Coronal plane deformity around the knee in the skeletally immature population: A review of principles of evaluation and treatment

Table 1 Principal causes of pathological genu varum and genu valgum

Genu varum	Genu valgum
Idiopathic
Tibia vara (blount disease)
Infantile form
Adolescent form
Post-traumatic
Physeal bar
Malunion
	Cozen’s phenomenon
Metabolic
Rickets
Renal disease
Local disorders
Infectious
Tumor or tumor-like lesion
Generalized disorders
Metabolic (e.g., rickets, renal osteodystrophy)
Constitutional disease of bone (i.e., bone dysplasia)
Juvenile arthritis
Neuromuscular

Table 2 Main differences between infantile and adolescent forms of Blount disease

		Infantile form	Adolescent form
Age (yr)	< 5		> 10
Clinical features	50% bilateral, overweight, lateral thrust during gait, possible internal rotation of the tibia		Usually unilateral, overweight/obese, male predominance
X-RAY appearance	Varus angulation at the epiphyseal-metaphyseal junction, metaphyseal beaking with apparent fragmentation, medial physeal line widening and irregularity; lateral tibial subluxation; possible compensatory distal femur valgus		Widening of the proximal medial physeal line, normal shape of the proximal tibial metaphysis; possible presence of distal femur varus and compensatory distal tibial valgus
Natural history	Depending on the stage (spontaneous resolution is possible)		Usually progressive without spontaneous resolution
Treatment options	Depending on the stage		Surgery only