Gonarthrosis of the knee joint is the most common localization of a degenerative dystrophic disease, characterized by gradual destruction of cartilage with subsequent changes in the articular surfaces, which is accompanied by pain and decreased mobility.
The disease is more likely to affect women over 40 years of age, especially those who are overweight and have varicose veins of the lower extremities.
The knee joint is made up of three compartments:
- medial tibiofemoral;
- lateral tibiofemoral;
- suprapatellar-femoral.
These compartments can be affected by osteoarthritis deformans (DOA) both individually and in any combination. 75% of all cases of gonarthrosis are the destruction of the medial tibiofemoral compartment (during movements, it experiences a load that exceeds body weight by 2-3 times).
In young patients, only one joint is most often destroyed: the right or the left (right-sided or left-sided gonarthrosis).
Causes of DOA of the knee joint
Several factors may be involved in the development of degenerative cartilage changes simultaneously:
- mechanical overload of the knee joint (some specialties, sports) with microtraumatization of the cartilage;
- consequences of injuries, surgical interventions (meniscectomy);
- inflammatory diseases of the knee (arthritis);
- anatomical inconsistencies of the joint surfaces (dysplasia);
- violation of statics (flat feet, curvature of the spine);
- chronic hemarthrosis (accumulation of blood in the synovial cavity);
- metabolic pathology (gout, hemochromatosis, chondrocalcinosis);
- excess body weight;
- violations of blood supply to the bone;
- osteodystrophy (Paget's disease);
- neurological diseases, loss of sensation in the extremities;
- endocrine disorders (acromegaly, diabetes mellitus, amenorrhea, hyperparathyroidism);
- genetic predisposition (generalized forms of osteoarthritis);
- violation of the synthesis of type II collagen.
But in 40% of cases, it is impossible to establish the root cause of the disease (primary arthrosis).
Pathogenesis of gonarthrosis
initial stage
At the initial stage of the disease, the processes of cartilage metabolism are disturbed. The synthesis and quality of the main structural unit of cartilage tissue, proteoglycans, responsible for the stability of the collagen network structure, is reduced.
As a result, chondroitin sulfate, keratin and hyaluronic acid are removed from the mesh and structurally defective proteoglycans can no longer retain water. It is absorbed into collagen, the swollen fibers of which lead to a decrease in the resistance of cartilage to stress.
In the synovial cavity, pro-inflammatory substances accumulate, under the influence of which the cartilage is destroyed even faster. Fibrosis of the joint capsule develops. The change in the composition of the synovial fluid hinders the supply of nutrients to the cartilage and makes it difficult for the joint surfaces to slide during movement.
Pathology progression
In the future, the cartilage gradually becomes thinner, rougher, and cracks form throughout its thickness. The epiphyses of the bones experience an increased load, which provokes the development of osteosclerosis and the compensatory proliferation of bone tissues (osteophytes).
This reaction of the body is aimed at increasing the area of the joint surfaces and redistributing the load. But the presence of osteophytes increases discomfort, deformity and further limits the mobility of the limb.
Microfractures form in the thickness of the bone, injuring the vessels and causing intraosseous hypertension. In the late stage of osteoarthritis, the joint surfaces are completely exposed, deformed, the movements of the limbs are severely limited.
Symptoms of gonarthrosis of the knee joint
Arthrosis of the knee joint is characterized by a chronic, slowly progressive course (months, years). The clinic grows gradually, without pronounced exacerbations. The patient cannot remember exactly when the first symptoms appeared.
Clinical manifestations of gonarthrosis:
- pain. At first, diffuse, brief (when standing for a long time, climbing stairs), and as arthrosis progresses, the pain becomes local (anterior and inner surface of the knee), its intensity increases;
- Local tenderness on palpation. Mainly inside the knee along the edge of the joint space;
- crunch. In stage I it can be inaudible, in stage II-III it accompanies all movements;
- increase in volume, deformation of the knee. As a result of the weakening of the lateral ligaments, a person develops an O-shaped configuration of limbs (it is clearly visible even in the photo);
- mobility restriction. At first, there are difficulties with bending the knee, then - with extension.
Causes of pain in DOA:
- mechanical friction of damaged joint surfaces;
- increased intraosseous pressure, venous congestion;
- synovitis adhesion;
- changes in the periarticular tissues (stretching of the capsule, ligaments, tendons);
- periosteal thickening;
- dystrophy phenomena in the adjacent muscles;
- fibromyalgia;
- compression of nerve endings.
Unlike coxarthrosis, DOA of the knee may show spontaneous regression of symptoms.
Clinical manifestations of gonarthrosis depending on the stage:
| Characteristic | I stage | second stage | third stage |
|---|---|---|---|
| Pain | Short, occurs more often when the knee is extended (standing for a long time, climbing stairs) | Moderate, disappears after a night's rest | Pronounced, haunting even at night. |
| mobility restriction | Not visible | There is a restriction of extension, slight lameness | Persistent flexo-extensor contractures, limp |
| crunch | Nope | Sensitive to palpation during movement | remote crackle |
| Deformation | Lost | Slight deviation of the axis of the limb anteriorly, muscular atrophy | Valgus or varus deformity. The joint is unstable, atrophy of the thigh muscles. |
| x-ray image | Mild joint space narrowing, early signs of subchondral osteosclerosis | The joint space is narrowed by 50% or more, osteophytes appear. | Almost complete absence of the joint space, significant deformation and sclerosis of the joint surfaces, areas of subchondral bone necrosis, osteoporosis |
A frequent complication of osteoarthritis of the knee joint is secondary reactive synovitis, which is characterized by the following symptoms:
- increasing pain;
- swelling;
- effusion into the synovial cavity;
- increased skin temperature.
Less frequent and more dangerous complications include: blockage of the joint, osteonecrosis of the femoral condyle, subluxation of the patella, spontaneous hemarthrosis.
Diagnosis of DOA of the knee joint
The diagnosis of gonarthrosis is based on the characteristic complaints of the patient, the changes detected during the examination and the results of additional tests.
To confirm osteoarthritis, it is prescribed:
- radiography of the knee joint in two projections (anteroposterior and lateral) - the most accessible way to confirm the diagnosis at the advanced stage of the pathology;
- Ultrasound - determination of the presence of effusion in the joint, measurement of the thickness of the cartilage;
- synovial fluid analysis;
- diagnostic arthroscopy (visual assessment of cartilage) with biopsy;
- Magnetic Resonance Imaging and Computerized Resonance Imaging (CT, MRI): The best method for diagnosing DOA in the early stages.
If the doctor has doubts about the diagnosis, he may prescribe:
- scintigraphy - examination of the joint after the introduction of a radioactive isotope;
- thermography - study of the intensity of infrared radiation (its strength is directly proportional to the strength of inflammation).
Treatment of gonarthrosis of the knee joint.
The treatment regimen for osteoarthritis combines several approaches: non-pharmacological methods, pharmacotherapy, and surgical correction. The proportion of each method is determined individually for each patient.
Non-pharmacological treatment
In the latest ESCEO (European Society for Clinical Aspects of Osteoporosis and Osteoarthritis) guidelines on how to treat osteoarthritis of the knee, experts place special emphasis on patient education and lifestyle modification.
The patient needs:
- explain what is the essence of the disease, prepared for long-term treatment;
- teach how to use assistive devices (canes, orthoses);
- prescribe a diet (for patients with a body mass index of more than 30);
- give a set of exercises to strengthen the thigh muscles and unload the knee joint;
- Explain the importance of increasing physical activity.
In the early stages of knee arthrosis, physiotherapy treatment methods give good results:
- massage;
- magnet therapy;
- UHF therapy;
- electrophoresis;
- hydrogen sulfide baths;
- paraffin applications;
- acupuncture.
Pharmacotherapy of gonarthrosis
The use of medications in DOA is aimed at relieving pain, reducing inflammation, and slowing down the rate of cartilage destruction.
Symptomatic treatment:
- analgesics;
- nonsteroidal anti-inflammatory substances (NSAIDs) from the group of COX-2 inhibitors in the form of tablets or suppositories;
- non-narcotic analgesics (with resistant pain syndrome).
Structure-modifying drugs (chondroprotectors):
- Chondroitin Sulfate;
- Glucosamine sulfate.
These drugs can be taken in the form of capsules in courses several times a year, injected intramuscularly or directly into the synovial cavity.
Local therapy includes near and intra-articular injections of glucocorticosteroids, hyaluronic acid preparations.
At stages I-II of DOA, an important place in complex therapy is the use of anti-inflammatory ointments, gels and creams based on NSAIDs. They help reduce the patient's need to take NSAIDs by mouth, reducing the risk of damage to the digestive tract.
Home remedies
The use of tinctures, decoctions, extracts, local applications of medicinal plants should be considered as auxiliary methods for the treatment of DOA, folk remedies cannot replace the therapy prescribed by the doctor.
Plants used in arthrosis: dandelion, ginger, Jerusalem artichoke, burdock, garlic, sea buckthorn.
Surgery
Surgical intervention may be necessary at all stages of gonarthrosis with insufficient effect of medical measures. The most common are endoscopic procedures, in the most severe cases the replacement of endoprosthesis is indicated.
Types of endoscopic interventions:
- review and rehabilitation of the joint: removal of inflammatory content from the synovial cavity, cartilage fragments;
- plasma or laser ablation - removal of mechanical obstructions in the synovial cavity;
- chondroplasty.
Corrective periarticular osteotomy is indicated for patients with early manifestations of axial limb deformity (not more than 15-20%).
The purpose of the operation is to restore the normal configuration of the joint, evenly distribute the load on the articular surface and remove damaged areas. This procedure allows you to delay arthroplasty.
Indications to replace the affected area (or the entire joint) with an artificial one:
- DOA grade II-III;
- severe axial deformity of the limb;
- aseptic necrosis of the subchondral bone layer;
- persistent pain syndrome.
Contraindications for knee arthroplasty:
- total damage to the joint;
- unstable ligamentous apparatus;
- DOA as a consequence of inflammatory arthritis;
- persistent flexion contracture, severe muscle weakness.
In this case, the patient undergoes arthrodesis - a comparison of the knee joint in a physiological position with the removal of the articular surfaces. This relieves pain but shortens the leg, causing secondary injuries to the contralateral knee, hip, and spine.
Prevention
Prevention of premature cartilage degeneration should begin in childhood.
Safety measures:
- scoliosis prevention;
- flat feet correction (shoes with arch supports);
- regular physical education (limit heavy sports);
- exclusion of fixed postures during work.