A Simple Guide to Knee Replacement Surgery

Knee replacement surgery, also known as knee arthroplasty, is replacing a worn, damaged or diseased knee with an artificial joint. The hope is that the knee replacement surgery will relieve pain and improve the function of a damaged knee. There are two types of knee replacement surgery – total knee replacement surgery and partial knee replacement surgery. 

Total Knee Replacement Surgery

Total knee replacement involves removing the surface of the damaged bones and cartilage and replacing them with an artificial implant. There are two types of total knee replacement designs. There is the posterior stabilized design and the cruciate-retaining design. Which design a patient receives depends largely on the PCL (posterior cruciate ligament). The posterior cruciate ligament is the big ligament on the back of the knee that provides support when you bend your knee. 

If the PCL cannot support a knee implant, the surgeon will remove it during the total knee replacement. They will replace the PCL with an implant (cam and post) to stabilize the knee so the patient is able to flex it. This is called the Posterior Stabilized Knee Replacement design.

If the PCL can support a knee implant, the surgeon will leave the PCL where it is and place an implant that has a groove to protect the PCL. This is the Cruciate-Retaining Knee Replacement Design. 

Partial Knee Replacement Surgery

If only one side of the knee is damaged, partial knee replacement surgery may be an option. This is only an option if the knee ligaments are strong and the rest of the cartilage is in good shape. 

Advantages of Knee Replacement Surgery

Relief of Pain

Pain relief is usually the main goal of knee replacement surgery. Most patients have a large reduction in pain after knee replacement surgery and some people eliminate the knee pain altogether. 

Increased Range of Motion

Knee replacement surgery also increases the joint’s range of motion. Sometimes arthritis can severely limit mobility. Knee replacement surgery may restore range of motion of the knee. 

Return to Enjoyable Activities

Knee arthritis can often rob people of many activities they used to enjoy, like hiking and bicycling. Knee replacement surgery may allow return to activities that people like. And often, these activities are beneficial for health in general. They often contribute greatly to cardiovascular health. 

Increase in Independence

Simple walking or climbing stairs or other activities of daily living may be limited due to knee problems. Knee replacement surgery may allow people to regain their ability to live independently.

Disadvantages of Knee Replacement Surgery

Possible Surgery Risks

Knee replacement surgery has a very good success rate but there could be complications as with any surgical procedure. The routine risks to surgery are many, including blood clots, infection and damage to nearby body parts. Serious complications occur in less than 2 percent of knee replacement surgeries. 

Cost

Knee replacement surgery may be very costly. The facility where the surgery is done and the type of implant needed, along with the personal insurance coverage, all factor into how expensive knee replacement surgery may be. Sometimes the out-of-pocket cost might be quite large. 

Time to Heal

It may take up to a year to heal from knee replacement surgery. During this time your activity may be limited. Physical therapy is also part of the process of healing.

It Is Not Permanent

You may ultimately have to have a knee implant replaced. Knee replacement surgery started in the early 1970s. At that time knee implants would only last about 10 years. Now, 80% of knee prosthetics last 25 years. People are living longer, however, so surgeons are cautious about recommending knee replacement surgery in people under 50 years old as they may be very likely to need a revision or replacement of the prosthetic. And, of course, complications of surgeries increase with age. 

Best Age to Have Knee Replacement Surgery 

So, if you get knee replacement surgery too young, you may need to have it redone when you are older, which is a higher risk surgery. But, if you wait too long, you will find yourself at an increased age risk anyway. So, what to do?

Most people have knee replacement surgery between the ages of 60 to 80. Some research finds the early 70s to be the best age to have knee replacement surgery, with low chance of needing another knee surgery and with low risk to the operation itself. This early 70s guideline is not cut and dry though. Each person is different. Risk factors of ongoing illnesses, activity limitations, degree of pain and social situations need to be taken into account. These all need to be discussed with your doctor before deciding at what age or time to have knee replacement surgery. 

Post Op

If you and your surgeon decide to proceed with knee replacement surgery, what happens after that? The average hospitalization after knee replacement surgery is five days. Length of hospitalizations must factor in at home support and health of the patient. It is necessary to have weight bearing on the knee with a walker or crutches because the quadricep muscles will be weak. 

In order to achieve an optimal outcome, multiple weeks of physical therapy are required. Physical therapy increases range of motion, improves circulation, decreases the risk of blood clots and strengthens muscles. Optimized range of motion is usually achieved within two weeks of physical therapy.

It takes about 10 months after surgery for most people to return to normal activity. Although, the operated leg may always be weaker than the nonoperated leg. This is not your original knee and in most cases will not be as strong and pain free as before the knee originally started having issues. Even so, 88% of people are able to return to their preoperative level of activities eventually.

There is a lot involved in knee replacement surgery. Yet, most people have reduced pain, improved mobility and an overall better quality of life after knee replacement surgery. If you are having knee pain, it is definitely worth discussing options with your doctor. 

For a personal story, read Diary of a Total Knee Replacement.

Let’s Have a Conversation:

Have you had knee replacement surgery or are you considering having knee replacement surgery? If you have had knee replacement surgery, how has that experience been for you? Tell us what have been the pros and cons of your knee replacement surgery?