BackgroundRotational alignment of the tibial component is important for long-term success of total knee arthroplasty (TKA). This study aimed to compare five axes in normal and osteoarthritic (OA) knees to determine a reliable landmark for tibial rotational alignment in TKA.MethodsOne hundred twenty patients with OA knees and 40 with normal knees were included. The angle between a line perpendicular to the surgical transepicondylar axis and each of five axes were measured on preoperative computed tomography. The five axes were as follows: a line from the center of the posterior cruciate ligament (PCL) to the medial border of the patellar tendon (PCL-PT), medial border of the tibial tuberosity (PCL-TT1), medial one-third of the tibial tuberosity (PCL-TT2), and apex of the tibial tuberosity (PCL-TT3), as well as the anteroposterior axis of the tibial prosthesis along the anterior tibial curved cortex (ATCC).ResultsFor all five axes tested, the mean angles were smaller in OA knees than in normal knees. In normal knees, the angle of the ATCC axis had the smallest mean value and narrowest range (1.6° ± 2.8°; range, −1.7°–7.7°). In OA knees, the mean angle of the ATCC axis (0.8° ± 2.7°; range, −7.9°–9.2°) was larger than that of the PCL-TT1 axis (0.3° ± 5.5°; range, −19.7°–10.6°) (P = 0.461), while the angle of the ATCC axis had the smallest SD and narrowest range.ConclusionThe ATCC was found to be the most reliable and useful anatomical landmark for tibial rotational alignment in TKA.

Shape‐controlled Pt‐based seeds lead to completely different M/Pt (M = Ru or Rh) structures of nanobox or octapod. Unusually high catalytic activities of Pt@Ru octapod toward the oxygen evolution reaction are observed due to a core–shell effect.

Impurity doping has yielded a number of useful optical and catalytic alloy nanoparticles, by providing synthetic routes to unprecedented nanostructures. However, Zn is difficult to use as a dopant in alloy nanoparticles due to the difficulty in reduction, and therefore little has been reported on Zn-doped alloy nanoparticles and their potential applications. Herein we report an unusual role of the dopant Zn as a crystal growth modifying agent to cause the formation of novel concave Rh nanostructures, namely nanotents. We could further prepare unprecedented hierarchically stacked Rh nanoframes and dendritic nanostructures derived from them by understanding the role of various surface-stabilizing moieties. We also report the usage of new Rh nanostructures in selective hydrogenation of phthalimides.

Regioselective growth of a heterophase on facet-controlled nanocrystals is an indispensable step towards generation of geometrically well-defined heteronanoarchitectures. The growth of a heterophase usually occurs on the most unstable surface features of a nanoparticle, such as vertices and edges, and therefore the ability to control the surface energy of facet-controlled nanocrystals is crucial for the rational synthesis of nanoarchitectures. It is, however, not easy to attain the ability to regioselectively grow a heterophase on a facet-controlled nanocrystal. Herein we introduce a simple strategy to pinpoint the site of heterophase growth on the surface of a faceted nanocrystal by controlling the concentration of surface-stabilizing moieties. Specifically, we show the regioselective growth of Au on a PtZn concave nanocube, covered with surface-bound CO moieties, forming two completely different Au–PtZn heteronanostructures of a filled-concave Au–PtZn surface mosaic nanocube and a vertex-covered Au–PtZn octapod. We also show their application in surface-enhanced Raman scattering (SERS)-based detection of small molecules.

Facet‐controlled nanoparticles as a substrate for heteroepitaxial growth can lead to disparate growth kinetics on different structural sites. H. Yang, K. Lee, and co‐workers report the synthesis of two completely different Pt@M heteronanostructures (M = Ru or Rh), namely, Pt@M nanoboxes and Pt@M octapods, using Pt cube seeds with slightly different morphologies. On page 4462, they identify the nanostructural features which boost catalytic performance toward the oxygen evolution reaction.