STRAIGHT FROM DR. STRYKER: TOTAL KNEE REPLACEMENT 101
WHAT IS A TOTAL KNEE REPLACEMENT?
Healthy knee anatomy
The knee is the largest joint in the body made up of the lower end of the thigh bone (femur), the upper end of the shinbone (tibia), and the kneecap (patella). The ends of these three bones are covered with cartilage to protect the bones and enable them to move smoothly within the joint. Traditionally, during knee replacement surgery the damaged cartilage and a small piece of bone are removed. Then, the surgeon would go through the front of the knee to put in a combination of metal and plastic to make up for the damaged cartilage. Once those components are in place, the knee moves smoothly similarly to how a regular knee would function.
Dr. Stryker’s Method
Implant in total knee replacement
Dr. Stryker has found great success using
a technique he created for first time knee replacement patients.
When performing first-time knee replacement surgery, he still makes an incision over the front of the knee. However, instead of cutting the tendon that attaches to the kneecap or the quadriceps tendon, he actually comes underneath the muscle and slides that muscle over the top to get into the knee. Then, he uses a computer to help him align the cutting guides. He would, then, shave off the very end of the thigh bone and the very top of the shin bone to replace those with metal caps.
Now, in select patients who have a good bone, he does something different. He uses uncemented implants.
Cemented vs. Uncemented Knee Replacement
The majority of knee implants are cemented implants. Traditionally, knee replacement surgery uses a quick-drying bone cement to bond the patient’s natural bone with the implant. The cement dries very quickly, so the implant is secured in place by the time the surgery is complete.
Cemented implants may be a better option for patients who have poor-quality bone, those who are older, overweight, and less active because future bone growth may not be sufficient to hold the implant in place. The benefit of a cemented implant is that the metal is securely bonded to the bone and is as strong as it ever will be at the time of surgery.
The downside of cemented implants is just that—the metal is as strong as it ever will be at the time of surgery and will only get weaker over time. The other downside is that the cement introduces grit into the knee that can wear the plastic component of the implant.
When deemed appropriate, Dr. Stryker uses what's called uncemented implants. This procedure eliminates the need for cement because the bone grows into the implant bonding the two, naturally.
The bone is shaped to fit the implant allowing the bone and implant to fuse together as the bone grows. Now, the bone doesn’t grow immediately, it does take time. However, the benefit of uncemented implants is that once the bone has grown, the knee is very durable and the patient avoids the grit of the cement that may affect the longevity of the implant.
WHEN SHOULD YOU CONSIDER A TOTAL HIP REPLACEMENT?
This decision is one that the patient or the decision maker and the surgeon should arrive at together.
Surgery does not have to be the only option to treat an orthopedic condition. All surgeries have risks, which is why the patient waits until they have done everything short of an operation. Luckily, there are many conservative treatment options when it comes to knee arthritis and knee problems.
Early on, those treatments may just be activity modifications. If it hurts when you jog more than 2 miles, you don't jog more than that. You change the way that you're doing things so that you can continue to do what you want without much pain or discomfort. Other treatment options include taking over-the-counter medications like acetaminophen, using braces, and getting injections while incorporating strengthening exercises, home programs, and physical therapy.
When you get to a point where you've done all of those things, but your quality of life is still suffering, that’s when we have a really serious discussion about joint replacement surgery.
WHAT ARE THE RISKS OF UNDERGOING A TOTAL HIP REPLACEMENT?
In terms of risk for knee replacement surgery, there's risk anytime you have an operation. Those risks are small, less than 1%, but not zero. There's always potential for damage to the nerves, blood vessels, muscles, ligaments, and tendons, as well as risk of an infection or blood clot. Over time, parts can wear out and become loose. Those risks are rare, but again, not zero.
A knee replacement is not a restoration of what you were born with. It is a reconstruction with metal and plastic. And because of that it doesn't act the same, it doesn't feel the same, and it doesn't even sound the same.
Knee replacement surgery is really advanced beyond what it was.
Not too long ago, patients would spend weeks in the hospital after a knee replacement surgery. Patients must be able to eat and drink, get out of bed, get to the bathroom, have their pain controlled, get around safely in terms of pain management to go home.
With all that in mind, Dr. Stryker has seen that upwards of 85% of his patients go home the same day. Patients are back to general activities and doing what they want to be doing within a four to six weeks.
Get to know DR. Stryker by scheduling an appointment with him or any of our orthopedic specialists at San Antonio Orthopædic Specialists
Rather listen than read? We get that.
We sat down with Dr. Stryker as he shares the ins and outs of a total knee replacement.