Knee Replacement Complications

Total Knee Replacement (also known as total knee arthroplasty) is generally a highly successful procedure with excellent long-term results. In a recent study, 97% of patients remained “revision-free” at 10 years 1. Despite these favorable outcomes, complications may still occur. Listed below are some of the more common complications of total knee replacement surgery.


Several steps are taken to prevent infection. For example, antibiotics are often given before, during and after knee replacement surgery. Still, a small percentage of knee replacements become infected. In a recent study of over 3000 replacements, 2.9% experienced “superficial” infections while 0.8% of infections occurred within the joint. An increased rate of infection was observed in patients who experienced complex surgery or who had certain characteristics such as obesity or poor pre-operative health. 2


Knee replacement components are affixed to the bone in two ways. In “press-fit” implants, long term fixation relies on the growth of bone into what is typically a porous surface or coating on the underside of the implant. Alternatively, the implants may be “cemented” into place with a strong polymer (PMMA) which is mixed and applied at the time of surgery. Both of these fixation methods can fail over time for a variety of reasons causing the implant to become loose and requiring revision (see Implant Poly Wear)


Deep Vein Thrombosis (DVT) is a rare but potentially very serious complication. Blood clots (thrombus) can sometimes form in the “deep” veins near the surgical site. This can cause pain, redness and swelling. Sometimes, the clot can become dislodged and travel through the bloodstream and into the lungs where it can become trapped. This is called a pulmonary embolism and can be fatal. Obviously, many, many precautions are taken to prevent this serious complication.

Patellar Clunk Syndrome

This complication involves interaction of the scar tissue at the top of the patella with the femoral component. See our article on Patellar Clunk Syndrome for more information.

Joint stiffness

Obviously, the joint will be soar and relatively stiff immediately after surgery, however, limited flexion after the immediate post-operative period is undesirable. To read more on stiffness following knee replacement surgery, visit our article joint stiffness following knee replacement surgery.

Allergic Reaction

A small number of patients may experience an allergic reaction or hypersensitivity to the metallic elements in the implants. A more detailed explanation of this complication can be found our article on this topic.

1 Barrington JW, SahA, Malchau H, Burke DW. Contemporary cruciate-retaining total knee arthroplasty with a pegged tibial baseplate. Results at a minimum of ten years. JBJS (Am.). 2009;91:874-878.

2. Jämsen E, Varonen M, Huhtala H, Lehto MU, Lumio J, Konttinen YT, Moilanen T. Incidence of Prosthetic Joint Infections After Primary Knee Arthroplasty. J Arthroplasty.2008 Dec 3.


3 Responses to “Knee Replacement Complications”

  1. Kuldip Kumar Vij on January 30th, 2014 5:41 am

    Can a Diabtic Patient who is on Insuline can undergo orthoplasty,if so is it absolutely safe?what should be the time difference between the surgery of two knees?

  2. Judy Miles on February 8th, 2014 5:45 pm

    I find after having my left knee replaced that my right leg is shorter. Is this a common problem with knee replacement surgery?

  3. Judy Miles on February 8th, 2014 5:47 pm

    After knee replacement surgery is it common for one leg to be longer than the other leg? Is this a common side effect from knee replacement surgery.

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