AbstractThe implantation of combined hydroxyapatite (HAP) and autogenous red bone marrow (BM) was used to repair bone defect resulting from fibrodysplasia of bone in one case. After one year, the specimen was studied under optical and electronic scanning microscopes in order to study the biological features, histological changes and osteogenesis of hydroxyapatite implanted in the body. The results showed that there was not any inflammatory, toxic, or immune reaction in the tissue surrounding HAP-BM, and that HAP implanted was almost completely replaced by newly formed bone, and was firmly united to the surrounding bony tissue. This indicated that in the body HAP had a good biocompatibility and that HAP-BM provided the scaffold for osseous ingrowth as wellas boneinduction substances. The whole result was to that of the autogenous bone graft.
In order to evaluate the long-term effect of total hip replacement (THR) in patients with steroid-induced femoral head necrosis, 40 cases of 50 hips received THR patients were followed up for an average of 8.5 years after operation. Evaluation was carried act according to Harris score system. In these cases, average score was seventy-five points. Revision rate among them was 2% after four years and 18% after five to eight and a half years, with as overall rate of 20%. It was found that the main reason for revision was looseness of the prosthesis. In this follow-up, it showed that besides foreigen body reaction, abnormal osseous remodelling was the main factor in long-term failure of this arthroplasty. It was also proved that it was a good selection to perform cemented total hip replacement in younger patients, which could improve living quality.
Objective To investigate the outcome of repairing the peripheral nerve defects with the tissue engineered nerve constructed by Schwann cells and fibrin glue. Methods Wallerian degenerated sciatic nerve were harvested from the 4-week-old New Zealand rabbits for culture of Schwann cells. The Schwann cells were then separated, amplified and purified, and then were identified by the S-100 protein immunochemical staining. The cultured Schwann cells (1×106/ml) were mixed with fibrin glue to form the Schwann cell-fibrin glue compound, which was observed by the inverted phase contrastmicroscope. The compound filled some silicone tubes (Group A) and biomembrane (Group B) to fabricate the tissue engineered nerves with a purpose of repairing the 10-mm defects in the New Zealand rabbit tibia nerves. The autologous nerve grafting was performed in Group C. The electrophysiological examination and the histomorphological analysis were performed at 10 weeks after the transplantation. Results All the rabbits survived through the experiment. In Group A, all the rabbits developed an ulcer in the soles of their left feet at 3-4weeks after the transplantation, while less ulceration developed in Groups B and C. At 10 weeks after the transplantation, the electrophysiological examination was performed, the elective stimulation failed to pass through the nerve grafts, and no composed muscular action potential was found in all the rabbits in Group A; the elective stimulation could pass through all the nerve grafts in Groups B and C, and could evoke the composed muscular action potential; the composed muscular action potential and the nerve conduct velocity in the two groups were 4.21±0.82 mV and 3.40±5.40 m/s vs. 4.80±1.15 mV and 36.55±6.43 m/s(Pgt;0.05). In Group A, no regrown axon was found in the nerve grafts, but neuromawas found to have formed in the both ends of the silicon tube. In Groups B and C, there was no obvious neuroma formation but regrown axons could be found to have regenerated. The histomorphological analysis on the regrown axons showed thatthere was no statistically significant difference between Groups B and C. Conclusion The tissue engineered nerve fabricated with Schwann cells, fibrin glue, and biomembrane can promote the nerve regeneration, and its reparative effect is similar to that of the autologous nerves; therefore, the future of its clinical practice is brilliant.