“Internal fixation of proximal humeral fractures using the Polarus intramedullary nail: our institutional experience and review of the literature”

Abstract Background The purpose of this study is to evaluate the functional outcome, union and complication rates after surgical treatment of unstable or displaced proximal humeral fractures using the Polarus intramedullary nail, by reviewing our institutional experience and the relevant current literature. Methods Twenty-seven patients were treated operatively for proximal humeral fracture using the Polarus nail. Fractures were classified according to Neer’s classification. A number of parameters including patient demographics, mechanism of injury, operative time, time to union and complications were recorded. Functional outcome was evaluated using the Constant Shoulder Score. A comparison among functional outcomes in patients >60 years in relation to the younger ones was performed. Moreover, a review of the literature was carried out to evaluate the overall union and complication rates. Results Two patients lost to follow-up were excluded from the analysis. For the twenty-five patients (mean age: 61 years), the mean follow-up was 36 months. There were 7 complications (28%), including one fixation failure, four protruded screws, one superficial infection and one case of impingement. The union rate was 96% (mean time to union: 4.2 months). The mean Constant score was 74.5 (range: 48–89). Patients under the age of 60 had a better functional outcome compared to patients >60 years of age (p0.05). From the literature review and from a total of 215 patients treated with a Polarus nail, the mean union rate was 95.8%, the overall reported complication rate, including both minor and major complications, ranged widely from 9.3% up to 70%. Conclusions The Polarus nail was found to be an effective implant for stabilisation of proximal humeral fractures. Functional outcome is for the vast majority of the cases excellent or good, but in elderly patients a lower Constant score can be expected.</p

MAPbI₃ on GaAs: A Washable Heterointerface with Robust Passivation Effect

We demonstrate that the deposition of methylammonium lead iodide (MAPbI3) on native nominally undoped (100) GaAs substrates generates an enhancement in the GaAs photoluminescence (PL) intensity by more than 3 orders of magnitude. We attribute this pronounced PL enhancement to some very efficient MAPbI3-induced passivation schemes of the GaAs surface. Time-resolved PL experiments reveal greatly enhanced carrier lifetimes next to the GaAs surface, in agreement with a passivation process. X-ray photoelectron spectroscopy measurements on ultrathin MAPbI3/GaAs and PbI2/GaAs samples suggest some Pb-related deoxygenation of the GaAs surface, as an atomistic mechanism possibly related to the passivation effect. Notably, the whole process is fully reversible, as it suffices to immerse the MAPbI3/GaAs sample in salt water and the MAPbI3 layer is completely removed, while the PL intensity and spectral features of the GaAs substrate return to their pristine condition

Proximal tibial fractures: early experience using polyaxial locking-plate technology

Between 2004 and 2009, 60 patients with proximal tibial fractures were included in this prospective study. All fractures were treated with the polyaxial locked-plate fixation system (DePuy, Warsaw, IN, USA). Clinical and radiographic data, including fracture pattern, changes in alignment, local and systemic complications, hardware failure and fracture union were analysed. The mean follow-up was 14 (12–36) months. According to the Orthopaedic Trauma Association (OTA) classification, there were five 41-A, 28 41-B and 27 41-C fractures. Fractures were treated percutaneously in 30% of cases. Double-plating was used in 11 cases. All but three fractures progressed to union at a mean of 3.2 (2.5–5) months. There was no evidence of varus collapse as a result of polyaxial screw failure. No plate fractured, and no screw cut out was noted. There was one case of lateral joint collapse (>10°) in a patient with open bicondylar plateau fracture. The mean Knee Society Score at the time of final follow-up was 91 points, and the mean functional score was 89 points. The polyaxial locking-plate system provided stable fixation of extra-articular and intra-articular proximal tibial fractures and good functional outcomes with a low complication rate