Observations on the Etiology of Tibia Vara

Varus deformity at the upper end of the tibia was reported by Erlacher (1922) and LUlsdorf (1931), who considered it to be a type of osteochondritis. Blount (1937) presented a personal series of thirt en cases and reviewed fifteen cases from the literature. He called the condition tibia vara and suggested that the term osteochondrosis was more appropriate than osteochondritis. Further reports of single or small numbers of cases were followed by a review of twenty-three cases by Langenskiold (1952). Altogether nearly 100 cases have been published (Gailey 1956). This paper reviews a personal series of thirty-one cases, twenty-eight in infants and three in adolescents. Tibia vara seems to be particularly common and severe in the West Indies. In this series, unlike those of Blount and of Langenskiold, the condition affected boys (seventeen) more commonly than girls (eleven). Tibia vara is characterised by a failure of growth localised to the postero-medial part of the upper tibial metaphysis and epiphysis. The growth of the epiphysial cartilage as well as that of the metaphysis and the epiphysis is disturbed, with consequent angulation of the tibia at the upper epiphysis which may, in untreated cases, produce bizarre deformities. It is always the postero-medial part of the epiphysial line which is affected, so that three deformities are produced: 1) Severe varus; 2) severe medial torsion of the tibia; and 3) a variable degree of fiexion of the diaphysis on the upper tibial epiphysis. The condition was grouped by Blount (1937) into an infantile type which occurred in the first year or so of life, and an adolescent unilateral type which appeared between six and thirteen years and never reached great severity. In this series there were twenty-eight cases of the infantile type and three cases of the adolescent type, which is relatively fewer than those presented by Blount (1937) who had twenty cases of the infantile type and nine of the adolescent. Langenskiold (1952) presented seventeen of the infantile type and six of the adolescent. Our three cases of the adolescent type show no remarkable features and will not be discussed further.