Anatomical and tensile mechanical analysis of hip joint capsule repair in total hip replacement / 中国骨伤

OBJECTIVE@#To explore the tensile mechanics and anatomical characteristics of the posterior hip capsule, and provide biomechanical and anatomical evidence for capsule repair in total hip replacement.@*METHODS@#Six bone-capsule-bone specimens were obtained from posterior hip joint of fresh frozen cadavers. The maximum strain, load, elastic modulus and load strain curves of the capsule ligament complex specimens were recorded by Instron Universal Material Testing Machine. Twelve cadaveric hip specimens were dissected to the capsule. The tensile strain of normal capsule and conventionally reconstructed capsule at 90 degrees of hip flexion were documented. The suture area of the posterior capsule was divided into nine sections, and the thicknessof different sections was measured and compared. Posterior capsule of the cadavers was repaired in conventionally way and anatomical way separately and simulated rehabilitation was conducted. The effect of rehabilitation on the repaired capsule was observed.@*RESULTS@#The load-strain curve of capsule ligament complex conforms to rheological and viscoelastic characteristics. The maximum tensile strain of the complex was (39.21±5.23)%, the maximum load was (142.06± 34.15) N, the tensile strength was (1.65±0.38) MPa, and the elastic modulus is (14.23±5.62) MPa. At 90 ° hip flexion, the tensile strain of repaired capsule was higher than that of normal capsule, and the difference was statistically significant (< 0.05). Tensile strain of conventionally reconstructed capsule is:upper part (37.0±4.9)%, middle part ( 53.3±1.1)%, lower part (68.3±6.2)%, tensile strain of normal capsule is:upper part (17.0±2.6)%, middle part (24.1±1.4)%, lower part (26.0± 4.3)% . The thickness of the posterior joint capsulein different sections is statistically significant (<0.05), and capsule at 0.5cm proximal to the femoral insertion is suitable for suture. There the average thickness of capsule is:upper part (3.48 ± 0.11) mm, middle part (2.36 ± 0.09) mm, lower part (1. 59±0.24) mm. The posterior inferior joint capsule is thinnest at (1.42± 0.02) cm proximal to the femoral insertion, and sutures should be avoided here. After simulating rehabilitation, avulsion occurred in the lower part of the posterior capsule repaired conventionally (10/12), and the anatomically repaired capsule remained intact.@*CONCLUSION@#The lower part of conventionally repaired capsule is overstretched and tends to fail. Anatomically repaired capsule conforms to tensile mechanics and is helpful to reduce the failure rate of repair.

Unusual Features in an Adult Pancreatic Hemangioma: CT and MRI Demonstration

Hemangiomas in the pancreas are very rare and only a few cases in adulthood have been reported in the literature. We describe a case of pancreatic hemangiomas in an adult with unique imaging findings. A 23-year-old woman visited the hospital for an incidentally detected pancreatic mass. CT and MRI revealed a multilocular cyst with fluid-fluid levels and no obvious enhancement. The patient underwent surgery and the mass was confirmed as a pancreatic hemangioma. The radiological features and differential diagnosis of this rare lesion are discussed.

Transfect bone marrow stromal cells with pcDNA3.1-VEGF to construct tissue engineered bone in defect repair / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>We previously showed that nano-hydroxyapatite/carboxymethyl chitosan (n-Ha/CMCS) displayed excellent mechanical properties, good degradation rates and exceptional biocompatibility, with negligible toxicity. The aim of this study was to determine the effect of the same composite with vascular endothelial growth factor (VEGF)- transfected bone marrow stromal cells (BMSCs) in a rabbit radial defect model.</p><p><b>METHODS</b>The nano-hydroxyapatite was produced through co-precipitation. The n-HA/CMCS scaffold was produced by particle filtration and lyophilization followed by genipin crosslinking. Total RNA from rabbit bone was reverse-transcribed to synthesize VEGF165-pcDNA3.1 that was transfected into the BMSCs. The composite was implanted into a rabbit radial defect model, and the osteogenic activity examined by gross morphology, X-ray examination and hematoxylin and eosin (HE) staining.</p><p><b>RESULTS</b>The microstructure and mechanical property of the n-HA/CMCS scaffold resembled natural cancellous bone. Compared with glutaric dialdehyde crosslinked scaffolds, the genipin crosslinked scaffold was less toxic, and displayed a higher capacity to promote cell adhesion and proliferation. Spontaneous fluorescence of the composite permitted visualization of the composite-bone interface and the adhesion behavior of cells on the scaffold under laser scanning confocal microscopy. The scaffold with VEGF-transfected BMSCs bridged the bony defect and promoted healing, with most of the implanted material being replaced by natural bone over time with little residual implant. Using X-ray, we noted obvious callus formation and recanalization of the bone marrow cavity. Furthermore, HE stained sections showed new cortical bone formation.</p><p><b>CONCLUSIONS</b>The n-HA/CMCS scaffold composite with VEGF-trasnfected BMSCs is biocompatible, nontoxic, promotes the infiltration and formation of the microcirculation, and stimulates bone defect repair. Furthermore, the degradation rate of the composite matched that of growing bone. Overall, this composite material is potentially useful for bone defect repair.</p>

Localized Castleman disease of plasma cell type in the abdomen / 中华医学杂志(英文版)

Castleman disease is a relatively rare entity, with the hyaline-vascular type the predominant form. Although the plasma cell type is uncommon, it still comprises approximately 10% of cases of localized diseases. In addition, the abdomen is a rare site for involvement and localized Castleman disease of the plasma cell type in the abdomen is rare. The radiologic features of localized plasma cell type in the abdomen are mostly limited to case reports. In addition to the conventional imaging findings, we present some new imaging findings of localized plasma cell type in the abdomen.