Efficacy of Accessory Facet Views in the Detection of Occult Patellar Malreduction: A Biomechanical Analysis.

A simulated fracture model was used to determine the ability of the medial and lateral patellar facet views in detecting magnitudes of articular displacement. Transverse patellar fractures were simulated in ten patients. Medial and lateral translation of the distal fragment were evaluated in 1 mm increments and rotational malalignment along the longitudinal axis of the patella was evaluated in 5 mm increments. In comparison to the true lateral view, the utilization of the medial and lateral patellar facet views considerably improves detection of occult articular surface malreduction.