The so-called X-legs, also known medically as genu valga, are axial malpositions of the legs. This is caused by the knees moving more towards the center of the leg axis than the actual leg axis. Since this means that the load (especially the body weight) is not distributed over the joints as anatomically intended, problems, incorrect loading and ultimately damage to cartilage and bone can occur. Especially in small children, however, X legs can also occur temporarily during normal development. In such a case, the X-legs usually recede in the further course of development.
Causes
In childhood, X legs are mainly caused by congenital malpositions, which often result from a whole series of small deviations in growth and embryonic development. The most frequent cause is a malposition of the feet. In older children, previous incorrect weight bearing, lack of muscle strength or malpositions of neighboring joints can also be responsible. In addition, knock-knees can also be caused after operations, accidents, by inflammatory processes or some systemic diseases, such as muscle or nerve disorders. Rickets (vitamin D deficiency) can also lead to knock-knees, but is then accompanied by other complaints.
Diagnosis
At the beginning of the diagnosis, the patient’s medical history is taken, with questions about complaints, pain or functional disorders. Previous accidents or similar illnesses in close relatives can also provide indications of a malposition. Increased wear of the pants on the inside of the knees is often conspicuous.
During the physical examination, especially the leg axes, the length of the legs, the stability of the knee and menisci, and mobility are examined. The distance between both knees when standing straight can also give an indication. Then any disorders or complaints of the gait pattern are also assessed.
In general, the adjacent joints should always be examined as well. This is because X legs are a malposition of the knee, but the original problem can often also lie in the hip joint or in the arch of the foot. This examination can be supplemented by an x-ray of the knee, or a so-called still image of the whole leg and the adjacent joints.
