Excursion of Oscillating Saw Blades in Total Knee Arthroplasty

Intraoperative disruption of the medial collateral ligament during total knee arthroplasty is an uncommon complication that can be avoided by retractor placement as well as by careful cutting of the femur and tibia. This study evaluated the excursion of a small and large oscillating saw blade and compared the data against the widths of both the medial and lateral femoral condyle cuts. We discovered that the large saw blade had a statistically significantly larger excursion than the medial and lateral condyle width in women, as well as the lateral condyle width in men. The small saw blade excursion did not exceed any condyle width. We conclude that the smaller saw blade should be considered when making these cuts because the excursion of the large saw blade may exceed the width of cut needed and endanger important structures such as collateral ligaments.     

两种植骨术治疗四肢陈旧性骨折骨不连的疗效对比

目的对比分析小切口环锯法植骨术与传统切开植骨术治疗四肢陈旧性骨折骨不连的疗效。方法选取2008年1月至2010年12月期间武冈市人民医院收治的四肢陈旧性骨折骨不连患者94例作为研究对象,将这些患者随机分为2组,观察组47例,接受小切口环锯法植骨术治疗;对照组47例,接受传统切开植骨术治疗。结果观察组的骨折愈合效果显著优于对照组,两组比较差异有统计学意义(P<0.05);观察组的骨折愈合时间显著短于对照组,两组比较差异有统计学意义(P<0.05)。结论小切口环锯法植骨术治疗四肢陈旧性骨折骨不连具有疗效好、恢复快等优点,该术式值得在临床上推广与应用。     

Pharmacological effects of saw palmetto extract in the lower urinary tract

Saw palmetto extract （SPE）, an extract from the ripe berries of the American dwarf palm, has been widely used as a therapeutic remedy for urinary dysfunction due to benign prostatic hyperplasia （BPH） in Europe. Numerous mechanisms of action have been proposed for SPE, including the inhibition of 5a-reductase. Today, al-adrenoceptor antagonists and muscarinic cholinoceptor antagonists are commonly used in the treatment of men with voiding symptoms secondary to BPH. The improvement of voiding symptoms in patients taking SPE may arise from its binding to pharmacologically relevant receptors in the lower urinary tract, such as al-adrenoceptors, muscarinic cholinoceptors, 1,4-dihyropyridine receptors and vanilloid receptors. Furthermore, oral administration of SPE has been shown to attenuate the up-regulation of α1-adrenoceptors in the rat prostate induced by testosterone. Thus, SPE at clinically relevant doses may exert a direct effect on the pharmacological receptors in the lower urinary tract, thereby improving urinary dysfunction in patients with BPH and an overactive bladder. SPE does not have interactions with co-administered drugs or serious adverse events in blood biochemical parameters, suggestive of its relative safety, even with long-term intake. Clinical trials （placebo-controlled and active-controlled trials） of SPE conducted in men with BPH were also reviewed. This review should contribute to the understanding of the pharmacological effects of SPE in the treatment of patients with BPH and associated lower urinary tract symptoms （LUTS）.     

Radiographic outcomes of intertrochanteric hip fractures treated with the trochanteric fixation nail

BACKGROUND: Intertrochanteric hip fractures have become more common as the elderly population continues to increase, and surgical stabilisation of these fractures remains a persistent challenge. The purpose of this study was to analyse the ability of a new helical blade device to stabilise intertrochanteric hip fractures, and to further determine which factors are important in implant stability. METHODS: Two hundred and fifty-five patients with an intertrochanteric hip fracture were treated with a trochanteric fixation nail (TFN), 97 of whom fit strict radiographic and follow-up criteria and were included in the study group. After adjusting for magnification and rotation, blade migration within the femoral head and telescoping of the blade along its axis were measured using a custom-designed grid system. Multivariate regression analyses were performed to determine which variables predicted blade migration and telescoping. RESULTS: Fifty-nine fractures were classified as stable, and the remaining 38 were unstable. Mean telescoping was 4.3 mm in the unstable group, compared to 2.6 mm in the stable group (p<0.05). Blade migration within the femoral head averaged 2.2 mm overall, with no difference between stable and unstable fractures. For both telescoping and blade migration, no significant change occurred after the 6-week time point in the stable or unstable group. Nail length, age, and gender did not have a significant effect on either blade migration or telescoping implant position change. Of the initial cohort of 255 patients, five cutouts and one nonunion occurred, three of which required subsequent procedures. CONCLUSIONS: Subtle migration ( approximately 2mm) of the tip of the blade within the femoral head occurred in all fractures, but this did not preclude maintenance of reduction and fracture healing, and was not predicted by fracture type, reduction quality, age, or gender. More telescoping occurred in unstable compared to stable fractures, but this averaged 4mm and did not affect stable fixation or fracture healing. All position changes occurred within the first 6 weeks postoperatively, with no subsequent detectable migration or telescoping. Clinical correlations will be needed in the future to determine the significance of small amounts of migration or differences in telescoping, but this device appears to provide effective fixation in both stable and unstable intertrochanteric hip fractures.     

The Callender modification of the Macintosh laryngoscope blade reduces the risk of tooth-blade contact in children

Background: Dental injury is well recognized as a potential complication of laryngoscopy and tracheal intubation. The flange of the Macintosh blade may contact teeth during laryngoscopy causing damage. The Callander modification of the Macintosh blade (Callander blade) with a shortened heel at the proximal end has been shown to increase the blade–tooth distance and reduce contact rates in adults. Aim: This study was designed to evaluate the effectiveness of the Callander blade on reducing dental contact in children. Methods: One hundred children, aged 4–14 years, scheduled for general anesthesia requiring endotracheal intubation were studied prospectively. The children were preoperatively evaluated for Mallampati score and dental defects, looseness, and avulsions. Following induction of anesthesia, laryngoscopy was performed twice on each child in succession, once with a standard Macintosh blade and once with a Callander blade of the same size in a random order. The blade–tooth distance and contact rate were compared between the two blades. Results: With the Callander blade, the blade–tooth distance was greater than with the Macintosh (1.78 ± 1.77 vs 0.28 ± 0.76 mm, P = 0.001). The frequency of direct contact was less with the Callander blade than it was with the Macintosh blade (33% vs 86%, respectively, P = 0.008). However, difficult laryngoscopy rate did not differ between the blades. Tracheal intubation was successful in all children and there was no dental injury. Conclusion: Our findings suggest that the Callander blade decreases the risk for dental injury and provides tracheal intubating conditions in children with normal airways similar to those obtained with a traditional Macintosh blade.     

Computational modelling of motion at the bone–implant interface after total knee arthroplasty: The role of implant design and surgical fit

Background

Aseptic loosening, osteolysis, and infection are the most commonly reported reasons for revision total knee arthroplasty (TKA). This study examined the role of implant design features (e.g. condylar box, pegs) and stems in resisting loosening, and also explored the sensitivity of the implants to a loose surgical fit due to saw blade oscillation.

Surgery-induced behavioral changes in aged rats

Elderly patients may experience impairments in cognition or mood following surgery. To study the development and underlying mechanisms of these postoperative behavioral changes, young (3 months) and aged (18–20 months) male rats were subjected to abdominal surgery followed by behavioral testing during a period of 6 weeks. Microglia activation (IBA-1) and neurogenesis (DCX) were immunohistochemically determined. In separate experiments, the effects of anesthesia and the cytokine response (IL-6) following surgery were evaluated.     

Effect of Pro-Ecological Cooling and Lubrication Methods on the Sharpening Process of Planar Blades Used in Food Processing

This work presents the results of an experimental study of the sharpening of planar technical blades used in the fish processing industry. Sharpening was carried out in the grinding process using several environmentally friendly methods of cooling and lubricating the machining zone (MQL method, CAG nozzle, hybrid method that is a combination of MQL and CAG methods, as well as WET flooding method as reference). The purpose of the research was to determine the possibility of reducing the negative environmental impact of the sharpening process of technical blades by minimizing the expenditure of coolant. The application of the MQL method and the hybrid MQL + CAG method provided a very good realization of the lubricating function so that the share of friction of dulled cutting vertices against the workpiece surface is reduced, which manifests itself in the reduction of the grinding force and the correlated grinding power. In the case of grinding under cooled compressed air delivery conditions, the average cutting force was as much as 91.6% higher (F = 22.63 N) compared to the result obtained for the most favorable flooding method, demonstrating the insufficient quality of the blade shaped under such conditions. A comprehensive comparison of test results on grinding power gain, cutting force and surface texture suggests that the most favorable sharpening results were obtained using the environmentally friendly MQL method of cooling and lubricating the grinding zone.     

Effect of the Granularity of Cubic Boron Nitride Vitrified Grinding Wheels on the Planar Technical Blades Sharpening Process

The most widely used method for shaping technical blades is grinding with abrasive tools made of cubic boron nitride (cBN) grains and vitrified bond. The goal of this work was to determine the effect of grinding wheel grain size (cBN grain number according to FEPA standards: B126, B181 and B251), kinematics (grinding with the circumference, face and conical surface of the wheel) and feed rate (v_f = 100; 150; 200 mm/min) on the effects of the grinding process evaluated by the cutting force of the blade after machining F, blade surface texture parameters (Sa, St, Smvr, Str, Sdq, Sdr and Sbi) as well as blade surface morphology. An analysis of output quantities showed that grinding wheels made of B181 cBN grains are most favorable for shaping planar technical blades of X39Cr13 steel in the grinding process.     

痹祺胶囊联合刃针治疗膝骨性关节炎的疗效观察

目的 探究痹祺胶囊联合刃针治疗早期膝骨性关节炎（knee osteoarthritis,KOA）的疗效。方法 采用随机数字表法将70例KOA患者随机分成2组,各35例。2组患者均用刃针治疗,1次/周,共2次;对照组患者联合口服塞来昔布胶囊200 mg/次,1次/d;试验组患者联合口服痹祺胶囊1.2 g/次,3次/d;治疗14 d。比较治疗前后及3个月随访的视觉模拟评分（visual analogue scale,VAS）及西安大略和麦克马斯特大学（Western Ontario and McMaster University,WOMAC）骨关节炎指数量表评分来判定疗效。结果 纳入研究的70例KOA患者中有8例脱落,共有62例纳入分析。2组治疗后VAS及WOMAC评分较治疗前均显著降低（P<0.01）,但对照组比试验组的VAS分值降低更明显（P<0.05）,WOMAC评分在治疗2周后和3个月随访均为试验组降低更明显（P<0.05）。治疗2周后,2组有效率较接近（试验组96.9%,对照组90%）,3个月随访试验组有效率（93.8%）优于对照组（63.3%）（P<0.01）。结论 采用痹祺胶囊联合刃针与塞来昔布联合刃针治疗KOA均疗效显著,但痹祺胶囊联合刃针改善关节功能更明显,且疗效更稳定持久。