Fetal study of soft tissue anomalies and osteocartilage anlagen defects in congenital club foot

Congenital talipes equinovarus (CTEV) is a common musculoskeletal entity that affects 1-2 per 1000 of live births worldwide. Most are idiopathic with a typical deformity of midfoot cavus, forefoot adductus, hindfoot varus, and equinus. Controversy exists whether CTEV results primarily from in-utero soft-tissue abnormality or the defect is in the osteocartilage anlagen. This fetus study aimed to elucidate the gross anatomical morphology and morphometry of bones, joints, and soft tissue in CTEV compared with the normal foot. This comparative cross-sectional study done on 12 normal feet and four CTEV (two bilateral and two unilateral) in nine fetuses without spinal defects, aborted between 16-18, 19-20, 22-24, 26-28, and 32-33 weeks, analyzed the morphological and morphometric parameters. In CTEV, the talus was plantarflexed with a short medially deviated neck, and the posterior facet was flat instead of the normal quadrilateral shape, with a less convex tibiotalar articular surface. Calcaneus in CTEV was slightly smaller, displaced into varus, equinus, and internal rotation, and the posterior articular surface was triangular and transversely flat. Angular measurements (α, β, γ, δ) of the talus were increased while the λ angle of the calcaneus was decreased to almost half. All morphometric measurements were statistically significant (P values 0.001 by Mann-Whitney U test). The soft tissues (muscle and tendon) were shorter in length compared to normal. Significant abnormalities were detected in multiple parameters in both osteocartilage anlagen as well as soft tissues in CTEV.