What is total knee replacement surgery? 

If your knee is damaged by arthritis or injury, it may be hard for you to do your daily activities. You may also have severe pain that keeps you from enjoying hobbies such as running and skiing. 

The most common reason for knee replacement surgery is osteoarthritis. Osteoarthritis occurs when the cartilage that cushions the bones of the knee wears away. A serious knee injury may also be a reason for total knee replacement surgery. 

Total knee replacement is a surgical procedure to replace a damaged or diseased knee joint with an artificial joint. It is a common and safe procedure. Total knee replacement resurfaces the bones around the knee with metal and plastic to allow pain free movement.

Partial Knee Replacement

Partial knee replacement, also called "unicondylar" knee replacement is a less common alternative to total knee replacement. If the arthritis changes in the knee are limited to the inside half of the joint, metal and plastic and be inserted to protect just the part of the knee that is damaged.

Recovery from partial knee replacement is easier than a total knee replacement. Patients can often go home the same day. There is still physical therapy involved and it can still take months before the new partial knee becomes pain free. Arthritis can progress in the knee even after a partial knee and occasionally patients will require more surgery years down the road. Ask your doctor if a partial knee replacement is right for you.

What are the risks and/or side effects? 

There are risks with any surgical procedure. These risks will depend on your age and overall health. Your physician will discuss these risks with you before your surgery.
Risks for total knee replacement include:

  • Infection
  • Blood clots in the legs or the lungs
  • Problems with the implants
  • Scar tissue and stiffness around the knee
  • Nerve injury
  • Problems with medication prescribed after surgery
  • Problems with anesthesia
  • Chronic pain

What are the benefits? 

Total knee replacement should increase mobility and decrease most of your pain. It is unlikely that knee replacement will result in 100% pain relief. You may be able to enjoy activities that you were forced to give up because of the pain from the damaged or diseased knee joint. Walking long distances, stair climbing, and standing tolerance are all improved after a successful knee replacement. Many patients return to sports and recreation after knee replacement.

How do I prepare? 

Preparation for surgery is important to minimize the risk of complications. Prior to surgery, you may be asked to exercise or lose weight in preparation for surgery. Your doctor may do a complete medical history and in some cases, you may need permission from your other doctors. Those who smoke will be asked to stop before surgery. Diabetic patients will need to verify good blood sugar management.

Make a list of all the medicines you are currently taking. Be sure include any prescription medications, over-the-counter medicines (like cough syrup or allergy pills), inhalers, patches, vitamin supplements, and herbal remedies.

You can also attend a joint replacement class offered by Intermountain Healthcare. The classes are taught by registered nurses with special training in orthopedic care and will help you prepare for the surgery and answer questions.

How is it done or administered? 

The surgery is done in an operating room at a hospital or a surgery center. Once you are admitted to the hospital, a member of the anesthesia team will talk with you about your options. Most knee replacements are performed with spinal anesthesia which will numb your legs for 3-4 hours. During that time, you will be asleep with medication through your IV. There are four basic steps to a knee replacement surgery.

  • The damaged cartilage surfaces at the ends of the femur and tibia are removed along with a small amount of underlying bone.
  • The cartilage and bone are replaced with metal parts that recreate the surface of the joint.
  • The kneecap is resurfaced to fit with the new parts.
  • A medical-grade plastic spacer is placed between the metal parts to create a smooth, gliding joint.

After surgery, you will be transferred to the recovery room to wake up relaxed and pain free. Your legs may be numb for an hour or so after you wake up. Once you have been monitored in the recovery room, you will be taken to a hospital room to continue your recovery. You will eat as soon as you are awake and alert.

Pain medicine is given as feeling in your legs return and you start to feel pain. Patients are expected to walk with assistance the same day as their operation. Some patients can safely return home the same day if they are cleared to go home by physical therapy. Depending on the timing of surgery and the needs of the patient, spending one or occasionally two nights in the hospital is common.

When will I know the results? 

Your doctor will talk with you about your surgery with you before you go home. How well you recover from total knee replacement surgery will depend on your commitment to your rehabilitation. Physical therapy is an important part of a successful surgery. Most of these exercises and stretches can be done on your own. The physical therapist acts as a coach to make sure you are making progress. Typically, you will meet with a therapist once or twice a week for at least a month. You will continue a stretching and exercise routine on your own for months after the surgery.

What are follow-up requirements and options? 

Your healthcare team will give you instructions once you are discharged from the hospital. These instructions will help you:

  • Avoid infection
  • Prevent blood clots
  • Care for your surgery site
  • Take your medicine safely
  • Prevent swelling
  • Protect your new joint

It is important that you follow these instructions. You will also begin physical therapy a few days following your surgery. Your physical therapist will create an exercise plan to help you strengthen your muscles as you get used to using your new joint. Call your doctor if you have:

  • Bleeding or drainage from the surgical site after the first few days
  • Increasing pain, especially in your lower leg (calf)
  • Uncontrolled nausea or constipation

What should I expect during recovery? 

During your recovery, you will likely experience pain and discomfort from the surgery. Getting pain relief at home will help you rest better and heal properly.

  • Take your pain medicine exactly as your doctor ordered. Rest and leg elevation will relieve pain. Have a family member or friend stay with you to care for you and help you move around the first week or so after surgery. This person can also help you manage your pain medicine.
  • While taking pain medication, it is likely you will become constipated. Stool softeners in addition to a formal laxative (Milk of magnesia or Miralax) is usually needed until you can stop the pain medicines.
  • Expect to follow up in your doctor’s office within a few weeks of surgery to discuss any concerns.
  • Knee replacement recovery takes months to feel like you have fully recovered. While you may resume normal activities within the first few weeks, it is likely you will have significant knee pain into the second and third month after surgery.
  • Walking aids are only necessary until your confidence and balance allow you to move safely without them. Crutches or walkers may be used for a week to a month after surgery. Your therapist will coach you when it is right to stop the walking aids.