Congenital dislocation of the patella.

Abstract

Our objective was to present the imaging findings for congenital dislocation of the patella, an uncommon condition with variable clinical manifestations in patients of different ages. Sonography can clearly illustrate the presence and location of the laterally displaced patella and the anatomy of adjacent joint structures. The high resolution for soft-tissue, cartilaginous, and bony structures of the immature skeleton makes sonography a valuable tool in the management of congenital dislocation of the patella. Conventional radiography is a simple method for diagnosis once ossification of the patella has commenced and for postoperative follow-up. MRI allows visualization of fine anatomic details and relationships between the involved structures of the extensor mechanism and is the technique of choice for preoperative planning.