A Low-Energy Patella Vertical Dislocation in an Adolescent: A Case Report

Intra-articular dislocation of the patella is considered a rare case where it was reported that limited cases are existing in the literature and the exact mechanism of the injury is still undetermined. Patellar dislocation is divided into extra-articular and intra-articular dislocation. We report a patient with vertical dislocation of the patella caused by a low-energy injury that is very rare according to the previous study. The patient came with a deformity, skin tenting, and pain with pressure on the superior and medial sides of the patella. During the physical examination, a deformation of skin tenting was observed with the characteristic of a "dorsal-fin" appearance over the laterally displaced patella. This paper will discuss the dislocation of the patella, which can be further classified into extra-articular and intra-articular. Vertical patellar dislocation most commonly occurred in adolescence. The outcome was considered satisfactory, and this case provides further knowledge of the mode of injury of vertical dislocation and also the possible risk factors.