Bowlegs – Causes, Symptoms & Therapy

Bow legs are referred to in medical jargon as genu varum or varus position of the knee. In the healthy leg, the vertical load axis runs right through the middle of the knee joint.

The inner angle between the upper and lower leg is about 186°. One speaks of bowlegs when the knee joint deviates outwards with regard to the load axis. The inner angle between the upper and lower leg is then smaller than the physiological 186° angle.

causes

Infants and young children naturally have bowlegs. However, by the age of three at the latest, these early childhood bowlegs should recede. If the skeletal development is normal, they even turn temporarily into knock knees (genu valgum), until the normal leg axis is finally formed from the age of 10.If bowlegs that are too severe or permanent occur in childhood, rickets is usually the cause. Rickets is a bone growth disorder caused by either a lack of calcium intake or a lack of vitamin D. Both lead to insufficient bone mineralization, to a disorganization of the growth plates and ultimately to the deformation of the long bones.

In addition to rickets, other bone diseases can lead to bowlegs, e.g. B. achondroplasia , osteogenesis imperfecta , tumors or trauma , especially if they affect the growth plates. In addition, bow legs can also simply be congenital. In adulthood, one-sided training can also lead to axial misalignments of the legs.

Bow legs are favored by sports in which the muscle group of the adductors on the inside of the thigh is trained more than the external abductors. The most famous example of such a sport is soccer. Paralysis that leads to muscular imbalances can have a similar effect and cause bowlegs as well.

symptoms and course

Bow legs lead to improper strain on the knees and feet. In the knee joint, the medial menisci and central cartilage areas in particular experience excessive stress. Overloading leads to signs of wear. The clinical picture is called varus gonarthrosis. Typical symptoms are knee pain under load and morning start-up pain. Overloading, arthrosis and pain can also occur in the ankle joints.

Bow legs often promote the development of flat feet. If there is only a unilateral bowleg, the spine is also affected by oblique loads. In contrast to the physiological bowlegs in early childhood, bowlegs never go away on their own in later life, but continue to worsen due to joint wear and tear.

Diagnose

Severe bowlegs can be identified by visual diagnosis. When a patient with bow legs stands upright with their ankles closed, their knees do not touch. In addition, the patient usually reports very typical symptoms such as medial knee pain.

To determine the exact extent of the deformity, an X-ray of the whole leg is taken . The physiological load axis is drawn in this image for comparison, so that the deviation of the bowlegs can be measured in degrees. Children must always be tested for hormonal and metabolic disorders .

treatment and therapy

The treatment of bowlegs depends on the cause, the extent of the deformity and the age of the patient. In the case of rachitic bowlegs, the underlying disease must first be treated with high doses of calcium or vitamin D substitution. Therapy for growing children is mainly based on individually fitted shoe inserts: Wedge-shaped inserts on the outside of the shoe force the leg into a supination position and lead to straighter growth over the long term.

Physiotherapy can complement the treatment. Orthopedic shoe adjustments or insoles can also help adult patients if there is only a slight deformity.In the case of severe, painful signs of wear and tear, an operation is usually necessary: ​​In what is known as an osteotomy, the surgeon cuts through the tibia below the knee joint and moves the lower leg outwards into a slightly overcorrected position. The construction is secured with titanium plates and screws. The metal parts remain in the body for a total of around 1.5 years, but the patient can put full weight on his leg again just 3 months after the operation.

Surgical correction can stop or slow down the wear and tear of the joints, but it cannot heal cartilage damage that has already occurred. Therefore, bowlegs should always be corrected as early as possible and not only when chronic pain is already present.

prevention

You can prevent bowlegs in childhood with an adequate supply of calcium and vitamin D. Athletes should pay attention to a balanced training that uses all muscle groups and does not allow any imbalances to develop. Since obesity puts strain on the joints of the lower extremities and increases the risk of bowlegs, healthy nutrition and endurance sports are also sensible preventive measures.