BACKGROUND: Core decompression can delay early osteonecrosis of the femoral head, but cannot completely repair the necrotic femoral head. Eventually, femoral head collapse, even bone necrosis, will occur.
OBJECTIVE: To explore the curative effect of implantation of gelatin sponge carrying Foxc2-transfected bone marrow mesenchymal stem cells on the repair of experimental femoral head necrosis in rabbits.
METHODS: Forty New Zealand white rabbits were selected, and femoral head necrosis models were prepared successfully in 24 of 40 rabbits. Then, model rabbits were randomized into four groups: blank control group (n=4) with no treatment, core decompression group (n=4), GFP group (n=8) subjected to core decompression and implantation of gelatin sponge carrying GFP-transfected bone marrow mesenchymal stem cells, and Foxc2 group (n=8) subjected to core decompression and implantation of gelatin sponge carrying Foxc2-transfected bone marrow mesenchymal stem cells. At 1, 2, 4 weeks after implantation, ELISA was used to detect Foxc2 protein levels in the transplanted region. At 4, 8, 12 weeks after implantation, MRI scan of the hip was performed, and femoral head tissues were taken and sliced into sections for hematoxylin-eosin staining to observe bone growth. At 12 weeks after implantation, histomorphometry measurement and transmission electron microscope observation were carried out.
RESULTS AND CONCLUSION: At 1, 2, 4 weeks after implantation, Foxc2 was highly expressed in the femoral head in the Foxc2 group, which was significantly higher than that in the GFP group. At 4, 8, 12 weeks, only a few of new bone formed in the core decompression group and GFP group; at 12 weeks, fibrous tissues formed in the decompression channel. New bone formation was evident in the Foxc2 group, and at 12 weeks, the necrotic region was repaired completely. MRI findings showed normal femoral head morphology and signals in the Foxc2 group at 12 weeks, but there were decreased signals of the femoral head in the core decompression group and GFP group. These findings indicate that Foxc2-transfected bone marrow mesenchymal stem cell transplantation via core decompression has good curative effects on experimental femoral head necrosis in animals.