Proposal for a classification system of radiographic bone changes after cervical disc replacement.

Area of Science:

• Orthopedic surgery
• Radiology
• Biomedical engineering

Background:

• Periprosthetic bone changes are common after cervical disc replacement (cTDR).
• Standardized classification systems are needed for accurate radiographic assessment of these changes.
• Current methods lack consistent nomenclature for describing bone loss and other radiographic findings.

Purpose of the Study:

• To propose a novel classification system for radiographic observations of periprosthetic bone changes following cTDR.
• To establish a common nomenclature for reproducible identification and assessment of bony changes.
• To enhance the accuracy and consistency of reporting in cTDR radiographic studies.

Main Methods:

• A panel of experts developed a classification system using serial radiographs from cTDR cases.
• The system categorizes bone loss (endplate rounding, cystic erosion) and its progression.
• It also records additional findings like radiolucent lines, heterotopic ossification, and device migration.

Main Results:

• The classification system was evaluated by 6 experienced investigators on serial radiographs from 19 patients (25 devices).
• Overall agreement among investigators ranged from 49.9% to 94.7%.
• Good agreement was observed for identifying bone loss, radiolucencies, and the progression of radiolucent lines.

Conclusions:

• The proposed classification system demonstrated good concordance among experienced investigators.
• This novel system represents a useful advancement for improving reporting in cTDR studies.
• It facilitates more accurate and reproducible assessment of radiographic changes after cTDR.