Although there is no physical reason why you should be unable to kneel after a unicompartmental knee replacement, you may find that you are unable to do this comfortably. This is a normal finding after most knee replacement surgeries and although a greater portion of patients who received unicondylar knee arthroplasties do find that they cannot kneel down without discomfort as compared to the total knee arthroplasty population, there is a small risk that you may not be able to kneel comfortably after the surgery.