This study aims to evaluate the ability of C-arm cone-beam CT to detect intracranial hematomas in canine models. Twenty one healthy canines were divided into seven groups and each group had three animals. Autologous blood and contrast agent (3 mL) were slowly injected into the left/right frontal lobes of each animal. Canines in the first group, the control group, were only injected with autologous blood without contrast agent. Each animal in all the 7 groups was scanned with C-arm cone-beam CT and multislice computed tomography (MSCT) after 5 minutes. The attenuation values and their standard deviations of the hematoma and uniformed brain tissues were measured to calculate the image noise, signal to noise ratio (SNR) and contrast to noise ratio (CNR). A scale with scores 1-3 was used to rate the quality of the reconstructed image of different hematoma as a subjective evaluation, and all the experimental data were processed with statistical treatment. The results revealed that when the density of hematoma was less than 65 HU, hematomata were not very clear on C-arm CT images, and when the density of hematoma was more than 65 HU, hematomata showed clearly on both C-arm CT and MSCT images and the scores of them were close. The coherence between the two physicians was very reliable. The same results were obtained with C-arm cone-beam CT and MSCT grades in measuring SD value, SNR, and CNR. The reasonable choice of density detection range of intracranial hematoma with C-arm cone-beam CT could be effectively applied to monitoring the intracranial hemorrhage during interventional diagnosis and treatment.
ObjectiveTo study intraoperative reduction strategy in treatment of femoral neck fracture using cannulated screw fixation and the relationship between excellent and good rate of reduction and postoperative effectiveness. MethodsA retrospective analysis was made on the clinical data of 174 cases of femoral neck fracture treated between August 2005 and March 2015. There were 78 males and 96 females with an average age of 53.8 years (range, 23-75 years). The injury causes were falling in 85 cases, traffic accident in 61 cases, and falling from height in 28 cases. According to Garden typing, there were 35 cases of type I, 56 cases of typeⅡ, 47 cases of typeⅢ, and 36 cases of typeⅣ. The time from injury to operation was 1-7 days (mean, 2.74 days). Based on reduction strategy, closed 3 hollow compression screws were used; evaluating standards for fracture reduction effect were also established. Harris score was used for effectiveness evaluation. ResultsAll the cases received follow-up of 12-42 months (mean, 36.5 months). Bone healing was obtained in 152 cases at 6-12 months (mean, 9 months). Non-union and internal fixation failure occurred in 9 and 3 patients respectively, who underwent hemiarthroplasty; femoral head necrosis occurred in 6 patients after removing internal fixator at 15-26 months (mean, 18.5 months) after operation, who underwent total hip arthroplasty; 4 patients with non-union received vascular pedicle iliac flap transplantation. No other serious complications were observed. At last follow-up, the excellent and good rate of reduction was 94.29% for Garden type I, 91.07% for typeⅡ, 87.23% for typeⅢ, and 75.00% for typeⅣ, with a total excellent and good rate of 87.36%; the excellent and good rate of Harris score was 97.14% for Garden type I, 78.57% for typeⅡ, 68.09% for typeⅢ, and 50.00% for typeⅣ, with a total excellent and good rate of 73.56%. ConclusionTo obtain high Harris score in fixation of femoral neck fractures by using hollow screws, surgeons not only need reasonable technology, but also follow correct and good reduction strategy and assessment, fracture complexity is inversely proportional to excellent and good rate of reduction. Higher excellent and good reduction rate of complexity fracture should be obtained as much as possible in order to achieve good prognosis.