Angular Deformity of Knee/ Genu Valgum (Knock Knee)

Genu valgum, commonly known as knock knee, is a type of angular deformity that is characterized by the knees bending inward causing the ankles to remain apart while the knees touch or “knock” one another, even when a person is standing with their ankles apart. While it is often a normal part of development in children aged 2 – 5, it can persist into adolescence and adulthood due to genetic factors, nutritional deficiencies like rickets, or underlying health issues. For adults, genu valgum can result from injuries, infections, or arthritis

Treatment options in Cuba for genu varum is based on the underlying condition and can include bracing, physical therapy and surgery. If knock knees are left untreated, especially in severe cases or in adults, several complications can arise over time:

• Increased Joint Stress.
• Altered Gait.
• Muscle Imbalance.
• Reduced Physical Activity.
• Development of arthritis.
• Development of Secondary Conditions.
• Difficulty with Daily Activities.

Types and Causes of Knock Knee

Genu valgum, or knock knees, can be categorized into different types based on the underlying causes and characteristics of the condition.

• Physiological Knock Knee: Common in young children between ages 2 and 5 as a normal part of growth and development and often resolves naturally by age 7 without intervention.
• Pathological Knock Knee: Caused by underlying health conditions or structural abnormalities, including:
• • Rickets: A condition caused by a deficiency in vitamin D, calcium, or phosphate, leading to the softening and weakening of bones.
  • Blount’s Disease: A growth disorder of the shinbone (tibia) that causes the bone to grow abnormally.
  • Genetic Disorders: Conditions such as skeletal dysplasia, Marfan syndrome, and Ehlers-Danlos syndrome impact the structural integrity and alignment of bones, leading to abnormalities in the way the legs grow and develop.
  • Infections: Infections such as osteomyelitis, can disrupt the normal growth and development of bones.
  • Trauma: Injuries to the knee or leg bones that heal improperly.
• Compensatory Knock Knee: Develops as a compensatory mechanism due to issues in other parts of the body.
• Age-Related Knock Knee: Develops in older adults, often due to degenerative joint conditions.
• Post-Surgical Knock Knee: Occurs as a complication or outcome of previous knee surgeries.
• Incorrect Bone Healing: After fractures or surgical procedures.

Symptoms of Knock Knee

The most noticeable symptom of knock knee is a separation of a person’s ankles when their knees are positioned together. Other symptoms, including:

• Knee and/or hip pain
• Foot and/or ankle pain
• Stiff or sore joints
• Limp while walking
• Reduced range of motion in hips
• Difficulty walking or running
• Knee instability
• Progressive knee arthritis in adults

Diagnosis of Knock Knee 

Diagnosing genu valgum involves a comprehensive approach that includes a detailed medical history, physical examination, and, if necessary, imaging studies.

• Medical History:
  • Patient History: A detailed medical history, including questions about the onset of symptoms, duration, and any family history of similar conditions.
  • Developmental Milestones (for children): Assessment of the child’s developmental milestones, walking age, and any previous medical issues or nutritional deficiencies.
  • Medical Conditions and Lifestyle Factors (for adults): Evaluation of any existing medical conditions, such as metabolic bone diseases, arthritis, or previous surgeries. Occupational activities, physical activities, and nutritional habits that might contribute to the condition will also be assessed.

• Physical Examination:
  • Visual Assessment: Inspecting the legs for outward curvature, identifying the degree of bowing, asymmetry, and any visible deformities.
  • Gait Analysis: Observing the patient’s walking pattern to assess any abnormalities in gait to assess the impact on mobility and identify any compensatory mechanisms.
  • Joint Examination: Assessing the range of motion in the hips, knees, and ankles to check for stiffness, instability, or pain.
  • Muscle Strength and Tone: Assessing the strength and tone of the muscles around the knees and legs.

• Imaging Studies:
  • X-Rays: X-ray imaging is the primary in assessing the degree of bowing and identifying any underlying bone abnormalities, such as growth plate issues or bone deformities.
  • MRI (Magnetic Resonance Imaging): MRI imaging is carried out when soft tissue abnormalities, cartilage damage, or ligament issues are suspected.
  • CT Scan (Computed Tomography): Used more for complex cases where precise anatomical details are necessary.
  • Bone Density Scan (for adults): To assess bone mineral density and evaluate for osteoporosis or other metabolic bone diseases.
• Laboratory Tests
  • Blood Tests: To check for nutritional deficiencies (e.g., vitamin D, calcium, and phosphate levels) or markers of bone metabolism.

Treatment Options for Knock Knee

Determination for treatment for knock knees is based on the following:

• Severity of the condition.
• Underlying causes.
• Presence of any associated symptoms or complications.
• Age and overall health
• Skeletal age

Non-Surgical Options:

• Bracing and Orthotics: Bracing and orthotics are effective treatment options for both adults and children.
• For children: Custom braces and orthotic devices are frequently utilized to guide leg growth into a straighter position, aiding in the correction of alignment over time and preventing further progression of the condition.
• For adults: Custom orthotic devices, such as shoe inserts or custom orthotics, are employed to distribute weight more evenly across the legs, alleviate pain, and enhance gait by offering additional support and stability.
• Nutritional Supplements: Nutritional supplements are especially important for both adults and children when the condition is related to deficiencies like rickets, as they ensure adequate intake of vitamin D, calcium, and phosphate, which are crucial for bone health and development.
• Physical Therapy: Physical therapy focuses on strengthening the muscles surrounding the knees, hips, and legs to improve alignment and stability. Typically, the program includes:
  • Leg lifts
  • Hamstring stretches
  • Quadriceps strengthening exercises to enhance muscle strength and support proper leg positioning.
  • Balance and coordination exercises
  • Manual therapy

Surgical Options

Surgical treatment for knock knees in both children and adults is typically considered when conservative treatments like bracing, physical therapy, and orthotic devices are ineffective, or if the condition is severe. Surgical intervention involves various procedures based on the severity of the condition, the patient’s age, and the patient’s overall health.

• Guided Growth Surgery (for children): This minimally invasive surgery is primarily used in growing children with moderate to severe inward angling of the knees. The procedure involves placing small plates or screws on one side of the growth plate in the knee. This technique slows down growth on one side while allowing the other side to continue growing, gradually correcting the leg alignment.
• Osteotomy: This procedure is used for skeletally mature adolescents and adults and involves cutting and realigning the bones to improve leg alignment. Typically, the tibia (shinbone) is treated, but there are situations when the femur or both the femur and tibia are treated. The procedure involves creating a controlled break in the bone and repositioning it to achieve a straighter configuration, which is then stabilized using plates, screws, or external fixators.

In children, this procedure leverages their ongoing growth to facilitate correction, while in adults, it helps redistribute weight more evenly across the knee joint, alleviating pain and improving function.

• Knee replacement (for adults): Knee replacement is indicated when there is severe joint damage or osteoarthritis causing significant pain and functional impairment that has not responded to conservative treatments. involves removing the damaged knee joint and replacing it with an artificial implant. This procedure corrects knee alignment, alleviates pain, and improves joint function by reshaping the ends of the femur and tibia to fit the prosthetic components, which are then secured in place.
• Post-Surgical Rehabilitation: Physical therapy and pain management is an essential part of recovery after surgery with a focus on regaining strength, flexibility, and function.