Steps of a Knee Replacment Surgery
A knee replacement surgery is performed as a treatment for arthritis of the knee joint. The surgery has several goals, but essentially the goal is to provide a functional, pain-free knee. In order for the knee to function well, your surgeon will ensure that the following goals will be met:
- Restore normal alignment of the joint
- Ensure a stable knee that bends well
If the knee is not aligned, if the joint is stiff or unstable, the function can be a problem. Therefore it is important to stick to a proven technique that is most likely to lead to a good, functional knee replacement.
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. The people who recover the fastest and the best tend to be those individuals who are best prepared for the surgery and the post-surgical recovery.
Many surgeons and hospitals now utilize a joint replacement education class prior to surgery. Typically, a group of patients who will be undergoing this procedure in the coming weeks and months will gather and hear from different team members including nurses, therapists, and social workers to prepare for their upcoming replacement surgery. It has been found that patients who undergo this type of preoperative education tend to have shorter hospitalizations, better pain control, and less issue during their recovery. The more you know heading into surgery, the better prepared you will be and the smoother your recovery will likely be.
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. More commonly, anaesthesiologists are using a variety of nerve blocks to help control pain and lessen the need for systemic medications at the time of the surgery and after the surgery. A peripheral nerve block is administered to one of the large nerves in the lower extremity and can provide pain relief for hours or even days following your surgery. Even if having general anaesthesia, this often means that you awaken from anaesthesia with less pain and have fewer side effects from the general anaesthesia.
Selecting anesthesia for surgery may depend on some medical conditions you have. Many patients will be able to choose their preferred anesthetic, but some may have an option that is safer for them because of an underlying medical condition.
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.
Most patients who undergo a knee replacement will have some type of regular follow-up with their surgeon in the years after surgery. While some surgeons will tell patients to follow up on if having a problem, others may recommend a periodic follow up every few years just to make sure the implant is holding up well. Certainly, if you develop problems with your implant, including worsening pain, swelling, or loss of mobility, you should check with your surgeon to see if the implant is performing as expected.
- “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).