Does arthroscopic knee surgery ever not work?

Yes. Knee arthroscopy is only a tool for us to take care of a specific problem in the knee. If we suspect a tear in the meniscus, a knee arthroscopy can be used to fix the problem. Unfortunately, sometimes the pain is coming from other sources such as hamstring tendinitis caused by weak quad muscles. In that case, the knee arthroscopy would not help. Or you may have arthritis that would also not help.
Arthroscopic surgery. Yes as with any type of surgery there are occasions when arthroscopic surgery may not completely cure the problem. One example is with an arthritic knee.