Total knee replacement (TKR) is usually a very reliable way to give arthritis patients relief from their symptoms. About 95 percent of all TKR patients have a good result after surgery. But in five percent problems of pain, stiffness, and swelling can persist.

There are many possible causes for this outcome. If your father hasn't been to his doctor, a re-examination is important. The surgeon will conduct a careful evaluation to see if the problem is coming from inside or outside the joint.

Many older adults have multiple health problems. These are called comorbid conditions. Neurologic problems, poor circulation, even depression are just a few comorbidities that can affect the results of surgery.