Having bowlegs is a normal part of physiological development for most babies and toddlers. When that’s the case, pediatricians typically allow it to run its course, according to Christine Caltoum, MD, a pediatric orthopedic surgeon with Riley Hospital for Children at Indiana University Health.
That approach may shift if a physician suspects an underlying condition like Blount’s disease or rickets, both of which can cause bowlegs. “In Blount’s disease, abnormal development of the inside part of the tibia’s growth plate stunts growth,” Caltoum says. “That can lead to ongoing problems that won’t get better without intervention because it’s not physiological.”
A risk for abnormal development from Blount’s disease often comes from a combination of two factors:
- when children walk at an early age—eight or nine months
- when children are overweight
African American children are also more prone to Blount’s disease, suggesting probable genetic causes. “One reason we think Blount’s disease occurs is from abnormal stress on the inside part of the growth plate of the tibia," Caltoum says. "When a child walks early, at 8 to 10 months, the legs are normally somewhat bowed. The combination of physiologic bowing at a young age, and increased weight, stresses the growth plate. This combination can adversely affect growth.”
Bowlegs can also be caused by abnormal metabolism of vitamin D, or by rickets. While rickets can result from a lack of calcium and vitamin D in the diet, or nutritional rickets, Caltoum says there are other kinds, too. The underlying cause of rickets may stem from an inability to properly metabolize calcium and vitamin D. Depending on the cause, better nutrition or medication can help those patients.
Surgical intervention for bowlegs is rarely necessary. Caltoum says most patients have physiologic bowing, and will outgrow it.
In some cases, surgical treatment is needed. Surgeons manipulate growth plates to promote faster growth on one side of the growth plate. This allows the legs to gradually straighten as the child grows. In older children or in more advanced conditions, surgeons can also perform osteotomies, where the bone is cut and repositioned.
Why worry about bowlegs or knock-knees, especially if there isn’t an underlying abnormality of the bone? One reason to be concerned is that children who don’t achieve a normal leg alignment may suffer long-term consequences as adults, according to Caltoum.
“Whether you are bowlegged or knock-kneed, every time you take a step, your weight goes through your leg in a certain way,” she says. “If the weight is always applied on the inside or outside part of the knee, over a lifetime, it can lead to premature wear on the inside or outside part of the knee, depending on your condition.”
For an appointment with a physician specializing in pediatric orthopedics, call 317-948-2550.