Reliability and Clinical Validity of a Morphology-Based Classification System for Radial Meniscal Tears: A...

Area of Science:

• Orthopedics
• Biomedical Engineering
• Sports Medicine

Background:

• Radial meniscal tears (RMTs) disrupt knee joint mechanics and accelerate cartilage wear.
• Current RMT reporting lacks standardization due to heterogeneous taxonomies and nominal agreement statistics.
• Inconsistent reporting hinders accurate biomechanical analysis and clinical decision-making.

Purpose of the Study:

• To assess the interobserver and intraobserver reliability of a novel 5-type morphology-based classification system for RMTs using ordinal agreement metrics.
• To evaluate the criterion validity of the classification system against arthroscopy.
• To examine the construct validity by comparing tear types to a prespecified treatment matrix.

Main Methods:

• A cross-sectional study involving 400 RMTs across 5 centers, classified by 47 knee surgeons.
• Test-retest reliability assessed using ordinal metrics (Light kappa, Gwet AC2) with a 1-page atlas and explicit criteria.
• Criterion validity evaluated against arthroscopic reference (n=260); construct validity assessed via morphology-treatment concordance.

Main Results:

• High interobserver reliability (Light kappa ≈ 0.90) and intraobserver reliability (weighted kappa ≈ 0.91) were observed.
• Classification agreement remained stable across different meniscal compartments and gap magnitudes.
• Strong criterion validity (weighted kappa ≈ 0.89) and construct validity (exact agreement 86.2%) were demonstrated.

Conclusions:

• The 5-type RMT classification system exhibits high reproducibility and clinical validity.
• This system provides a practical, standardized framework for RMT reporting and treatment selection.
• The classification serves as a defensible tool for future clinical trials and meta-analyses.