Objective:To study the consistency between post-processing bone mineral density(BMD)values of multi-slice spiral computed tomography(MSCT)scan and the BMD value of quantitative computed tomography(QCT)for lumbar vertebra,so as to explore the feasibility of utilizing MSCT scan-based post-processing BMD values for lumbar vertebra in clinical practice.Methods:The MSCT equipment and QCT equipment were respectively adopted to conduct imaging scan for the L2-L4 of lumber vertebra of QRM-ESP145 European Spine Phantom(ESP),and L2-L4 of lumbar vertebra of adult sheep,and L2-L4 of lumbar vertebra of adult volunteer.The L2-L4 of ESP lumber vertebra and L2-L4 of lumbar vertebra of adult sheep were scanned respectively MSCT and QCT for three times,so as to measure BMD values.The L2-L4 of lumbar vertebrae of volunteers were scanned respectively by the two methods for one time according to the standard of clinical examination,which were reconstructed by three times so as to obtain mean of them.The BMD values of QCT scan were set as control group,and the BMD values of MSCT scan were set as experiment group.The experiment group was further divided into experiment 1 group[two dimension(2D)regional volumetric BMD values of the lumbar vertebra]and experiment 2 group[three dimension(3D)global volumetric BMD post-processing of the lumbar vertebra]according to the reliability of experiment.Then,the consistency between the MSCT 3D post-processing BMD values of three groups and QCT-measured BMD values was compared and analyzed.Results:The MSCT 3D post-processing BMD values of L2-L4 of ESP lumbar vertebra of three groups were respectively(120.83±0.97),(199.57±0.54)and(119.19±1.04)mg/cm3,and that of L2-L4 of lumbar vertebra of adult sheep of three groups were respectively(414.89±1.72),(410.50±0.77)and(420.25±2.71)mg/cm3,and that of L2-L4 of lumbar vertebra of volunteer were respectively(141.22±0.09),(137.38±0.37)and(152.03±1.03)mg/cm3.There were not statistically significant differences in BMD values between MSCT examination and QCT examination(P＞0.05).Conclusion:MSCT 3D post-processing BMD values on lumbar vertebra has high consistency with that of QCT measurements,which post-processing technique can replace QCT to conduct BMD examination,and reduce unnecessary radiation exposure and examination costs for patients.

Objective:To study the consistency between post-processing bone mineral density(BMD)values of multi-slice spiral computed tomography(MSCT)scan and the BMD value of quantitative computed tomography(QCT)for lumbar vertebra,so as to explore the feasibility of utilizing MSCT scan-based post-processing BMD values for lumbar vertebra in clinical practice.Methods:The MSCT equipment and QCT equipment were respectively adopted to conduct imaging scan for the L2-L4 of lumber vertebra of QRM-ESP145 European Spine Phantom(ESP),and L2-L4 of lumbar vertebra of adult sheep,and L2-L4 of lumbar vertebra of adult volunteer.The L2-L4 of ESP lumber vertebra and L2-L4 of lumbar vertebra of adult sheep were scanned respectively MSCT and QCT for three times,so as to measure BMD values.The L2-L4 of lumbar vertebrae of volunteers were scanned respectively by the two methods for one time according to the standard of clinical examination,which were reconstructed by three times so as to obtain mean of them.The BMD values of QCT scan were set as control group,and the BMD values of MSCT scan were set as experiment group.The experiment group was further divided into experiment 1 group[two dimension(2D)regional volumetric BMD values of the lumbar vertebra]and experiment 2 group[three dimension(3D)global volumetric BMD post-processing of the lumbar vertebra]according to the reliability of experiment.Then,the consistency between the MSCT 3D post-processing BMD values of three groups and QCT-measured BMD values was compared and analyzed.Results:The MSCT 3D post-processing BMD values of L2-L4 of ESP lumbar vertebra of three groups were respectively(120.83±0.97),(199.57±0.54)and(119.19±1.04)mg/cm3,and that of L2-L4 of lumbar vertebra of adult sheep of three groups were respectively(414.89±1.72),(410.50±0.77)and(420.25±2.71)mg/cm3,and that of L2-L4 of lumbar vertebra of volunteer were respectively(141.22±0.09),(137.38±0.37)and(152.03±1.03)mg/cm3.There were not statistically significant differences in BMD values between MSCT examination and QCT examination(P＞0.05).Conclusion:MSCT 3D post-processing BMD values on lumbar vertebra has high consistency with that of QCT measurements,which post-processing technique can replace QCT to conduct BMD examination,and reduce unnecessary radiation exposure and examination costs for patients.

Objective:To compare short-term clinical efficacy between femoral neck system (FNS) and cannulated compression screws (CCS) in the treatment of femoral neck fractures in young adults.Methods:Retrospectively analyzed were the data of 94 patients with femoral neck fracture who had been admitted to Department of Orthopedics and Traumatology, The First Affiliated Hospital to University of Science and Technology of China, Department of Orthopaedics, The First Affiliated Hospital to Anhui Medical University and Department of Orthopaedics, The Second Affiliated Hospital to Anhui Medical University from October 2019 to October 2020. They were divided into 2 groups according to their modes of internal fixation: a FNS group ( n=47) and a CCS group ( n=47). In the FNS group there were 30 males and 17 females with a mean age of (47.8±9.8) years; in the CCS group there were 26 males and 21 females with a mean age of (43.7±13.1) years. The 2 groups were compared in terms of operation time, incision length, intraoperative blood loss, fracture healing time, weight-bearing time, Harris hip score and complications. Results:There was no significant difference in preoperative general data or follow-up duration between the 2 groups, showing comparability between groups ( P>0.05). In the FNS group, operation time [(47.7±9.4) min] was significantly shorter than that in the CCS group [(66.1±3.8) min], postoperative partial and full weight-bearing time [2.0 (2.0, 3.0) weeks, (6.4±2.1) weeks] significantly earlier than that in the CCS group [8.0 (3.0, 9.0), (10.1±3.4) weeks], fracture healing time [3.0(3.0, 4.0) months] significantly shorter than that in the CCS group [3.0(3.0, 4.0) months], Harris hip score at the last follow-up [95.0 (93.0, 95.0) points] significantly higher than that in the CCS group [90.0 (88.0, 95.0) points], incidence of lateral thigh irritation [0% (0/47)] significantly lower than that in the CCS group [31.9% (15/47)], and neck shortening length (4.3±3.9 mm) significantly shorter than that in the CCS group (6.9±4.5 mm) (all P<0.05). There was no significant difference in the rate of avascular necrosis of the femoral head or rate of internal fixation failure between the 2 groups ( P>0.05). Conclusion:In the treatment of femoral neck fractures in young adults, compared with CCS fixation, FNS fixation can shorten operation time and fracture healing time, allow patients to ambulate early after surgery, which is beneficial to maintenance of femoral neck length and to functional recovery of the hip.