomes.
• Potential risks include lumbar plexus injury, necessitating methods to identify high-risk patients.
• Existing classifications aim to predict neurological deficits associated with LLIF.

Purpose of the Study:

• To propose a novel, simple classification system for L4-L5 anatomy to guide lateral approach decision-making.
• To evaluate the feasibility of lateral lumbar interbody fusion based on easily identifiable anatomical landmarks.
• To reduce the risk of neurological complications during LLIF procedures.

Main Methods:

• Retrospective analysis of 50 high-quality preoperative MRI scans of patients aged over 18.
• Classification of L4-L5 anatomy into Type I, II, or III based on key structures and consensus among three observers.
• Exclusion criteria included anatomical variations or poor MRI quality hindering landmark identification.

Main Results:

• 70% of L4-L5 anatomies were classified as Type I, 18% as Type II, and 12% as Type III.
• No Type III L4-L5 anatomies were approached using the lateral technique in this cohort.
• The proposed classification demonstrated a correlation with the feasibility of the lateral approach.

Conclusions:

• The developed classification system provides an easy and simple method for assessing the suitability of a lateral approach for L4-L5 fusion.
• This tool can aid surgeons in pre-operative planning and patient selection for LLIF.
• Implementation of this classification may enhance safety and reduce neurological injury risks in LLIF.