Common radiographic imaging modalities fail to accurately predict capitate morphology

Area of Science:

• Orthopedic surgery
• Radiology
• Anatomy

Background:

• Capitate bone morphology (flat, spherical, V-shaped) impacts wrist biomechanics after proximal row carpectomy (PRC).
• Altered radiocarpal joint articulation post-PRC necessitates understanding capitate morphology.
• Current diagnostic imaging's reliability in distinguishing capitate types is unclear.

Purpose of the Study:

• To evaluate the accuracy of plain radiographs, 2D-CT, 3D-CT, and MRI in predicting capitate morphology.
• To determine the most reliable imaging modality for classifying capitate types.

Main Methods:

• 47 fresh frozen cadaver wrists were analyzed using plain radiographs, 2D-CT, 3D-CT, and MRI.
• Hand surgeons and a fellow classified capitate morphology from each imaging modality.
• Gross dissection determined the true capitate morphology for comparison.

Main Results:

• All tested modalities demonstrated low sensitivity and specificity for predicting capitate morphology.
• Sensitivities/specificities ranged from 0.46/0.57 (radiographs) to 0.56/0.65 (MRI).
• All modalities showed high negative predictive values for the V-shaped subtype, with poor inter-rater reliability.

Conclusions:

• Plain radiographs, CT, and MRI are not effective for preoperative determination of capitate morphology.
• Plain radiographs offer comparable utility to advanced imaging for excluding V-shaped capitates and are more cost-effective.