Arthropathy means a pathological process characterized by dystrophy and degeneration of articular cartilage. As a rule, the issue is not limited to cartilage - later the pathology spreads to the (hypochondriac) bone tissue below the cartilage. Therefore, arthropathy is also called osteoarthritis. And since all of these disorders eventually lead to a change in joint structure, this process is called deforming osteoarthritis, which can affect any joint. In clinical practice, in most cases there is arthropathy of the knee joint or knee joint.
The essence of pathology
In terms of frequency and prevalence, knee arthropathy is second only to hip arthropathy (coxarthrosis). To find out what caused it, it is worthwhile to dwell briefly on the characteristics of the anatomical structure of the knee and the functions it performs. This is one of the most massive joints, in the formation of which 3 bones are involved - the femur, the tibia and the patella. Thus, it is a complex joint formed by 2 joints - the patellofemoral and the patellofemoral.
The articular surfaces of all 3 bones are covered with cartilage, which facilitates movement in the joint and protects the subchondral bone tissue from mechanical wear. In addition to the articular cartilage itself, the knee has menisci - paired cartilaginous formations that enhance the anatomy (anatomical correspondence) of the articular surfaces. Articular cartilage does not have its own blood vessels. It is nourished diffusely by the intra-articular (synovial fluid). Like a sponge, cartilage contracts under mechanical stress during movement, carrying heavy loads. At this time, the waste is released from the cartilage tissue into the surrounding synovial fluid. On the contrary, at the moment of relaxation, rest, the synovial fluid and the nutrients contained in it penetrate into the cartilage of the knee.
For various reasons, the nutrition of the articular cartilage of the knee joint is disturbed, which leads to arthropathy of the knee. At the same time, in the beginning, there is a lack of nutrients in the cartilage tissue - chondroitin sulfate, glucosamine, calcium and other trace elements. Moisture is lost. It is a process of dystrophy, followed by degeneration - thinning of the articular cartilage. In turn, these negative processes lead to structural and motor disorders in the knee joint.
Knee arthritis is often confused with salt deposition. For example, some minerals, including table salt, are deposited in the form of microcrystals in the joint cavity, which leads to pain and movement disorders. This is not true. Obviously, a completely different procedure is taken for the deposition of salts. In response to the destruction of articular cartilage in the subchondral bone, marginal bone growths - osteophytes - are formed in order to stabilize the knee at least to some extent. However, in the future, osteophytes only aggravate arthropathy and contribute to the further destruction of cartilage.
Causes
The causes of the knee joint are varied and may be due to the pathology of the knee itself or to other diseases and metabolic disorders. In this regard, the knee joint can be primary or secondary. The mechanism of primary arthropathy is not fully understood. It is believed that in this case, the disease is caused by a combination of factors, such as:
- Advanced age, when degenerative changes occur not only in the articular cartilage, but also in all organs and tissues.
- Excess weight, which increases the mechanical stress on the joint.
- Physical inactivity, or conversely, excessive physical activity.
- Some congenital anatomical disorders of the knee, in which the articular cartilage and hypochondriac bone are initially altered.
- General metabolic disorders that lead to a change in the composition of the mineral components of the synovial fluid.
Secondary arthropathy of the knee joints is a complication of other diseases. Most often, such diseases are arthritis of various natures - gout, rheumatism, rheumatoid, septic, tuberculous, etc. In these diseases, various pathological factors (infection, distorted immune reactions, uric acid crystals) form inflammation of the synovial membrane in the form of the so-called. arthritis. Arthritis is necessarily accompanied by a deterioration in the quality of synovial fluid, which, in turn, leads to arthritis.
Another common cause of joints is knee injuries. Post-traumatic arthropathy of the knee joint is a consequence of an intra-articular fracture of the femur and tibia, hemorrhage (joint bleeding), damage to the knee and meniscus ligaments. Here, the pathology is based on a mechanical factor (damage) and damage that develops after it (arthritis). In addition, osteoporosis is often accompanied by arthritis. Deficiency of calcium in the bones leads to the destruction not only of the bones, but also of the cartilage tissue.
Symptoms
The main symptoms of the knee joint:
- Pain;
- Knee movement disorder.
- Difficulty walking;
- Singing while moving.
- First - pathological tension and then - muscular atrophy of the lower limb.
- Deformity of the knee joint.
In the beginning, as a rule, the patellar joint suffers, which is responsible for most of the functional load. In general, the kneecaps are probably the most vulnerable. Dystrophic changes in arthropathy begin in the cartilage of the patella. Clinically, this is manifested by swelling and pain when feeling this bone. As a result of dystrophic changes, the articular cartilage undergoes sclerotic changes - it loses its elasticity, it is replaced by thick connective tissue.
Then the articular sac and the ligament device undergo sclerotic changes. The joint configuration changes. Initially due to concomitant arthritis it is swollen, inflammatory. Then, with the development of degeneration and sclerosis, the amount of synovial fluid decreases sharply, the joint space narrows, which inevitably leads to movement disorders. At first walking is difficult and the limb muscles are tense. Ankylosis develops - complete immobility of the knee and, as a result, atrophy of the muscles of the thigh and lower leg. All these changes take place over a long period of time. In this regard, there are 3 degrees of arthritis:
- Arthritis of the 1st degree knee joint. The pains are located mainly in the area of the patella and along the inner surface of the knee joint. The pains are "initial" in nature - they appear at the beginning of the movement, and then subside. Also, the pain can appear with significant effort (long walk, weight transfer) and disappear after rest. There are no structural changes in the joint at this stage.
- Arthritis of the 2nd degree knee joint. The pain can appear even at rest and bother for a longer period of time. Limitations of range of motion (contractions) appear in the knee. The patient limps, must move with a stick. Inflammatory and dystrophic changes form in the joint, which are externally manifested by an increase in the knee due to edema.
- Arthritis of the 3rd degree knee joint. Severe pain in the knee that does not stop even after long hours of rest. Serious irreversible disturbances in the structure of the joint, leading to ankylosis and loss of mobility. Change in the configuration of the entire lower extremity, which is manifested by the curvature of the flap or the flap (in the shape of O or X).
The diagnosis of the knee joint is made based on the above symptoms and complaints of the patient, as well as X-ray data (narrowing of the joint space, osteophytes, osteoporosis, hardening of the bones). Knee arthritis is treated in a complex with the use of drugs and natural procedures. With 3rd degree joints, surgery is indicated during which various types of plastic knee joint are performed.