Tibialis Spastic Varus Foot with Tarsal Coalition.

Anomalies of tarsal coalition have been described by anatomists (Anderson 1 880, Pfitzner I 896) but their correlation with the clinical manifestation of spastic flat foot was not appreciated until Slomann (1921) and Badgley (1927) published their reports. Harris and Beath (1948) described the important part played by tarsal coalition as a cause of peroneal spastic flat foot. Their contribution created wide interest, and various reports have appeared during the past fourteen years (Webster and Roberts 1951, Outland and Murphy 1953, Jack 1954, Kendrick 1960). It is now accepted that tarsal coalition is commonly associated with peroneal spastic flat foot. In these cases the peroneal muscles are always in spasm and the long extensors of the toes and the tibialis anterior muscle may also be so (Hohmann 1934, Lapidus 1946, Jack 1954). Kendrick (1960) reported a case of a calcaneo-navicular bar associated with tibialis anterior spasm, but no particular deformity of the foot was mentioned. Lapidus (1946) described spastic flat foot as “ a painful condition of the foot and ankle, associated with spasm always limited to the pronator (evertor) group. Chiefly the peroneal muscles, sometimes the long extensors of the toes, occasionally also the anterior tibial muscles are contracted, all acting as pronators.” The mechanism by which the peroneal muscles are put into spasm is not clear, and the reason why these muscles are the ones to be affected is not evident. The purpose of this paper is to suggest the possibility that reflex spasm associated with tarsal coalition may affect other muscles than the peronei, producing a different clinical deformity.