Willow also has luxating patellas. She's had them since we got her. She can correct it herself by stretching her back leg out when it happens. It hasn't worsened in five years. They grade them and depending on the grade they might need surgery. But, if your dogs is going in and out on it's own my experience has been they don't operate on those.
You would be surprised the info and orthopedic surgeon can give you. They can palpate and really move the joints around. Willow was sedated with medication. And, we found out that what we thought was arthritis in the leg areas was really in the shoulder. And, worse on the side that she usually didn't favor.
It was definately worth the money for the consult. We hand carried our own x-rays and he did want to take more views for himself that day.