Difficult reductions in traumatic patellar dislocation.

A traumatic lateral dislocation with internal rotation of the patella can be unreducible using conventional maneuvers. These unusual dislocations may involve locking of the patella on the lateral femoral condyle. In these cases, reduction can be achieved by applying a downward force to the lateral aspect of the patella, which reduces the rotational deformity and unlocks the medial patellar facet.