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Leg axis correction for X and O legs
Repositioning osteotomy by the specialist from Vienna

Pronounced X legs and O legs can lead to significant pain. Wear and tear, discomfort and functional limitations can be further consequences of X and O leg malalignment. Therefore, a straight leg axis is a prerequisite for the optimal distribution of forces between the inner and outer components of the knee joint. I am your expert for leg axis correction! Contact me!


Beinachsenkorrektur Experte Wien

Why is the leg axis so important?

The leg axis is the imaginary line running through the middle of the leg from the hip joint to the ankle joint. This line is important because it helps to distribute the weight of the body evenly on the leg. If the leg axis is not properly aligned, this can cause uneven pressure on the knee joint, which in turn can cause pain and other problems.

There are several ways in which the leg axis can be misaligned. A common cause is the so-called “genu valgum”, in which the knees point inward when standing with the feet together (X legs). Another possibility is the so-called “genu varum”, in which the knees point outwards when standing with the feet together (O legs).


X legs | O legs - When is surgery necessary?
Dr. Martin Gruber clarifies

Complaints with a leg axis malposition

People with leg axis malalignment often complain of pain in the knee joint. The pain is usually worse when walking or standing for long periods of time. In some cases, the pain can be severe enough to limit walking or other activities.

In addition to pain, patients with leg axis deformity may also experience swelling of the affected joint. Swelling is usually worst after physical activity and can make it difficult to move the joint through its full range of motion. Over time, the joint may become stiff and difficult to move.

If you experience any of these symptoms, be sure to see a doctor so that the cause can be diagnosed and appropriate treatment can be given! Contact me now for an appointment!

How does the axial misalignment of the legs occur?

The leg axis can be affected by factors such as injury, arthritis, or birth defects. In some cases, the cause of the malalignment of the leg axis is unknown.

Articular cartilage, meniscal tissue, and the knee joint itself can be overly stressed when uneven load distribution occurs between the internal and external components of a joint. This usually leads to reduced load-bearing capacity and discomfort in the knee joint. If the damage and misalignment continue unchecked, the lateral ligaments on the other side of the knee will become increasingly stretched, causing pain in that area and instability.

Causes of leg axis malposition at a glance

Causes for X leg malposition

Beinachsenkorrektur bei X Beinen - Umstellungsosteotomie

The following causes can lead to a knock-kneed leg:

Causes for X leg malposition

Beinachsenkorrektur bei O Beinen - Umstellungsosteotomie

The following causes can lead to a bow leg:

Once an accurate diagnosis of the causes of your leg deformity is available, the necessary treatment can be suggested. I - Dr. Martin Gruber - am a specialist in orthopedics and a specialist in axis correction for leg obliquity and will work with you to find a suitable therapy option for you.

How is a leg axis malposition determined?

Leg axis malalignment is diagnosed by physical examination and imaging techniques. I look for signs of malalignment, such as bent legs or knee pain. X-rays are consulted to precisely define the patient’s malposition and record the degree of axial misalignment.

Contact me!

Would you like to have your leg axes examined in detail to determine whether you suffer from a leg misalignment and possibly have a leg axis correction performed? In my office in 1080 Vienna I make a comprehensive diagnosis and find together with you a suitable therapy option!

Beinachsenkorrektur bei Dr. Martin Gruber aus Wien

Conservative treatment for X and O legs

In the correction of leg axis malpositions, a distinction is made between treatments in adulthood and childhood. Since growth can correct leg deformities to some degree on its own, children are often waited until they are fully grown. In adults, orthopedic care, such as insoles or appropriate footwear, is often used.

Physiotherapy treatment to build up the knee, thigh and hip muscles is also recommended. If there are already inflammatory changes in the knee joint due to the increased load, measures such as hyaluronic acid injections or autologous blood therapies can be tried. In addition, the affected person should avoid excess weight and heavy lifting in order not to put additional strain on the knee joint.

Advanced axial malalignment always requires surgical bone realignment to prevent secondary damage such as osteoarthritis.

Autologous blood therapy

Leg axis correction during growth - epiphysiodesis

Dr. Martin Gruber während einer Beinachsenkorrektur in Wien

Epiphysiodesis is a surgical procedure to correct leg axis deformities during growth. This procedure involves cutting and realigning the bones in the legs. Epiphysiodesis can be used to treat knock knees, bow legs, and other malalignments of the leg axis. It can also help prevent further damage to the joints and bones.

Epiphysiodesis is usually performed on children and adolescents who are still growing, as deviation towards the X or O leg may occur at an early age. In the case of the bow leg, this can be pain on the inside of the knee or – in the case of the knock-kneed leg – disabilities when walking and running due to touching and stumbling.

In this operation, the growth of a bone on the corresponding side is prevented by a staple until the leg is back in a straight axis.

Leg axis correction by means of surgery - realignment osteotomy

If no improvement has been achieved by conservative methods over a long period of time, a bony realignment (osteotomy) can correct the axial malalignment.

An osteotomy is a surgical procedure in which a bone is cut and realigned. This can be done to correct a deformity, such as an X leg or an O leg. A realignment osteotomy can improve the alignment of the leg bones and relieve pain. It can also help prevent further damage to the joints and bones.

Dr. Martin Gruber während einer Beinachsenkorrektur in Wien

What happens during a conversion operation (leg axis correction)?

The surgery is performed by me under general or partial anesthesia in a hospital.

Depending on the type of malposition, the upper and lower leg bones (tibia) are reamed, slightly opened up and screwed into the new position during the realignment osteotomy. Special implants (titanium plates) and so-called angle-stable screws are used here. The gap in the boil grows closed and the leg stands straight. The advantage: patients can put weight on the leg immediately after the procedure.

What are the advantages of a leg axis correction or repositioning osteotomy?

My patients are generally satisfied with the results of the surgery. The surgery has the advantage of reducing pain and improving the load on the knee joint. It also ensures that the joint is preserved in the long term and that there is no wear and tear of the bones (arthrosis).

What happens if I leave a leg malposition untreated?

A pronounced leg obliquity can cause your joints to be loaded incorrectly, which can lead to other medical problems such as cartilage damage, wear and tear of the
or osteoarthritis.

Therefore, it is particularly important to clarify your complaints with your doctor in good time in order to avoid consequential damage! Contact me now to schedule an exam!

Follow-up treatment after surgical correction of the deformity (leg axis correction)

It is important that you follow your surgeon’s instructions for aftercare following leg axis correction. This will help ensure a successful outcome and quick recovery. After surgery, the treated area needs rest and relief above all. The physician’s follow-up instructions may include the following:

Frequently asked questions about X and O legs

There are several possible explanations for why women often have knock knees. One possibility is that women are on average smaller than men. This means that their bones are shorter and their joints are closer together, which can lead to misalignment of the legs. Another cause may be that women usually have a wider pelvis than men, with the thigh bone standing further inward in the hip joint (valgization).

Another possibility is that women wear high heels more often than men. Over time, this can also lead to a misalignment of the legs. Finally, pregnancy and childbirth can also cause a malposition of the legs. This is due to the extra weight and pressure on the joints and bones during pregnancy and childbirth.

There are several possible explanations for why soccer players are often affected by O legs. One possibility is that soccer players’ joints are more stressed when passing or shooting than in other sports. The muscles on the inside of the leg that are used in soccer movements are used more than the muscles on the outside of the leg. The stronger muscles bend the leg into its typical O-shape.


Surgical interventions in the knee – such as meniscus, cruciate ligament or cartilage operations – often do not lead to the hoped-for improvement if the legs are not straight. Joints remain unevenly and incorrectly loaded, and areas that have been operated on quickly wear out again. Therefore, leg alignment is often the prerequisite for a permanent rehabilitation of the knee joint in the first place.

My treatment spectrum

Other clinical pictures