The pathophysiology of patellofemoral arthritis.

Faced with a patient suffering from patellofemoral arthritis, the surgeon must determine the pathophysiology of the condition, because different causes demand different treatments. Possible causes include malalignment, patellofemoral dysplasia, patellofemoral instability, patellofemoral trauma, obesity, osteoarthritis, inflammatory arthritis, and a genetic predisposition. Arthritis secondary to malalignment, dysplasia, instability, or trauma is less likely than arthritis secondary to the other causes to progress to femorotibial arthritis.