Knee replacement surgery is a medical procedure that is aimed to treat a knee joint that has been damaged due to arthritis or other complications. Arthritis is a condition that results from the breakdown of joint cartilage plus the underlying bone. Knee replacement surgery is used when other means such as physiotherapy and medications fail to relieve the stiffness and pain from the joint.
During this type of surgery, your surgeon will first cut off the damaged bone and cartilage and then replace it with an implant. An implant can be an artificial joint made of metal or plastic. Knee replacement can help you relieve the joint pain, enable normal movement, and eliminate joint stiffness.
Just like other types of surgery, knee replacement surgery is associated with many risks ranging from infections to blood clots. The risks and complications include:
Risks from Anesthesia
Before knee replacement surgery, anesthesia is given so that you will not feel any pain during the procedure. Under general anesthesia, patients fall into a deep sleep and are unconscious during the operation.
General anesthesia can cause a number of side effects such as:
- Heart attack
- A sore throat due to the breathing tube inserted through the throat.
Patients with an existing heart disease or lung problem are more likely to have serious complications with general anesthesia.
Spinal anesthesia is an alternative used sometimes in knee surgery in place of general anesthesia. This anesthesia is injected on the surgical area to numb the tissue and reduce pain. This type of anesthesia has fewer complications compared to general anesthesia.
The side effects of this anesthesia include:
- Urination difficulties
- Allergic reactions
- Nerve injury resulting from the needle used to administer the anesthesia. This complication is rare.
Bleeding is also another risk you may encounter during and after a knee replacement surgery. Although it is normal to bleed during surgery, sometimes, in rare cases a person may lose a lot of blood that may require a transfusion. Sometimes after surgery, a pool of blood can collect on the surgery site causing it to swell. If this happens, another surgery is required to release the blood to prevent formation of a clot.
Infection is another risk you would rarely escape with an open wound. Bacteria can enter the wound and cause infection. Signs of an infection include:
- Swelling on the knee
- Fluid discharge on the surgical site
Infection can be treated or prevented by use of antibiotics. However, your surgeon should take precautions to avoid any infection during knee replacement surgery.
Such precautions include:
- Prescription of antibiotics before, during, and after surgery to prevent bacterial infection.
- Use of filters that limit any particles in the air.
- Scrubbing in and dressing well should be done to meet sterility standards of an operation room.
- Implants and surgical instruments should be well sterilized before entering the operating room.
One of the biggest risks you can have from a knee replacement surgery are blood clots. If your knee blood vessel is damaged, or you happen not to move your leg for several days, blood flow can slow. This can cause a blood clot to form. A clot formed in one of the legs deep vein is referred to as deep vein thrombosis (DVT). If the clot gets a way through, it can move to the lungs and block the flow of blood. This is known as a pulmonary embolism and can become life-threatening.
Blood clots can be prevented through:
- Improving blood circulation – Some techniques can be used to enhance your blood flow. They include wearing support stockings, exercises to lower your leg, elevation of the leg, and calf pumps.
- Blood thinning drugs – Blood thinners should be taken after the operation. They include drugs such as heparin, warfarin, enoxaparin, and aspirin. These drugs will help you reduce the risk of blood clots.
This condition is rare, but many people have problems when they have a deep breath after a surgery. This can be common when a general anesthesia is used during knee replacement surgery. If you have little air reaching your lungs, mucus can accumulate which can lead to pneumonia. Your doctor will discuss with you on how you can take deep breathes to make sure your lungs are working properly.
Swelling and Pain
Swelling and pain is something you can’t avoid after any surgery. However, the severity of the pain and swelling may be different in different people. Prescribed or over the counter pain relievers can be used to get rid of pain. The pain relievers should be used for a short period but if the pain persists, they can be continued for a few weeks or months. In case of swelling in the knee after surgery, ice packs can be used to bring down the swelling.
Damage to the nerves around the knee are very rare. However, it is very possible for the blood vessel or nerve on the knee muscle to get numbed after the procedure. The complication will disappear after a few weeks once the nerves and knee tissue heal.
Damage to the arteries can also occur after knee replacement surgery since the major leg arteries are located behind the kneecap. So, there is a slight risk that the arteries may be damaged.
It is rare for people to have an allergic reaction when they get in contact with metal components. However, it is possible for some patients, who have metal allergies, to have an allergic reaction after a metallic knee implant is fixed.
For those with metal allergies, an implant can trigger a reaction that can be followed by blisters, a rash, and swelling. Allergic reactions can bring symptoms such as diarrhea, a feeling of weakness, headache, and loss of function to the implant. Those who experience allergic reactions on their skin should discuss these allergies with their surgeon prior to the operation.
Although joint technology has been improved over the years, it is not yet perfect. A new joint implant can wear out, loosen, and even lose stability within a short period. If the joint fails, the patient will continue to feel pain and stiffness after surgery. Another correction surgery is needed to repair this.
The risks of experiencing complications after surgery are rare, but you should do something to get rid of them. This calls for you and your surgeon to make proper preparations to make the surgery a success. Some control measures can be used to lower some of the risks as well.