- Who is a candidate for partial knee replacement?
- What is a partial knee replacement?
- What is the benefit of partial knee replacement?
- What is the main risk of partial knee replacement surgery?
- Differences between a partial and total knee replacement:
- What does it entail to have a partial knee replacement surgery?
- Do I need to go to an in-house rehabilitation facility after partial knee replacement?
- How is a partial knee replacement performed?
- What are other advantages of partial knee replacement?
- Do I need to be on a blood thinner after a partial knee replacement?
- Back in the game patients’ stories
- Why should I have my surgery at the Hospital for Special Surgery?
Who is a candidate for partial knee replacement?
Patients with advanced arthritis in only one compartment of the knee of any age can be candidates for partial knee replacement surgery. It is important that the pain and arthritic changes are confined to one compartment of the knee. In addition, we only consider patients with relatively good range of motion and patients that do not have excessive deformity of the knee candidates for partial knee replacement since the options of restoring alignment and range of motion for patients with very stiff or deformed knees are limited with a partial knee replacement. In addition, a partial knee replacement might not be indicated in very heavy patients beyond 200 pounds or patients with inflammatory arthropathies.
What is a partial knee replacement?
A partial knee replacement is the implantation of an artificial joint in only one compartment of the knee. A partial knee replacement can be performed for either the medial or lateral compartment as well as the patellofemoral compartment. Most partial knee replacements are fixed using cement and metal on plastic is the most common bearing option.
What is the benefit of partial knee replacement?
The main benefit of partial knee replacement is that it is a less invasive and traumatic surgery with a lower risk of medical or surgical complication. A partial knee replacement is usually performed as an outpatient procedure and patients can return to their activities faster than after standard total knee replacement surgery. Most patients will regain their range of motion and ability to walk within two weeks after the surgery and will often be able to return to work within two to four weeks after surgery. The medical risks including the risk for blood clots and the risk of blood transfusion is significantly lower than for patients undergoing total knee replacement.
What are the main risks of partial knee replacement surgery?
The main risk of partial knee replacement is that over time arthritis can affect the other compartments of the knee and patients might develop pain secondary to progression of arthritis in the other compartments which might ultimately require revision to a total knee replacement. Modern partial knee replacements often have longevity beyond 10 or 15 years and the risk of revision surgery is rather low within the first 15 years. Therefore, partial knee replacement might be an especially appealing option for older patients or very young patients that one way or the other will face the risk of revision surgery. Whether a partial knee replacement is a good option for patients in their sixties is less clear since many will live more than 20 years and for them the higher risk of revision surgery might outweigh the short-term benefit of faster recovery.
Other complications of partial knee replacement are related to the surgery itself and can include neurovascular injury to the neurovascular structures, intraoperative fractures, malalignment of the components or loosening of the component requiring revision surgery. In addition, patients with a partial knee replacement can develop postoperative infections which might require removal of the components and antibiotic treatment. Overall, the risk of medical or surgical complications is lower with partial knee replacement than with total knee replacement.
Differences between a partial and total knee replacement:
Dr. Boettner has extensive experience in performing both partial and total knee replacement. Whether you are a better candidate for one or the other should be discussed based on your individual situation during an office appointment. It makes little sense to rely on your neighbors’ experience or dr. google. Deciding which approach is right for you takes careful balancing of risk and benefits taking into consideration your level of activity, age, extend of arthritis etc.. During your office visit we can discuss this in detail but the following table provides you with some basic differences of these surgeries:
- Partial Knee Replacement
- Total Knee Replacement
- Treatment option for weight > 200 pounds?
- Treatment for severe bow legs or knocked knees?
- Treatment for stiff knees (less than 100 deg. of range of motion)?
- What happens to the anterior and posterior cruciate ligament during surgery?
- What ist he Hospital Stay?
- Usually 1-2 nights
- Minimal Invasive
- Spinal Anesthesia with periarticular injection and Saphenous Nerve Block
- Spinal Anesthesia with epidural catheder, periarticular injection
- Risk of deep venous thrombosis (estimate)
- Ca. 5%
- Risk of blood transfusion (estimate)
- Time to normal range of motion of the knee
- 2-4 weeks
- 4-6 weeks
- Off narcotic pain medication within:
- 1-2 weeks
- 4 weeks
- Return to work after surgery:
- 2-4 weeks
- 6 weeks
- Function at 3 months:
- Risk of deep Implant Infection in my practice:
- Risk of Revision surgery at 10 Years (estimate)
- Risk of Revision surgery at 20 Years (estimate)
What does it entail to have a partial knee replacement surgery?
Usually after you undergo medical clearance you are admitted to the hospital the day of your surgery. You will undergo a spinal anesthesia, a regional anesthesia that allows to be mobilized the day of surgery and has less risks than general anesthesia. In addition, a saphenous nerve block and periarticular injection of local anesthetics is used to decrease postoperative pain. The surgery itself takes about 45-60 minutes and after the surgery you initially will be transferred to a postoperative recovery room where your vital signs and the weaning off of the anesthesia is monitored by an anesthesiologist. You are mobilized as soon as the spinal is worn off and you can leave the hospital once you cleared physical therapy. Most patients leave the hospital on the day of surgery. The first days after surgery I recommend to take it easy, ice the knee and focus on range of motion and make sure that the swelling comes down. Limit your waling in the first week. You should work on full extension and flexion with the goal to achieve 90 degrees of knee flexion by 2 days after surgery, 100 deg. by 5 days and 110 deg. by 10 days after surgery. Also work on full extension placing a towel under the ankle and pushing your knee straight by activating the quadriceps pushing the knee into the bed. Make sure the incision is dry and contact the office if there is drainage.
Do Not massage the knee or the incision!
Do Not use weights or rubber bands to strengthen your knee!
Do Not do not walk too much in the first 3-4 weeks!
Do I need to go to an in-house rehabilitation facility after partial knee replacement?
All patients after partial knee replacement will go home. Some of our older patients prefer to stay in the hospital overnight but in general most patients (>90%) leave the hospital to go home the day of surgery. We start home physical therapy within the first week and switch to outpatient physical therapy 3 to 4 weeks after surgery.
How is a partial knee replacement performed?
Today partial knee replacements can be performed using robotic-assisted surgery. This allows the surgeon to plan the surgery based on preoperative CT scans and intraoperative physical exam and then allows the implantation of the component in a very precise manner utilizing a robotic arm with a burr or saw. This allows for optimized component alignment and fixation. I also use manually implanted partial knee replacements. Please discuss which implant is right for you during your office visit.
What are other advantages of partial knee replacement?
Besides faster rehabilitation, the main advantages of partial knee replacement is that some patients will be able to regain better range of motion than after total knee replacement surgery. Most patients will reach more than 130 degrees of flexion and will come close to their natural range of motion. In addition, partial knee replacement is less traumatic, is associated with less blood loss and therefore has less impact on the overall health and facilitates faster return to normal activities. Partial knee replacement preserves the anterior and posterior cruciate ligament which are usually resected when a total knee replacement is performed and therefore preserves the normal kinematic and motion of the knee which might results in better overall function of partial knee replacements.
Do I need to be on a blood thinner after a partial knee replacement?
Dr. Boettner recommends 325 mg of aspirin twice a day for the first three to four weeks after surgery for blood clot prophylaxis. Xarelto or more aggressive anticoagulation is almost never indicated.
Find encouragement in our back in the game stories:
Please find our back in the game stories on the HSS website. backinthegame.hss.edu/
Why should I have my surgery at the Hospital for Special Surgery?
Please find more information about the Hospital for Special Surgery here www.hss.edu/reasons-to-choose-hss.asp
Learn more about partial knee replacement at hss.edu link: www.hss.edu/condition-list_partial-knee-replacement.asp