Genu Valgum

Genu valgum (knocked knees) is part of the coronal plane deformities of the lower extremity. The majority of patients are asymptomatic and have no functional limitations. This activity reviews the evaluation and treatment of genu valgum and highlights the role of the interprofessional team in the care of patients with this condition.

Genu valgum or "knocked knees" are part of the coronal plane deformities of the lower extremity. The majority of patients are asymptomatic and have no functional limitations. This condition can be preceded by flat feet and occasional medial foot and knee pain. Children start developing physiologic genu valgum starting by age 2, and it becomes most prominent between ages 3 to 4. After that, it typically decreases to a stable, slightly valgus position by age 7 years. In the adolescent age group, minimal, if any, change in this alignment is expected. Intermalleolar distance has been used to assess the degree of genu valgum. It is the distance between the medial malleoli in a standing patient with touching medial femoral condyles. Intermalleolar distances greater than 8 cm is considered pathologic. Rarely, in cases where valgus alignment continues to increase, it can be associated with an out-toed gait, lateral subluxation of the patella, and rubbing of the knees together as the child ambulates.
Bilateral Genu Valgum:
Physiologic genu valgum
Skeletal dysplasias
Metabolic bone diseases
Lysosomal storage diseases
Unilateral Genu Valgum:
Most patients present to the clinic between ages 3 to 5 years for the evaluation of genu valgum. The most common site of pathologic deformity is the distal femur, however, it can arise from the tibia as well.
History and Physical
Most patients present to the clinic between ages 3 to 5 when parents generally become concerned about knocked kneed appearance. Bilateral genu valgum in this age group is typically physiologic but can also be secondary to skeletal dysplasia such as spondyloepiphyseal dysplasia and chondroectodermal dysplasia (Ellis van Creveld syndrome), metabolic bone diseases such as rickets (renal osteodystrophy and hypophosphatemic rickets), and lysosomal storage disease such as Morquio syndrome. Unilateral genu valgum is most often secondary to physeal or metaphyseal trauma. Radiographs should be assessed for physeal narrowing, premature closing, and the presence of growth recovery lines (Park-Harris lines), giving attention to their morphology.
Cozen phenomenon is a post-traumatic valgus deformity seen after proximal tibial fractures. Of note, this can be seen even in the presence of non-displaced fractures. The most accepted theory of this phenomenon is the increased vascularity that occurs during fracture healing resulting in medial metaphyseal overgrowth. Other causes of genu valgum include radiation, infection, and tumors (osteochondromas, multiple hereditary exostoses, fibrous dysplasia).

Gait and rotational profile analysis are important aspects in the workup of angular deformities and help providers to identify the etiology of angular deformities, especially in the pediatric population. Primary or true valgus deviations about the knee can present as a stance-phase valgus thrust as seen in metabolic bone disease like renal osteodystrophy and longitudinal deficiency of the fibula that is associated with lateral femoral condyle hypoplasia. Secondary or apparent valgus gait deviations are associated with both axial and sagittal plane deviations. For example, increased femoral anteversion has an apparent valgus angulation attributed to internal rotation of the distal femur. 

Radiographs are not indicated in children in the physiologic valgus phase. However, they are indicated in the setting of asymmetrical findings, excessive genu valgum clinically, age group beyond which is expected of physiologic changes, patients whose height falls below the tenth percentile for their age, and a history of trauma or infection. Radiographic assessment begins with obtaining weight-bearing long leg alignment images in which both patellae are facing forward. Coronal plane angulation of the lower extremities can be analyzed based on the deviation of the center of the knee from the mechanical axis and the tibiofemoral angle. The mechanical axis is a line connecting the center of the femoral head to the center of the ankle. In normal coronal alignment, the mechanical axis passes through the center of the knee. There is lateral and medial deviation of the center of the knee with respect to the mechanical axis of the lower extremity in genu varus (bowed legs) and genu valgum (knocked knee), respectively.
The tibiofemoral angle is the acute angle formed between the longitudinal axes of the tibial and femoral shafts. At birth, there is between 15 to 20 degrees of varus tibiofemoral angulation. As the child grows, this corrects to neutral by about age 2 and between 10 to 15 degrees of valgus tibiofemoral angulation between ages 3 and 4. At this point, the limb’s valgus angulation then starts to gradually decrease to approximately 3-5 degrees of valgus by age 7. This is the residual normal coronal plane angulation of the lower extremity that will be carried to adulthood and should not increase.
It is important to determine whether the deformity is primarily originating from the femur or tibia. This is done by measuring the mechanical lateral distal femoral angle (angle between the femoral shaft and the mechanical axis of the femur) and medial proximal tibial angle (angle between the tibial plateau and mechanical axis of the tibia). The normal range of these angles is between 85 and 90 degrees.

Deterrence and Patient Education
Most patients present to the clinic between ages 3 to 5 when parents generally become concerned about the knocked kneed appearance. Parents should be educated that genu valgum in this age group is often physiologic that improves spontaneously with age.
Enhancing Healthcare Team Outcomes
Genu valgum is often a clinical diagnosis. Patients with this condition are typically asymptomatic but may present with medial-sided knee and/or ankle pain. While a history and physical exam are sufficient for diagnosis, there are certain indications that warrant further evaluation for pathologic conditions. While the primary care provider is usually the first clinician involved in the care of these patients, it is important to consult with an interprofessional team Outcomes are improved with prompt consultations and good communication with subspecialty groups.
How The viyanacare can help you
 you will know that your feet need good care all the time, and proper foot healthcare looks at the bigger picture. Your feet are connected to the function of your knees, hips and lower back, and as sport expert we build better bodies from your feet up.

At The viyanacare, our team of experience, enthusiastic and highly qualified has worked with numerous professional sports athletes and recreational sport lovers. We will be happy to assess your Genu valgum, provide advice on useful exercises to adjust anything that sits outside the normal range
So if you have any questions about Genu valgum, please come and see us at The viyanacare site.