What is gonarthrosis (degenerative osteoarthritis of the knee joint)?
Before talking about gonarthrosis, it is necessary to briefly mention the structure of the knee joint.
The knee joint is a hinge type joint consisting of 3 bones, femur, tibia and patella and it is the largest joint in the body. With the bone structures forming the joint, the ligaments, the joint capsule, and meniscus in the knee joint provide the stability of the joint.
The unique structure of the knee joint provides flexion and extension, abduction and adduction during flexion, and also internal and external rotation during movement.
The medial and femoral condyles forming the knee joint of the femur are asymmetrical in shape, size, and location. This asymmetry supports the working mechanism of the ties that contribute to the stability of the joint, as well as the movement and maintains the equilibrium between the ties at different spans. The groove called the trochlea between the two condyles forms the path in which the largest sesamoid bone of the body, called the patella, moves. In addition to being one of the bone structures that make up the knee joint, the patella strengthens the mechanism of extension of the knee.
The tibial joint surface is the structure that forms the joint with the femoral condyles. All movements of the knee joint take place between the joint surfaces of these two bones.
Apart from these bone structures, in the knee joint there are medial and lateral menisci, anterior and posterior cruciate ligaments, external and internal lateral ligaments. Diseases of these structures, apart from this, have a significant negative impact on the stability of the knee joint.
The knee joint is actively flexing 140 °, while the extension is 5 ° -10 °. The range of motion required for normal walking is 75 °, and 90 ° for running. The movement range for climbing up and down the stairs is 90 ° on average.
Osteoarthritis is a chronic degenerative process characterized by progressive cartilage destruction and loss, particularly in the load-bearing joints. It may develop as a primary, or secondary to another disease.
Primary osteoarthritis is generally hereditary and shows autosomal dominant inheritance in women and autosomal recessive inheritance in men.
Secondary osteoarthritis may be due to metabolic, traumatic or inflammatory causes.
Age, female gender and obesity, genetic structure, joint disorders, trauma, occupational difficulties, muscle weakness, lack of physical activity, smoking, diabetes are risk factors for osteoarthritis.
Gonarthrosis is osteoarthritis of the knee joint (Figure 1) and is more common in women. Medial femorotibial, lateral femorotibial or patellofemoral compartments may be involved either alone or in more than one compartment at the same time. Complaints vary depending on the area involved.
The main complaints are pain in the knee joint that increases with movement, decreases with rest, joint stiffness after long rest and tenderness around the joint.
In gonarthrosis, joint pain is the first complaint and pain is associated with movement at the beginning of the disease, but as the disease progresses, the pain persists. Pain is caused by structures other than cartilage, intraarticular and extraarticular. Later muscle weakness and joint contractures also contribute to pain.
Mismatches in the joint faces, muscle spasms, and contractures, free bodies and osteophytes are the mechanical causes of movement limitation.
Synovitis is more common in gonarthrosis than in osteoarthritis of other joints.
Examination findings vary depending on the severity of the disease and the compartment affected.
Routine radiological (X-ray) examinations may be inadequate to detect changes in cartilage during the initial stages of gonarthrosis. With the progression of the disease, radiological changes become evident. The deformation of the knee joint is detected by standing radiographs.
Treatment of Gonarthrosis
It is not possible to reverse the factors that cause gonarthrosis. However, symptoms can be treated with lifestyle changes, physical therapy, drug use or arthroplasty surgery as a last resort.
The first step in conservative treatment is to introduce the patient to his / her own disease and to tell them what to do. Since losing weight will reduce the burden on the knee joint, it will contribute to the patient’s complaints. In addition, it is very important to perform the exercises recommended by the doctor to maintain or increase joint range of motion and muscle strength.
Patients with gonarthrosis should not remain inactive. However, he should know to stop before the pain reaches the limit. Should not hesitate to use walking aids such as walking sticks. In this way, both the load on the knee joint will be reduced and a measure will be taken against the tripping and falling due to restriction in the range of motion. Choosing suitable shoes and a proper trail for walking is very important.
Patients will also benefit from medications to be used under the supervision of a doctor during this period and, if necessary, intra-articular injections (hyaluronic acid, PRP, stemcell). In addition, rehabilitation during this period will help patients maintain their range of motion and muscle strength.
The main indications for surgical treatment of gonarthrosis are pain that does not respond to medical treatment, night pain and disruption of sleep patterns, severe difficulty in maintaining daily activities, and severe limitation of movement.
Surgical treatment options for gonarthrosis are high tibial osteotomy (Figure 2), unicondylar knee arthroplasty (Figure 3) and trichompartmental (Figure 4) arthroplasty.
The indications for high tibial osteotomy and unicondylar knee arthroplasty vary, but are mainly suitable for patients with arthrosis findings in the medial compartment of the knee joint. Trichompartmental knee arthroplasty is performed if arthrosis of all (medial, lateral and patellofemoral) compartments is present.
Patients with gonarthrosis are often present when arthritic changes occur in all three compartments, and therefore total knee arthroplasty (total knee replacement) is very common.
The long-term results of total knee arthroplasty are very good and have a positive effect on the quality of life of the patient.
In conclusion, knee pain is a pathology that should be considered by patients. Early diagnosis and conservative treatment options will improve the quality of life of the patient and prolong the process leading to arthroplasty. Arthroplasty of the knee used in late-stage gonarthrosis will allow patients to return to an active life in competent hands.