How bow legs are fixed depends entirely on what’s causing them and the age of the person. Most children under two outgrow bow legs without any treatment at all. When bowing persists or appears in adults, the options range from targeted exercises and bracing to surgical correction, with the best approach determined by the underlying cause.
Why Bow Legs Happen
The most common cause in babies and toddlers is physiologic genu varum, a natural bowing that develops from being curled up in the uterus. The pressure of that cramped position causes the leg bones to develop with extra rotation, which is completely normal. These legs typically straighten on their own by age two as the bones grow and remodel.
When bowing doesn’t resolve by age two, or when it gets worse, other causes come into play. Blount’s disease is a growth plate disorder in the upper shin bone that prevents one side from growing properly. Rickets, caused by severe vitamin D or calcium deficiency, softens bones enough that they bend under body weight. Less commonly, bow legs result from fractures that healed at an angle, skeletal conditions like dwarfism, or even lead or fluoride poisoning. In adults, bow legs are often the result of untreated childhood conditions or osteoarthritis wearing down the inner side of the knee joint over time.
When Bow Legs Need Treatment
A simple way doctors assess severity is by measuring the gap between the knees when a child stands with their ankles together. A gap greater than 6 centimeters is considered severe and typically warrants further evaluation. Beyond that measurement, doctors look for bowing that’s getting worse rather than better, affects only one leg, or persists past age two.
For adults, the concern shifts from growth and development to joint damage. Persistent bowing concentrates weight on the inner part of the knee, which accelerates cartilage breakdown. If you’re experiencing knee pain, difficulty walking, or progressive changes in alignment, those are signs the bowing may need active treatment.
Exercises That Improve Alignment
Exercise won’t reshape bone in adults, but it can meaningfully change how the legs move and how forces distribute across the knee. A 16-week corrective exercise program studied in children with bow legs produced significant improvements in walking mechanics: internal rotation at the foot dropped by 53%, internal knee rotation decreased by 40%, and excessive hip rotation improved by 60%. These changes reduce the compensatory movement patterns that make bowing worse and contribute to joint pain.
The types of exercises involved focus on strengthening the muscles along the outer hip and thigh while stretching tight inner thigh muscles. Hip abductor strengthening, single-leg balance work, and targeted stretching of the hip rotators form the core of most corrective programs. For adults, these exercises won’t eliminate a structural bow, but they can reduce pain and slow down joint wear by improving how your leg tracks during walking and movement. A physical therapist can design a program matched to your specific alignment.
Bracing for Young Children
For children with early-stage Blount’s disease, bracing can work well if started early enough. The brace used is a knee-ankle-foot orthosis (KAFO), which holds the knee straight and applies a gentle outward force to encourage the growth plate to develop more evenly. Bracing is most effective in children under three years old with mild to moderate disease (early radiographic stages).
The success of bracing drops significantly in certain situations: children over three, those with severe obesity, and cases where both legs are affected. It’s also worth noting that studies on early-stage Blount’s disease have found that mild cases (stages I through III) sometimes resolve on their own at roughly the same rate whether a brace is used or not. This makes the decision to brace a nuanced one that depends on the severity and trajectory of the bowing.
Fixing Rickets With Nutrition
When bow legs are caused by rickets, the fix starts with aggressive vitamin D and calcium replacement. The global consensus treatment calls for a minimum of 2,000 IU of vitamin D daily for at least three months, with higher doses for older children: 3,000 to 6,000 IU daily for kids aged one to twelve, and 6,000 IU daily for those over twelve. Alongside vitamin D, a daily calcium intake of at least 500 milligrams is essential, whether from diet or supplements.
After three months, doctors reassess whether the bones are healing and whether longer treatment is needed. Once the deficiency is corrected, maintenance doses of 400 to 600 IU of vitamin D per day prevent recurrence. In many cases of nutritional rickets caught early, correcting the deficiency allows the softened bones to harden and straighten as the child grows, sometimes avoiding surgery entirely.
Guided Growth Surgery for Children
Children whose bowing won’t correct on its own have a unique surgical advantage: their bones are still growing. Guided growth surgery uses this to its benefit by placing a small metal plate with two screws across one side of the growth plate near the knee. The plate acts as a tether, temporarily stopping growth on the inner side while the outer side continues. Over months, the child’s own growth gradually straightens the bone.
This procedure is far less invasive than cutting and realigning bone. It works only while growth plates are still open, which means the window closes around age 14 for girls and 16 for boys. The surgeon needs to estimate whether enough growing time remains to achieve full correction. Once the leg is straight, the plate is removed and normal growth resumes across the entire growth plate.
For Blount’s disease specifically, guided growth using a plate on the outer side of the upper shin bone has become increasingly popular as a simpler alternative to traditional bone-cutting surgery. However, more advanced Blount’s disease may still require an osteotomy, particularly if the growth plate is already significantly damaged.
Osteotomy for Older Children and Adults
When growth plates are closed or the deformity is too severe for guided growth, the remaining option is osteotomy: surgically cutting the bone and realigning it. For Blount’s disease, this procedure works best when performed before age four in children with moderate disease, as earlier correction carries a lower risk of the bowing returning.
In adults, the most common version is a high tibial osteotomy, where the surgeon cuts the upper shin bone and opens a wedge to shift the leg’s weight-bearing line from the worn inner compartment toward the healthier outer side of the knee. This procedure is best suited for younger, active adults with damage limited to the inner knee compartment. It’s generally not recommended for people with arthritis affecting multiple parts of the knee, significant obesity, smokers, or those with stiff knees that can’t fully straighten.
What Recovery Looks Like
Recovery from a tibial osteotomy requires patience. You won’t be able to put any weight on the surgical leg for the first four weeks. After that, weight-bearing increases gradually over about two weeks until you’re walking fully on the leg again. The bone itself takes several months to heal completely, and most people return to full activity between three and six months after surgery. Physical therapy plays a central role throughout recovery, rebuilding strength and restoring normal movement patterns.
For children undergoing osteotomy for Blount’s disease, gradual correction using an external frame (a metal device attached to the bone through the skin) allows surgeons to simultaneously address multiple components of the deformity, including rotation, angulation, and any leg length difference. Surgeons often intentionally overcorrect slightly into a knock-kneed position, because there’s a known tendency for the bowing to partially return as the child grows.
Choosing the Right Approach
The path to fixing bow legs follows a clear logic. For babies under two with physiologic bowing, the answer is watchful waiting. For toddlers with early Blount’s disease, bracing before age three gives the best nonsurgical results. For children still growing, guided growth surgery offers correction with minimal disruption. For older children, teens, and adults whose growth plates have closed, osteotomy is the definitive fix. And for rickets, treating the nutritional deficiency comes first, with surgery reserved for cases where the bones don’t straighten after the deficiency is corrected.
Adults with mild bowing and no knee pain may benefit most from a structured exercise program that improves muscle balance and walking mechanics. Those with progressive knee arthritis from years of misaligned weight-bearing may need osteotomy to preserve the joint, or eventually knee replacement if the damage is advanced enough. The key variable is always what’s driving the bowing and how much it’s affecting function and joint health.