Removal of a broken guide wire entrapped in a fractured femoral neck / 中华创伤杂志(英文版)

Guide wire plays an important role in the fixation of femoral neck fracture with dynamic hip screw (DHS). Breakage of a guide wire during operation is a very rare condition. We met such a dilemma in DHS fixation of a 54-year-old male patient who sustained Garden type IV fracture of the right femoral neck. The distal end of the guide wire broke and was entrapped in the fractured femoral neck. We tried to get the broken part out by a cannulated drill. Reaming was started with the cannulated drill slowly rotating around the guide K-wire until the reamer fully contained the target under fluoroscope. A bone curette was used to get the broken wire out but failed, so we had to use the cannuated drill to dredge this bone tunnel. Finally the broken wire end was taken out, mixed with blood and bone fragments. Through the existing drilling channel, DHS fixation was easily finished. The patient had an uneventful recovery without avascular necrosis of femoral head or non-union of the fracture at one year's follow-up. A few methods can be adopted to deal with the broken guide wire. The way used in our case is less invasive but technically challenging. When the guide wire is properly positioned, this method is very practical and useful.

Generation of transient receptor potential vanilloid 6 gene knockout mouse model / 第二军医大学学报

Objective To create transient receptor potential vanilloid 6 (Trpv6) gene knockout mouse model, so as to pave a way for further research of its biological function and its role in bone metabolism in vivo. Methods Mouse genomic DNA sequence of Trpv6 gene was obtained from Ensembl database. Trpv6 gene knockout vector (pBR322-MK-Trpv6) was constructed. Trpv6 knockout vector was transferred into the embryonic stem (ES) cells by electroporation and screening of both G418 and Ganciclovoir resistant clones were performed routinely. The homologous recombined ES cell clones were identified by PCR. The correct homologously recombined ES cells were microinjected into C57BL/6J mouse blastocysts to obtain chimera mouse. Male mice with a chimera rate of 50% were mated with C57BL/6J female mice; the offsprings with gray fur were obtained, which were identified as heterozygote mice by PCR. Heterozygote mice were intercrossed to generate homozygote mice. Results Targeting vector PBR322-MK-Trpv6 were successfully constructed. A total of 24 correct homologously recombined clones were gained after electroporation. The efficiency of homologous recombination was 25%. Four male mice with a chimera rate of more than 50% were acquired after homologously recombined clones through microinjection. After the chimera mice were mated with C57BL/6J mice,57 grey-fur mice originated from ES cell were gained, including 17 (29. 8%) with heterozygous genotype. Heterozygote mice were intercrossed to generate homozygote mice. Western blotting analysisshowed no Trpv6 protein expression in homozygote mice. Conclusion We have successfully established Trpv6 gene knockout mouse model, and there is no embryonic lethality in homologous mutant mice.

Diagnosis and treatment for the injury of cervical disc and longitudinal ligament / 中华外科杂志

<p><b>OBJECTIVES</b>To study the diagnosis and treatment for the injury of cervical disc and longitudinal ligament.</p><p><b>METHODS</b>From 2001 to 2005, the clinical data of sixty-three patients with cervical disc and longitudinal ligament injury were studied. Early treatment was done based on spinal cord injuries and spinal stabilities by X rays and MRI. Early operation was done in fifty-four cases and early non-operation in nine cases.</p><p><b>RESULTS</b>The follow-up time was six to forty-one months in all patients. The neurological recovery was found in two of eight complete SCI post-operation, thirty-one in thirty-nine incomplete SCI. Cervical collar or plaster orthotic were used in nine cases with four to six weeks. Evidence of instability was noted in four patients, who were operated with anterior decompression fusion. Neck chronic pain was found in two patients, anterior decompression and fusion was done in one with cervical spinal cord compression.</p><p><b>CONCLUSIONS</b>MRI examination is the most value measure for the diagnosis of cervical disc and longitudinal ligament injury. Early anterior decompression and fusion was an important approach for cervical disc and longitudinal ligament injury.</p>