Gonarthrosis of the knee joint is the most common localization of a degenerative-dystrophic disease, which is characterized by progressive destruction of cartilage with subsequent changes in the articular surfaces, which are accompanied by pain and mobilityscaled down.
The disease is more likely to affect women over 40, especially those with overweight and varicose veins in the lower limbs.
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 tibio-femoral compartment (during movement it experiences a load exceeding body weight by 2-3 times).
In young patients, only one joint is more often destroyed - the right or the left (right or left gonarthrosis).
Causes of DOA of the knee joint
Several factors may be involved simultaneously in the development of degenerative cartilage changes:
- 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 articular 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 limbs;
- endocrine disorders (acromegaly, diabetes mellitus, amenorrhea, hyperparathyroidism);
- genetic predisposition (generalized forms of osteoarthritis);
- violation of type II collagen synthesis.
But in 40% of cases, it is impossible to establish the origin of the disease (primary osteoarthritis).
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, which are responsible for the stability of the structure of the collagen network, is reduced.
As a result, chondroitin sulfate, keratin, hyaluronic acid are removed from the mesh, and structurally defective proteoglycans can no longer retain water. It is absorbed by collagen whose swollen fibers lead to a decrease in the resistance of the 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 makes it difficult to supply nutrients to the cartilage and impairs the sliding of the articular surfaces during movement.
Pathology progression
In the future, the cartilage gradually thins, becomes rough, 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 tissue (osteophytes).
This reaction of the body is aimed at increasing the surface area of the articular surfaces and redistributing the load. But the presence of osteophytes increases discomfort, deformation and further limits the mobility of the limb.
Microfractures form in the thickness of the bone, injuring the vessels and leading to intraosseous hypertension. At the last stage of arthrosis, the articular 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 and slowly progressive course (months, years). The clinic develops gradually, without pronounced exacerbations. The patient cannot remember exactly when the first symptoms appeared.
Clinical manifestations of knee osteoarthritis:
- pain. At first diffuse, short (with prolonged standing, climbing stairs), and as the osteoarthritis progresses, the pain becomes local (front face and inside face of the knee), their intensity increases;
- local tenderness on palpation. Mainly inside the knee along the edge of the joint space;
- bite. In stage I it may be inaudible, in stage II-III it accompanies all movements;
- increase in volume, deformity of the knee. As a result of weakening of the lateral ligaments, a person develops an O-shaped configuration of the limbs (it is clearly visible even in the photo);
- restriction of mobility. At first there are difficulties in bending the knee, later - with extension.
Causes of pain in DOA:
- mechanical friction of damaged articular surfaces;
- increased intraosseous pressure, venous congestion;
- synovitis adhesion;
- changes in periarticular tissues (stretching of the capsule, ligaments, tendons);
- thickening of the periosteum;
- phenomena of dystrophy in adjacent muscles;
- fibromyalgia;
- compression of nerve endings.
Unlike hip osteoarthritis, DOA of the knee may show spontaneous regression of symptoms.
Clinical manifestations of knee osteoarthritis according to stage:
| Characteristics | I stage | II stage | Stage III |
|---|---|---|---|
| Pain | Short, occurs more often when the knee is extended (prolonged standing, climbing stairs) | Moderate, disappears after a night's rest | Pronounced, disturbing even at night |
| Mobility restriction | Invisible | There is an extension restriction, a slight lameness | Persistent flexion-extensor contractures, lameness |
| bite | Not | Sensitive to palpation during movement | remote crisis |
| Deformation | Faded away | Slight deviation of the axis of the limb forward, muscle wasting | Valgus or varus deformity. The joint is unstable, atrophy of the thigh muscles |
| X-ray image | Mild narrowing of the joint space, first signs of subchondral osteosclerosis | The joint space is narrowed by 50% or more, osteophytes appear | Virtually total absence of joint space, significant deformation and sclerosis of joint surfaces, areas of subchondral bone necrosis, osteoporosis |
A common 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;
- increase in skin temperature.
Less frequent and more dangerous complications include: locking 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 patient's characteristic complaints, changes detected during examination and the results of additional tests.
To confirm osteoarthritis, it is prescribed:
- X-ray 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 cartilage assessment) with biopsy;
- magnetic and computed resonance imaging (CT, MRI): the best method for diagnosing DOA in the early stages.
If the doctor has doubts about the diagnosis, he may be prescribed:
- scintigraphy: scan 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 the inflammation).
Treatment of gonarthrosis of the knee joint
The treatment regimen for osteoarthritis combines several approaches: non-drug methods, pharmacotherapy and surgical correction. The ratio of each method is determined individually for each patient.
Non-drug 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 particular emphasis on patient education andlifestyle change.
The patient needs:
- explain what is the essence of the disease, set up for long-term treatment;
- learn to use assistive devices (canes, orthoses);
- prescribe a diet (for patients with a body mass index above 30);
- give a set of exercises to strengthen the thigh muscles and unload the knee joint;
- explain the importance of increased physical activity.
In the early stages of knee arthrosis, physiotherapy treatment methods give good results:
- massage;
- magnetic therapy;
- UHF therapy;
- electrophoresis;
- hydrogen sulfide baths;
- paraffin applications;
- acupuncture.
Pharmacotherapy of gonarthrosis
Medication use in DOA is aimed at relieving pain, reducing inflammation, and slowing the rate of cartilage destruction.
Symptomatic treatment:
- painkillers;
- 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 sulphate.
These drugs can be taken in the form of capsules in cures 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.
In 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.
Folk remedies
The use of tinctures, decoctions, extracts, local applications of medicinal plants should be considered auxiliary methods for the treatment of DOA, folk remedies cannot replace the therapy prescribed by the doctor.
Plants used in osteoarthritis: dandelion, ginger, Jerusalem artichoke, burdock, garlic, sea buckthorn.
Operation
Surgical intervention may be required at all stages of gonarthrosis with insufficient effect of medical measures. The most common are endoscopic procedures, in the most severe cases, stent replacement is indicated.
Types of endoscopic procedures:
- revision and rehabilitation of the joint: extraction of the inflammatory contents of the synovial cavity, fragments of cartilage;
- plasma or laser ablation: removal of mechanical obstructions in the synovial cavity;
- chondroplasty.
Corrective periarticular osteotomy is indicated in patients with initial manifestations of axial limb deformity (no 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 eliminate damaged areas. This procedure allows you to delay arthroplasty.
Indications for replacing the affected area (or the entire joint) with an artificial one:
- DOA II-III Diploma;
- severe axial deformity of the limb;
- aseptic necrosis of the subchondral bone layer;
- persistent pain syndrome.
Contraindications to knee arthroplasty:
- total joint damage;
- unstable ligament apparatus;
- DOA as a result 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 damage in the contralateral knee, hip, and spine.
Prevention
Prevention of premature cartilage degeneration should begin in childhood.
Precautionary measures:
- prevention of scoliosis;
- correction of flat feet (shoes with arch support);
- regular physical education (limit heavy sports);
- exclusion of fixed postures during work.