Reliability of a New Arthroscopic Discoid Lateral Meniscus Classification System: A Multicenter Video Analysis.

Area of Science:

• Orthopaedic Surgery
• Pediatric Orthopaedics
• Knee Anatomy and Pathology

Background:

• The discoid lateral meniscus (DLM) is a frequent congenital knee abnormality with diverse presentations.
• Existing classification systems inadequately capture the full spectrum of DLM pathomorphology.

Purpose of the Study:

• To develop and assess the reliability of a novel arthroscopic classification system for discoid lateral meniscus (DLM).
• To improve the diagnostic accuracy and description of DLM variations.

Main Methods:

• A new DLM classification system was developed, evaluating meniscal width, height, peripheral stability, and tear characteristics.
• A stepwise arthroscopic examination protocol was established.
• Interobserver and intraobserver reliability were assessed using the Fleiss κ coefficient on 50 video-recorded cases.

Main Results:

• The new classification system demonstrated substantial interobserver reliability for meniscal width, height, peripheral stability, and tear presence/type.
• Interobserver reliability was moderate for tear location.
• Intraobserver reliability was substantial for meniscal width and height, and excellent for peripheral stability.

Conclusions:

• The proposed arthroscopic DLM classification system offers moderate to substantial agreement across key diagnostic features.
• This system provides a more reliable framework for classifying discoid lateral meniscus abnormalities.