Abstract
1. Breech malposition and hormonal joint laxity produce atraumatic posterior dislocations in the hip joints of young rabbits.
2. Experimental studies were shown to cause the development of a limbus and other softtissue changes similar to those found in human congenital dislocations.
3. The development of femoral retroversion and anteversion in the presence of joint laxity is described.
4. The co-existence of breech malposition and hormonal joint laxity in utero, and their importance as prime factors in the etiology of congenital dislocation of the hip, are discussed.