The histopathological characteristics of the skin in congenital idiopathic clubfoot.

Abstract

Purpose:

To highlight the histopathological characteristics of the skin in congenital clubfoot

and correlate the clinical findings in clubfoot with the changes in the dermal

layers.

Materials and methods:

One hundred skin specimens, from 77 infants (6 to 12 months), were studied

between 2004 and 2008. Using the Pirani scoring system, the clinical severity

was recorded. The mobility of the skin and the correctability of the medial ray

were assessed clinically. A skin specimen (1cm x 1mm) was taken from the

medial side of the foot at surgery following failed plaster treatment. The layers

were studied under light microscopy. The thickness of the dermis and the

histopathological features of clubfoot skin were compared with 10 normal skin

specimens.

Results:

The dermis of clubfoot skin showed significant fibrosis with thick bundles of

collagen fibres (P = .001) on Haematoxylin and Eosin staining (H&E). The dermal

thickness ranged between 1.0mm and 5.2mm in clubfoot skin, compared with

controls (0.64-1.28mm). Fibrosis extended into the subcutis in a septolobular

fashion in 95% of the cases. Significant atrophy of eccrine glands was seen in

98% (P = .001). Hair follicles were absent in 78%. The elastic fibres of clubfoot

skin, stained with Elastic van Gieson staining (EVG), showed hypertrophy in

varying degrees in all skin specimens. They were fragmented, with loss of their

parallel arrangement. There was no significant inflammatory reaction in the

dermis. The Pirani score was significantly increased (mean 7.8).

Discussion:

Fibrosis and thickening of the dermis were the most significant histopathological

features of the clubfoot skin. The elastic fibres were also abnormal. There was

atrophy of the skin appendages due to the fibrosis. There was a strong

correlation between the Pirani score and the severity of the deformity(P 0.016).

The cases with poor outcome had a higher score than those with a satisfactory

outcome.Lack of a significant inflammatory reaction suggests that neither the

serial manipulations of the foot, nor the repeated plaster cast changes, were

responsible for the dermal fibrosis, which is probably present from birth and

contributes to the deformity.