Kim, I moved your question it its own thread. I think you'll get more discussion this way.
Jo will have to provide details, but I do not thinks these two surgeries are at all alike.
Arthroscopy is usually an outpatient procedure done with three small holes in your knee. It is usually done to "clean up" loose particles, smooth surfaces, or make minor repairs to the knee.
In a hip resurfacing, there is actually a device implanted and, although it is my understanding that it can be "minimally invasive," the opening(s) are not small holes like in arthroscopy. I think it requires a hospital stay and period of recovery afterwards.