This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Pediatric Ohopedics, Subject name: Orthopaedics
Which of the following statement is false with respect to Pes planus ? 
Select and explain. 
A. Obliterated/lost medial longitudinal arch leads to Pes planus ., B. If heel goes to lateral detion it is called Plano valgus ., C. Rigid type on Jack's test often require conservative intervention ., D. Most common cause is idiopathic .
C: Rigid type on Jack's test often require conservative intervention .
Answer: C: Rigid type on Jack's test often require conservative intervention . 
Explanation: Pes planus or Flat feet is a postural deformity due to medial longitudinal arch flatening. M\C cause-idiopathic Types ( on basis of Jacks test) 1)Flexible = arch disappears when placed on ground & comes back when foot is lifted off. Mx - conservative 2) Rigid = Flat on both ground & when lifted . Due to congenital veical talus/ RA/ infection or tarsal coalition (AD - talocalcaneal and calcaneo navicular) or tibialisposterior dysfunction -They often require surgical intervention Congenital veical talus (Rocker-bottom foot) Treatment as per age and severity: Children 1 to 4 years old- Open reduction and realignment of the talonavicular and subtalar joints. Children 4 to 8 years old- Open reduction and soft-tissue procedures combined with extraar-ticular subtalar ahrodesis. Children 12 years old or older- Triple ahrodesis for permanent correction of the deformity.