Diagnosis of Arthritis:
Once the diagnosis of severe knee arthritis is made, you will need to decide with your physician the optimal treatment course. There are signs to look for to decide if the time is right for a knee replacement. If simple treatments fail to help, then total knee replacement may be a reasonable option.
Preparing for Surgery:
While most people are concerned about the day of surgery, it is important to take some steps to prepare for knee replacement surgery. These steps include ensuring your body is sufficiently healthy for the procedure, as well as ensuring your home is ready for your recovery.
Selecting an Anesthetic:
You will discuss anesthetic options with your anesthesiologist. The type of anesthesia you choose will have no effect on your doctor's ability to perform the knee replacement. The surgery can be performed with general anesthesia, epidural or spinal anesthesia, or a regional nerve block. The advantage of epidural and regional blocks are that pain medicine can be given by these routes post-operatively.
Removing the Worn-Out Joint:
When a knee replacement is performed, the bone and cartilage on the end of the thigh bone (femur) and top of the shin bone (tibia) are removed. This is performed using precise instruments to create exact surfaces to accommodate the implant.
Knee replacement surgery itself takes about 60 to 90 minutes, but time in the operating room may be longer. You are left with a 6- to 8-inch incision over the front of the knee.
Selecting the Right Implant:
The specific implant used for your knee replacement will depend on factors including your age, your activity level, your surgeon's preference, and specific anatomic variations you may have. Determining the best knee replacement implant is complicated. Many companies now market knee implants directly to patients; you may hear advertisements for rotating knee replacements, female knee replacements, or custom knee replacements.
Implanting a Knee Prosthesis:
There are two ways to hold a knee replacement implant in the bone:
- Cemented Knee Replacements
The most commonly used knee replacements are cemented into the bone. Cemented implants fit tightly into position and are immediately solidly fixed into the bone. - Press-Fit Knee Replacements
Press-fit implants are designed with a rough surface that bone can grow into. Over time the surrounding bone grows into the implant holding it solidly in position.
Recovering From Surgery:
Once you have decided to have knee replacement surgery, you have committed yourself to a bit of work! Knee replacement surgery is successful, but the success of the procedure is due, in part, to the rehabilitation that follows the knee replacement surgery. For patients to expect a good result from knee replacement surgery, they must be an active rehab participant!
Down The Road:
Knee replacement implants can wear out over time. The implant is made of metal and plastic, and while these implants are designed to last many years, they all will eventually wear out. Studies have consistently shown knee replacement implants are functioning well in 90% to 95% of patients 10 to 15 years after surgery.
Sources:
"NIH Consensus Development Conference on Total Knee Replacement" National Institutes of Health, Consensus Development Conference Statement, December 8-10, 2003.
Agency for Healthcare Research and Quality; Evidence Report/Technology Assessment No. 86, "Total Knee Replacement" (AHRQ Publication No. 04-E006-2).
