Congenital Tibial Defects

Abstract

Since the first description by Otto in 1884, tibial hemimelia has been described under a variety of names, including congenital longitudinal deficiency of the tibia, congenital dysplasia of the tibia, paraaxial tibial hemimelia, tibial dysplasia, and congenital deficiency or absence of the tibia. This condition actually represents a spectrum of deformities ranging from total absence of the tibia (the most severe form) to mild hypoplasia of the tibia (the least severe form). It is a rare congenital condition producing severe talipes equinovarus, leg shortening and instability of the knee. As regards the development, the hypothesis of Shubin and Alberch says that the first event is the appearance of the femur as a de novo condensation. Next, it bifurcates into two more distal elements (tibia, tibiale, element Y, and, occasionally, the prehallux), which are in disagreement with the bifurcation of toes B and C, whereas the postaxial elements arise by a combination of branching and segmentation events. The postaxial series becomes dominant and gives rise to a digital arch, which produces the distal tarsals and digits by branching events. However, there are uncertain connections between the digital arch and the distal tarsal one.

Modern classification of limb deficiency in children is based on the system proposed by Franz and O'Rahilly in 1961. Tibial deficiency using this system is classified as a pre-axial longitudinal deficiency, which may be