We present the case of a 79-year-old woman who presented at our center with a periprosthetic tibial fracture with a popliteal artery injury after total knee arthroplasty. Anastomosis of the popliteal ...artery was performed on the day of injury, and was later treated by open reduction and internal fixation. The patient was able to walk 3 months after injury.
The present case was difficult to treat because of the arterial injury associated with periprosthetic fracture. Although revision of the implant was considered, open reduction and internal fixation was selected because of the severity of soft-tissue damage. The mechanism of injury is not uncommon, and it is expected that similar fractures will become more prevalent in the future as the number of knee replacement surgeries increases.
•We experienced a case of periprosthetic tibial fracture after total knee arthroplasty with popliteal artery injury.•There have been no reports of periprosthetic fracture associated with popliteal artery injury.•Because this injury process is not specific, the chances of encountering this injury are expected to increase in the future.
The anionic polymerizations of p-pentamethyldisilylstyrene (1), p-heptamethyltrisilylstyrene (2), and p-nonamethyltetrasilylstyrene (3) were carried out under various conditions. The polymerizations ...of 1 and 2 proceeded in a living manner in THF at −78 °C to quantitatively afford polymers with predictable molecular weights and narrow molecular weight distributions. Suitable initiators for these living anionic polymerizations were sec-BuLi, lithium, sodium, and potassium naphthalenides, cumylpotassium, and living oligomers of α-methylstyrene lithium, sodium, and potassium salts. Well-defined diblock copolymers, poly(1)-block-polystyrene, poly(2)-block-polystyrene, polystyrene-block-poly(1), and polystyrene-block-poly(2) were successfully synthesized under similar conditions by a two-step sequential monomer addition, namely, styrene followed by 1 or 2, or vice versa. In contrast, the polymerization of 3 was problematic. No polymer was obtained in the polymerization of 3 in either THF at −78 °C or benzene at 40 °C with sec-BuLi and oligo(α-methylstyryl)lithium. Using oligo(α-methylstyryl)potassium as an initiator, 3 was polymerized quantitatively in THF at −78 °C for 0.5 h. Unfortunately, the side reaction, presumably attack of the Si−Si−Si−Si bond by the growing chain-end anion, could not be completely suppressed during the polymerization, which resulted in the formation of high molecular weight polymers by coupling between polymer chains.
A series of polymers with 4-perfluoroalkyl-modified azobenzene side groups was investigated for its light-induced changes in surface properties. The ultraviolet (UV) light activated trans to cis ...isomerization of the azobenzene group, and the influence of molecular order and orientation on this process were studied using near-edge X-ray absorption fine structure (NEXAFS) spectroscopy and water contact angle measurements. Light-induced molecular reorganization in the near-surface region was studied by NEXAFS using in situ UV irradiation of polymer thin films. Differential scanning calorimetry and wide-angle X-ray scattering studies showed that sufficiently long fluoroalkyl groups formed well-ordered smectic mesophases in the bulk, as well as on the surface, which was evidenced by NEXAFS. The disruption of mesogen packing by photoisomerization was found to be influenced by the fluoroalkyl segment length. Surfaces with perfluorohexyl and perfluorooctyl groups that showed high orientational order were also highly resistant to light-induced changes. In such cases, the trans−cis isomerization resulted in greater lowering of the azobenzene phenyl ring order parameters than the perfluoroalkyl order parameters. UV exposure caused reorientation of the phenyl rings of the azobenzene group, but the terminal perfluoroalkyl segments remained more or less ordered.
AIM To examine the relationship between pancreatic hyperechogenicity and risk factors for metabolic syndrome.METHODS A general population-based survey of lifestyle-related diseases was conducted from ...2005 to 2006 in Japan. The study involved 551 participants older than 40 year of age. Data for 472 non-diabetic adults were included in the analysis. The measures included the demographic factors, blood parameters, results of a 75 g oral glucose tolerance test, and abdominal ultrasonography. The echogenicity of the pancreas and liver was compared, and then the subjects were separated into two groups: cases with pancreatic hyperechogenicity(n = 208) and cases without(controls, n = 264). The differences between both groups were compared using an unpaired t-test or Fisher’s exact test. Multiple logistic regression analysis was used to determine the relationship between the pancreatic hyperechogenicity and clinical and bio-chemical parameters.RESULTS Subjects with pancreatic hyperechogenicity had decreased serum adiponectin concentration compared to control subjects 8.9(6.5, 12.8) vs 11.1(7.8, 15.9), P < 0.001 and more frequently exhibited features of metabolic syndrome. Logistic regression analysis showed that the following variables were significantly and independently associated with pancreatic hyperechogenicity: Presence of hypoadiponectinemia, increased body mass index(BMI), higher homeostasis model assessment of insulin resistance(HOMA-IR) score, and presence of fatty liver. Similar associations were also observed in subjects with pancreatic hyperechogenicity without fatty liver. Multivariate association analysis of data from participants without fatty liver showed that hypoadiponectinemia was significantly associated with pancreatic hyperechogenicity(OR = 0.93, 95%CI: 0.90- 0.97, P < 0.001). This association was independent of other confounding variables. Additionally, an increased BMI and higher HOMA-IR score were significantly associated with pancreatic hyperechogenicity.CONCLUSION Pancreatic hyperechogenicity is independently associated with increased BMI, insulin resistance, and hypoadiponectinemia in the general population.
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