Objective To evaluate the biomechanical effect of cortical screw support technique in fixation of the femoral neck fractures. Methods The models of subcapital femoral neck fracture were made in eight matched pairs of embamled cadaver femurs and decided into experiment group and control group (four pairs per group). The side of experiment group was fixed using three cannulated compression screws with cortical screw support and that of control group with conventional screw placement. The speci-mens in two groups were tested in aspects of torsion and axial loading. Results In axial load test at load of 600 N and 800 N, the displacements in cortical screw support group were (0.677±0.135) mm and (0.907±0.132) mm respectively, while those of femoral head in conventional screw placement group were (0.899±0.160) mm and (1.202±0.152) nun respectively (P <0.05). There was signifi-cant difference between the two groups (P < 0.05). The maximal vertical loading for failure of the fixa-tion was (2 782±228) N in cortical screw support group and (1 950±281) N in conventional screw placement group (P < 0.01). In torsibility test at 4° and 6° torsibility, the torque-moments of cortical screw support group were (10.406±1.515) Nm and (15.328 ±1.471) Nm respectively and those of conventional screw placement group (6.628±1.163) Nm and (9.072±1.570) Nm respectively, with statistical difference between two groups (P <0.01). The maximal torque-moment for failure of the fixa-tion was (25.437±5.213) Nm in cortical screw support group and (13.235±3.012) Nm in conven-tional screw placement group (P < 0.01). Conclusion Fixation of femoral neck fractures by using cortical screw support can significantly enhance anti-torsion and anti-compression of internal fixation.

Non-bifurcating cervical carotid artery(NBCCA)is a very rare anatomical variation of the cervical carotid artery,which may be related to the abnormal development of internal carotid artery(ICA)and external carotid artery in embryonic period.Neither carotid bulb nor a true carotid bifurcation can be observed on the ultrasound of carotid artery while a"stump-like"change was showed at the expected bifurcation level of carotid artery on DSA.Few cases has been reported in China and abroad so far.This article reported a middle-aged male with a history of hypertension and type 2 diabetes and was admitted to the hospital due to dizziness for one month.The left NBCCA accompanied with severe stenosis of the right ICA was confirmed by cerebral angiography.The patient received the right ICA stent implantation surgery as well as antihypertensive and glucose-control treatment and was discharged as his symptoms improved.Clinical data of this case and related literatures were reviewed,in order to improve clinicians'especially imaging diagnostic physicians'understanding on NBCCA to avoid misdiagnosis and related complications.

OBJECTIVETo identify potential mutation of the colony stimulating factor 1 receptor gene (CSF1R) in a large Chinese family affected with hereditary diffuse leukoencephalopathy with spheroids (HDLS) and analyze the genotype-phenotype correlation.

METHODSThe proband was evaluated physically and radiologically to ascertain the HDLS phenotype. Genomic DNA was extracted from peripheral blood samples from family members. The coding region of the CSF1R gene was amplified with PCR and subjected to direct DNA sequencing.

RESULTSThere were 9 affected members (5 alive) in this five-generation family (1 member had died during the follow-up). A missense mutation c.2563C>A (p.P855T) of the CSF1R gene has been identified in the proband. The same mutation was identified in 3 affected and 1 unaffected members of the family.

CONCLUSIONThe family was consistent with autosomal dominant inheritance. CSF1R gene mutation is also a disease-causing mutation in Chinese patients.

Adult ; Asian Continental Ancestry Group ; genetics ; Base Sequence ; Child ; Female ; Genes, Dominant ; Humans ; Leukoencephalopathies ; genetics ; Male ; Middle Aged ; Molecular Sequence Data ; Mutation, Missense ; Pedigree ; Receptor, Macrophage Colony-Stimulating Factor ; genetics

Objective:To explore a set of procedures for the effictive granulation of cartilage,and to construct injectable cartilage graft with platelet-rich gel(PRG),and to evaluate its effects in nude mice models.Methods:The costal cartilage of adult male rab-bits was cut into pieces and placed in a mortar for 30-60 s freezing in liquid nitrogen and grinding for a short time to obtain granular cartilage.Blood was collected from the middle ear artery and PRG was prepared by double centrifugation.Granular cartilage and the mixture of granular cartilage and PRG were injected subcutaneously in nude mice of control group(n=5)and experimental group(n=5)respectively.8 weeks after injection,the gross morphology observation and histological examination were pertormed.The nasal dor-sum augmentation model of nude mice was established in the experimental group.Results:The cartilage particles were in the size of 10-500 pm in diameter after frozen grinding,and injection could be realized.In vitro culture showed that the cell survival rate of granular cartilage reached to 80％.In vivo test showed that the sample morphology of the control group was insignificant,and the sur-face was grainy.That of the experimental group was well maintained,and the surface was smooth with obvious capillaries.The sam-ples of experimental group achieved significant augmentation in the nude mouse model of nasal dorsum augmentation.Conclusion:Freeze-milling technology can achieve efficient granulation of cartilage,and the graft constructed with PRG gel is suitable for maxillo-facial cartilage transplantation repair.