Modification of a percutaneous transpedical interbody bone grafting apparatus and its application in cadaveric operation / 南方医科大学学报

<p><b>OBJECTIVE</b>To modify a percutaneous transpedical interbody bone grafting apparatus for better surgical performance in transpedical interbody bone grafting.</p><p><b>METHODS</b>The puncture needle, guide pin and expander were removed from the original design of interbody bone grafting apparatus, with also modification of the bone grafting funnel, obturator, wick and bone harvesting device. Percutaneous puncture and transpedical interbody bone grafting were performed using the modified apparatus on two cadavers, and the operative procedures, bone grafting scope and surgical trauma were observed.</p><p><b>RESULTS</b>This modified apparatus allowed increased bone grafting scope with shortened operative time, simplified operation procedures, and reduced surgical trauma.</p><p><b>CONCLUSION</b>Percutaneous puncture and transpedical interbody bone grafting can be easily and safely performed with the modified apparatus.</p>

Histological changes of an injectable rhBMP-2/calcium phosphate cement in vertebroplasty of rhesus monkey / 中华外科杂志

<p><b>OBJECTIVE</b>The histological changes of rhBMP-2/calcium phosphate cement (CPC) were evaluated in vertebroplasty on nonhuman primate models in order to determine the feasibility of this carrier formulation instead of PMMA.</p><p><b>METHODS</b>Percutaneous vertebroplasty (PVP) was performed in 4 adult rhesus monkeys which were evenly distributed in two groups. Ten vertebral bodies(VBs) from T10 to L7, of each rhesus were selected, and the 20 VBs in each group were randomly divided into 3 sub-groups. Group A:8 VBs, filled with rhBMP-2/CPC; Group B:6 VBs, filled with injectable PMMA; Group C:6 VBs, as control, filled with normal saline. The 2 rhesus monkeys in each group were killed at 2 and 6 months after operation, respectively, and the specimens of all the 40 VBs were collected for histological examination.</p><p><b>RESULTS</b>In group A,radiographic and histologic studies confirmed that part of the rhBMP-2/CPC cement degraded with new bone and new vessels ingrowth into the material after 2 months. No gap, fibrous hyperplasia or sclerotic callus was found in the interface. After six months, the cement was almost completely replaced by mature bone tissue. In group B, no new bone formation and material degradation but inflammatory cell infiltration and fibrous membrane gap were found 2 months after operation. After 6 months, the inflammatory cell infiltration subsided, the fibrous membrane gap became narrower, but there were still no new bone formation and material degradation. In group C, the tunnels were filled with irregular new trabeculae after 2 months and unrecognizable from the surrounding mature bone after 6 months, indicating the completion of bone healing.</p><p><b>CONCLUSIONS</b>With the characteristic of osteo-induction, the rhBMP-2/CPC can accelerate the healing of vertebral bone in nonhuman primates. Bone substitution is synchronous with material degradation, and the complete degradation of this material in late stage can avoid the potential adverse effects of PMMA on contiguous vertebral fracture and annulus degeneration. It might be a perfect bone substitute material for vertebroplasty instead of PMMA in the future.</p>

Low-temperature crystallization on porous titanium and in vivo evaluation on bone-bonding mechanics of the treated titanium / 中国医疗器械杂志

By the bioactivity technology of Low-Temperature Preparation of Anatase and Rutile Layers on porous Titanium Substrates, CPTi(Commercially pure titanium Phi4.0 mm x 20 mm) was processed and treated as experiment specimens while CPTi was treated as control specimens. Experiment specimens and control specimens were implanted into the holes (4.0 mm in diameter) in rabbit's right and left tibias respectively. After implantation for predetermined periods of 4,8,12, 16 weeks, the specimens were taken out with bone tissues, and were examined by a press-out tester to evaluate the shearing force between the implant and the bone tissue. It is found that the shearing force between the experiment specimen and the bone is more significantly higher than that between the control specimen and the bone, and the bonding time is shorter, the stabilization time is faster. This study has laid down a good foundation for the titanium metal's innovative applications in clinical orthopaedics.