Tibial developmental field defect is the most common lower limb malformation pattern in VACTERL association

Abstract

VACTERL association is one of the most common recognizable patterns of human malformation and has been recently defined as a multiple polytopic developmental field defect. Limb anomalies are a key component of this condition and characteristically reflect perturbation of radial ray development. However, the pattern of appendicular malformations in VACTERL association is wider and includes a broad spectrum of additional and apparently nonspecific anomalies. We report on the sporadic case of a 4-10/12-year-old boy presenting with multiple costovertebral defects, dextrocardia, bilateral radial ray hypo/aplasia, unilateral kidney agenesis and anal atresia. Homolaterally to the more severe radial ray defect and kidney aplasia, he also has a complex lower limb malformation, consisting of distal tibial aplasia, clubfoot, hallucal deficiency and preaxial polydactyly. Literature review identifies 24 additional patients with VACTERL manifestations and lower limb malformations (excluding cases with isolated secondary deformations). Tibial hypo/aplasia with or without additional tibial field defects, reported in about 2/3 (68%) of the patients, represents the most common finding, while involvement of the fibular ray is rare (20%) and very often accompanies tibial anomalies. The relatively high frequency of tibial ray anomalies in VACTERL patients could easily be explained by the principle of homology of the developmental field theory. Careful search of lower limb anomalies of the "tibial type" is, therefore, indicated in all patients with multiple polytopic developmental field defects.