The metaverse has been settled as a platform that is widely beloved by digital natives that are familiar with mobile devices and immersive contents. Thanks to the protocol enabling hedonic interaction, the user experience provides significant value from its communication, enabling learning experiences anytime and anywhere. However, the research topics are focused on the promotions of technology development, marketing effects, and relevant investment consensus. Surprisingly, the biggest problem was the lack of research from the perspective of the young generation, who mainly use the metaverse. This paper intends to examine the usability of digital native participants in detail and suggest how immersive contents, usage environment, and interface aspects should be designed from their point of view. As a result, the significant engagement factors and improvements, through heuristic usability evaluation considering content and user control, were discovered from individual interviews. Conversely, the elements to be supplemented in user experience were derived from information architecture and usage environment categories. In conclusion, the theoretical basis of the empirical usability evaluation on metaverse platforms and following recommendations with practical implications could gain more importance from this research.

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Results: Schwannomas arose from the acoustic nerve(n = 18) , the trigemin a l nerve(n = 2) , the glossopharyngeal -vagal-accessory nerve complex (n=2) , and the olfactory nerve(n=1l. Intracranial schwannomas were well defined , lobulaled and inhomogeneously or homogeneously enhancing masses on CT and MR , and were located along the course of the specific cranial nerve. Acouslic schwannomas involved both the internal auditory canal(IAC) and the cerebellopontine angle(CPA) in 14 cases , the IAC in three , and the CPA in two. Two trigeminal schwannomas involved both middle and posterior cranial fossa and were in the shape of a dumbbell One of the two schwannomas that invelved lower cranial nerve complex(9 -11 th) was located in the medullary cistern and jugular foramen ; the other was located in the central posterior cranial fossa. A case of olfactory schwannoma was localed in lhe right cribriform plate. The precontrast CT scan showed low density in 13 cases (62 % ), isodensily in seven(33%) and high density in one(5%). On postcontrast CT scan , enhancement was seen in 20 cases(95 % ). Of lhe 15 cases with MR , 12 had low signal intensity on T1 weighted image and 14 had high signal intensity on T2 weighted image. MR imaging after Gd-DTPA infusion showed enhancement in 14 cases Enhancement was inhomogeneous in 14 cases on CT and in 13 on MR. Of 24 cases , intratumoral necrosis was seen in 19, ring enhancement in five and severe cystic change in one. Other findings were intratumoral calcification(21 %) , hemorrhage(8%) , pressure bony erosion(70.8 % ), midline shift(58 % ), peritumoral edema(29 % ) and hydrocephalus(33%). On MR , there was in all 15 cases a peritumoral low signal intensity rim on T1-and T2-weighted images and on a T1 weighted image following gadolium infusion.

Purpose Recently, the Persona total knee arthroplasty (TKA) system with more anatomical features and a similarly high flexion to the previous version, LPS-Flex, was introduced and is widely used. This study aimed to compare the early outcomes obtained using Persona versus an LPS-Flex fixed PS implant. Methods A total of 784 knees that underwent primary TKAs (162: Persona group and 622: LPS-Flex group) were included. After 1:2 propensity score matching, there were 143 and 286 knees in Persona and LPS-Flex groups, respectively. Range of motion at the 2-year follow-up was the primary variable. Secondary variables were functional score, ability to perform activities requiring deep knee flexion, patient satisfaction, and radiographic measurements, including radiolucent line (RLL). ResultsThe average postoperative maximal flexion measured by goniometer at 2 years after TKA was 126.1° ± 10.8° (range 95°-140°) for the Persona group and 132.7° ± 11.7° (range 103°-145°) for the LPS-Flex group (P < 0.05). This significant difference was observed from 1 year postoperatively (P < 0.05). The two groups did not show a significant difference in functional score, postoperative ability in high flexion activities, and satisfaction at the 2-year follow-up. The rate of RLL was significantly lower in the Persona group (P < 0.05). Conclusion At the 2-year follow-up, the Persona group had less maximal flexion; however, the difference in flexion did not seem to affect clinical outcomes. According to the radiological results, the Persona system shows less RLL than does the LPS-Flex system. Level of evidence III.