Value of imaging in the preoperative diagnosis of pygopagus conjoined twins / 中华儿科杂志

<p><b>OBJECTIVE</b>To explore the value of imaging in the preoperative evaluation of pygopagus conjoined twins (PCT), and analyze the significance of imaging for separation surgery plan and prognosis.</p><p><b>METHODS</b>Imaging data of a case with PCT, including ultrasound, X-ray, CT, MRI were collected from the case with PCTs treated in our hospital. The features of the images were analyzed for identification of the conjoined region, size, and structures and for judgement of other organ malformation and general body state.</p><p><b>RESULTS</b>The conjoined region located at the lumbosacral spine of which anteroposterior diameter was 7.9 cm, and 6.0 cm for cranial-caudal diameter. Spina bifida were found below L3 in bilateral twins. There were no bone structures but cartilage fusion in spine and pelvis. The neural structure such as spinal cord and cauda equina, lower GI tract and anus, and urinary tract were separated. The dural sac were fused. There were cryptorchidism in one twin, patent ductus arteriosus in both twins. The intraoperative finding matched with imaging results. Crossing V-shaped skin flap was used to cover the wound surface. The dura of conjoined twins were sutured. Successful separation of the PCT was achieved. There were no complications of infection, cerebrospinal fluid leakage and neurological deficit. The healing of the skin flap was good. With 6 months follow-up, the growth and neurological function were normal.</p><p><b>CONCLUSIONS</b>Imaging methods were selected according to the type of conjoined twins and the clinical symptoms and signs. The radiologic investigation can reveal the structure and size of conjunction area. Imaging investigation has important significance for the prediction of difficulty in surgery, selection of surgical procedures, and evaluation of prognosis.</p>

Effect of nano-hydroxyapatite/collagen composite and bone morphogenetic protein-2 on lumbar intertransverse fusion in rabbits / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To investigate the effect of nano-hydroxyapatite/collagen (nHA/collagen) composite as a graft extender and enhancer when combined with recombinant human bone morphogenetic protein-2 (rhBMP-2) on lumbar intertransverse fusion in rabbits.</p><p><b>METHODS</b>Sixty-four adult female New Zealand white rabbits, aged 1 year and weighing 3.5-4.5 kg, underwent similar posterolateral intertransverse process arthrodesis and were randomly divided into 4 groups based on different grafts: autogenous cancellous bone alone (ACB group), nHA/collagen alone (HAC group), half autogenous cancellous bone and half nHA/collagen (ACB+HAC group) and nHA/collagen combined with rhBMP-2 (HAC+BMP group). The fusion masses were analyzed by manual palpation, radiography, biomechanical testing and histological examination.</p><p><b>RESULTS</b>Fusion was observed in 4 cases in the 6th week and in 5 cases in the 10th week after surgery in ACB group. No case showed fusion in HAC group. In ACB+HAC group, there was fusion in 3 cases in the 6th week and in 4 cases in the 10th week after surgery. In HAC+BMP group, fusion in 1 case was found in the 4th week, in 5 cases in the 6th week and in 6 cases in the 10th week after surgery. It suggested that ACB, ACB+HAC and HAC+BMP groups showed similar fusion ratio and mechanical strength in the 6th and 10th week after surgery. According to the microstructure analysis of the samples, nHA/collagen had no negative effect when implanted together with ilium autograft. In HAC+BMP group, new bone-like tissue was observed in the 2nd week postoperatively, and nearly all of the implanted composites were replaced by mature bone matrix and new bones in 10th week postoperatively.</p><p><b>CONCLUSIONS</b>The nHA/collagen, especially combined with rhBMP-2, is a promising bone substitute, for it has quick biodegradation, fine bone-bending ability, and high osteoconductivity on posterolateral spinal fusion in rabbits.</p>