Abnormal axial positions
We call the advanced stage of cartilage destruction in the knee joint gonarthrosis. The causes are wear and tear due to age, metabolic disturbances (e.g., gout or diabetes), chronic joint inflammations (e.g., rheumatism), or late consequences of fractures or instabilities. The inner or outer joint area and the knee disk joint may be affected. The patient in this stage can no longer be permanently helped with arthroscopic operating procedures. Depending on the severity and the location of the arthrosis, open joint operations are necessary.
Abnormal axial position
Most frequently the arthrosis is localized on the inner part of the knee. Patients complain about pains during weight-bearing and while at rest. In the later stage, the joint swells and pains occur at night. The leg axis slowly changes, and a so-called bowlegged position occurs. The joint mobility decreases. A correct leg axis is absolutely necessary for the functioning of the knee joint. The shifting of the axis leads to an overload of the inner joint part, and the wearing away of the cartilage continues constantly. The x-ray image shows a narrowing of the inner joint cavity. We speak of a varus gonarthrosis. After removal of a meniscus, we find the most common causes to be one-sided wearing away of the cartilage layer. Without correction by an operation on the leg axis, the malformation and the pain symptoms increase.
Operating technique for correction of the axes
Operative straightening of the leg axis involves a procedure to maintain the joint, which reduces the pressure load of the damaged joint area and thus prevents or at least delays the progress of the arthrosis. The operating physician sees on the x-ray image the extent of the malformation of the knee joint, and calculates the desired angle of correction. The correct leg axis can be achieved by removing a wedge of bone on the outer head of the tibia. In the much less common knockknee malformations, correction takes place on the upper leg bone. The stability of the leg is maintained because our operating technique does not completely sever the bones. Partial load bearing with half the body weight is therefore possible immediately. In order to maintain the correction angle, the bones are stabilized with a metal plate. Additional joint imaging is necessary for axis correction in order to perform required operations on the cartilage or the meniscus (e.g., smoothing of the meniscus). An existing joint instability (cruciate ligament damage) can also be combined with the axis correction. Good results can be achieved with this operating method. A (short) inpatient stay is required.
Rehabilitation begins on the first day after the operation. The knee is also moved passively on a motorized splint. Immediate partial load bearing is possible. A period of 3-4 months should be reckoned on for rehabilitation.