Bow Legged: Symptoms, Types, Causes and Treatment

Bow legs, also known as genu varum, are a condition where the legs curve outward at the knees, creating a noticeable gap between the knees when the ankles are together. This condition can affect people of all ages, from infants just learning to walk to older adults coping with joint changes. Understanding bow legs is crucial not only for early recognition and management but also for preventing potential complications in the future. In this article, we’ll explore the symptoms, types, causes, and treatments of bow leggedness, drawing on the latest research and clinical insights.

Symptoms of Bow Legged

Recognizing the symptoms of bow legs is the first step toward effective management. Symptoms can range from mild to severe, and while some individuals may experience only cosmetic concerns, others might struggle with pain or functional limitations. Knowing what to look out for helps in seeking timely advice and intervention.

Symptom	Description	Age Group	Source(s)
Outward Curving	Legs curve outward at the knees	Children, Adults	6 9
Gait Changes	Noticeable changes in walking pattern	Children	7 9
Knee Pain	Discomfort or pain around the knee	Adults	9
Progressiveness	Deformity can worsen over time	Children	1 3 7

Table 1: Key Symptoms

Understanding the Common Symptoms

The most immediately visible symptom of bow legs is the characteristic outward curvature at the knees, making it easy to spot in both children and adults. This curvature may be symmetrical (both legs) or, less commonly, affect just one leg 6 9.

Outward Curving of Legs

• The hallmark of bow leggedness is that the knees stay apart even when the ankles are together.
• In children, this outward bowing is often most evident when they start walking—sometimes as early as 10 months of age 7.

Changes in Gait

• Children with bow legs often develop a distinctive walking pattern, sometimes described as a waddling gait.
• This altered gait can be the first sign noticed by parents or caregivers 7 9.

Pain and Functional Difficulties

• While bow legs in young children are often painless, adults may experience chronic pain, particularly around the knees, due to abnormal joint stress 9.
• In severe or progressive cases, individuals may struggle with activities like walking or sitting cross-legged.

Progressiveness and Severity

• Some types of bow legs can worsen over time, especially if the underlying cause is not addressed.
• Early recognition is important as progressive bowing can lead to further deformities and complications 1 3 7.

Types of Bow Legged

Not all bow legs are the same. The underlying type helps determine both the cause and the best course of action. Let’s explore the main types seen in clinical practice.

Type	Description	Key Features	Source(s)
Physiologic	Normal variant in infants/toddlers; self-resolving	Symmetrical, resolves	6 7
Pathologic	Due to disease or structural abnormality	Progressive, severe	1 3 5 6
Blount’s Disease	Growth disorder of tibia causing severe bowing	Progressive, asymmetric	3 5 6
Dyschondroplasia	Cartilage to bone transformation issue	Severe, young children	1
Metaphyseal Chondrodysplasia	Genetic disorder affecting bone development	Familial, persistent	2 6

Table 2: Main Types of Bow Legged

Major Types Explained

Physiologic Bow Legs

• Common in infants and toddlers, physiologic genu varum is a normal part of growth.
• Usually appears when children start walking and gradually improves on its own by age 2-3 6 7.
• It is typically symmetrical and does not cause pain or functional problems.

Pathologic Bow Legs

• Pathologic bowing is caused by an underlying condition such as rickets, bone dysplasia, or trauma 4 6.
• These cases are often more severe, may be asymmetrical, and can worsen over time.

Blount’s Disease (Tibia Vara)

• Blount’s disease is a growth disorder affecting the inner part of the upper tibia, resulting in progressive bowing 3 5 6.
• It is more common in certain populations and can present as early as infancy.
• Radiographs show characteristic changes in the bone structure, and the condition can transition from mild to severe if untreated 3.

Dyschondroplasia

• A rare disorder where the transformation from cartilage to bone is impaired, usually localized to the upper tibial epiphysis 1.
• Presents with significant and progressive bowing, often in young children.

Metaphyseal Chondrodysplasia

• A genetic type of bow legs, such as Schmid metaphyseal chondrodysplasia, is linked with mutations like COL10A1 2.
• Family history and persistent bowing are typical, and diagnosis may require genetic testing.

Causes of Bow Legged

Understanding the causes behind bow legs is vital for effective management and prevention. The condition can arise from natural developmental processes, specific diseases, or genetic factors.

Cause	Mechanism/Explanation	Age Group/Context	Source(s)
Physiologic Growth	Normal development during early walking	Infants, Toddlers	6 7
Blount’s Disease	Abnormal tibial growth, especially medially	Children, Adolescents	3 5 6
Rickets	Vitamin D deficiency affecting bone mineralization	Children	4 6
Genetic Disorders	Mutations affecting cartilage/bone formation	Children, Familial	2 6
Dyschondroplasia	Impaired cartilage-to-bone transformation	Young children	1
Trauma/Injury	Damage to growth plates or bones	Any age	4 6
Osteoarthritis	Degenerative changes causing bowing in adults	Older adults	9

Table 3: Main Causes of Bow Legged

Key Causes in Detail

Physiologic Growth

• In healthy infants and toddlers, bowing often reflects the natural shape of the legs as they start bearing weight 6 7.
• This self-corrects over time as the child grows.

Blount’s Disease

• Also known as osteochondrosis deformans tibiae, Blount’s disease involves abnormal growth at the inner part of the tibia 3 5 6.
• The condition leads to progressive and sometimes severe bowing, often requiring intervention.

Rickets

• Rickets is caused by vitamin D deficiency, affecting bone strength and shape 4 6.
• The bones become soft and more prone to bending under the weight of the body.

Genetic Disorders

• Certain genetic mutations, such as in the COL10A1 gene, can impair the formation of bone and cartilage, leading to persistent and familial bowing 2 6.
• These cases may be recognized by family history and the persistence or progression of the deformity.

Dyschondroplasia

• This rare disorder causes localized impairment in the transformation of cartilage to bone, typically resulting in severe, progressive bowing in young children 1.

Trauma and Osteoarthritis

• Injuries to the growth plates or bones can result in abnormal growth patterns and bowing at any age 4 6.
• In older adults, osteoarthritis can lead to bowing due to uneven wear and joint degeneration 9.

Treatment of Bow Legged

Treatment for bow legs depends on the type, cause, and severity of the deformity, as well as the age and symptoms of the individual. Management ranges from observation and reassurance, to physical therapy, and, in some cases, surgical intervention.

Treatment Type	Application/Indication	Expected Outcome	Source(s)
Observation	Physiologic, mild cases in young children	Spontaneous resolution	6 7
Physical Therapy	Pain management, functional improvement	Improved mobility, less pain	9
Medical Therapy	Treat underlying rickets or metabolic issues	Correction of cause	4 6
Surgery	Severe, progressive, or structural cases	Mechanical realignment	3 5 8
Genetic Counseling	Familial/genetic cases	Informed management	2 6

Table 4: Main Treatment Options

Approaches to Treatment

Observation and Monitoring

• Most children with physiologic bow legs do not require any intervention. Regular monitoring during well-child checkups is recommended to ensure the deformity is resolving as expected 6 7.
• Simple clinical assessments and measurements can help differentiate between normal and pathologic cases.

Physical Therapy

• For adults or children experiencing pain or functional difficulties, physical therapy can help improve mobility, strengthen muscles, and reduce discomfort 9.
• Rehabilitation may include exercises, electrotherapy, and gait training, often resulting in significant improvement.

Medical Therapy

• When bow legs are caused by rickets or another metabolic disorder, treating the underlying issue (e.g., vitamin D supplementation) is crucial 4 6.
• Early intervention can prevent progression and help correct the deformity.

Surgical Intervention

• Surgery may be indicated for severe or progressive cases, particularly with underlying structural abnormalities such as Blount’s disease or congenital deformities 3 5 8.
• Procedures like double level tibial osteotomy can realign the limb and restore normal biomechanics, especially in cases where the deformity involves both the knee and ankle 8.
• In some cases, additional operations may be needed to correct deformities in the distal femur.

Genetic Counseling

• For families with a known genetic predisposition, genetic counseling can provide important guidance on management and expectations 2 6.

Conclusion

Bow legs, or genu varum, encompass a broad spectrum of conditions ranging from normal developmental variations to complex diseases and genetic disorders. Early recognition, understanding the underlying type, and appropriate management are key to achieving the best outcomes. Here’s a quick summary of the key points:

• Bow legs present with outward curving of the legs, often noticeable when standing or walking, and can range from mild to severe.
• Types include physiologic (self-resolving), pathologic (due to disease), Blount’s disease, dyschondroplasia, and genetic forms like metaphyseal chondrodysplasia.
• Causes vary from normal growth, Blount’s disease, rickets, and trauma, to genetic mutations and osteoarthritis.
• Treatment is tailored to the cause and severity: observation for mild cases, physical therapy and medical therapy for symptomatic or metabolic causes, and surgery for severe or progressive deformities.

With prompt diagnosis and the right approach, most people with bow legs can achieve excellent functional outcomes and minimize long-term complications.