Risks and Complications of Knee Replacement Surgery

• Complications of knee replacement surgery are rare, but still need to be taken into consideration before having the intervention.
• In addition to the risks that exist in the operating theatre, there are possible complications that can occur after knee replacement surgery.
• In this article, we explain everything you need to know about common and rare complications associated with total knee replacement surgery.

When a person is advised to undergo knee replacement surgery, it is by no means a decision taken lightly. Most often it is because the patient has gone through a series of stages of degenerative joint disease, more specifically degeneration of the cartilage covering the bone, which has led to the assertion that knee replacement surgery is the best option.

Although, as we will discuss throughout the article, there are possible complications in knee replacement surgery, it is also very true that the problems caused by, for example, advanced osteoarthritis are so serious that they can even invalidate the patient who suffers from it, causing, among other symptoms, joint pain, deformation of the knee and loss of mobility, preventing the patient from leading a normal life. 

You can find out all about it in our article: Knee osteoarthritis, what it is, symptoms and treatments.

Once the patient, along with the specialist in traumatology and orthopaedic surgery, has decided to undergo total knee replacement surgery, he or she should be aware of the risks and possible complications of the procedure, however unusual they may be, so that he or she can make an informed decision. 

The risks of knee replacement surgery are not related exactly to the joint to be replaced, but are those that appear in all informed consents prior to any surgery, being these:

• Urinary and respiratory infections: Due to the use of the catheter in the case of urinary infections or because there is a possibility of bacteria entering during the operation.
• Appearance of clots: Both in the legs, called thrombosis, and in the lungs, which we call embolisms.

However, in order to reduce the chances of these problems, antibiotic and anticoagulant medication is often used to minimise the chances of this happening.

In any case, when someone thinks about the possible complications of a total knee replacement operation, what they are really referring to is the fact that everything is going to be fine, whether they are really going to recover their quality of life, among other aspects. 

The most usual thing is that replacement surgery works perfectly and the prosthesis lasts the estimated useful life of between 15 or 20 years without problems, but there are cases in which the complications that we indicate in the following section can occur.

Complications following knee replacement surgery are rare, as are intraoperative complications, but they are nevertheless important to be aware of. 

Some are directly related to the prosthesis and others to the surgical procedure and are as follows:

Infection

The infection may be due to the surgical wound or the structures surrounding the prosthesis inside the leg. In these cases, and provided that antibiotic treatment has not solved the problem, the surgeon may suggest to the patient the possibility of replacing the knee prosthesis because it has been colonised by germs that cannot be eliminated in any way other than replacing the implanted joint.

The signs and symptoms that indicate that something is wrong can be fever, a feeling of general malaise, pain in the joint with oedema and flushing (reddening of the area), distillation of some liquid from the surgical wound, joint deformity, etc. In these cases, the best option is to contact the doctor who performed the surgery as soon as possible.

Deep vein thrombosis

The formation of thrombi in the venous system of the legs is one of the most common complications, despite the fact that prophylactic, preventive treatment is administered to prevent it from occurring. This treatment consists of administering low molecular weight heparin subcutaneously with a syringe, which dilutes the blood to prevent the formation of clots.

It is important to point out that immobility is a very important risk factor for the formation of clots, so the patient should be mobilised the day after the operation as advised by the doctor.

Finally, one of the rarest complications is pulmonary vein thrombosis, which occurs in cases where a thrombus in the leg breaks loose and travels to the lung. It is rare because of the precautions taken.

Problems with the knee prosthesis

If the knee prosthesis is not fitted correctly, respecting the alignment and physiological joint arch, it is possible that over time it may cause problems, the key to this being that the surgeon is an expert in carrying out this intervention.

On rare occasions there are cases of rejection due to allergy to some of the prosthetic materials, as this has usually been managed beforehand to avoid them and make use of a prosthesis that is suitable for the patient.

Finally, in other cases, excess weight or physical overload of the knee can ruin the surgery by affecting the joint. The new knee provides us with many improvements, but we must take care of it so that it lasts as long as possible.

Chronic joint pain

In a very small percentage of patients, some patients may have chronic joint pain despite having had their knee replaced with a prosthesis. The cause of this pain is uncertain. Even so, when it occurs, we must carry out a thorough study, with examination and complementary tests if necessary, to determine its origin and find a possible solution.

Injury to nerves and blood vessels

These are very rare injuries that involve blood vessels or nerves during surgery. They can leave permanent sequelae as they are irreversible injuries, such as paralysis of the foot, amputation of a limb due to vascular necrosis, etc. This is rare and less so in cases where the surgeon is sufficiently experienced.

Despite all the possible complications aforementioned, it must be said that these are rare and that there are ways to reduce the chances of their occurrence. 

The most important thing in these cases is to listen to the specialist who has treated us, but it is also important to follow a series of guidelines to help us get the maximum benefit from having undergone major surgery such as total knee replacement surgery.

Among other aspects, it is advisable to put yourself in the hands of a physiotherapist to help you with rehabilitation, as the key to the success of this surgery lies in the work carried out during the year following surgery. 

In addition to the above, the following is important:

• Maintaining weight: In the same way that when treating osteoarthritis of the knee in the early stages of the disease it is important to maintain a balanced weight to avoid overloading the joints, it is important to do the same with the new prosthesis to avoid overloading and overexertion that could cause it to loosen or accelerate wear and tear.
• Taking antibiotic medication: In cases where the doctor has prescribed it, it is vital to take it into account in order to minimise the possibility of infection of the prosthesis, as if this is the case, it will require a complex replacement operation, which, although viable, is not a guarantee of maximum success.
• Avoid forcing the prosthesis: Although the joint prostheses are of a very advanced technical quality, it is still an artificial knee and should be cared for without forcing it excessively, avoiding certain sporting activities and gradually and progressively getting used to it day by day.

All this information should be checked with the surgeon in each specific case during the consultation prior to surgery, in order to solve any questions you may have. 

If you are considering the possibility of undergoing total knee replacement surgery with us, below you will find a way to start the process to meet our orthopaedic surgeons.

In order to consider having knee replacement surgery performed privately, the first thing to do is to meet the specialist who will perform the intervention. Trough Operarme, you can request a free pre-surgical consultation with our specialists by clicking below: