gonarthrosis

Gonarthrosis: where does it originate?

The gonarthrosis is a joint wear (arthrosis) in the knee: The articular cartilage wears off. Later, adjacent joint areas such as bone parts are damaged.

Osteoarthritis always forms between two parts of the bone. The knee joint is formed by three bones:

• Femur (femur)
• Kneecap (patella)
• Tibia (tibia)

There is a joint connection between these bones. The tibia, with its middle (medial) and lateral (lateral) part, even forms two joints with the thigh. In technical terms this is called the different compartments in the knee.

Arthrosis forms in the knee

Osteoarthritis in the knee can affect one or more parts (compartments) of the knee joint:

• Gonarthrosis in 1 compartment (unicompartmental gonarthrosis): It exists either between kneecap and femur or between tibia and femur.
• Gonarthrosis in 2 compartments (bicompartmental gonarthrosis): The osteoarthritis affects the tibia and femur.
• Gonarthrosis in 3 compartments (tricompartimental gonarthrosis or pangonarthrosis): The joint wear affects all three parts of the knee joint.

The division into uni-, bi- and tricompartimental gonarthrosis is important if the joint wear is to be operated on.

Medial and lateral gonarthrosis

If the inner portion of the knee joint is affected by the wear, there is a medial gonarthrosis. If it is a knee osteoarthritis in the outer area, it is called a lateral gonarthrosis.

Activated gonarthrosis

A worn joint can easily ignite. Cartilage parts come off, cells are destroyed. They accumulate in the synovial fluid and attract inflammatory cells. From a simple gonarthrosis, an activated gonarthrosis develops. The knee joint and surrounding tissue can swell painfully. The activated gonarthrosis can, however, return to a non-inflamed osteoarthritis in the knee joint with proper therapy.

Gonarthrosis: symptoms

Knee wear does not always cause discomfort (such as pain); if so, it is called a symptomatic osteoarthritis in the knee.

Those affected report knee pain, for example when climbing stairs. In advanced gonarthrosis, persistent pain can also occur. The knee joint is less mobile. Gear insecurity can occur.

In many patients, the knee pain is also weather-dependent: they increase, for example, in cold or wet weather. The affected then report on “weather sensitivity”.

More about possible symptoms of gonarthrosis (and other types of osteoarthritis) can be found in the article Osteoarthritis symptoms.

Gonarthrosis: frequency

Knee joint arthrosis is the most common form of arthrosis in Germany. The information on frequency vary greatly. The reason is that there are no uniform criteria for the diagnosis of gonarthrosis. Most diagnoses are based on the radiological signs of osteoarthritis. These are indications of joint wear in X-rays, computed tomography or magnetic resonance tomography.

With age, the likelihood of knee osteoarthritis increases. Men are more frequently affected before the age of 45. Later, more women develop a gonarthrosis.

Gonarthrosis: diagnosis

If there is a suspicion of gonarthrosis, the doctor will first ask the patient to give a detailed description of his symptoms. He also asks about possible injuries or illnesses that currently exist or have occurred in the past. For example, meniscal damage or joint inflammation (arthritis) may favor knee joint arthrosis.

In the next step, the doctor will examine the knee joint and check its mobility. An X-ray and other imaging techniques help clarify a gonarthrosis.

How a gonarthrosis (and other types of arthritis) are diagnosed accurately, you read in the review arthritis.

Gonarthrosis: therapy

For gonarthrosis and other forms of osteoarthritis some general therapies apply. This includes, for example, to relieve the affected joint, but still to move regularly.

Heat applications such as heating pads or baths help against chronic arthritis pain. Acute complaints, on the other hand, can be alleviated with cold applications such as ice packs. If necessary, medicines for the pain are also prescribed.

More about general therapy measures for gonarthrosis and other forms of osteoarthritis you will find in the article Arthrosis.

Osteoarthritis exercises

To stop the progression of the disease, people with osteoarthritis should do knee exercises. These aim to strengthen the muscles on the knee. You can better absorb stress, which relieves the cartilage in the knee joint.

Watch out: The exercises must not harm the already damaged knee joint additionally! Therefore, body weight should not weigh on the knee during exercise. Especially suitable are therefore water aerobics and cycling.

Also useful is a special device training for people with osteoarthritis. However, knee exercises must always be arranged with a trained physiotherapist and must not be selected independently.

Gonarthrosis therapy: surgery without joint replacement

In knee osteoarthritis, it may be helpful to rinse the joint (lavage). In addition, rough cartilage surfaces in the joint can be smoothed (debridement). Both procedures are performed as part of a joint mirroring (arthroscopy).

Another option for gonarthrosis surgery is corrective osteotomy. The bones that build the joint are positioned differently. This should reduce the stress on the arthrosis areas.

More about lavage, debridement and corrective osteotomy in the article Osteoarthritis.

Gonarthrosis Therapy: Joint replacement surgery

Sometimes people with osteoarthritis can not adequately relieve knee discomfort through conservative or joint-preserving procedures. In case of severe gonarthrosis, the affected knee joint is sometimes replaced by a prosthesis:

If knee osteoarthritis affects only one compartment, a single-compartment endoprosthesis may be used. In a knee osteoarthritis in several compartments is a total endoprosthesis into consideration.

Unicompartmental endoprosthesis

A so-called unicondylar prosthesis primarily supplies a moderate degree of lateral or medial gonarthrosis. The partial denture replaces only the articular surface. The joint continues to be guided through the capsule-band apparatus. Such a partial denture is also referred to as a sled prosthesis.

Patients with a partial denture often assess the functionality of joint replacement better than people with a total endoprosthesis. Besides, they are usually happier with the result of the operation. However, a sled prosthesis is not an option for every patient. If one of the following points applies, the person concerned is more likely to come to a total endoprosthesis:

• Age over 65 years
• Gonarthrosis of the kneecap
• Damage (lesion) of the joint capsule or ligaments
• relevant joint misalignments of more than 10 degrees

Totalendoprothese

There are various forms of total endoprosthesis that can be used in gonarthrosis. Among other things, they differ in terms of material, structure and anchoring.

Younger patients are more likely to receive cementless prostheses. These can only be fixed in a stable bone. If necessary, they can be exchanged relatively easily.

In older patients, prostheses tend to be cemented. The reason: The bone structure is often loosened up with them, and another anchoring would be less stable.

In the case of gonarthrosis, two groups of total endoprostheses are distinguished:

• the uncoupled surface replacement
• the axle-guided prosthesis

Uncoupled surface replacement

In uncoupled resurfacing, only the articular surfaces are restored prosthetically. There is no firm connection between the prosthesis parts of the thigh and the tibia. In some cases, a so-called inlay is placed between these two parts of the prosthesis. As a result, the knee joint remains easily movable.

The prerequisite for this form of total endoprosthesis is that the natural capsule-ligament apparatus is sufficiently stable. Otherwise, an axis-guided prosthesis should be used.

Axis-guided total endoprostheses

In case of a severe gonarthrosis with a defective ligamentous apparatus, guided total endoprostheses are used. They have a firm connection between the two parts of the prosthesis on the femur and tibia. As a result, the force no longer needs to be held by the capsule or straps on the knee. However, the prosthesis is more heavily loaded and can relax more easily.

Gonarthrosis prosthesis: complications

Knee joint replacement with knee replacement, like all surgeries, involves general risks. These include, for example, bleeding or infection.

In addition, the prosthesis used can relax over time. Then usually has to be operated again. Sometimes the prosthesis has to be replaced.

A further danger after the insertion of a prosthesis in gonarthrosis concerns the kneecap: It can loosen, break or cause pain. In addition, the bony structures may break around the prosthesis. Physicians call this a periprosthetic fracture. Affected gonarthrosisPatients need to be re-operated.

Additional information

Book recommendations:

• Knee Vulnerability: Targeted Pain, Injury and Osteoarthritis, Kay Bartrow, 2015, TRIAS Circulation 1.
• Knee active: 100 exercises in osteoarthritis and after joint replacement, injuries, operations, Joachim Merk and Thomas Horstmann, 2013, S. Hirzel Verlag; Edition: 5