Idiopathic congenital club foot is a birth defect that is marked primarily by a deformed ankle and heel as well as the forepart of the foot, that gives the foot a characteristic "club - like" ap­pearance. Thus the infant's foot points downward and inward.
We evaluated in the present work the abductor haliucis muscle of 9 chil­dren with club feet, age (9 months to 48 months). Histological examination of muscle sections from club feet cas­es revealed histopathologic changes in the form of marked variation of muscle fiber size, multiple vacuolation of the sarcoplasm in some fibers and wide separation of muscle fibers with increased connective tissue compo­nent in between them.
demonstrated that, succinic dehy-drogenase enzyme activity in the muscle fibers of club feet cases was markedly decreased. Inhibition of that enzyme activity indicates impaired muscle energy metabolism due to al­teration of mitochondria! structure and function.
Transmission electron micro­graphs revealed wide separation of myofibrils of club feet cases with focal areas of degeneration. In addition, disruption of myofibrils and derange­ment of 2 bands were noticed. Mito­chondria showed bizarre shape and distribution in some fibers with in­creased connective tissue compo­nents in between muscle bundles. These affected fibers were surround­ed by normal ones.