Gonarthrosis of the knee joint is the most common localization of a degenerative-dystrophic disease, characterized by a gradual destruction of the cartilage with subsequent alterations of the articular surfaces, accompanied by pain and reduced mobility.
The disease is more likely to affect women over the age of 40, especially those with overweight and varicose veins in the lower limbs.
The knee joint consists of three compartments:
- medial tibiofemoral;
- lateral tibiofemoral;
- supra-patellar-femoral.
These compartments can be affected by deforming osteoarthritis (DOA) both individually and in any combination. 75% of all cases of gonarthrosis is the destruction of the medial tibiofemoral compartment (during movements it undergoes a load that exceeds the body weight by 2-3 times).
In young patients, only one joint is most often destroyed: the right or the left (gonarthrosis of the right or left side).
Causes of DOA of the knee joint
Several factors can be involved in the simultaneous development of degenerative changes in the cartilage:
- 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 the 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 arthrosis);
- 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 osteoarthritis).
Pathogenesis of gonarthrosis
initial state
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 collagen network structure, are reduced.
As a result, chondroitin sulfate, keratin and hyaluronic acid are removed from the mesh and structurally defective proteoglycans can no longer hold water. It is absorbed by collagen, the swollen fibers of which 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 cartilage is destroyed even faster. Joint capsule fibrosis develops. The change in the composition of the synovial fluid makes it difficult to supply nutrients to the cartilage and hinders the sliding of the joint surfaces during movement.
Pathology progression
In the future, the cartilage gradually becomes thinner, becomes rough, cracks are formed throughout its thickness. The epiphyses of the bones undergo increased load, which provokes the development of osteosclerosis and 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.
In the thickness of the bone, microfractures are formed, which damage blood vessels and lead to intraosseous hypertension. In 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 grows gradually, without pronounced exacerbations. The patient cannot remember exactly when the first symptoms appeared.
Clinical manifestations of gonarthrosis:
- ache. At first diffuse, short (with a prolonged standing position, climbing stairs), and with the progress of arthrosis, the pain becomes local (anterior and inner surface of the knee), their intensity increases;
- local sensitivity to palpation. Mainly inside the knee along the edge of the joint space;
- crunch. In phase I it can be imperceptible, in phase II-III it accompanies all movements;
- increase in volume, deformation of the knee. Due to the weakening of the lateral ligaments, a person develops an O-shaped configuration of the limbs (it is also clearly visible in the photo);
- mobility limitation. At first, there are difficulties in bending the knee, then - with extension.
Causes of pain in DOA:
- mechanical friction of damaged joint surfaces;
- increased intraosseous pressure, venous congestion;
- adhesion of synovitis;
- alterations of the periarticular tissues (stretching of the capsule, ligaments, tendons);
- thickening of the periosteum;
- phenomena of dystrophy in adjacent muscles;
- fibromyalgia;
- compression of nerve endings.
In contrast to coxarthrosis, DOA of the knee can show spontaneous regression of symptoms.
Clinical manifestations of gonarthrosis depending on the stage:
| Features | me on stage | II stage | III stage |
|---|---|---|---|
| Ache | Short, occurs most often when the knee is extended (long standing, climbing stairs) | Moderate, disappears after a restful night | Pronounced, disturbing even at night |
| Mobility limitation | Invisible | There is a limitation of extension, slight lameness | Persistent flexion-extensor contractures, lameness |
| nibble | Do not | Sensation on palpation during movement | creak from a distance |
| Deformation | Missing | Slight deviation of the axis of the limb anteriorly, muscle atrophy | Valgus or varus deformity. The joint is unstable, atrophy of the thigh muscles |
| X-ray image | Mild narrowing of the joint space, initial signs of subchondral osteosclerosis | The joint space is narrowed by 50% or more, osteophytes appear | Almost complete absence of 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, characterized by the following symptoms:
- growing 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.
Knee Joint DOA Diagnosis
Diagnosis of gonarthrosis is based on the patient's characteristic complaints, changes detected during the examination, and the results of further 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 in the advanced stage of the pathology;
- Ultrasound - determining the presence of effusion in the joint, measuring the thickness of the cartilage;
- synovial fluid analysis;
- diagnostic arthroscopy (visual assessment of cartilage) with biopsy;
- Computed and magnetic 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 - scanning 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-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 the Clinical Aspects of Osteoporosis and Osteoarthritis) guidelines on how to treat osteoarthritis of the knee, experts place particular emphasis on patient education and lifestyle modification.
The patient needs:
- explain what the essence of the disease is, predisposed for long-term treatment;
- teach how to use aids (stick, orthosis);
- 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 osteoarthritis of the knee, physiotherapeutic methods of treatment give good results:
- massage;
- magnetotherapy;
- UHF therapy;
- electrophoresis;
- hydrogen sulphide baths;
- paraffin applications;
- acupuncture.
Pharmacotherapy of gonarthrosis
The use of drugs in DOA is aimed at relieving pain, reducing inflammation and slowing the rate of cartilage destruction.
Symptomatic treatment:
- analgesics;
- non-steroidal 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.
In stages I-II of the DOA, an important place in complex therapy is the use of NSAID-based anti-inflammatory ointments, gels and creams. They help reduce the patient's need to take NSAIDs by mouth, thereby 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 as 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.
Surgery
Surgical intervention may be required at all stages of gonarthrosis with insufficient effect of medical measures. The most common are endoscopic procedures, in severe cases replacement of the endoprosthesis is indicated.
Types of endoscopic interventions:
- revision and rehabilitation of the joint: extraction of inflammatory contents 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 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 joint 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 limb deformity;
- aseptic necrosis of the subchondral bone layer;
- persistent pain syndrome.
Contraindications for knee arthroplasty:
- total damage to the joint;
- unstable ligament 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 joint 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.
Precautionary measures:
- prevention of scoliosis;
- correction of flat feet (shoes with orthotics);
- regular physical education (limit heavy sports);
- exclusion of fixed positions during work.