I took Kaji to 3 vets when I found out about the LP. One wanted to rush to surgery. I was perplexed because I had yet to any reading on the subject, and Kaji showed no signs of discomfort. 2 years later, he still doesn't. My only responsibilities now are to monitor him and keep his weight down.
Do what the others recommend, and have Thor seen by an orthopedic surgeon.