Abstract:

Objective　To analyze the effects of insulin-like growth factor-1(IGF-1) on reconstruction of femoral head and chondrification of articular cartilage from the periost and aponeurosis of the greater trochanter bone flap surface.  Methods    Animal models of bilateral avascular necrosis of femoral head (ONFH) using liquid nitrogen frozen skill were performed. Animals were randomly divided into A and B groups , with the number of 20 for every group. The joint capsule of left femoral head were sutured after the treatment, however, the right femoral head underwent different approaches. For group A(bone flap treatment group), femoral head reconstruction were performed using the greater trochanteric bone flap with vessel pedicle, and for group B (bone flap and IGF-1 gene therapy treatment group), intra-articular injection of Ad-IGF-1 were performed after the femoral head reconstruction by greater trochanteric bone flap. At the 3, 6, 12, 18 and 24 weeks point after treating, 4 animals were killed at every time point respectively, for morphologic observation, histopathologic detection of bone flaps. Results   Tissue nevrosis appeared at the frozen left femoral head for all animals, accompanied by fiber coverage, and debris-like tissue repair. Histologic detection confirmed that, hyaline cartilage cells appeared in the right bone area at the 6 week point for group A, whereas, hyaline cartilage cells appeared in group B as early as 3 week point, which implied the better repair effects of group B, compared to that of group A.  Conclusions    The periost and the aponeurosis of greater trochanteric bone flap are capable of chondrometaplasia, which will be prompted by the help of IGF-1. Our work is a beneficial attempt for applying cytokines during the treatment of ONFH.

Key words: Osteonecrosis of femoral head, Adenovirus vector insulin-like growth factor-1, Chondrification of articular cartilage,  , Immunnohistochemy