Intra- and Inter-observer Variability in Different Methods of Measuring Carpal Collapse.

Area of Science:

• Orthopedics
• Radiology
• Medical Imaging

Background:

• Carpal collapse is a feature of wrist disorders such as rheumatoid arthritis and Kienbock's disease.
• Existing methods for measuring carpal collapse include the carpal height ratio (CHR), revised carpal height ratio (RCH ratio), and capitate radius distance (CR index).
• The comparative intra- and inter-observer variability of these measurement techniques is not well-established.

Purpose of the Study:

• To determine which of the three methods (CHR, RCH ratio, CR index) exhibits the least intra- and inter-observer variability in measuring carpal collapse.

Main Methods:

• Fifty normal wrist postero-anterior radiographs were analyzed by three independent assessors.
• Assessors measured the CHR, RCH ratio, and CR index.
• Measurements were repeated after one month by the same observers to assess intra-observer variability, and comparisons between observers assessed inter-observer variability.

Main Results:

• Statistical analysis revealed a p-value <0.001 for the CR index across all three assessors, indicating the lowest intra-observer variability.
• The inter-observer variability, assessed by the intra-class coefficient, was 0.9 for the CR index, signifying minimal variability between observers.

Conclusions:

• The capitate radius distance (CR index) is the most reproducible method for quantifying carpal collapse.
• Accurate measurement of carpal collapse using the CR index can improve the staging and management of carpal disorders.