I've seen a number of questions posted by amputees regarding various aspects of using their prosthesis.
One of them is:
"What prosthetic knee should I have?"
Well, there are over 200 different prosthetic knee systems.
The question is which one is the best one for you and your everyday activities? And you will be the decider of that.
Your prosthetist's responsibility is to understand what your daily activities are - whether you're going to be performing just general walking, or if you want to be a little more active in sports and recreational activities. Being in the water is also a significant factor.
Once we understand what you're going to be doing, we then can choose 2-4 or more different knee systems - some might be microprocessor knee control, some are mechanical with very complicated hydraulic and pneumatic or hydropneumatic systems - that match your walking style.
Then we will do the biomechanical alignment to make sure we maximize the efficiency, stability, and safety factors for you.
Then you'll leave the clinic and test it by walking & performing the activities that you want to for a few days, and evaluate that knee.
Then you'll come back, we'll swap the knee out, and you'll go out and test the different knee.
We may have to make adjustments to both the knee and the foot (they need to be tuned together) and we might change the foot along with the knee, because certain knees work in harmony with a particular foot/ankle.
This process of testing different knee/foot systems is what we call Step-Wise Refinement; we'll get better and better and better with each one, and you'll decide which one is ultimately best for you.