Shape memory Ni-Ti alloy swan-like bone connector for treatment of humeral shaft nonunion.

From August 1990 to December 2007, 156 patients with humeral shaft nonunion were treated with our patented Ni-Ti shape memory alloy swan-like memory pressure connector (SMC). The SMC device cooled with ice before implantation was warmed to 40-50 degrees C after implantation to produce balanced axial and compression forces to stabilise the fracture three-dimensionally. This combined with autologous bone grafting achieved bone tissue regeneration in the fracture and promoted smooth recovery of joint function, with a nonunion healing rate of 98.7% after a single SMC implantation. Failure of nonunion healing occurred in only two cases but was successfully managed by a further operation. Complications were not found in any of these patients apart from four with pre-existing radial nerve injuries. These results demonstrate the effectiveness of the SMC device for the management of humeral shaft nonunion. The device provides continuous compression of the fracture with minimal trauma to the local blood supply.

Effects of RNA interference-mediated knockdown of livin and survivin using monomethoxypolyethylene glycol-chitosan nanoparticles in MG-63 osteosarcoma cells.

MG-63 human osteosarcoma cells were transfected with short hairpin RNA (shRNA) against livin and survivin using monomethoxypolyethylene glycol­chitosan (mPEG­CS) nanoparticles (NPs) as carriers, with the aim of evaluating the effect on cell proliferation and apoptosis. mPEG­CS NPs sized ~100 nm were prepared by ionic crosslinking. mPEG­CS­livin shRNA, mPEG­CS­survivin shRNA and mPEG­CS­(livin shRNA + survivin shRNA) NPs were constructed by electrostatic adsorption at NP suspension/gene solution ratios of 3:1 to transfect MG­63 cells. The expression levels of livin and survivin mRNA and protein were measured by reverse transcription­polymerase chain reaction and western blotting, respectively. The inhibitory effects of downregulated livin and survivin expression on cell proliferation were measured using an MTT assay. The apoptosis­inducing effects of livin and surivin knockdown were investigated using a Hoechst staining kit. All shRNA groups resulted in reduced expression of livin and survivin mRNA and protein in MG­63 cells. The MTT assay and Hoechst staining indicated that simultaneous knockdown of livin and survivin genes inhibited the proliferation of MG­63 cells and promoted their apoptosis, to a greater extent than knocking down either gene individually. The simultaneous interference mediated by mPEG­CS NPs significantly reduced livin and survivin expression in MG­63 cells, suppressed proliferation and facilitated apoptosis, to a greater extent than knockdown of either livin or survivin alone were. Thus the results indicate a synergistic effect of livin and survivin.

Periosteal osteosarcoma: a review of clinical evidence.

Periosteal osteosarcoma (PO) is a rare primary malignant bone tumor and a variant of osteosarcoma. It is a surface lesion without evidence of medullary involvement. The radiologic appearance of periosteal osteosarcoma is a broad-based surface soft-tissue mass that causes extrinsic erosion of thickened underlying diaphyseal cortex and perpendicular periosteal reaction extending into the soft-tissue component. The tumour presents as non-homogeneous masses of speculated osteoid matrix progressively denser from the periphery to their cortical base. The average age is around 28 and the most common location is the proximal third of the femur; with all the lesions diaphyseal in location. The treatment usually indicated is amputation, but in selected cases, radical segmental resection is appropriate. Long-term disease-free survival is possible after resection of the local recurrence. Limb-salvage therapy seems to offer survival equivalent to amputation, and there does not seem to be a substantial risk of late recurrence, dedifferentiation, or disease progression. The current review also highlights on various rare occurrences of periosteal osteosarcoma including the one of calcaneum, fifth metatarsal, mandible cranium, jaws, clavicle, maxilla, sphenoid bone with extensive periosteal extension, metacarpal in a paediatric age group and bilateral metachronous periosteal osteosarcoma. Recent findings relating to genetic factors governing the pathogenesis of PO is also presented.

[Treatment of Seinsheimer type V subtrochanteric femoral fractures with dynamic hip screw and shape memory alloy bow-teeth screw].

OBJECTIVE: To investigate the clinical effect of Seinsheimer type V subtrochanteric femoral fractures with dynamic hip screw and shape memory alloy bow-teeth screw. METHODS: Twelve patients with Seinsheimer type V subtrochanteric femoral fractures were retrospectively analyzed. There were 8 males and 4 females with an average age of 53 years (range 31 to 65 years). Seven cases were caused by traffic accident, 4 cases by falling from hight, 1 case by heavy object. According to the Seinsheimer classification, all the cases were type V fractures. All the cases accepted the surgical treatment with dynamic hip screw and shape memory alloy bow-teeth screw fixation. RESULTS: The mean period of follow-up was 28 months (range 20 to 38 months). All the cases obtained bone union in average 3.3 months (from 3 to 4.5 months). There were no complications such as deep infection, deep vein thrombosis, pulmonary embolism and bone nonunion. The results of clinical evaluation according to Merle d'Aubigne scores were 16.75 +/- 1.14 and excellent in 4 cases, good in 8 cases. CONCLUSION: Application of dynamic hip screw and shape memory alloy bow-teeth screw as a superior option can get satisfactory reduction with reliable fixation and will be one of a better choice for fixation of Seinsheimer type V subtrochanteric femoral fractures.