Classification Systems for Knee Osteochondritis Dissecans: A Systematic Review.

Area of Science:

• Orthopedics
• Radiology
• Sports Medicine

Background:

• Osteochondritis dissecans (OCD) of the knee is a joint condition affecting subchondral bone.
• Accurate classification systems are crucial for guiding treatment decisions in knee OCD.
• Existing classification systems vary in their application and validation.

Purpose of the Study:

• To systematically review and describe all classification systems for knee osteochondritis dissecans (OCD) lesions.
• To evaluate the accuracy and reliability of these classification systems.
• To assess the utilization of different knee OCD classifications in the scientific literature.

Main Methods:

• A comprehensive systematic literature search was conducted in July 2021.
• Databases searched included PubMed, Web of Science, and Cochrane Collaboration.
• Identified studies were analyzed to list OCD classification systems and quantify their application in clinical studies.

Main Results:

• 30 studies identified 33 distinct knee OCD classification systems (11 radiographic, 13 MRI, 9 arthroscopic).
• Arthroscopic classifications were most frequently applied (64.2%), followed by radiographic (35.8%) and MRI (35.2%).
• The International Cartilage Repair Society (ICRS) arthroscopic classification has been the most utilized in recent decades, yet data on accuracy and reliability remains scarce.

Conclusions:

• Multiple classification systems exist for knee OCD, with the ICRS arthroscopic system being predominant.
• While arthroscopy confirms stability, noninvasive imaging (radiography and MRI) guides initial management.
• MRI is increasingly important for early detection and distinguishing stable/unstable lesions to inform conservative or surgical treatment.