When the pain of arthritis doesn't go away, replacing the problem joint may be an option. For the knee, the procedure to implant a new joint is called total knee arthroplasty (TKA). For most patients, TKA gives pain-free motion and return of function.
For a small number of patients, the result isn't good. Painful swelling and loss of function can make them wish they'd never had the procedure. These patients can be helped. The doctor must make a careful search to find the cause of the problem before correcting it. There are many possible causes for a painful TKA.
Problems from inside the knee may be the cause of painful symptoms. Recent changes in the design of the joint implant have helped solve some of these problems. Infection and bleeding are the first two things the doctor looks for. This can be assessed using laboratory test results.
Scar tissue and pinching of the joint lining can cause a painful, stiff knee. This can be found using an arthroscope. The scope is a slender device with a tiny TV camera on the end. It is inserted into the joint. The doctor looks for uneven wear of the joint, loose pieces of tissue, or other changes within the joint. The problem can be found and treated with this single procedure.
Sometimes a painful TKA is caused by something outside the knee joint. This could be from hamstring or quadricep tendinitis. There could be a small break in one of the bones called a stress fracture. Again, improved knee joint implants have helped decrease these problems.
Finally, a painful TKA could be coming from other places. For example, the hip or a herniated disc in the back can send pain messages to the knee. Disease affecting blood flow to lower part of the body can also cause leg and knee pain. Patients who are depressed or anxious have a greater chance of knee problems after TKA.
Total knee replacements for arthritis are a great answer for 95 percent of all patients. For those patients who end up with a painful, stiff knee after joint replacement, doctors must search carefully for the cause before treating. This can be something inside the joint, outside the joint, or unrelated to the joint altogether.
Thomas S. Thornhill, MD. Painful Total Knee Arthroplasty. In Orthopedics. September 2002. Vol. 25. No. 9. Pp. 965-967.'