Knee Osteoarthritis
Osteoarthritis is a very common disease in the population and one of the main causes of disability. It affects around 250 million people around the world and is characterized by degenerative and progressive involvement of the joints.
Osteoarthritis, also known as osteoarthrosis or osteoarthritis, has a more specific name when it affects the knee: gonarthrosis.
Gonarthrosis is a disease that generally progresses slowly, lasting from 10 to 15 years.
Risk Factors
Some factors are related to a higher chance of developing osteoarthritis. The main ones are:
1. Age - Osteoarthritis mainly affects elderly patients, over 65 years of age. Literature papers show that the disease can affect more than 75% of the population over 75 years of age.
2. Sex - Women have a higher chance of developing osteoarthritis.
3. Obesity - Obesity is a risk factor for both the onset and progression of osteoarthritis, as there is a constant mechanical overload on the knee and a systemic inflammatory process.
4. Joint injuries. Patients with knee injuries, such as ligament ruptures, meniscus and cartilage injuries, joint fractures, among others, tend to develop osteoarthritis earlier.
5. Hereditary factors. Those related to genetic mutations that can increase the individual's predisposition to developing osteoarthritis.
6. Congenital factors. Anatomical abnormalities around the knee, with which the patient is born, which facilitate joint degeneration.
What the Patient Feels
Patients with knee osteoarthritis often experience joint pain, which can worsen depending on the type of activity performed, such as longer walks, squats, and lifting weights, among others. The pain is progressive and worsens over time if no treatment is provided. The patient may also experience joint noises, such as crepitus when performing flexion and extension movements, and knee deformity.
Patient with knee osteoarthritis and varus deformity.
Complementary Exams
Some imaging exams are important to help the doctor diagnose and classify knee osteoarthritis. The main one is a simple X-ray of the knee, which can show important changes, such as the following:
Panoramic radiography of the lower limbs is also an important imaging exam used to assess osteoarthritis. This X-ray shows the axis of the affected lower limb and is used to analyse whether there is significant varus or valgus deviation. A valgus knee is also known as an "X" knee, in which the knees are closer together and the ankles are further apart. Varus knee deviation is characterized by the knees moving apart and the ankles moving closer together.
X-ray showing a case of osteoarthritis associated with valgus deviation of the knees.
Treatment
Initial treatment for knee osteoarthritis is based on non-operative measures such as medication, physiotherapy to improve pain and rebalance the muscles around the knee, and weight control. It is important to note that obesity has a direct relationship with osteoarthritis.
Healthy Habits
Patients with osteoarthritis, especially in less severe cases, can perform some simple and potentially very beneficial activities. Light exercises with little or no impact are recommended, such as water aerobics, swimming, walking, group exercise, among others.
If the patient is obese, appropriate treatment should be introduced, which involves, in addition to the sports practice mentioned above, changing eating habits and seeking specific help. In these situations, we recommend that the patient undergo an evaluation with a nutritionist and an endocrinologist so that these professionals can assist him/her in this process.
Physiotherapy
Physiotherapy treatment is essential for patients with osteoarthritis. Modalities to improve the pain are used initially and, when the patient's pain improves, the rebalancing of the muscles of the lower limb is started.
Medicines
Several medications can be used to treat osteoarthritis.
Analgesics, such as paracetamol and dipyrone, and anti-inflammatories, such as ketoprofen, nimesulide, diclofenac sodium, celecoxib, among others, are used most frequently. It is important to emphasize that any medication should only be used after medical recommendation, since there are potentially serious side effects related to its use.
There are other medications available on the pharmaceutical market that are widely discussed, which are the so-called cartilage protectors or chondroprotectors. These are glucosamine and chondroitin, diacerein, collagen, etc. The benefits of using these substances are highly debatable in the medical literature.
Joint Infiltrations
Intra-articular injections are therapeutic options for knee osteoarthritis.
There are basically two options, corticosteroids and hyaluronic acid, which are used according to the severity of the osteoarthritis.
Joint injections with corticosteroids have been performed for a long time and aim to reduce the inflammatory process caused by osteoarthritis. They can be performed on an outpatient basis, that is, in the doctor's office, and generally promote an improvement in joint pain. However, repeated injections can be harmful to the joint, causing degeneration of the cartilage and ligaments of the knee.
Infiltration with hyaluronic acid, or viscosupplementation of the knee, can also be performed in the doctor's office. The procedure is performed with the patient lying down or sitting, with the knee flexed 90 degrees, or with the knee extended. The substance aims to improve the joint inflammatory process and the biomechanical properties of the joint fluid, functioning as a lubricant. There are different options for hyaluronic acid on the pharmaceutical market.
Surgical Treatment
When non-surgical treatment fails or when the patient has severe osteoarthritis, some surgical treatment options may be used.
ARTHROSCOPY. Arthroscopy is a form of video-assisted surgical approach, through which some conditions present in the knee of patients with osteoarthritis can be treated. As it is a less invasive surgery, arthroscopy is used to treat degenerative meniscal injuries, to remove loose cartilage bodies within the joint, etc.
OSTEOTOMIES. Osteotomies are surgeries that may be indicated when the patient has osteoarthritis in only one of the compartments of the knee and a deviation of the axis of the lower limb in varus or valgus. The objective of the procedure is to transfer the load that passes through the knee to an area with less or no wear so that pain and knee function improve. There are several techniques of osteotomies, but generally a controlled fracture is performed in the femur or tibia, which is fixed with a plate and screws.
ARTHROPLASTY. Arthroplasty, also known as knee replacement surgery, is the substitution of the joint with metal and polyethylene components. The surgery is indicated for cases of more severe osteoarthritis that do not respond well to less invasive treatments. The prosthesis can replace just one compartment of the knee, which are unicompartmental prostheses, or replace two or three compartments, which are total prostheses.
Examples of total knee replacement components.
Total knee replacement is a procedure frequently performed worldwide, as it is a definitive treatment that shows satisfactory results related to improving pain and knee function in patients. This is a surgery in which bone cuts are made in both the femur and the tibia, through which the worn part of the joint is removed. After the bone resection, metal components are placed. To facilitate the sliding of the joint, a polyethylene component is fixed to the metal tibial base. The patellar component may or may not be used, depending on the surgeon's choice.
Undoubtedly, knee replacement surgery greatly improves the quality of life of patients with severe osteoarthritis. However, as with any surgical procedure, the risks and benefits of arthroplasty should be discussed between the doctor and the patient before the procedure is indicated.
Learn More
