There are many causes of knee pain, including fractures due to external knee injury, ligament damage, meniscal damage or if you have osteophytes, osteoarthritis, or even simple soft tissue contusions, etc. If you go to the hospital for an emergency, the cost of an emergency registration is usually around$10-20, but of course it can vary greatly from place to place. After having this process, the doctor will decide what special tests need to be done after the visit. For example, to rule out a fracture, an x-ray can be done for about$110, and to suspect ligament or meniscus damage, an MRI of the knee will be done, which costs about$500. If a color ultrasound of the knee is needed to detect a large amount of hematoma, this can be done for$200-300. If there is nothing serious wrong with the pain after the examination, pay attention to recuperation, do hot compresses and physiotherapy, simple treatment can be done, then no other costs are needed, just go home and recuperate yourself.