
Knee joint deformities in children (leg curvature)
General information about knee joint deformities
Knee joint curvature is characterized by a disturbance of the correct leg contour as a result of “X” and “O” shaped deformities of the femur and tibia, which form the knee joint, as well as an uneven distribution of soft tissue in the lower leg. This deformity can also occur when only the femur or tibia is curved. The curvature of the knee joints is not considered just a cosmetic defect, because if the load on the hip and knee joints is not distributed evenly, it can lead to the development of gonarthrosis and osteoarthritis.
Valgus and varus deformity of knee joints
In valgus (X) knee deformity, the knees are in contact with each other, while in varus (O) deformity, they are apart.

The figure shows a picture of normal, varus, and valgus knee joints
When the lower extremity is correctly positioned, the line drawn along the upper edge of the hip joint, runs between the I and II toes of the foot. Crossing beyond this line disturbs the healthy biomechanics of the limb. The ideal shape of the feet is characterized by spindle-shaped contours of the knee joints and the upper 1/3 of the tibia, as well as the inner edge of the foot.
In what forms does knee joint curvature occur?
Definition
Knee joint curvature can be true and false. True knee joint curvature is associated with a deformity of the tibia, and there are two variations of this curvature: the valgus (“X”-shaped) type and the varus (“O”-shaped) type.
In valgus deformity, the legs resemble the letter “X”. A slight deviation of the shins outward is considered normal, with an angle of 5-7 degrees for men, and 10 degrees for women. With “X”-shaped curvature of the legs, the external angle is greater than normal, when the knee joints are in contact, there is a deviation of the feet from each other for a long distance.
In the varus type of knee joint curvature, the legs take the contours of the letter “O”. This type of curvature manifests itself by an abnormal internal angle from the foot to the crotch. There are two forms of varus deformity: legs with the angle opening outward and deviation of the curvature apex backward with recurvation; legs with the angle opening backward and direction of the curvature apex forward with kyphosis.
True curvature of the knee joints has a very strong effect on the motor function and condition of the foot. Varus curvature of the knee joints leads to valgus deformity of the foot and development of secondary flatfoot in children. In valgus curvature of the knee joints, flatfoot is more common.
False curvature is formed not as a result of bone deformation, but because of the uneven distribution of the soft tissues of the lower leg. In such cases, when joining the legs, you can observe a gap between the soft tissues in the shin area. False curvature of the legs is considered only an aesthetic (cosmetic) disorder, and it can be removed by applying special exercises for the muscles. With a serious degree of damage, implantation of soft prostheses should be carried out.
What are the causes of knee joint deformities?
Knee joint curvature can be congenital or acquired. Secondary curvature is formed due to underdevelopment, as a child may suffer from rickets, inflammatory bone diseases and metabolic disorders. Congenital curvature of the knee joints is associated with hereditary factors and diseases of the woman during pregnancy, and it can also develop if the fetus was without air in utero, born early.
Diseases of the musculoskeletal system that affect mineral metabolism and the metabolism of other substances can further aggravate the condition in congenital deformities of bone, cartilage and muscle tissue, increases the degree (angle) of leg curvature. For this reason, children from an early age should be registered with an orthopedist.
In adolescence, the lack of certain factors can lead to a curvature of the bones of the lower leg. These factors include a lack of calcium in the diet, vitamin D, clean air and sunlight, as well as inadequate muscle strain. In adults, knee joint deformity most often occurs due to trauma, pathological processes in the hip and knee joints.
Treatment of curvature of knee joints
Such a problem as a curvature of the knee joints cannot be corrected (restored) if you do only physical exercises. Plastic surgery of contours of the lower leg (the use of soft prostheses) is used when the muscles of this area are underdeveloped, deformities and asymmetries. If it is impossible to correct the curvature of the knee joints with the help of plastic surgery contours or implants, orthopedic surgery is resorted to.
Surgical treatment is performed with a corrective osteotomy: the bone is first cut open, corrected and then fixed. In addition to correcting the curvature, this method also promotes growth.
During osteotomy, a wedge-shaped incision is made in the bone, then it is brought into the right position and fixed with a titanium plate and screws. For varus or O-shaped deformities, an osteotomy is performed on the tibia, and for valgus or X-shaped deformities, an osteotomy is performed on the femur. In order to increase the stability of the knee joint, in most cases osteotomies are performed along with reconstructive chondroplastic surgery. Reconstructive surgery should be performed after the completion of growth (after 18 years of age) and bone formation.

This x-ray shows surgery (osteotomy and fixation) to correct a varus knee joint deformity