Gonarthrosis is a deforming arthrosis of the knee joint. It is accompanied by damage to the hyaline cartilage of the articular surfaces of the tibia and femur, has a chronic progressive course. Clinical symptoms include pain that increases with movement, restriction of movement and synovitis (accumulation of fluid) in the joint. In the later stages, the support on the leg is violated, there is a pronounced restriction of movements. Pathology is diagnosed on the basis of anamnesis, complaints, physical examination and radiography of the joint. Conservative treatment: drug therapy, physiotherapy, physical therapy. With significant destruction of the joint, endoprosthetics is indicated.
M17 Gonarthrosis [arthrosis of the knee joint]
Gonarthrosis or deforming arthrosis of the knee joint is a progressive degenerative–dystrophic lesion of intra-articular cartilage of a non-inflammatory nature. Gonarthrosis is the most common arthrosis. It usually affects middle-aged and elderly people, women are more likely to suffer. After an injury or constant intense exertion (for example, during professional sports), gonarthrosis may occur at a younger age. Prevention plays an important role in preventing the occurrence and development of gonarthrosis.
Contrary to popular belief, the cause of the development of the disease lies not in the deposition of salts, but in a violation of nutrition and a change in the structure of intra-articular cartilage. With gonarthrosis, foci of deposition of calcium salts may occur at the site of attachment of tendons and ligamentous apparatus, but they are secondary and are not the cause of painful symptoms.
In most cases, it is impossible to single out any one cause of the development of pathology. As a rule, the occurrence of gonarthrosis is caused by a combination of several factors, including:
- Injuries. Approximately 20-30% of cases of gonarthnosis are associated with previous injuries: fractures of the lower leg (especially intraarticular), meniscal injuries, tears or ruptures of ligaments. Gonarthrosis usually occurs 3-5 years after a traumatic injury, although an earlier development of the disease is possible – 2-3 months after the injury.
- Physical activity. Often the manifestation of gonarthrosis is associated with excessive loads on the joint. The age after 40 is a period when many people understand that regular physical activity is necessary to maintain the body in good condition. Starting to practice, they do not take into account age-related changes and unnecessarily load the joints, which leads to the rapid development of degenerative-dystrophic changes and the appearance of symptoms of gonarthrosis. Running and intensive fast squats are especially dangerous for knee joints.
- Excess weight. With excessive body weight, the load on the joints increases, both microtrauma and serious damage (meniscus tears or ligament tears) occur more often. Gonarthrosis is especially severe in overweight patients with severe varicose veins.
The risk of gonarthrosis also increases after arthritis (psoriatic arthritis, reactive arthritis, rheumatoid arthritis, arthritis with gout or ankylosing spondylitis). In addition, among the risk factors for the development of gonarthrosis are genetically determined weakness of the ligamentous apparatus, metabolic disorders and violation of innervation in some neurological diseases, traumatic brain injuries and spinal injuries.
The knee joint is formed by the articular surfaces of two bones: femoral and tibial. On the anterior surface of the joint there is a patella, which, when moving, slides along the depression between the condyles of the femur. The fibula is not involved in the formation of the knee joint. Its upper part is located on the side and just below the knee joint and is connected to the tibia by means of an inactive joint.
The articular surfaces of the tibia and femur, as well as the posterior surface of the patella are covered with smooth, very strong and elastic dense elastic hyaline cartilage 5-6 mm thick. Cartilage reduces friction forces during movements and performs a shock-absorbing function under shock loads.
At the first stage of gonarthrosis, blood circulation in small intraosseous vessels feeding hyaline cartilage is disrupted. The surface of the cartilage becomes dry and gradually loses its smoothness. Cracks appear on its surface. Instead of a soft, unobstructed sliding, the cartilages “cling” to each other. Due to constant microtrauma, the cartilage tissue becomes thinner and loses its cushioning properties.
At the second stage of gonarthrosis, compensatory changes occur on the part of bone structures. The joint pad is flattened, adapting to increased loads. The subchondral zone is compacted (the part of the bone located immediately under the cartilage). On the edges of the articular surfaces, bone growths appear – osteophytes, which resemble spikes in their appearance on the radiograph.
The synovial membrane and capsule of the joint in gonarthrosis also degenerate, become “wrinkled”. The nature of the articular fluid changes – it thickens, its viscosity increases, which leads to deterioration of lubricating and nourishing properties. Due to a lack of nutrients, cartilage degeneration is accelerated. The cartilage becomes even thinner and disappears completely in some areas. After the disappearance of cartilage, the friction between the articular surfaces increases sharply, degenerative changes progress rapidly.
At the third stage of gonarthrosis, the bones are significantly deformed and seem to be pressed into each other, significantly limiting movement in the joint. Cartilage tissue is practically absent.
Taking into account the pathogenesis in traumatology and orthopedics, there are two types of gonarthrosis: primary (idiopathic) and secondary gonarthrosis. Primary gonarthrosis occurs without previous injuries in elderly patients and is usually bilateral. Secondary gonarthrosis develops against the background of pathological changes (diseases, developmental disorders) or knee joint injuries. It can occur at any age, usually one-sided.
Taking into account the severity of pathological changes , there are three stages of gonarthrosis:
- The first stage is the initial manifestations of gonarthrosis. Periodic dull pains are characteristic, usually after a significant load on the joint. A small, self-disappearing swelling of the joint is possible. There is no deformation.
- The second stage is an increase in the symptoms of gonarthrosis. The pains become more prolonged and intense. Often there is a crunch. There is a slight or moderate restriction of movement and a slight deformation of the joint.
- The third stage – clinical manifestations of gonarthrosis reach a maximum. The pain is almost constant, the gait is broken. There is a pronounced limitation of mobility and noticeable deformation of the joint.
The disease begins gradually, gradually. At the first stage of gonarthrosis, patients are concerned about minor pain during movement, especially during climbing or descending stairs. There may be a feeling of stiffness in the joint and “tightening” in the popliteal region. A characteristic symptom of gonarthrosis is “starting pain” – painful sensations that occur during the first steps after lifting from a sitting position. When a patient with gonarthrosis “diverges”, the pain decreases or disappears, and after a significant load appears again.
Externally, the knee is not changed. Sometimes patients with gonarthrosis note a slight swelling of the affected area. In some cases, at the first stage of gonarthrosis, fluid accumulates in the joint – synovitis develops, which is characterized by an increase in the volume of the joint (it becomes bloated, spherical), a feeling of heaviness and restriction of movements.
At the second stage of gonarthrosis, the pain becomes more intense, occurs even with small loads and increases with intense or prolonged walking. As a rule, the pain is localized on the anterior-inner surface of the joint. After a long rest, painful sensations usually disappear, and with movements they arise again.
As gonarthrosis progresses, the volume of movements in the joint gradually decreases, and a sharp pain appears when trying to bend the leg as much as possible. A rough crunch is possible during movements. The configuration of the joint changes, it seems to expand. Synovitis appears more often than in the first stage of gonarthrosis, characterized by a more persistent course and accumulation of more fluid.
At the third stage of gonarthrosis, the pain becomes almost constant, bothering patients not only while walking, but also at rest. In the evenings, patients spend a long time trying to find a comfortable position to fall asleep. Often, the pain appears even at night.
Flexion in the joint is significantly limited. In some cases, not only flexion is limited, but also extension, which is why a patient with gonarthrosis cannot fully straighten his leg. The joint is enlarged in volume, deformed. In some patients, valgus or varus deformity occurs – the legs become X-shaped or O-shaped. Due to the limitation of movements and deformity of the legs, the gait becomes unstable, waddling. In severe cases, patients with gonarthrosis can move only with the support of a cane or crutches.
The diagnosis of gonarthrosis is made on the basis of patient complaints, objective examination data and X-ray examination. When examining a patient with the first stage of gonarthrosis, external changes usually cannot be detected. At the second and third stages of gonarthrosis, coarsening of bone contours, joint deformation, restriction of movements and curvature of the limb axis are detected. When the patella is shifted in the transverse direction, a crunch is heard. Palpation reveals a painful area inside of the patella, at the level of the articular gap, as well as above and below it.
With synovitis, the joint increases in volume, its contours become smoothed. Bulging is detected along the anterolateral surfaces of the joint and above the patella. During palpation, fluctuation is determined.
Knee x-ray is a classic technique that allows you to clarify the diagnosis, establish the severity of pathological changes in gonarthrosis and observe the dynamics of the process by taking repeated pictures after a while. Due to its availability and low cost, it remains the main method for the diagnosis of gonarthrosis to this day. In addition, this method of investigation makes it possible to exclude other pathological processes (for example, tumors) in the tibia and femur.
At the initial stage of gonarthrosis, changes in radiographs may be absent. Subsequently, the narrowing of the articular gap and the compaction of the subchondral zone are determined. The articular ends of the femur and especially the tibia expand, the edges of the condyles become pointed.
When studying the radiograph, it should be borne in mind that more or less pronounced changes characteristic of gonarthrosis are observed in most elderly people and are not always accompanied by pathological symptoms. The diagnosis of gonarthrosis is made only with a combination of radiological and clinical signs of the disease.
Currently, along with traditional radiography, modern techniques such as computed tomography of the knee joint are used to diagnose gonarthrosis, which allows for a detailed study of pathological changes in bone structures and MRI of the knee joint, used to detect changes in soft tissues.
Traumatologists-orthopedists are engaged in treatment. Gonarthrosis therapy should be started as early as possible. During the period of exacerbation, a patient with gonarthrosis is recommended to rest for maximum relief of the joint. The patient is prescribed therapeutic gymnastics, massage, physiotherapy (UHF, electrophoresis with novocaine, phonophoresis with hydrocortisone, diadynamic currents, magnetic and laser therapy) and mud therapy.
Drug therapy for gonarthrosis includes chondroprotectors (drugs that improve metabolic processes in the joint) and drugs that replace synovial fluid. In some cases, intra-articular administration of steroid hormones is indicated for gonatrosis. Subsequently, the patient may be referred for sanatorium treatment.
A patient with gonarthrosis may be recommended to walk with a cane to unload the joint. Sometimes special orthoses or individual insoles are used. To slow down degenerative processes in the joint with gonarthrosis, it is very important to follow certain rules: exercise, avoiding excessive loads on the joint, choose comfortable shoes, monitor weight, properly organize the daily routine (alternating load and rest, performing special exercises).
With pronounced destructive changes (at the third stage of gonarthrosis), conservative treatment is ineffective. With severe pain syndrome, impaired joint function and disability, especially if a young or middle–aged patient suffers from gonarthrosis, they resort to surgery (knee replacement). Subsequently, rehabilitation measures are carried out. The period of full recovery after joint replacement surgery for gonarthrosis takes from 3 months to six months.