<prompt> Most common cause of CTEV DEFORMITY IS ?Ahrogryposis multiplex congenitaSpina bifidaIdiopathicNeural tube defect  <response>: Aeitiology of CTEV can be - idiopathicmajoritysome of the theories proposed to the aetiology of idiopathic clubfoot : aMechanical theory - raised intrauterine pressure forces the foot against the wall of the uterus in position of the deformity bischaemic theory - ischemia of the calf muscles during intrauterine life, due to some unknown factor ,results in contracture,leading to foot deformities. cgenetic theory - some genetically related disturbance in the development of foot is held responsible for deformity secondary clubfoot : a paralytic disorder when there is a muscle imbalance as in polio ,spina bifida,myelodysplasia, Friedreich;s ataxia bahogryposis multiplex congenita- disorder of defective development of muscles. Muscles are fibrotic result in foot deformities ,deformities at other joint. REF:Essential ohopedics ,Maheshwari,9th edition ,pg.no.211 