My Orthopaedic Surgeon

SOA Textbook Chapter in preparation
Torsion of the femur and tibia, as well as genu varum and genu valgum, are considered physiological variations of development that occur in normal infants and children. Infants commonly present with anteversion of the femur, medial tibial torsion and genu varum. With growth, the femoral anteversion decreases and the tibia rotates laterally. The genu varum gradually resolves and genu valgum develops. Abnormality of growth or disease can result in malalignment. Adequate management is based on an understanding of the cause and the natural history of the malalignment and the effectiveness of various treatments.

Authors Peter M Stevens, MD & Michael C Holmstrom, MD
Genu valgum is the Latin-derived term used to describe knock-knee deformity. While many otherwise healthy children have knock-knee deformity as a passing trait, some individuals retain or develop this deformity due to hereditary or genetic disorders or metabolic bone disease. The typical gait pattern is circumduction, requiring that the individual swing each leg outward while walking in order to take a step without striking the planted limb with the moving limb. Not only are the mechanics of gait compromised but also, with significant angular deformity, anterior and medial knee pain are common. These symptoms reflect the pathologic strain on the knee and its patellofemoral extensor mechanism.
Synonyms and related keywords: physiologic genu valgum, pathologic genu valgum, adolescent idiopathic genu valgum, knock-knee deformity, osteotomy, hemiphyseal stapling, vitamin D resistant rickets, vitamin D-resistant rickets, guided growth, 8-plate

Notes from FP Notebook

Genu valgum is frequently seen between the ages of 2 and 4 years. The condition is usually benign if symmetrical and independent of any other abnormality. The majority of cases resolve by the age of 6 years. The degree of genu valgum is assessed by measuring the inter-malleolar gap. This is the distance between the two malleoli when the knees are gently touching with the legs in adduction. An inter-malleolar gap of 4 inches (or less) at 4 years-of-age normally will correct with growth. If the condition is severe and progressive then rickets or scurvy must be considered.

Diagnostic and Therapeutic Alternatives
GR White and GA Mencio
Genu valgum is a common orthopaedic problem in children. The vast majority of cases are physiologic variants, which resolve normally. However, there are pathologic entities due to both focal and systemic processes in which the deformity often progresses and usually requires treatment. Differentiating between the two forms is facilitated by a thorough understanding of the natural history of the development of the tibiofemoral angle in children. In this review, an approach to the evaluation and diagnosis of genu valgum is presented, and therapeutic alternatives are discussed.(Abstract)

Genu valgum aka/or Knee joint valgus deformity * may be caused by or feature of Miscellaneous syndromes * Osteomalacia Congenital conditions * Fibular hemimelia Autosomal dominant conditions * Parastremmatic dwarfism * Pseudoachondroplasia * Wagner vitreoretinal degeneration syndrome Autosomal recessive conditions * Cohen syndrome * Ellis-van Creveld syndrome * Galactosamine-6-sulfatase deficiency * Sclerosteosis Nutritional conditions * Vitamin C deficiency Degenerative conditions * Osteoarthritis Autoimmune conditions * Rheumatoid disease

bilateral angular deformity: common and is most often physiologic; - normal knee alignment progresses from 10-15 deg of varus at birth to maximal valgus angulation of 10-15 deg at age of 3-3.5 yrs; - neutral alignment: - neutral femoral-tibial alignment occurs at 12-14 months old; - Greene: neutral femoral-tibial alignment at 14 months old; - unilateral genu valgum: often occurs from pathological conditions; - fibrous dysplasia - Ollier's disease - dyschondrosteosis - neurofibromatosis - physeal injury - idiopathic fibrous tether;

Genu valgum, commonly called "knock-knees", is a condition where the knees angle in and touch one another when the legs are straightened. Individuals with severe valgus deformities are typically unable to touch their feet together while simultaneously straightening the legs.