Varus and Valgus Deformities: Understanding Bowlegs, Knock-Knees, Causes, and Treatments

What is a Vara Valga?

The term "vara valga" does not refer to a single anatomical structure or condition, but rather describes two distinct types of angular deformities of a joint: "varus" (inward angulation) and "valgus" (outward angulation), most commonly observed at the knee joint.

Understanding Angular Deformities

In the realm of exercise science, anatomy, and orthopedics, "varus" and "valgus" are critical terms used to describe deviations in the alignment of bones relative to a joint. These terms indicate the direction of angulation of the distal (farther) segment of a limb relative to the proximal (closer) segment. When observed, these deformities typically manifest as a visible bowing or knocking of the limb. While they can occur at various joints—including the hip (coxa vara/valga), elbow (cubitus varus/valgus), and ankle (talipes varus/valgus)—they are most frequently discussed and recognized in the context of the knee.

Defining Genu Varum (Bowleg)

Genu varum, commonly known as "bowleg," describes an angular deformity where the lower leg (tibia) angles inward relative to the thigh (femur), causing the knees to appear bowed outwards when the ankles are together.

• Anatomical Alignment: In genu varum, the mechanical axis of the lower limb (an imaginary line from the center of the hip to the center of the ankle) passes medial (inside) to the center of the knee joint.
• Weight Distribution: This alignment leads to increased compressive forces and stress on the medial compartment (inner side) of the knee joint.
• Musculoskeletal Impact: Over time, this can contribute to the accelerated degeneration of articular cartilage in the medial compartment, potentially leading to medial compartment osteoarthritis.

Defining Genu Valgum (Knock-Knee)

Genu valgum, often referred to as "knock-knee," is an angular deformity where the lower leg (tibia) angles outward relative to the thigh (femur), causing the knees to touch or almost touch when the ankles are apart.

• Anatomical Alignment: In genu valgum, the mechanical axis of the lower limb passes lateral (outside) to the center of the knee joint.
• Weight Distribution: This alignment places increased compressive forces and stress on the lateral compartment (outer side) of the knee joint.
• Musculoskeletal Impact: Similar to genu varum, this can contribute to the premature wear of articular cartilage in the lateral compartment, predisposing individuals to lateral compartment osteoarthritis. It can also be associated with patellofemoral pain syndrome due to altered quadriceps pull.

Causes of Varus and Valgus Deformities

The etiology of angular deformities can be diverse, ranging from normal physiological development to pathological conditions.

• Physiological Development: It is common for infants and toddlers to exhibit physiological genu varum (bowed legs) up to around 2 years of age, followed by a period of physiological genu valgum (knock-knees) between ages 2 and 6. Most children naturally correct these alignments as they grow.
• Pathological Causes:
  • Metabolic Bone Diseases: Rickets (vitamin D deficiency) is a classic cause, leading to weakened bones and deformities.
  • Growth Plate Disorders: Blount's disease, a condition affecting the growth plate of the tibia, is a common cause of progressive genu varum in children and adolescents.
  • Trauma: Fractures involving the growth plates (epiphyseal plates) in children can lead to angular deformities.
  • Osteoarthritis: Unicompartmental osteoarthritis, particularly in the medial compartment, can worsen existing varus deformity or induce it.
  • Rheumatoid Arthritis: Inflammatory arthritis can lead to joint destruction and subsequent deformities.
  • Infection: Osteomyelitis or septic arthritis can damage bone and growth plates.
  • Genetic Conditions: Certain skeletal dysplasias or genetic syndromes can predispose individuals to angular deformities.
  • Overweight/Obesity: Excess body weight can exacerbate or contribute to the progression of these deformities, especially in children.
  • Muscle Imbalances & Ligamentous Laxity: While not primary causes of structural bony deformities, these factors can contribute to joint instability and progression of symptoms.

Identifying Symptoms and Diagnosis

Recognizing varus or valgus deformities typically involves a combination of visual assessment, physical examination, and imaging studies.

• Visual Inspection: The most evident symptom is the visible angular deviation of the limb. For genu varum, the knees bow outwards; for genu valgum, the knees touch.
• Gait Abnormalities: Individuals may exhibit compensatory walking patterns, such as a waddling gait (valgus) or a stiff-legged gait (varus) to minimize discomfort or improve stability.
• Pain: Joint pain is a common complaint, often localized to the compartment experiencing increased load (medial knee in varus, lateral knee in valgus). Pain may worsen with activity.
• Instability: A feeling of the knee "giving way" can occur, particularly if associated with ligamentous laxity.
• Functional Limitations: Difficulty with activities requiring full knee extension or flexion, running, jumping, or prolonged standing.
• Diagnosis: A healthcare professional will perform a physical examination, assessing alignment, range of motion, and stability. Standing weight-bearing X-rays are crucial for accurately measuring the mechanical axis and degree of deformity. In some cases, MRI or CT scans may be used to assess soft tissue structures or complex bone morphology.

Potential Health Implications

Left unaddressed, significant varus or valgus deformities can lead to a cascade of musculoskeletal issues.

• Accelerated Joint Degeneration: The primary concern is the increased stress on one side of the joint, which accelerates the breakdown of articular cartilage and leads to early-onset or rapidly progressing osteoarthritis in the affected compartment.
• Ligamentous Imbalances: Chronic malalignment can lead to compensatory tightening or laxity of collateral ligaments (e.g., medial collateral ligament stretch in valgus, lateral collateral ligament stretch in varus).
• Patellofemoral Pain: Genu valgum, in particular, can alter the patellar tracking, increasing the risk of patellofemoral pain syndrome.
• Muscle Imbalances: The altered biomechanics can lead to compensatory muscle imbalances throughout the kinetic chain, affecting the hips, ankles, and feet, and potentially leading to pain in these areas.
• Functional Disability: Over time, pain and reduced mobility can severely impact an individual's ability to participate in daily activities, exercise, and sports.

Management and Treatment Approaches

Treatment strategies for varus and valgus deformities depend on the severity, cause, age of the patient, and presence of symptoms.

• Non-Surgical Management:
  • Observation: For physiological varus/valgus in children, regular monitoring is often sufficient as most cases resolve spontaneously.
  • Orthotics and Bracing: Custom shoe orthotics or knee braces (e.g., unloader braces for varus knees) can help redistribute forces and reduce pain.
  • Physical Therapy: Targeted exercises to improve muscle strength, flexibility, balance, and gait mechanics.
  • Weight Management: Reducing excess body weight can significantly decrease stress on the knee joints.
  • Pain Management: Over-the-counter anti-inflammatory drugs (NSAIDs) or corticosteroid injections may be used for symptomatic relief.
• Surgical Intervention:
  • Osteotomy: This is a common surgical procedure, especially for younger, active individuals with significant deformities. It involves cutting and reshaping the bone (e.g., high tibial osteotomy for genu varum) to realign the mechanical axis and shift weight-bearing to the healthier compartment.
  • Guided Growth (in children): For growing children, a less invasive procedure involves placing plates or screws on one side of the growth plate to temporarily slow growth, allowing the other side to catch up and correct the deformity.
  • Joint Replacement (Arthroplasty): For severe, end-stage osteoarthritis with significant deformity, total knee arthroplasty may be the most appropriate solution.

The Role of Exercise and Rehabilitation

While exercise cannot fundamentally change the bony structure of a varus or valgus deformity, it plays a crucial role in managing symptoms, improving function, and potentially slowing the progression of associated joint degeneration.

• Goals of Rehabilitation:
  • Reduce pain and inflammation.
  • Improve muscle strength and endurance around the affected joint and throughout the kinetic chain.
  • Enhance flexibility and range of motion.
  • Improve balance and proprioception.
  • Optimize gait mechanics and movement patterns.
• Targeted Exercise Strategies:
  • For Genu Varum: Focus on strengthening the vastus lateralis and lateral hamstrings, improving hip abductor strength (e.g., gluteus medius), and increasing flexibility of the iliotibial band (IT band).
  • For Genu Valgum: Emphasize strengthening the vastus medialis obliquus (VMO) and medial hamstrings, improving hip external rotator strength, and increasing flexibility of the adductor muscles.
  • Core Stability: A strong core provides a stable base for limb movement and can help optimize kinetic chain alignment.
  • Gait Retraining: Working with a physical therapist to analyze and correct walking patterns can reduce abnormal stresses on the knee.
  • Proprioceptive Exercises: Balance boards, single-leg stands, and other balance exercises can improve joint stability.
• Important Considerations: Exercise programs should be individualized and supervised by a qualified physical therapist or exercise professional to ensure proper form and avoid exacerbating the condition. High-impact activities may need to be modified or avoided depending on the severity of the deformity and associated symptoms.

When to Seek Professional Advice

It is important to consult with a healthcare professional, such as an orthopedic surgeon or physical therapist, if you or a child exhibit signs of angular limb deformity.

• Persistent Pain: Especially if it interferes with daily activities or sleep.
• Progressive Deformity: If the bowing or knock-knee appearance worsens over time, particularly outside the typical physiological developmental stages.
• Unilateral Deformity: If only one leg is affected, as this often indicates a pathological cause.
• Significant Functional Limitations: Difficulty walking, running, or performing other physical activities.
• Associated Symptoms: Such as limping, swelling, redness, warmth around the joint, or fever.

Early diagnosis and appropriate management are key to preventing long-term complications and maintaining optimal joint health and function.