Whether for a career or physical fitness, hard work and pain are often necessary for improvement. No pain, no gain, as they say. Therefore, even if physical therapy hurts after total knee replacement surgery, it is still crucial for recovery. Physical therapy enables you to gradually regain knee strength and mobility to get back to your regular routines. During surgery, your knee's worn-out, diseased, and damaged portions will be removed and replaced with prosthetic implants. However, the success of a knee replacement depends in large part on recovery and rehabilitation.