PURPOSE: To find out whether or not the computed tomographic (CT) classification systems of the calcaneal fracture are efficient in illuminating displaced posterior facet fragment and the degree of displacement can be evaluated by analyzing serial CT images. MATERIALS AND METHODS: Seventy-seven hundred calcaneal fractures were classified by CT classification systems including Sanders classification, and the sagittal rotation angle of the posteior facet fragment was measured on the plain lateral radiograph. Among the serial axial CT images, a number of images with the cortical bone embedded in the cancellous portion were recorded and any significant relationship between each data were evaluated. RESULTS: The conventional CT classification systems are rather insufficient in illuminating the extent of sagittal rotatory displacement. However, the number of CT images in which the cortical radiodensity was observed showed a significantly related with the degree of displacement. CONCLUSION: The conventional CT classification of the calcaneal fractures is unsatisfactory in expressing the degree of sagittal rotatory displacement of the posterior facet fragment; this problem may be alleviated by observing the number of axial CT images in which cortical radiodensity was revealed within the calcaneal body.
Calcaneus ; Classification

STATEMENT OF PROBLEM: Intraoral corrosion not only affects the esthetic and function of metallic dental restoration, but also has biologic consequences as well. Therefore, corrosion is considered a primary factor when choosing the dental alloy and laboratory technique. PURPOSE: The objective of this study was to compare the effects of solder and laser weld on corrosion. MATERIAL AND METHODS: Test specimens were made of 2 types of gold alloys, Co-Cr and Ni-Cr alloy and fabricated 3 methods, respectively: as cast, solder, and laser weld. For the analysis of corroding properties, potentiodynamic polarization test and immersion test conducted. The potentiodynamic polarization scan curve were recorded in 0.9% NaCl solution(pH 7) using Potentiostat/Galvanostat Model 273A. All specimens were exposed to 0.9% NaCl solution(pH 2.3) during 14 days. Elemental release into corrosive solution was measured by atomic emission spectrometry. Differences in corrosion potential and mass release were determined using ANOVA. RESULTS AND CONCLUSION: Through analyses of the data, following results were obtained. 1. In Pontor MPF and Wiron 99, corrosion potential of the solder group was statistically lower than as cast and laser weld group(p<0.05), but there was no difference between corrosion potential of solder group and laser weld group in Pontor MPF and no differences between as cast and laser weld group(p>0.05). In Jel-Bios 10 and Wirobond, there was no difference of corrosion potential according to joining methods(p>0.05). 2. In all tested alloys, the amount of released metallic ion was greatest in the solder group(p<0.05). There was no difference between as cast group and laser weld group in Jel-Bios 10 and Wirobond(p>0.05). 3. In scanning electron microscopic examination, except soldered Wiron 99 specimens, it is impossible to discriminate the corrosive property of solder and laser weld. 4. Under the this experimental circumstances, laser weld appears superior to the solder when corrosion is considered.
Alloys ; Corrosion* ; Dental Alloys* ; Gold Alloys ; Immersion ; Spectrum Analysis

Methods: We evaluated patients who underwent EPTLIF with a minimum 24-month follow-up. Clinical parameters of the Visual Analog Scale (VAS) and Oswestry Disability Index (ODI) were measured at the preoperative, 1-week postoperative mark, postoperative 3-month mark, and final follow-up. Preoperative and 1-year postoperative magnetic resonance imaging measurement of preoperative and postoperative Kjaer grade, right and left psoas muscle mass area, and right and left paraspinal muscle mass area was performed. Results: EPTLIF with a minimum 24-month follow-up of 35 levels was included. The complication rate was 6%, and the mean Bridwell’s fusion grade was 1.37 (1–2). There was statistically significant improvement at 1 week, 3 months, and 2 years in VAS (4.11±1.23, 4.94±1.30, and 5.46±1.29) and in ODI (40.34±10.06, 46.69±9.14, and 49.63±8.68), respectively (p <0.05). Successful operation rate with excellent and good MacNab’s criteria at 2 years was 97%. There was an increment of statistically significant bilateral psoas muscle cross-sectional area, right side (70.03±149.1 mm²) and left side (67.59±113.2 mm²) (p <0.05). Conclusions Uniportal EPTLIF achieved good fusion and improved clinical outcomes with favorable paraspinal musculature bulk at the 2-year follow-up.

Background: The occurrence of Graves’ disease and Hashimoto thyroiditis after coronavirus disease 2019 (COVID-19) raised concerns that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may trigger thyroid autoimmunity. We aimed to address the current uncertainties regarding incident thyroid dysfunction and autoimmunity among COVID-19 survivors. Methods: We included consecutive adult COVID-19 patients without known thyroid disorders, who were admitted to Queen Mary Hospital from July 21 to September 21, 2020 and had serum levels of thyroid-stimulating hormone, free thyroxine, free triiodothyronine (fT3), and anti-thyroid antibodies measured both on admission and at 3 months. Results: In total, 122 patients were included. Among 20 patients with abnormal thyroid function tests (TFTs) on admission (mostly low fT3), 15 recovered. Among 102 patients with initial normal TFTs, two had new-onset abnormalities that could represent different phases of thyroiditis. Among 104 patients whose anti-thyroid antibody titers were reassessed, we observed increases in anti-thyroid peroxidase (TPO) (P<0.001) and anti-thyroglobulin (P<0.001), but not anti-thyroid stimulating hormone receptor titers (P=0.486). Of 82 patients with negative anti-TPO findings at baseline, 16 had a significant interval increase in anti-TPO titer by >12 U, and four became anti-TPO-positive. Worse baseline clinical severity (P=0.018), elevated C-reactive protein during hospitalization (P=0.033), and higher baseline anti-TPO titer (P=0.005) were associated with a significant increase in anti-TPO titer. Conclusion Most patients with thyroid dysfunction on admission recovered during convalescence. Abnormal TFTs suggestive of thyroiditis occurred during convalescence, but infrequently. Importantly, our novel observation of an increase in anti-thyroid antibody titers post-COVID-19 warrants further follow-up for incident thyroid dysfunction among COVID-19 survivors.

Background: The occurrence of Graves’ disease and Hashimoto thyroiditis after coronavirus disease 2019 (COVID-19) raised concerns that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may trigger thyroid autoimmunity. We aimed to address the current uncertainties regarding incident thyroid dysfunction and autoimmunity among COVID-19 survivors. Methods: We included consecutive adult COVID-19 patients without known thyroid disorders, who were admitted to Queen Mary Hospital from July 21 to September 21, 2020 and had serum levels of thyroid-stimulating hormone, free thyroxine, free triiodothyronine (fT3), and anti-thyroid antibodies measured both on admission and at 3 months. Results: In total, 122 patients were included. Among 20 patients with abnormal thyroid function tests (TFTs) on admission (mostly low fT3), 15 recovered. Among 102 patients with initial normal TFTs, two had new-onset abnormalities that could represent different phases of thyroiditis. Among 104 patients whose anti-thyroid antibody titers were reassessed, we observed increases in anti-thyroid peroxidase (TPO) (P<0.001) and anti-thyroglobulin (P<0.001), but not anti-thyroid stimulating hormone receptor titers (P=0.486). Of 82 patients with negative anti-TPO findings at baseline, 16 had a significant interval increase in anti-TPO titer by >12 U, and four became anti-TPO-positive. Worse baseline clinical severity (P=0.018), elevated C-reactive protein during hospitalization (P=0.033), and higher baseline anti-TPO titer (P=0.005) were associated with a significant increase in anti-TPO titer. Conclusion Most patients with thyroid dysfunction on admission recovered during convalescence. Abnormal TFTs suggestive of thyroiditis occurred during convalescence, but infrequently. Importantly, our novel observation of an increase in anti-thyroid antibody titers post-COVID-19 warrants further follow-up for incident thyroid dysfunction among COVID-19 survivors.

Methods: Magnetic resonance imaging (MRI) and clinical evaluation were performed for patients with single-level uniportal endoscopic lumbar decompression with a minimum follow-up of 2 years. Results: A total of 126 patients were recruited with a minimum follow-up of 26 months. The incidence of epidural fluid hematoma was 27%. Postoperative MRI revealed a significant improvement in the postoperative dura sac area at postoperative day 1 and at the upper endplate at 6 months in the hematoma cohort (39.69±15.72 and 26.89±16.58 mm2) as compared with the nonhematoma cohort (48.92±21.36 and 35.1±20.44 mm2), respectively (p <0.05); and at the lower endplate on postoperative 1 day in the hematoma cohort (51.18±24.69 mm2) compared to the nonhematoma cohort (63.91±27.92 mm2) (p <0.05). No significant difference was observed in the dura sac area at postoperative 1 year in both cohorts. The hematoma cohort had statistically significant higher postoperative 1-week Visual Analog Scale (VAS; 3.32±0.68) pain and Oswestry Disability Index (ODI; 32.65±5.56) scores than the nonhematoma cohort (2.99±0.50 and 30.02±4.84, respectively; p <0.05). No significant difference was found at the final follow-up VAS, ODI, and MRI dura sac area. Conclusions Epidural fluid hematoma is a common early postoperative MRI finding in lumbar endoscopic unilateral laminotomy with bilateral decompression. Conservative management is the preferred treatment option for patients who do not have a neurological deficit. Symptoms last only a few days and are self-limiting. A common endpoint is a remodeled fluid hematoma and the subsequent expansion of the dura sac area.