Pathophysiology of lateral patellar dislocation

Abstract

Patellofemoral disorders represent 20-40% of all knee problems and can be one of the most common complaints in sports related injuries. These disorders are a major cause of disability, particularly in females, and in extreme cases may contribute to termination of athlete's career and could lead to degenerative arthritic changes of the knee joint. For these reasons, disorders and in particular patellar instability often pose a diagnostic and therapeutic dilemma for the orthopedic surgeon. This dilemma implies that usually no single pathophysiology or therapeutic approach can fully explain and solve patellofemoral instability. In fact the patellofemoral joint is biomechanically one of the most complex human articulations with different anatomical components like bone shape, capsuloligament structures, and muscle that could alone or in combination be responsible for patellar instability. These factors are often present in combination in one patient, but the severity of each pathology can be different resulting in variable patterns of instability and pain that determine that each patient is almost unique; thus the characterization in a classification is a simplification of a very complex issue. Moreover the multifactoriality and variability of pathogenesis has determined in the past numerous misunderstanding. These misconceptions have been responsible for the high variety of surgical procedures proposed to treat patellofemoral instability, leading to less than completely satisfactory clinical results also related to iatrogenic cause. © 2010 Springer-Verlag Berlin Heidelberg.