Knock Knees (Genu Valgum) in Children: Causes, When to Worry, and Treatment Options

How to fix knock knees in kids?

Addressing knock knees in children typically involves a multi-faceted approach, starting with professional diagnosis to differentiate between normal physiological development and cases requiring intervention, often emphasizing conservative management through targeted exercises, physical therapy, and lifestyle adjustments.

Understanding Knock Knees (Genu Valgum) in Children

What are Knock Knees? Genu valgum, commonly known as knock knees, is a condition where the knees angle inward and touch, or "knock" together, when the legs are straightened, while the ankles remain apart. This alignment discrepancy can be observed when a child stands with their feet together, revealing a noticeable gap between their ankles.

Normal Development vs. Concern It's crucial to understand that genu valgum is a common and often normal part of a child's growth.

• Physiological Genu Valgum: Most children naturally develop a degree of knock knees between the ages of 2 and 4 years as their legs grow and their musculoskeletal system matures. This is a normal phase of development, and in the vast majority of cases, the alignment spontaneously corrects itself by the time the child reaches 7 to 8 years old.
• When to Be Concerned: Persistent or worsening knock knees beyond the age of 7-8, asymmetry (one leg more affected than the other), pain, difficulty walking, or a rapid progression of the condition may indicate an underlying issue requiring medical evaluation.

Potential Causes While most cases are physiological, some can be pathological:

• Physiological Development: The most common cause, resolving naturally.
• Nutritional Deficiencies: Rickets, caused by severe vitamin D or calcium deficiency, can lead to bone softening and deformities like knock knees.
• Obesity: Excessive weight can place increased stress on developing knee joints, potentially exacerbating or contributing to genu valgum.
• Genetic Conditions: Certain genetic syndromes or metabolic bone diseases can predispose children to skeletal deformities.
• Trauma or Infection: Injury or infection to the growth plates around the knee can disrupt normal bone growth.
• Connective Tissue Disorders: Conditions affecting ligaments and joints can contribute to misalignment.

When to Seek Professional Guidance

Parents and caregivers should consult a healthcare professional if they observe any of the following:

• Age: Knock knees persist or worsen beyond 7-8 years of age.
• Asymmetry: One leg appears more affected than the other.
• Pain: The child experiences pain in the knees, hips, or ankles.
• Gait Issues: The child walks with an unusual gait, frequently trips, or struggles with physical activity.
• Rapid Progression: The condition seems to be worsening quickly.
• Short Stature: Knock knees accompanied by significantly shorter height for age.
• Underlying Medical Conditions: If there's a history of rickets, metabolic disorders, or other systemic diseases.

Healthcare professionals who may be involved include pediatricians, orthopedic specialists (pediatric orthopedists), and physical therapists.

Assessment and Diagnosis

A comprehensive assessment is essential to determine the cause and appropriate management.

• Clinical Examination:
  • Visual Inspection: Observing the child's stance, gait, and symmetry of the legs.
  • Measurement of Intermalleolar Distance (IMD): The distance between the inner ankles when the knees are touching. An IMD greater than 8-10 cm in an older child is often considered significant.
  • Range of Motion: Assessing the flexibility and strength of the hip, knee, and ankle joints.
  • Gait Analysis: Observing how the child walks to identify compensatory movements or inefficiencies.
• Imaging Studies:
  • X-rays: Standing long-leg X-rays may be performed to assess the precise alignment of the bones and identify any underlying bone abnormalities or growth plate issues.
  • Blood Tests: If nutritional deficiencies (e.g., vitamin D, calcium) or metabolic disorders are suspected.

Management and Treatment Approaches

The approach to fixing knock knees in kids depends heavily on the cause, severity, and the child's age. Most cases resolve with conservative management.

Conservative Management (Most Common)

• Observation: For physiological genu valgum in younger children, regular monitoring by a pediatrician is often the primary approach. This involves periodic check-ups to track the progression or resolution of the condition.
• Exercise and Physical Therapy: A cornerstone of conservative treatment for persistent or symptomatic knock knees. A physical therapist can design a targeted program focused on:
  • Strengthening: Muscles that help stabilize the knee and pull the leg into better alignment, such as the hip abductors (e.g., gluteus medius), hip external rotators, and the vastus medialis obliquus (VMO) of the quadriceps.
  • Stretching: Muscles that may be tight and contributing to the inward knee alignment, such as hip adductors, hamstrings, and the iliotibial (IT) band.
  • Proprioception and Balance Training: Improving body awareness and stability, which can enhance overall gait and posture.
  • Gait Retraining: Teaching the child proper walking mechanics to reduce stress on the knees.
• Orthotics and Bracing:
  • Foot Orthotics (Arch Supports): May be prescribed if flat feet (pes planus) are contributing to the knee valgus, as they can help improve the alignment chain from the foot up.
  • Night Bracing: In some cases, custom braces worn at night may be considered, though their effectiveness is debated and they are less commonly used than in the past.
• Nutritional Considerations: If rickets or other nutritional deficiencies are identified, supplementation with vitamin D and calcium will be recommended under medical supervision.
• Weight Management: For children with obesity, weight loss can significantly reduce stress on the knee joints and improve alignment.

Surgical Intervention (Rare) Surgery is typically reserved for severe cases of pathological genu valgum that cause significant pain, functional limitations, or progressive deformity, especially in older children approaching skeletal maturity.

• Guided Growth Surgery (Hemiepiphysiodesis): This is the most common surgical procedure for knock knees in growing children. A small metal plate and screws are temporarily placed on one side of the growth plate (epiphysis) near the knee (usually the inner side of the femur or tibia). This slows growth on that side, allowing the other side to catch up, gradually correcting the alignment as the child grows. The hardware is removed once the correction is achieved.
• Osteotomy: In older adolescents or when growth plates have closed, an osteotomy may be performed. This involves cutting and reshaping the bone (usually the femur or tibia) to correct the alignment, followed by fixation with plates and screws.

The Role of Exercise and Movement in Correction

A well-structured exercise program, guided by a physical therapist, is crucial for strengthening the muscles that support proper knee alignment.

Targeted Muscle Groups and Actions:

• Hip Abductors (Gluteus Medius, Gluteus Minimus): These muscles on the outside of the hip are vital for stabilizing the pelvis and preventing the knees from collapsing inward (hip adduction and internal rotation).
  • Exercises: Clamshells, side-lying leg raises, standing hip abduction with resistance band.
• Hip External Rotators (e.g., Piriformis, Obturator Internus): These muscles help rotate the thigh outward, counteracting internal rotation that often accompanies knock knees.
  • Exercises: Seated external rotation with resistance, standing hip external rotation.
• Vastus Medialis Obliquus (VMO): The innermost part of the quadriceps, crucial for tracking the patella (kneecap) and stabilizing the knee joint.
  • Exercises: Terminal knee extensions (straightening the last 15-30 degrees of knee extension), squats with focus on knee alignment over the second toe.
• Core Stabilizers: A strong core (abdominal and back muscles) provides a stable base for limb movement and improves overall posture.
  • Exercises: Planks, bird-dog, pelvic tilts.
• Ankle and Foot Stability: Addressing any ankle pronation or flat feet can improve the entire kinetic chain.
  • Exercises: Calf raises, single-leg balance exercises, toe yoga.

Importance of Proper Form: Emphasis must be placed on performing exercises with correct technique to ensure the targeted muscles are engaged and to avoid compensatory movements that could worsen the condition or lead to other issues. Supervision by a qualified professional is highly recommended.

Fun and Engaging Activities: For children, exercises should be made enjoyable and integrated into play whenever possible. Incorporate activities that naturally promote strength and balance, such as:

• Cycling (with proper bike fit)
• Swimming
• Dance
• Sports that encourage varied movements (e.g., soccer, basketball, but with careful monitoring for excessive stress)
• Balance games and obstacle courses

Lifestyle and Home Management Tips

• Footwear: Ensure children wear supportive shoes that fit well and provide adequate arch support, especially if they have flat feet.
• Activity Modification: Discourage prolonged W-sitting (sitting with knees bent and feet out to the sides) as it can exacerbate internal rotation at the hips and stress the knee joints. Encourage cross-legged sitting or sitting with legs extended.
• Parental Involvement: Consistency is key. Parents should encourage adherence to exercise programs and provide a supportive environment for active play and healthy habits.
• Monitor Progress: Regularly observe your child's gait and leg alignment, and communicate any changes or concerns with their healthcare provider.

Prognosis and Long-Term Outlook

The prognosis for genu valgum in children is generally excellent.

• Typical Outcomes: The vast majority of physiological knock knees resolve spontaneously as the child grows, requiring no specific intervention beyond observation. Even in cases requiring physical therapy, significant improvement is often seen.
• Potential Complications if Untreated (Rare for Physiological Cases): If severe pathological knock knees are left unaddressed, potential long-term complications can include:
  • Chronic knee pain
  • Patellofemoral pain syndrome (pain around the kneecap)
  • Increased risk of osteoarthritis in adulthood due to uneven stress on the knee joint
  • Difficulty with physical activities and gait abnormalities
• Ongoing Monitoring: Even after correction or resolution, periodic follow-up with a healthcare provider may be recommended to ensure continued healthy development and address any new concerns.

Conclusion

Knock knees in children are a common developmental phase that usually corrects itself. However, understanding when to seek professional medical advice is paramount. A comprehensive approach involving assessment by a pediatrician or orthopedic specialist, and potentially a physical therapist, is crucial for distinguishing normal development from conditions requiring intervention. With appropriate conservative management, including targeted exercises, lifestyle adjustments, and in rare cases, surgical intervention, the vast majority of children with knock knees achieve excellent outcomes, ensuring healthy musculoskeletal development and active futures.