Bow leggedness, medically known as genu varum, is a condition where the legs curve outward, creating a noticeable space between the knees when a person stands with their feet together. While often a normal part of infant development and frequently resolving without intervention, some cases may require medical evaluation and treatment.
Identifying Bow Leggedness
Genu varum is characterized by an outward bowing of the legs, meaning the lower leg angles inward relative to the thigh’s axis, giving the limb the appearance of an archer’s bow. When a child stands with their feet and ankles together, a distinct space remains between their lower legs and knees. This appearance can be exaggerated when walking.
Physiological genu varum is common in children under two years old and is considered a normal variation in leg appearance. This type of bowing often results from the baby’s position in the womb and typically resolves spontaneously by three to four years of age. However, bow leggedness can also be pathological, stemming from underlying conditions such as Blount’s disease, rickets, or certain skeletal dysplasias. Blount’s disease involves an abnormality of the growth plate in the upper shinbone, causing a sharp curve below the knees. Rickets, a bone growth problem, occurs due to a deficiency in vitamin D or calcium, which weakens bones and can lead to bowing.
Medical evaluation is advisable if bowing persists beyond two to three years of age, appears to worsen, affects only one leg, or is accompanied by pain or limping. An awkward walking pattern or intoeing (feet pointing inward) may also be observed. Diagnosis typically involves a physical examination, where a healthcare provider assesses leg alignment and measures the distance between the knees. X-rays may be ordered, especially if the child is older than two, if bowing is asymmetrical, or if an underlying condition like Blount’s disease or rickets is suspected. Blood tests can also help identify nutritional deficiencies that might cause rickets.
Conservative Treatment Options
For many children with physiological genu varum, observation is the primary approach. This type of bowing often corrects itself as the child grows, typically by three to four years of age, so medical professionals monitor its progression.
Bracing is an option for certain types of pathological bow leggedness, such as Blount’s disease, especially in toddlers. Braces apply corrective forces to guide bone growth and help straighten the legs. This treatment is generally more effective in younger children.
Physical therapy can play a supportive role, especially if muscle imbalances or gait issues contribute to the condition. Therapists design exercise programs to strengthen leg muscles, improve flexibility, and provide gait training for proper posture and weight distribution.
Nutritional interventions are important when rickets is the underlying cause of bow leggedness. Increasing dietary intake of vitamin D and calcium, often through supplements, can strengthen bones and help resolve the bowing. Addressing the deficiency can lead to significant improvement within weeks to months.
Surgical Solutions
Surgery is typically considered when conservative treatments are insufficient, bowing is severe, or the condition progresses despite non-surgical efforts. It is also an option for older children, adolescents, or adults experiencing significant functional impairment or pain due to the deformity. Surgical intervention aims to correct the alignment, improve function, and prevent long-term complications such as arthritis.
One common procedure for growing children is guided growth, also known as hemiepiphysiodesis. This technique involves placing small plates or screws on one side of a bone’s growth plate near the knee. This temporarily slows growth on the healthy side, allowing the other side to catch up and gradually straighten the leg. Once desired alignment is achieved, the plates or screws are removed.
For more severe cases, or when growth plates are closed in older children and adults, an osteotomy is performed. This procedure involves cutting and reshaping the bone, most commonly the tibia (shinbone) just below the knee. The surgeon realigns the bone to correct the curvature, then stabilizes it with internal fixation, such as plates and screws, or an external frame. This allows the bone to heal in the corrected position.
Recovery and Outlook
Recovery after treatment for bow leggedness varies based on the intervention. Following surgical correction, patients typically experience restricted weight-bearing for several weeks, often requiring crutches. For example, after an osteotomy, non-weight bearing might be required for four weeks, gradually progressing to full weight-bearing over several months. Pain management and activity restrictions are part of post-operative care to ensure proper healing.
Physical therapy is important for recovery, helping to restore strength, flexibility, and range of motion in the affected leg. Rehabilitation programs often begin shortly after surgery and continue for several months, involving exercises to strengthen muscles and improve gait. Regular follow-up appointments with X-rays monitor bone healing and ensure the correction is maintained.
The long-term outlook for individuals treated for bow leggedness is generally favorable, with most achieving good outcomes and leading active lives. Early diagnosis and appropriate intervention can prevent bowing from worsening and reduce the risk of future complications such as joint pain or arthritis. While complications like infection, delayed healing, or recurrence are possible, they are uncommon. Treatment helps restore proper leg alignment and improves both function and quality of life.