Primary traumatic patellar dislocation

Abstract

Acute traumatic patellar dislocation is a common injury in the active and young adult populations. MRI of the knee is recommended in all patients who present with acute patellar dislocation. Numerous operative and non-operative methods have been described to treat the injuries; however, the ideal management of the acute traumatic patellar dislocation in young adults is still in debate. This article is intended to review the studies to the subjects of epidemiology, initial examination and management.

Figure 1

The plain Merchant axial radiograph demonstrates an osteochondral fracture of the medial facet of the patella in a first-time traumatic patellar dislocation, a secondary sign of an injury to the medial patellofemoral ligament, at the patellar attachment.

Figure 2

An axial T2-weighted fast-spin-echo magnetic resonance imaging scan illustrates a eighteen year-old female sustaining a primary traumatic lateral dislocation of the patella while jumping. Complete avulsion of the medial patellofemoral ligament from its femoral insertion can be seen (arrow) (Figure 2A). The bone contusions (stars) (Figure 2B) of the lateral femoral condyle and the medial patellar facet are noted.