Orthotic Correction of Blount's Disease

Infantile tibia vara is the result of abnormal growth in the proximal tibial epiphyseal late of the tibial plate. Blount first identified the condi­ tion as osteochondrosis deformans tibialis in 1937. Clinically, tibia vara presents itself as a severe bowing of the proximal tibia, without the associated bowing of the tibial shaft or the femur, which is evident in physiological bowleg. On radiological examination of the child with tibia vara, a beaking of the medial aspect of the tibia metaphysis is noted. In 1964, Langenskiold and Riska developed a grading system for chronologically staging the development of the Blount's disease. Mitchell, et al. 3 advocated the use of the epiphyseal metaphyseal angle (E-M angle) as a simple quantitative measurement for Blount's disease in 1980. This method is useful to determine the severity of the disease and monitor treatment. Historically, the use of orthotic management in the correction of Blount's disease has not proven to be as successful as hoped. The lack of correction and increased laxity of the joint cap­ sule of the knee have been the main reasons for not continuing with orthotic management. To this point, the treatment of choice for individuals with Stage IV or an E-M angle of greater than 30° has mandated that the child undergo one of sev­ eral types of tibial osteotomies. Because of the high incidence of complications and the re­ currence of the condition, the authors felt that a new orthotic approach should be investigated. The result of that investigation has been the de­ velopment of a knee-ankle-foot orthosis. This orthosis has successfully been used in seven cases of Blount's disease.