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Knee Replacement Complications

Knee replacement is a major surgical procedure but most people do well and are pleased with the outcome, and it has some of the largest increases in quality of life measures of all medical interventions. As with hip replacement there are potential risks and complications and the surgeon should explain these to you before the operation.

Giving out good knee replacement surgery information is vital so patients know what to expect, can prepare for knee replacement surgery and can cooperate to the fullest extent in their rehabilitation, with the knee replacement surgery risks spelled out clearly.

Many people have their new knee joint without problems for ten to fifteen years, but a small percentage have complications which delay the knee replacement recovery. Most complications are quickly treated and of minor significance but some are important and take much longer to resolve, adding greatly to the knee replacement cost of what is already an expensive operation.

Revision knee replacement may entail an extended period of healing and rehabilitation with the physiotherapist who will monitor the knee replacement exercises.

Knee surgery of any kind carries with it the normal risks of surgery and the specific ones to do with the joint in question. There are different types of knee replacement surgery to suit the clinical requirement of the patients. Partial knee replacement or unicompartmental knee arthroplasty may be chosen if only half of the knee joint, the medial or lateral compartment, is affected by the knee arthritis. This technique is cheaper than total knee arthroplasty and may allow quicker recovery and reduced operating time, all likely to reduce the incidence of complications

Developments in this field include knee replacement components designed specifically for people with smaller bones, especially women, and a bespoke guidance system based on MRI of the person's leg called the Signature knee replacement system allows alignment guides for the operation to be generated from this 3D image

To understand the risks and complications, it can be really useful to watch a knee replacement surgery video as this shows exactly what is done and what the knee tissues have to cope with during the operation. A partial knee replacement surgery video is also available.

If there is a significant problem there may be need of a total knee replacement medical malpractice claim but thankfully this is rare as training for this kind of surgery is rigorous. Further information about complications of total knee replacement is available at The Hip and Knee Institute and on Wikipedia.

Risks and complications

  • Fat Embolism occurs when the fat from the marrow cavity enters the bloodstream and can cause serious problems. Having both knees done at once increases the likelihood of this occurring.

  • Nerve damage after knee replacement is more common in those who have epidurals, people who have had lumbar operations and those people with knock knees and inability to straighten the knee pre-operatively. The overall occurrence of this problem has been reported to be 0.58% after knee replacement.

  • The occurrence of arterial complications is from 0.03% to 0.2% of knee replacements. It is more likely in those with calcification of the arteries in the area and those people in whom the foot pulses cannot be felt.

  • Fractures around the prosthesis (artificial joint) can occur during the operation or afterwards,and how they are managed depends on whether they are displaced (not in line) and whether the joint replacement is itself affected.

  • Excess bone formation (heterotopic ossification) occurs in some cases and causes a restriction in range of movement of the knee after operation.

  • Recurrent bleeding(haemarthrosis) into the knee joint can occur but the cause may not be clear. Treatment may include aspiration (drawing the blood off with a needle), ice, resting and stopping of any anticoagulants.

  • The skin may be numb to the outside of the operation scar and this does not usually improve.

  • Loosening of the metal components may occur over time or due to trauma. This may cause few problems or be serious enough to have the joint revised. In a paper by Li, Zamora and Bentley, the rate of knee revision due to this problem was 2.7%.

  • Infection is a rare complication but a serious one. Li, Zamora and Bentley reported a 3.4% revision rate due to this. Infection may occur soon after the operation or many years afterwards. Treatment may initially be with antibiotics but surgical revision of the joint is often needed in these cases.

  • Thromboses (blood clots) may form in the veins of the legs or pelvis and cause inflammation, swelling and pain. A serious condition can result if some of a clot breaks off and enters the circulation (eg pulmonary embolism). Treatments include wearing support stockings, using footpumps while people are in bed, getting people up and about soon after surgery and using anticoagulant drugs.

Knee replacement complications - a comprehensive view entails looking at all the risks and evaluating them although if you think about these things too much it might put you off agreeing to something where the risks are acceptable and the potential benefits very high. To get the personal views of people who have been through these procedures it is useful to read a total knee replacement blog or an after knee replacement blog as this reflects real life experiences rather than dry generalisations.


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