Bowed legs in adolescents may refer to several entities. Called genu varum in medical terminology, bowed legs in young children is usually due to positioning in the uterus. The curve in the lower legs due to this positioning typically corrects itself when the child reaches the age of two years.
Rickets may also cause bowing of the upper or lower legs. In the United States, this is exceedingly rare due to nutritional deficiencies since milk is supplemented with vitamin D; however, rickets may be caused by other underlying metabolic disorders.
Knock-knees or genu valgus refers to a clinical situation where the inner aspects of an adolescent’s knees touch each other when he or she is standing. After bowlegs in infants is corrected by age two years, there may be an over correction in young children and this can cause knock-knees. Normal alignment of the knees usually is attained between ages five and eight years. But it is normal to have some appearance of knock-knees during childhood. Specialists measure the angle of the knock-knees, and if the angle is larger than the normal ranges, then a genu valgus or true knock-knee situation may be present.
Femoral anteversion refers to a situation where the femur or upper leg bone is angulated toward the outside. If one is standing and twists the upper legs to the outside, then one can demonstrate anteversion.
Who is likely to develop bowed legs?
Adolescents who have rickets from nutritional or metabolic causes may have bowed legs. History of a fracture of an upper or lower leg bone may also cause bowed legs. A late onset of bowed legs can be seen in certain adolescents. In male teens who are markedly obese, and mostly in African Americans, one can see bowing of the lower legs. For many teens, however, there is no cause for the bowed deformity. Aside from an injury, knock-knees are due to the body’s over correction of bowed legs.
What are the symptoms of bowed legs?
If an adolescent has bowed legs due to rickets, then there usually are skeletal deformities. Teens may have bone pain or bone tenderness as well as pain in the hips. Muscular weakness may also be present, and the adolescent may have a waddling gait.
A teen with knock-knees may be relatively uncoordinated. This could result in higher chance of injury during athletics.
Patellofemoral pain may be caused by femoral anteversion. This is a pain around or beneath the kneecap that is more common in females and probably due to inflamed, irritated tissues. Some authorities believe biomechanical factors are implicated in the cause of this pain. Beside femoral anteversion, knock-knees may also be an implicating factor.
How are bowed legs evaluated?
A good history and physical examination should be performed. If rickets is suspected, then blood chemistries and x-rays may be ordered. Orthopedic specialists may be consulted if there is no metabolic cause of the bowed legs. Typically, x-ray studies are performed to measure the angle of the bowing. Orthopedic specialists also evaluate teens with knock-knees and persistent patellofemoral pain.
How are bowed legs treated?
If bowed legs are due to disease such as rickets, then the rickets should be medically evaluated and treated. Surgical correction of bowed legs may be necessary if the deformity is significant since the abnormal mechanical stresses from the curves may bring on arthritis of the leg joints. Knock-knees rarely require surgical correction.
Knee pain due to femoral anteversion may be treated by modification of the teen’s activities. While total cessation of sports is unnecessary, lessening repetitive knee flexion and extension may be helpful. Quadriceps exercises and straight leg raising may be helpful. Certain sports that include hill running, stadium running, hill climbing in cycling can worsen patellofemoral pain so cessation of these sports activities may be helpful. Also worn or poor quality athletic shoes can alter the mechanics of the lower extremity and contribute to patellofemoral pain.
How are bowed legs prevented?
Since most of these problems are developmental in nature, there is no prevention. Most if not all rickets due to malnutrition can be prevented by a diet with normal amounts of vitamin D and calcium. Periodic annual examinations would be helpful in identifying bowed legs.
Related topics:
Athletic injuries, calcium, exercise, hip displacement, knee disorders
