Genu_valgus__genu_varus.ppt 24n21

GENU VALGUS & GENU VARUS

Natural History of normal evolution of the alignment of the lower limbs Bowlegs in new born and infant With medial tibial torsion = fetal position

Becomes straight by 18/12 By 2 or 3 genu valgus develop (avg. 12°)

By 7 spontaneous correction To the normal of adult valgus ( 8°♀ and 7°♂)

Persistent genu varum • Worried parents

• About 3 years old +bow legs +mild lateral thrust at the knees + in-toeing • Assessment: - History - etiologic factors

Examination • Height • See ( front, back & side) • Measure   

IC distance, lateral thigh-leg angle, center of gravity

• Site of varus

Causes • • • •

Lateral ligament laxity Blount’s disease Congenital pseudoarthrosis of tibia Coxa vara

In ligamentous laxity notelat.Widening Of knee ts

In Blount angulation at med.tib metaphysis

In cong. Pseudarthrosis of tibia,the angulation is in the distal ⅓

In coxa vara ,angulation at the neck shaft level

• Gait: intoeing, lateral thrust-the fibular head and upper tibia shift laterally in Blount due to laxity and incompetence of the lat. Collat. Lig.

• Stability • Symmetry • Level of fibular head, normally at the level of the upper tibial growth plate, while it is proximal in Blount, cong.longitudinal dificiency of the tibia and achondroplasia

X-ray • 3 years and older • Getting worse • Abnormal site of angulation • Large physis and epiphysis • History – taruma, infection, possible metal intoxication(lead or floride)

Metaphysial/diaphysial angle ≥ 18°

Finding • Metaphysis, thick and frayed in rickets

• In physiologic genu varum no intrinsic bone disease, gentle curve, medial cortices thickening, horizontal t lines of the knee & ankle are tilted medially

Knock Knees / Genu Valgum • Legs are bowed inwards in the standing position. Bowing occurs at or around the knee. On standing with knees together, the feet are far apart.

Investigations 1 • Measurement of intermalleolar distance. i.e Distance between two malleoli when the knees are gently touching with legs in adduction. • Up to 3 and a half inches (9 centimeters) with child lying down is acceptable. • 75% of children aged 2 - 4 years have some degree of intermalleolar separation.

Investigations2 • Intermalleolar separation under 3 inches is normal at any age. • Periodic observation and measurement if less than 3.5 inches. • If > 3.5 inches, need AP X-Ray with both legs on same film for knee deformity, hip and ankle ts and view of both long bones.

Indicators of Serious Disease • Pronounced asymmetry • Short stature • Other skeletal abnormalities • Intermalleolar separation greater than 3.5 inches

Aetiology • Developmental • Miscellaneous syndromes e.g Rickets (Alk Phos raised, with x-ray changes) • Rare Genetic disorders e.g Cohen Syndrome • Nutritional conditions e.g Vitamin C deficiency • Autoimmune e.g RA • Degenerative e.g OA

When to refer • • • •

Age > 7 with knock knee Unilateral problem i.e Asymmetry of legs Intermalleolar distance > 3.5 inches (9 cms) Associated symptoms e.g Pain, Limp