Knee prosthesis or knee arthroplasty is a procedure in which the knee joint is replaced by an artificial implant. This has metal and plastic components designed to reproduce the functionality of the knee. It is an intervention that is performed to alleviate the pain of patients suffering from knee osteoarthritis and improve their quality of life.
In what cases is a knee prosthesis necessary?
The knee prosthesis is only recommended in cases of advanced osteoarthritis associated with a significant functional limitation, and in which other conservative treatment measures have failed, such as physical activity without impact, use of oral anti-inflammatory analgesics, weight loss, and infiltrations.
What causes the deterioration of the knee so that a prosthesis is necessary?
Knee osteoarthritis or gonarthrosis consists of a progressive deterioration of the articular cartilage associated with aging. But this also depends on genetic factors, the alignment of the knee, the patient’s weight, physical work or practice of impact sports, previous fractures, joint infections or ligament injuries of the knee.
What types of knee prostheses exist?
There are several types of knee prostheses. The most commonly used are called RC (which retain the posterior cruciate ligament) and PS (post-stabilized, which do not retain the posterior cruciate ligament). Both types have proven effective in the treatment of osteoarthritis of the knee. There are also other types that can be used depending on the degree of joint deterioration. The least invasive are the unicompartmental ones, which only replace one joint compartment and preserve the rest of the joint. The most invasive are the constrained and hinge, which are used in major instabilities or significant bone defects.
What will knee replacement surgery and the postoperative period be like?
Knee arthroplasty can be performed under intradural anesthesia with sedation or general anesthesia. It is performed through an incision of about 15-20 cm in the anterior edge of the knee and usually lasts between 80-120 minutes. The hospital stay can vary between 2-7 days depending on the evolution of the patient. Mobilization of the knee is recommended from the first day after surgery to avoid possible stiffness and accelerate the recovery process. The work of physiotherapists is of utmost importance to meet these objectives. Cures are usually performed every 72 hours and the staples are removed after 2 weeks. The recovery process lasts about 6 months, during which the patient experiences a progressive improvement.
What advances have been made in knee prostheses in recent years?
In recent years, the design of prosthetic implants has improved to adapt more precisely to the morphology of the knee. Surgical techniques have also evolved, with kinematic alignment techniques, which attempt to reproduce the natural alignment of the knee, becoming more popular in recent years. Unicompartmental implants and mobile plates are also gaining importance.