SCHNEIDERnatomy of a congenitally dislocated hip in a child of 13 months who died of pneumonia. Retardation of normal development was manifest in delayed appearance of epiphysial nuclei in the upper and lower extremities. This report constitutes further proof of the etiologic significance of hypoplasia of the joint ends of the bones. Ordinary muscle tone will then have sufficient force to cause a luxation. In the presence of slight hypoplasia the joint may develop normally, but the addition of some exogenous factor may cause dislocation. The earliest date for dislocation is during the third fetal month. The higher incidence of dislocation of the left hip is attributed to factors governing the generally less decided development of left-sided structures.
Heidsieck152 describes a case of voluntary dislocation in a girl 2 years of age, which was observed accurately by means of the roentgenogram. He states that he has already described 1
GILL AB. PROGRESS IN ORTHOPEDIC SURGERY FOR 1945 A Review Prepared by an Editorial Board of the American Academy of Orthopaedic SurgeonsVI. CONGENITAL DISLOCATION OF THE HIP. Arch Surg. 1947;54(2):218-219. doi:10.1001/archsurg.1947.01230070223010