Soong Classification Using Radiographs Only Moderately Correlates With Distal Radius Plate Position on Computed...

Area of Science:

• Orthopedic surgery
• Radiology
• Biomedical engineering

Background:

• The Soong classification assesses volar locking plate prominence for distal radius fractures.
• Increased prominence is linked to flexor tendon irritation and potential plate removal.
• Previous studies show mixed results on the classification's predictive value.

Purpose of the Study:

• To investigate the correlation between Soong classification on X-rays (XR) and computed tomography (CT).
• To determine if imaging modality affects the accuracy of the Soong classification.
• To identify potential reasons for the decreased predictive accuracy of the Soong classification.

Main Methods:

• Reviewed 50 distal radius fractures treated with volar locking plates from the ICUC database.
• Assessed Soong classification on both XR and CT by two hand surgeons, using CT as the gold standard.
• Compared grade distribution using Pearson's χ² test and calculated correlation with Matthews correlation coefficient (MCC).

Main Results:

• Moderate correlation (MCC = 0.65) was found between XR and CT for Soong classification.
• Positive predictive values (PPVs) varied by grade: Grade 2 (0.96), Grade 0 (0.63), and Grade 1 (0.60).
• Significant differences in Soong grade distribution were observed between XR and CT (P < .001).

Conclusions:

• The Soong classification shows only moderate agreement between radiographs and CT scans.
• Discrepancies in classification between imaging modalities may impact its clinical predictive accuracy.
• Further research is needed to refine the assessment of plate prominence and its clinical implications.