▁more ▁than ▁ 6 0 ▁degrees , ▁progress ive ▁de form ity , ▁neck sh aft ▁angle ▁< 9 0 ▁degrees , ▁development ▁of ▁Tr end elen burg ▁g ait ▁ ▁S urg ery : ▁subt ro chan ter ic ▁val g us ▁o ste ot omy ▁with ▁ade qu ate ▁internal ▁rotation ▁of ▁dist al ▁fragment ▁to ▁correct ▁ante version ; ▁common ▁comp lication ▁is ▁rec urrence . ▁If ▁HE ▁angle ▁is ▁reduced ▁to ▁ 3 8 ▁degrees , ▁less ▁evidence ▁of ▁rec urrence ; ▁ ▁post ▁oper ative ▁sp ica ▁cast ▁is ▁used ▁for ▁a ▁period ▁of ▁ 6 – 8 ▁weeks . ▁ ▁C ox a ▁var a ▁is ▁also ▁seen ▁in ▁Niem ann – P ick ▁disease . ▁ ▁Cong en ital ▁ ▁Pres ence ▁at ▁birth ▁is ▁extremely ▁rare ▁and ▁associated ▁with ▁other ▁con gen ital ▁anom al ies ▁such ▁as ▁proxim al ▁fem oral ▁foc al ▁def ic iency , ▁fib ular ▁hem im elia ▁or ▁anom al ies ▁in ▁other ▁part ▁of ▁the ▁body ▁such ▁as ▁cle id oc ran ial ▁dy ast osis . ▁The ▁fem oral ▁de form ity ▁is ▁present ▁in ▁the ▁subt ro chant ric ▁area ▁where ▁the ▁b one ▁is ▁bent . ▁The ▁cort ices ▁are ▁thick ened ▁and ▁may ▁be ▁associated ▁with ▁over lying ▁skin ▁dim ples . ▁External ▁rotation ▁of ▁the ▁fem ur ▁with ▁val g us ▁de form ity ▁of ▁kne e ▁may ▁be ▁noted . ▁This ▁condition ▁does ▁not ▁resolve ▁and ▁requires ▁surg ical ▁management . ▁S