I was part of this Delphi consensus statement, which endeavored to come up with a consensus of treatment of patellar instability. When I finished my fellowship in 2002, I was taught that most cases of patellar instability could and should be treated with physical therapy.
We have learned over the past 21 years that this is not the case, as we have surgical options for the vast majority of patients suffering from patellar instability or unstable knee caps.
Modified Delphi Consensus Statement
Check out the research here, which was published in two parts in The Bone & Joint Journal:
A modified Delphi consensus statement on patellar instability: part I:
A modified Delphi consensus statement on patellar instability: part II: