Partial Knee Replacement Surgery

Submitted by Nic on October 16, 2012

A partial knee replacement surgery or a unicompartmental knee anthroplasty is a minimally invasive operation that can help treat severe knee damage caused by an injury or diseases like arthritis. Originally, people used to undergo a total knee replacement surgery for this purpose, where all the cartilage from the knee joint was replaced with metal and plastic prosthetics. However, in the partial knee replacement surgery procedure, only the damaged area of the cartilage is removed from the joint and the healthy parts of the joint are left intact. Therefore, if you go in for the partial knee replacement surgery, most of your original knee structure remains intact.

Not everyone is a suitable candidate for the partial knee replacement surgery. Your physician may only advise you to undergo this procedure if -

  • The disease (arthritis) or injury has affected only one side of your knee
  • The range of motion in the knee is fairly good
  • You are on the thinner side and do not lead a very active life

You may also be eligible for this surgery, in case you are over 60 years old and are suffering from extreme pain in the knee.


Before your operation begins, your orthopedic surgeon will give you anesthesia (general or regional) to numb the pain. After the anesthesia takes its effect, your doctor will -

  • Make a small incision, which is around 3 to 5 inches long, on your knee.
  • Examine the entire knee joint carefully, to determine the exact extent of the damage.
  • Remove the tissues and the bone parts that need to be replaced.
  • Place a synthetic joint made of metal and plastic into the knee.
  • Sew the wound shut, using stitches.

The incisions used in the partial knee replacement surgery procedure are much smaller than total knee replacement surgery. Therefore, partial knee replacement surgery recovery is usually faster than total knee replacement.


If no complications crop up, you may be allowed to go home one day after the surgery. You should be able to put your entire weight on your knee immediately. During this stage, it is good for you to take short, frequent walks, with someone helping you. For the first 3 or 4 weeks after the surgery, you will need support to move around. After 4 weeks, you should be able to walk around without any help. However, make sure that you continue physical therapy for at least 3 months. Mild exercises like swimming, walking and cycling are good for your knee after the surgery; though you need the doctor's approval. It is important that you avoid high-impact activities like jogging, running and sprinting.

In case you notice any side effects after the surgery, make sure that you seek emergency medical attention.


There are a few risks associated with most surgical procedures. Some of the complications that may arise after the partial knee replacement surgery include -

  • Buildup of fluid in the knee joint
  • Formation of blood clots
  • Implant failure
  • Blood vessel or nerve damage
  • Pain while kneeling
  • Reflex sympathetic dystrophy (rare instances)

Cost of the surgery

The cost of partial knee replacement surgery in the US could be anywhere between US$ 30,000 and US$ 60,000, depending upon your doctor's fees as well as the state and hospital you choose to get operated in. If you are going in for the surgery, because it has been ordered by a doctor, your insurance should pay for it. However, do call your insurance company to confirm that this procedure is covered by your plan.


  • John H Newman, Unicompartmental knee replacement, The Knee, Volume 7, Issue 2, 1 April 2000, Pages 63-70, ISSN 0968-0160, 10.1016/S0968-0160(99)00032-0.
  • Steven F Harwin, Complications of unicompartmental knee arthroplasty, Seminars in Arthroplasty, Volume 14, Issue 4, October 2003, Pages 232-244, ISSN 1045-4527, 10.1053/j.sart.2003.09.001.
  • Crockarell JR, Guyton JL. Arthroplasty of the knee. In: Canale ST, Beatty JH, ed. Campbell's Operative Orthopaedics. 11th ed. Philadelphia, Pa: Mosby Elsevier;2007:chap 6
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