Bow-leggedness, medically known as genu varum, is a condition where the legs curve outward at the knees, creating a bow-like shape when standing with feet and ankles together. While this alignment is often a normal part of development in infants and young children, it can sometimes lead to discomfort or other health concerns.
Understanding Bow-leggedness
The appearance of bow-leggedness is characterized by an outward curve of the legs, where the knees do not touch even when the ankles are held together. In babies, this presentation is often a normal physiological development, typically resolving by 18 months to 4 years of age.
Beyond typical development, bow-leggedness can result from certain underlying conditions. Blount’s disease, a growth disorder affecting the shinbone’s growth plate, can cause progressive bowing. Rickets, a bone-weakening disorder due to insufficient vitamin D, calcium, or phosphorus, also leads to bowed legs. Other causes include genetic bone development disorders, improperly healed fractures, or conditions like lead or fluoride poisoning.
Current Pain and Associated Symptoms
For many individuals, especially young children, bow-leggedness does not cause immediate pain or discomfort, nor does it interfere with walking, running, or playing. However, in some cases, particularly as individuals age or if the bowing is significant, pain and other symptoms can emerge due to uneven weight distribution across the joints.
Pain often manifests in the knees, especially on the inner side, where increased pressure is placed. This uneven loading can also lead to discomfort in the hips and ankles. Individuals might experience stiffness in the affected joints or a limited range of motion. An altered or waddling gait, as well as knee instability, may also be noticeable.
Long-Term Health Considerations
The prolonged presence of bow-leggedness, especially when it is more pronounced, can lead to significant long-term health concerns. The uneven distribution of stress across the knee joint places a disproportionate load on the inner, or medial, compartment of the knee. This consistent, abnormal mechanical stress can contribute to the gradual wear and tear of the cartilage in this area.
Over time, this increased strain raises the risk of developing osteoarthritis, specifically in the medial compartment of the knee. Osteoarthritis is a degenerative joint condition where the protective cartilage that cushions the ends of bones wears down, leading to pain, swelling, and reduced joint function. The progression of this condition can impact mobility and overall quality of life, potentially leading to chronic pain and difficulty with daily activities.
When to Seek Professional Advice
It is advisable to consult a healthcare professional if bow-leggedness persists beyond early childhood, typically after age 2 or 3, or if it appears to worsen over time. Other indicators for seeking medical evaluation include persistent pain in the knees, hips, or ankles that is not related to an injury, or if only one leg is affected (unilateral bowing). Difficulty walking, a noticeable limp, or reduced range of motion in the joints also warrant professional assessment.
A doctor will typically perform a physical examination to observe the leg alignment and gait, and may measure the distance between the knees. Imaging tests, such as X-rays, might be ordered to assess bone structure and identify any underlying causes like Blount’s disease or rickets, especially if the bowing is severe or persists past certain ages. Management approaches can range from observation for physiological bowing to physical therapy, bracing, or, in more severe cases, surgical options like osteotomy to realign the leg.