Total Knee Arthroplasty

The knee is a hinge joint where the femur (thighbone) meets the tibia (shinbone) and the patella (kneecap). This joint is lined with cartilage that allows for smooth movement and absorbs shock. Over time, this cartilage wears down and the bones can start to rub against each other, a condition known as osteoarthritis, which can manifest as chronic debilitating knee pain and stiffness. Other causes of damage to the cartilage of the knee include trauma and rheumatoid arthritis.

Usually, the first attempts at treating osteoarthritis of the knee consist of exercise and weight loss, topical analgesics such as diclofenac creams (e.g. Voltaren), oral painkillers such as ibuprofen (e.g. Advil), and intra-articular glucocorticoid injections. However, none of these solutions cure the underlying issue of cartilage and bone erosion, and in some cases, a total knee replacement is needed.

Total knee arthroplasty (TKA), also known as total knee replacement, is a surgical procedure designed to alleviate chronic pain and restore function in a severely damaged knee. This involves replacing the damaged cartilage and bone with artificial components made of metal and plastic.

During TKA, the surgeon first makes an incision over the knee to access the joint. Then, the damaged cartilage and bone surfaces are then shaved off from the femur, tibia, and the patella to make way for the insertion of the prosthetic components. After the bone surfaces are reshaped, a femoral (upper), typically metallic component and a tibial (lower), typically plastic component are inserted; a patellar plastic component is added on the front of the knee joint if needed. These three components are then fixed in place, usually with specialized bone cement, allowing for smooth and pain-free movement of the knee joint. Throughout the surgery, the surgeon may use a tourniquet to minimize blood loss.

As with any surgery, TKA carries risks. Complications specific to this procedure include:As with all surgeries, a UKA comes with its specific risks, which include:
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● Periprosthetic fracture (1.5-3%): Fractures to the femur or the tibia
● Periprosthetic infection (1-2%): Infection of the new prosthetic joint
● Aseptic loosening: Loosening of the prosthetic joint over time
● Superficial wound infections: Infection of the skin or superficial tissues at the knee area
● Necrosis: Tissue death due to deep infections at the knee area
● Peroneal palsy: Damage to the peroneal nerve, which allows for lower leg movement and sensation
● Ligament injury: Injury to other ligaments stabilizing the knee (e.g. MCL: 1.2%)
● Arterial injury (0.17%): Injury to an artery supplying the knee and lower leg area
● Tourniquet-related ischemic injury: Injury related to blocking the blood flow during the procedure
● Persistent stiffness or pain
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General minor risks associated with surgery and anesthesia include nausea, vomiting, headaches, sore throat, and urinary retention. Major general risks include blood clots, potentially leading to heart attack or stroke, allergic reactions, and pneumonia. Your surgeon will make sure to discuss the relevant risks with you prior to your surgery and take precautions to minimize the risk of any complications.General minor risks associated with surgery and anesthesia include nausea, vomiting, headaches, sore throat, and urinary retention. Major general risks include blood clots, potentially leading to heart attack or stroke, allergic reactions, and pneumonia. Your surgeon will make sure to discuss the relevant risks with you prior to your surgery and take precautions to minimize the risk of any complications.

Before your surgery, your surgeon will examine your knee and conduct a thorough pre-surgical workup, which may include imaging studies such as X-rays or MRI to assess the state of your knee and visualize its anatomy. Preoperative investigations may also involve further testing such as blood tests to ensure the surgery is right and safe for you.

The procedure can be performed under general anesthesia or regional anesthesia (e.g. spinal or epidural), depending on your medical profile, the assessment of your care team, and your discussion with them.

To manage pain effectively after the operation, a multimodal pain control strategy is employed, which consists of combining different modalities to treat your pain, including acetaminophen (e.g. Tylenol), NSAIDs (e.g. Advil, Aleve), opioids (e.g. oxycodone), other pain medications such as pregabalin, and potentially nerve blocks, a minor procedure where a regional nerve gets frozen with the injection of a local anesthetic medication.

After an outpatient TKA, you will typically get to go home the same day, provided your surgeon determines that your recovery is on the right track. You will most likely be able to walk on day one after your surgery using an assistive device; in fact, you will be encouraged to begin walking with the aid of a walker or crutches soon after your surgery to ensure you regain your strength and mobility in the next couple of months. Early physical therapy will be a crucial component of your recovery process. You will be encouraged to perform low or moderate-intensity exercises such as walking, swimming, and cycling; all while avoiding high-impact activities such as manual labor or heavy lifting. You should be able to go back to your usual activities after six weeks and progressively restart strenuous activities by six months, but you will likely need to continue your exercises for up to a year after the procedure to fully recover your strength and mobility.

Your pain will most likely be managed using a multimodal pain control strategy as described above, and your surgeon may also prescribe additional medication to reduce your risk of blood clots. Regular follow-up visits with your surgeon will help monitor your recovery and ensure your new prosthesis is functioning correctly.