Unfortunately, zero risk does not exist in surgery. Any operation has its risks and limitations, which you must accept or not undergo the operation. However, if an operation is proposed, the surgeon and the anaesthetist consider that the expected benefits far outweigh the risk incurred.
Some risks, such as microbial infections of the surgical site, are common to all types of surgery. Fortunately, this complication is rare but when it occurs requires another operation and a course of antibiotics. Some infections may require the implants to be replaced. Bruising can also appear around the surgical site. This is usually prevented or reduced with a suction drain inserted at the end of the operation and removed in the days following the operation. However, in the case of severe bleeding during or following the operation, another operation to stop the haemorrhage or a blood transfusion may be required.
Knee surgery also increases the risk of phlebitis, which can lead to a pulmonary embolism. To minimise this risk, blood thinners (in the form of daily injections or tablets) are prescribed for the entire month following the operation.
In rare cases, the knee remains stiff, hot, and painful for several months after the operation. This complication, known as algodystrophy or Chronic Regional Pain Syndrome (CRPS), is unpredictable and sometimes takes a long time to heal.
Finally, rarer complications can also occur. A fracture can occur when removing the implants and will require osteosynthesis (bone fixation). Blood vessels (arteries, veins) can be accidentally damaged and will require vascular surgery (bypass). Nerves can also be damaged accidentally during the operation with a risk of paralysis or loss of feeling in the limb operated on, which can be transitory or permanent.
If you have any concerns about the operation, do not hesitate to talk to your surgeon or the anaesthetist and they will answer any questions you may have.