The simplest method to classify CAM lesions.

Area of Science:

• Orthopedic Surgery
• Radiology
• Medical Imaging

Background:

• Femoroacetabular impingement (FAI) is a significant cause of hip osteoarthritis.
• Current classification systems for CAM lesions lack standardization.
• Accurate classification is crucial for effective surgical planning and treatment.

Purpose of the Study:

• To introduce a simple, reproducible classification system for CAM lesions.
• To evaluate the reliability of this system across different surgical experience levels.
• To enhance pre-operative and intra-operative management of FAI.

Main Methods:

• Utilized CT 3D reconstructions from 91 preoperative scans of FAI patients.
• Developed a four-type classification system based on lesion shape and position.
• Assessed inter-observer and intra-observer reliability among hip surgeons.

Main Results:

• The classification system demonstrated high agreement among senior surgeons (91/91 cases).
• Excellent intra-observer reliability scores (0.90 and 0.91) were achieved by senior surgeons.
• A high Kappa coefficient (0.87) confirmed the system's reliability, even for junior surgeons.

Conclusions:

• The proposed classification system for CAM lesions is simple, reproducible, and reliable.
• It provides a valuable tool for surgical decision-making in FAI cases.
• Implementation can lead to optimized portal placement, reduced capsular resection, and improved surgical outcomes.