ObjectiveTo evaluate the physical and chemical properties, immunogenicity, and osteogenesis of two antigen-extracted xenogeneic bone scaffolds—decalcified bone matrix (DBM) and calcined bone.MethodsBy removing the inorganic and organic components of adult pig femus, xenogeneic DBM and calcined bone were prepared respectively. The density and pH value of the two materials were measured and calculated, the material morphology and pore diameter were observed by scanning electron microscope, and the surface contact angle was measured by automatic contact angle measuring instrument. The safety, osteogenic activity, and immunogenicity of the two materials were evaluated by cytotoxicity test, osteoblast proliferation test, DNA residue test, and human peripheral blood lymphocyte proliferation test. The two materials were implanted into the 5 mm full-thickness skull defect of 6-week-old male Sprague Dawley rats (the blank control group was not implanted with materials). The materials were taken at 4 and 8 weeks after operation, the repair effect of the materials on the rat skull was observed and evaluated by gross observation, Micro-CT scanning, and HE staining observation.ResultsCompared with calcined bone, DBM has lower density and poor hydrophilicity; the pH value of the two materials was 5.5-6.1, and the pore diameter was 160-800 μm. The two materials were non-cytotoxic and could promote the proliferation of osteoblasts. The absorbance (A) values of osteoblast proliferation at 1, 4, and 7 days in the DBM group were significantly higher than those in the calcined bone group (P<0.05). The DNA residues of the two materials were much lower than 50 ng/mg dry weight, and neither of them could stimulate the proliferation and differentiation of human peripheral blood lymphocytes. The results of animal experiments in vivo showed that the bone volume/total volume (BV/TV) in DBM group and calcined bone group were significantly higher than that in blank control group at 4 weeks after operation (P<0.05), and that in calcined bone group was significantly higher than that in DBM group (P<0.05); at 8 weeks after operation, there was no significant difference in BV/TV between groups (P>0.05). HE staining showed that at 4 and 8 weeks after operation, the defect in the blank control group was filled with fibrous connective tissue, the defect was obvious, and no bone growth was found; the defect in DBM group and calcined bone group had been repaired to varying degrees, and a large number of new bone formation could be seen. The material degradability of DBM group was better than that of calcined bone group.ConclusionThe physical and chemical properties and degradability of the two kinds of xenogeneic bone scaffolds were slightly different, both of them have no immunogenicity and can promote the repair and reconstruction of skull defects in rats.
Objective To analyse the correlative factors of secondary vertebral fracture after percutaneous kyphoplasty (PKP) in treatment of osteoporotic vertebral compression fracture (OVCF) at different levels (adjacent and/or nonadjacent levels). Methods Between December 2002 and May 2008, 84 patients with OVCF were treated with PKP, and the cl inical data were analysed retrospectively. There were 11 males and 73 females with an average age of 70.1 years (range, 55-90 years). All patients were followed up 24-96 months (mean, 38 months). Secondary vertebral fracture occurred in 12 cases at 3-52 months after PKP (secondary fracture group), no secondary fracture in 72 cases (control group) at over 24months. The preoperative bone mineral density, postoperative vertebral height compression rate, postoperative Cobb angle, amount of injected bone cement per vertebra, puncture pathway (uni- or bilateral puncture), age, gender, number of fracture segment, and cement intradiscal leakage were compared between 2 groups to find correlative factors of secondary vertebral fractures. Results There was no significant difference in preoperative bone mineral density, postoperative vertebral height compression rate, postoperative Cobb angle, amount of injected bone cement per vertebra, puncture pathway, age, gender, and number of fracture segment between 2 groups (P gt; 0.05). But the incidence of cement intradiscal leakage was much higher in secondary fracture group than in control group (χ2=5.294, P=0.032). Conclusion Cement intradiscal leakage may be the correlative factor of secondary vertebral fracture after PKP in OVCF.
ObjectiveTo summarize the related research results of minimally invasive treatment of anterior pelvic ring fracture, and to improve the understanding of minimally invasive treatment of anterior pelvic ring fracture.MethodsThe literature of minimally invasive treatment of anterior pelvic ring fracture at domestic and overseas in recent years was reviewed, and the reduction and fixation methods of minimally invasive treatment were summarized and analyzed.ResultsThe pelvic reduction frame may be an effective auxiliary method for minimally invasive reduction of pelvis. The fixation methods of anterior pelvic ring include percutaneous screw fixation, stent fixation, and percutaneous plate fixation.ConclusionOne kind of fixation is not applicable to all types of anterior pelvic ring fracture, and the fixation method should be selected according to the type of fracture and the patient’s condition to minimize the complications.
Objective To evaluate the effectiveness of pedicle subtraction osteotomy (PSO) and non-osteotomy techniques in treatment of medium-to-severe kyphoscoliosis by retrospective studies. Methods Between January 2005 and January 2009, 99 patients with medium-to-severe kyphoscoliosis were treated by PSO (PSO group, n=46) and non-osteotomytechnique (non-osteotomy group, n=53) separately. There was no significant difference in sex, age, Cobb angle of scol iosis on coronal plane, and Cobb angle of kyphosis on saggital plane between 2 groups (P gt; 0.05). The operation time and blood loss were recorded; the Cobb angle of scol iosis on coronal plane and kyphosis on sagittal plane were measured at pre- and postoperation to caculate the rates of correction on both planes. Results The operation was successfully completed in all the patients. The operation time and blood loss of the patients in PSO group were significantly greater than those of the patients in non-osteotomy group (P lt; 0.05). All patients were followed up 12-56 months (mean, 22.4 months); no spinal cord injury occurred, and bone fusion was achieved at last follow-up. The Cobb angles of scol iosis and kyphosis at 2 weeks and last follow-up were significantly improved when compared with the preoperative angles in the patients of 2 groups (P lt; 0.05). There was no significant difference in Cobb angle of scol iosis and the rate of correction between 2 groups (P gt; 0.05), but the correction loss of PSO group was significantly smaller than that of non-osteotomy group (P lt; 0.05) at last follow-up. At 2 weeks and last follow-up, the Cobb angle of kyphosis, the rate of correction, and correction loss were significantly better in PSO group than in non-osteotomy group (P lt; 0.05). Conclusion There is no signifcant difference in scol iosis correction between PSO and non-osteotomy techniques.PSO can get better corrective effect in kyphosis correction than non-osteotomy technique, but the operation time and blood losswould increase greatly.