The knee is an essential joint for leg mobility and gait. Dr. José María Amorós explains that it is always subjected to an overload due to its location between the femur and the tibia. Because of this pressure, its soft parts and osteocartilaginous structures can wear out, alter and produce a serious functional deficit and disabling pain.
The main processes of knee arthritis are:
- Osteoarthritis is a type of articular cartilage wear arthritis, related to age, as it usually occurs in people over 50 years of age. Thus, the cartilage that covers the bones of the knee softens and wears down to the point that the bones rub against each other, causing pain and functional limitation.
- Rheumatoid arthritis is a chronic disease in which the synovial membrane surrounding the knee joint becomes inflamed and thickened, causing the destruction of the cartilage with denudation of the bone and a picture of chronic pain and stiffness of the limb.
- Post-traumatic arthritis usually occurs after a serious injury to the knee, both bone by a fracture or intercurrence of meniscal injuries, and ligamentous type, which previously have been treated or not surgically and destabilize the knee causing abnormal movements that deteriorate the joint.
When do you need to operate the knee with arthritis?
Surgery is recommended when severe pain and stiffness prevent or limit daily activities such as walking, sitting and getting up from a chair, going up and down stairs, getting in and out of a car and even if it prevents rest. Swelling, inward or outward bowing of the knee (varus-valgus) and pharmacological and physiotherapeutic treatments or the need for a walking cane will also be factors to be taken into account.
To determine if the patient needs a knee prosthesis, it will be taken into account if the pain and the mobility problem are of long evolution. Imaging tests will be performed with a relative but not determining value, which will be an X-ray and telemetry, necessary to assess the desaxation (loss of the normal axis of a movement). On the other hand, there are no age or weight restrictions for prosthetic knee surgery.
The orthopedic surgeon will assess the patient individually, will be informed about your medical history of surgical history, treatments received, sports habits and work activity. It is also essential for the specialist to understand the patient’s attitude so that he/she is aware of what the intervention entails and to convey to him/her the realistic expectations that the joint change entails. The socio-economic and social environment should also be taken into account.
Advantages and limitations of knee replacement
An important factor in the decision to undergo prosthetic knee surgery is to know its advantages and limitations.
- Advantages: the most important is the drastic reduction of pain and experiencing a great improvement in the ability to perform common activities of daily living, such as unlimited walking, swimming, driving a car or motorcycle, golf, cycling, light hiking, ballroom dancing and others.
- Limitations: high impact activities such as running, jumping, jogging and contact sports will be limited.
Possible complications of surgery
The rate of complications in total knee replacement surgery is low. Serious complications, such as joint infection, occur in less than 2% of patients. Other major complications, such as myocardial infarction or thromboembolism are also exceptional.
On the other hand, suffering from certain chronic diseases such as diabetes or autoimmune diseases may increase the risk of complications, although this would still be low, and complete recovery could be prolonged or limited.
Postoperative period in prosthetic knee surgery
It is essential to discuss with the orthopedic surgeon all the details of the surgery and the postoperative and hospital stay. The operation usually does not require blood transfusion and antibiotic and antithromboembolic prophylaxis is applied; the patient will be able to get up and sit up after 12 hours and will start flexion and extension exercises independently, without the aid of machines. The following day the patient will begin to ambulate with two crutches and on the third day the patient will be able to be discharged home. Instructions will be given for the practice of a table of exercises to be performed at home. At two weeks the patient will abandon one crutch and at 5-7 weeks he/she will be able to walk freely.
Prolonging the life of the knee prosthesis
Currently, more than 90% of total knee replacements continue to function well 15 to 20 years after surgery. However, overuse and longevity sometimes lead to loosening of the prosthesis and the need for replacement. It is important to be aware, not afraid, of this possibility, which will entail a new intervention with results comparable to the first.