and open knee surgery
are two different procedures that have different risks and different benefits. Depending on the problem in your knee, one or the other might be required. Without knowing exactly what is occurring in the knee, it is hard to say if one is more appropriate. I would recommend that your discuss this problem with a skilled orthopedic surgeon
In total open surgery a large incision (often vertical) is needed. This requires significant time for recovery and there are many risks of infection and blood clots. Arthroscopy is a procedure that was developed in order to limit the large incision needed in total open surgery. In arthroscopy, the surgeon does not make the full incision. There are only two or three small holes that are made where a camera and a device or two are inserted. This procedure has less risks because the incisions are smaller. With that, obviously a arthroscopy is easier to recover from and safer. But as you can imagine, there are some procedures that require total access with an open surgery, and some that can easily be done with only one or two small devices.
It really depends on what is wrong in your knee. Talk to an orthopedic surgeon for more answers.