Symptoms
Generally speaking, pain is the first thing that occurs. Due to the malposition of the legs, the knee is constantly under incorrect load. In the case of bandy legs, the inner side of the knee joints is the most stressed.
This leads to increased and above all early wear and tear of the knee joint on the inner side. The meniscus (especially the inner meniscus) and the cartilage suffer most. It is not only in the knee joint that problems arise.
Also knee-lowering feet can develop. This also serves to compensate, i.e. to correct the malposition of the legs. The foot bends outwards, so that the inside of the foot points too far down. During the clinical examination of the knee joint, tension and pressure pain, especially of the outer ligament, and typical symptoms of arthrosis (joint effusion, rubbing in the knee joint, pain in movement and strain) can be detected.If the so-called genu varum is only present on one side, this can lead to a lateral misalignment of the spine via a pelvic obliquity in order to compensate for the pelvic obliquity. Because of these deformities, children must be presented to a doctor (preferably an orthopedic specialist).
Diagnosis of bow legs
The diagnosis is of course made clinically in pronounced forms. Here the malposition can be easily recognized from the outside. In lighter forms, the X-ray image can be helpful.
In this case, the thigh bone, the knee joint and the ankle joint are x-rayed in a so-called axial image. To objectively record the extent of the deformity, an imaginary line is drawn from the femoral neck of the femur through the knee joint to the ankle joint. Normally, this line passes through the middle of the knee joint.
In bow legs, this connecting line hits the knee joint too far inwards, i.e. towards the other leg. A further diagnostic possibility exists through a running analysis. The therapy of bow legs depends strongly on the age of the patient, as well as on their causes and the extent of the malposition.
In infancy bow legs are part of the normal development. An excessive degree of malalignment is often due to a disturbance in bone growth (rickets) caused by a lack of vitamin D or a disturbance in the absorption of calcium in the intestine. The therapy therefore consists of a high dose of calcium or vitamin D. If the knee malposition is only slightly pronounced, it is possible to treat it conservatively, i.e. non-operatively.
In most cases, individually adapted insoles are used. These are wedge-shaped elevations of the outer edges of the shoe, forcing the knee into a position tilted towards the center and thus straightening the leg axis as a whole. Especially for children, but also for adults, wearing these insoles daily for many years promises good therapeutic success.
This therapy is often supplemented by physiotherapeutic exercises. Since there is a risk of severe and painful long-term damage (signs of wear and tear) to the knee joint, conservative therapy is usually no longer sufficient for more severe forms of bow legs (genu varum). A surgical intervention, the so-called repositioning osteotomy, is necessary to permanently correct the malposition of the leg axis.
The tibia is cut through and the leg is brought into a straight position by removing a wedge-shaped piece of bone on the outside of the tibia or by spreading the end of the bone on the inside. Titanium plates and screws are used to stabilize the tibia. The separated bone ends grow together without scarring over the next months to years. Full loading of the leg is possible again after about 3 months.
