According to an article published by Gregory M. Martin, MD, there are approximately 700,000 knee replacements performed every year in the United States. This number is expected to continue to growing as the United States population shifts to an older population (I.e. baby boomers).
Knee replacements are no walk in the park! The recovery process can be challenging but fortunately, it has come a long way since 1968 when the first knee replacement was done.
If the less invasive options like injections are no longer working for you and you’ve decided to move forward with a knee replacement, it’s good to know what to expect going into it. To fully understand the process, it’s important to know the anatomy of the knee and what your rehabilitation will look like.
Anatomy of the Knee
Did you know the knee is the largest joint in the human body? It is made up of the femur (thigh bone), tibia (shin bone), and the patella (kneecap). Cartilage covers where these three bones meet, providing, cushion and allowing the joint to move smoothly.
Between the thighbone and shin is a structure known as the meniscus. There are actually two meniscus in each knee, the medical and lateral. These C-shaped structures act as a cushion in the joint; withstanding shear, tension and compression. Most people hear that the meniscus is responsible for shock absorption, but few know that it also helps in load-bearing, load transmission, while also providing lubrication and nutrition to the articular cartilage (located at the ends of both the tibia and femur, and on the back of the kneecap).
There are four main ligaments in the knee: the medical collateral ligament (MCL), the lateral collateral ligament (LCL), anterior cruciate ligament (ACL), and posterior cruciate ligament (PCL). Throughout the body, ligaments connect bone to other bone. The MCL is located on the inside of the knee and the LCL on the outside. These collateral ligaments are responsible for the sideways motion of the knee and help to brace it in the event of unusual movement. The cruciate ligaments form an “X” and control the back and forth movement of the knee joint. The ACL is located in the front and the PCL in the back.
Tendons throughout the body serve to connect muscles to bone. There are two main tendons within the knee joint known as the quadriceps tendon, connecting the muscles in the front of your thigh to your patella, and the patella tendon connecting your shin to patella.
What is Knee Replacement?
A knee replacement, or knee arthroplasty, is a surgical procedure done to remove the diseased knee joint and replace it with artificial material. You may hear some people have a partial knee replacement and others a total knee replacement. The difference? In a partial knee replacement, only the affected component of the knee is replaced whereas in a total knee replacement, all three components are replaced.
Prior to Surgery
If you are at the early stages of knee pain, your doctor may recommend you trying less invasive treatment options. These may include physical therapy, injections, and other medications. When you’ve tried all of these options or you and your doctor have decided knee replacement is your best option, the clearance process begins.
Before surgery takes place, you will meet with your surgeon to go over your medical history in-depth. They will ask you questions regarding your pain levels and limitations caused by your knee. They will measure your range of motion, strength and alignment, as well. Additionally, they will ask you to get imaging to determine the extent of damage in the knee and possible deformities.
Depending on your overall health and medical conditions, you may also be required to get blood tests, and MRI, and even be cleared by a cardiologist. Again, these are not always needed but some doctors may ask you to have them done.
In short, knee replacement is a four-step process. The surgery itself takes anywhere between 1 to 3 hours. Depending on your overall health as decided by your surgeon, the process can either be done as an outpatient procedure or may require a hospital stay. The process is as follows:
1) Prep the bone
The damaged surfaces of the femur and tibia are removed.
2) Position the implants
Once the damaged portions of the knee are removed, the bone is replaced with metal components. These parts are either cemented or press-fit into the bone.
3) Resurface the kneecap
On a case-by-case basis, the kneecap may be resurfaced by adding a plastic button on its’ underside.
4) Insert a spacer
A plastic spacer is then put in between your new metal components, acting like a meniscus; creating a smooth surface.
5) Move the knee
Before the doctor closes the incision, they will move your knee to make sure the position and function is correct. They will both bend and rotate your knee.
Now that your out of surgery, the your work begins! Once the doctor completes the procedure, you will be moved into recovery as you are monitored as you wake up from anesthesia; also monitoring your pulse, blood pressure, and breathing. Once awake, you will be moved to a hospital room.
You will actually begin physical therapy in the hospital. Shortly after your surgery, a physical therapist will meet with you to develop an exercise program for you. If the therapist doesn’t begin helping you move your ankle and knee joint, you may be placed on a CPM machine that does the work for you while lying in bed. Unfortunately, surgery is painful! The doctor will have you on a pain medication as you start your recovery journey.
After you discharge from the hospital, you may have a physical therapy at home and eventually outpatient physical therapy (like us!). You will work to improve your strength and range of motion to help you get back to your normal activities – but now without pain!
As the surgical site heals, you will need to keep it clean and dry to avoid infection. At your follow-up visit with your surgeon, they will remove any stitches or surgical staples when healed. You will notice swelling and will need to ice and elevate your leg. If you notice bleeding, drainage, or redness at the incision site, or experience a fever or increased pain, notify your doctor immediately.
Out Patient Physical Therapy for Knee Replacement
Your road to recovery, unfortunately, is not over once your home physical therapist leaves. Once you are discharged from in-home (home health) care, you will begin out patient physical therapy at a facility like Envision Sport Physical Therapy & Pilates. We would love to say that the process will be easy, but the reality is there will be work and there may be some pain as you begin to move through your range of motion. So, what will you be working on in out patient physical therapy? How long will the process take?
Your first few visits should be relatively simple. Your physical therapist will start working with you on improving your range of motion, getting your quadricep on the affected leg to engage, and decrease some of the inflammation at the surgical site. Again, keep in mind that you recently had surgery and probably haven't been moving your leg too much at this point. As you work on improving your range of motion, you may experience some discomfort. It will get better with time!
Your physical therapist will slowly start to progress your plan of care; incorporating some additional strengthening exercises, increasing your range of motion, and working towards getting you back to your previous level of function. At our clinic, we utilize Pilates-based exercises with our knee replacement patients specifically as they experience lower levels of pain with the non-weight bearing exercise form.
The average total knee replacement patient is typically with their out patient physical therapist for three months. However, the process may be shorter or longer depending on your health prior to surgery. It is important to be doing the exercises given to you by your therapist regularly!
Knee replacements have come a long way! Physicians are performing this surgery more and more often and the life expectancy of the replacement itself is becoming longer.
If you have put off having the surgery, have questions about the recovery process, or need a recommendation of a surgeon to consult with, please feel free to contact our office at (949) 713-6445 and ask to speak with one of our physical therapists. We would love to help you get back to the things and people you love most without knee pain!