Hip arthroscopy provides very good clinical outcomes if precisely indicated and performed. It is, however, a demanding procedure with many possible pitfalls and complications. According to our study, at least 100 procedures are needed to gain basic technical and indication skills. The presence of a more skilled surgeon in the beginning of the learning curve is advised to reduce the complication rate.

Purpose Preoperatively planned correction for tibial osteotomy surgery is usually based on weightbearing long-leg Xrays, while the surgery is performed in a supine non-weightbearing position. The purpose of this study was to assess the differences in lower limb alignment in three different weightbearing conditions: supine position, double-leg (DL) stance and single-sleg (SL) stance prior to performing a medial opening wedge high tibial osteotomy (MOWHTO) for varus malalignment. The hypothesis of this study was that progressive limb-loading would lead to an increased preoperative varus deformity.Material and methods This retrospective study included 89 patients (96 knees) with isolated medial knee osteoarthritis (Ahlbäck grade I or II) and significant metaphyseal tibial vara (> 6°). The differences between supine position, DL stance and SL stance were analysed for the hip-knee-ankle angle (HKA), lateral distal femoral angle (LDFA), medial proximal tibial angle (MPTA), weight-bearing line ratio (WBL) and joint line convergence angle (JLCA). Results From a supine position to DL stance, the HKA angle slightly increased from 175.5° ± 1.1° to 176.3° ± 1.1° and JLCA changed from 2.0° ± 0.3° to 1.8° ± 0.3° without a statistically significant difference. From DL to SL stances, the HKA angle decreased from 176.3° ± 1.1° to 174.4° ± 1.1° (p < 0.05) and the JLCA increased from 1.8° ± 0.3° to 2.6° ± 0.3° (p < 0.05). A significant correlation was found between ΔHKA and ΔJLCA between the DL and the SL stances (R 2 = 0.46; p = 0.01). Conclusion Varus malalignment increases with weight-bearing loading from double-leg to single-leg stances with an associ-ated JLCA increase. Thus, single-leg stance radiographs may be useful to correct preoperative planning considering patient-specific changes in JLCA. Level of clinical evidence III, retrospective comparative study.

Objective:This study compared groups of patients with calcaneal fractures of Sanders types II and III. One group was treated with ORIF using an LCP (plate), while the second was treated with a minimally invasive method using a C-Nail.Methods:The study included 217 patients in the ORIF group and 19 patients in the minimally invasive nail osteosynthesis group.Results:In the LCP group, the outcomes were excellent for 35.7% of the patients; good, 38.9%; satisfactory, 19.7%; and poor, 5.7%. In the C-Nail group, the outcomes were excellent for 36.9% of the patients; good; 31.6%; satisfactory, 21%; and poor, 10.2%. The mean values of the restoration of Böhler's angle from post-injury were 6.8° to 32.3° in the LCP group and 7.1° to 33.3° in the C-Nail group. After 12 months, there was only a minimal decrease in Böhler's angle to 29.2° in both the LCP and C-Nail groups.Conclusion:The outcomes obtained with C-Nail fixation are statistically identical to those obtained with LCP fixation. We conclude that osteosynthesis with a C-Nail is suitable as the first-choice treatment for Sanders types II and III fractures. Level of evidence IV, retrospective observational study.

Biofuels have become an integral part of everyday life in modern society. Bioethanol and fatty acid methyl esters are a common part of both the production of gasoline and diesel fuels. Also, pressure on replacing fossil fuels with bio-components is constantly growing. Waste vegetable fats can replace biodiesel. Hydrotreated vegetable oil (HVO) seems to be a better alternative. This fuel has a higher oxidation stability for storage purposes, a lower temperature of loss of filterability for the winter time, a lower boiling point for cold starts, and more. Viscosity, density, cold filter plugging point of fuel blend, and flash point have been measured to confirm that a fuel from HVO is so close to a fuel standard that it is possible to use it in engines without modification. The objective of this article is to show the properties of different fuels with and without HVO admixtures and to prove the suitability of using HVO compared to FAME. HVO can also be prepared from waste materials, and no major modifications of existing refinery facilities are required. No technology in either investment or engine adaptation of fuel oils is needed in fuel processing.

is an attorney who serves as a researcher at the Institute of Criminology and Social Prevention in Prague, Czech Republic. His main research interests include drug related crime, criminal justice systems, and drug policy.