[Surgical treatment of the complex bicondylar tibial plateau fracture using a midline longitudinal incision].

Objective: To explore the outcomes after treatment of the complex bicondylar tibial plateau fracture through a midline longitudinal approach. Methods: A review of fifteen patients with an average age of (51.3±12.3) years old (range17-65yers;7 males, 8 females) surgically treated from October 2013 to Febuary 2018 were included. Sahatker Ⅴ in 10, Sahatker Ⅵ in 5; fractures of medial and lateral columns in 9, fractures of three columns in 6. All the patients were adopt a midline longitudinal approach combined with the posterior approach and bone grafting were conducted. Results: All cases were followed-up for (14.4±3.8) month, with an average of 12-24 month. All patients gained bone union during 12-16 weeks after operation, with an average of (15.2±1.3) weeks. There were significant differeces in both tibial plateau angle and posterior slope angle on radiography between preoperation and postoperation (P<0.05), there were no significant differeces in either tibial plateau angle or posterior slope angle on radiography between immediate postoperation and 12 months postoperation (P>0.05). At final follow-up,both the Lachman test and the Pivot-shift test were negative. All patients had complete knee extension, knee flexion angle 100°-135°, with an average of 117.7°±11.3°. The HSS (the Hospital for Special Surgery) score were 66-98, with an average of 85.1±9.3, six cases were excellent and seven cases were good, two cases was fair, the excellent and good rate was 86.7%. The Rasmussen radiological evaluationre were 9-18, with an average of 15.1±2.5, three cases were excellent and eleven cases were good, one cases was fair, the excellent and good rate was 93.3%. 1 patient had fat liquefactionof in antero incision, and got good outcomes after debridement dressing. Conclusion: The treatment of the complex bicondylar tibial plateau fracture through a midline longitudinal approach combined with the posterior approach can result in good exposure and satisfying knee function in short-term.

Formation of microbeads during vapor explosions of Field's metal in water.

We use high-speed video imaging to investigate vapor explosions during the impact of a molten Field's metal drop onto a pool of water. These explosions occur for temperatures above the Leidenfrost temperature and are observed to occur in up to three stages as the metal temperature is increased, with each explosion being more powerful that the preceding one. The Field's metal drop breaks up into numerous microbeads with an exponential size distribution, in contrast to tin droplets where the vapor explosion deforms the metal to form porous solid structures. We compare the characteristic bead size to the wavelength of the fastest growing mode of the Rayleigh-Taylor instability.

Leaping shampoo glides on a lubricating air layer.

When a stream of shampoo is fed onto a pool in one's hand, a jet can leap sideways or rebound from the liquid surface in an intriguing phenomenon known as the Kaye effect. Earlier studies have debated whether non-Newtonian effects are the underlying cause of this phenomenon, making the jet glide on top of a shear-thinning liquid layer, or whether an entrained air layer is responsible. Herein we show unambiguously that the jet slides on a lubricating air layer. We identify this layer by looking through the pool liquid and observing its rupture into fine bubbles. The resulting microbubble sizes suggest this air layer is of submicron thickness. This thickness estimate is also supported by the tangential deceleration of the jet during the rebounding.

Satellite Formation during Coalescence of Unequal Size Drops.

The coalescence of a drop with a flat liquid surface pinches off a satellite from its top, in the well-known coalescence cascade, whereas the coalescence of two equally sized drops does not appear to leave such a satellite. Herein we perform experiments to identify the critical diameter ratio of two drops, above which a satellite is produced during their coalescence. We find that the critical parent ratio is as small as 1.55, but grows monotonically with the Ohnesorge number. The daughter size is typically about 50% of the mother drop. However, we have identified novel pinch-off dynamics close to the critical size ratio, where the satellite does not fully separate, but rather goes directly into a second stage of the coalescence cascade, thus generating a much smaller satellite droplet.