[Distribution and expression of TGF-ß2 in the capsule of children with developmental dysplasia of the hip].

OBJECTIVE

This study examined the distribution and expression of transforming growth factor-ß₂ (TGF-ß₂) in the hip capsule of children with developmental dysplasia (dislocation) of the hip (DDH) and non-DDH children in order to investigate the roles of TGF-ß₂ in hip joint laxity.

METHODS

Eight children with DDH and eight age- and gender-matched non-DDH children (control group) were enrolled. The immunohistochemical technique (S-P method) was used to examine the distribution and content of TGF-ß₂ in the hip capsule. Semiquantitative RT-PCR method was used to detect mRNA expression of TGF-ß₂ in the hip capsule. The quantitative analysis of TGF-ß₂ was performed by professional image software.

RESULTS

A high expression of TGF-ß₂ was observed in the synovial layer with fibroblast regularly arranged parallel to the joint surface. There was decreased expression of TGF-ß₂ in the fibrous layer of the capsule. The percentage of positive fibroblasts and the gray-scale density in the fibrous layer in the DDH group were significantly lower than those in the control group (P < 0.01). TGF-ß₂ mRNA expression in the DDH group decreased compared with that in the control group (P < 0.05).

CONCLUSIONS

The decreased TGF-ß₂ in distribution, content and mRNA expression in the hip capsule might contribute to hip joint laxity in children with DDH.