Gonarthrosis, or osteoarthritis of the knee, is a degenerative condition caused by the progressive deterioration of articular cartilage. This smooth tissue covers the ends of the bones within the knee joint, allowing them to glide with minimal friction. As this protective layer wears away, the bones can begin to rub together. While frequently associated with aging, this condition can also develop in younger people, as the breakdown of cartilage outpaces the body’s ability to repair it.
Symptoms and Causes
The initial signs of gonarthrosis develop gradually, starting with pain that worsens with activity and improves with rest. Morning stiffness or discomfort after sitting is also common, improving after a few minutes of movement. As the condition advances, symptoms can include persistent swelling, a decreased range of motion, and a grinding or popping sensation known as crepitus. This reduced mobility can make daily activities like climbing stairs difficult.
The cause of gonarthrosis is the mechanical wear of the knee’s cartilage, which is categorized as either primary or secondary. Primary gonarthrosis is idiopathic, developing without a direct cause and is largely attributed to the cumulative effects of aging. Over time, the body’s ability to repair minor cartilage damage diminishes, leading to its gradual degradation.
Secondary gonarthrosis results from specific factors that accelerate cartilage breakdown. These include:
- Previous knee injuries, such as meniscus tears or ligament ruptures.
- Excess body weight, which places additional stress on the knee joints.
- A genetic predisposition to the condition.
- Certain occupations that involve repetitive knee bending or heavy lifting.
Diagnosis and Staging
A diagnosis for gonarthrosis begins with a physical examination. A physician will assess the knee for tenderness, swelling, and grinding sounds during movement. They will also evaluate the joint’s stability and range of motion to pinpoint the source of pain and rule out other potential issues.
Imaging tests are used to confirm a diagnosis. X-rays are the primary tool and can show a narrowing of the space between bones, indicating cartilage loss, as well as the formation of bone spurs (osteophytes). An MRI scan may be ordered for a more detailed view of soft tissues like cartilage, ligaments, and menisci.
Once diagnosed, gonarthrosis is classified by severity using a staging system like the Kellgren-Lawrence classification, which grades the condition from 1 to 4. Grade 1 represents minor changes with minimal symptoms. Grades 2 and 3 show more definite joint space narrowing and bone spur formation on X-rays, with more pronounced symptoms. Grade 4 signifies severe gonarthrosis, where little cartilage remains, and bone-on-bone contact causes significant pain and impairment.
Non-Surgical Treatment Approaches
Management of gonarthrosis focuses on alleviating pain and improving joint function through non-surgical methods. Lifestyle modifications are a starting point, with weight management recommended to reduce the load on the knee joint. Shifting from high-impact activities like running to low-impact exercises such as swimming or cycling can also help.
Physical therapy strengthens the muscles that support the knee, particularly the quadriceps. Stronger muscles absorb more shock and improve joint stability, relieving pain. A therapist also guides patients through exercises to improve flexibility and range of motion, making daily movements easier.
Over-the-counter pain relievers like acetaminophen and nonsteroidal anti-inflammatory drugs (NSAIDs) are common treatments for controlling pain and inflammation. For more significant discomfort, a doctor might prescribe stronger anti-inflammatory medications.
Physicians may also administer injections directly into the knee joint for targeted relief. Corticosteroid injections deliver a potent anti-inflammatory medication for rapid, though often temporary, relief from pain and swelling. Another option is hyaluronic acid injections, which supplement the joint’s natural fluid to provide lubrication and help bones move more smoothly.
Surgical Interventions
When non-surgical treatments no longer provide adequate relief for advanced gonarthrosis, surgery may be considered. The specific procedure recommended depends on the patient’s age, activity level, and the extent of the joint damage.
Arthroscopy
An arthroscopy is a minimally invasive procedure where a surgeon uses a small camera to view the inside of the knee. The joint can be “cleaned up” by trimming torn cartilage or removing loose debris.
Osteotomy
A more substantial surgery is an osteotomy, which involves cutting and reshaping the tibia (shinbone) or femur (thighbone). This realigns the knee to shift the body’s weight from the damaged portion of the joint to a healthier area.
Arthroplasty (Knee Replacement)
Arthroplasty, or knee replacement, is a common solution for severe gonarthrosis. In a total knee replacement, the surgeon removes damaged cartilage and bone, replacing them with artificial components. For individuals with damage confined to one area, a partial knee replacement may be an option.