Ceramic Femoral Heads Exhibit Lower Wear Rates Compared to Cobalt Chrome: A Meta-Analysis

BackgroundWear between the femoral head and acetabular liners continues to limit the longevity of total hip arthroplasty implants despite advances in implant materials. The purpose of this meta-analysis was to compare linear wear rates of cobalt-chromium (CoCr) and fourth-generation ceramic femoral heads on highly cross-linked polyethylene (XLPE) liners.MethodsA systematic review following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines was conducted to identify all studies between 2003 and 2020 that examined in vivo wear rates of either fourth-generation ceramics or CoCr femoral heads on XLPE liners. Studies were analyzed in a weighted means analysis of wear rates and a random effects meta-analysis.ResultsA total of 36 studies met inclusion criteria (1,657 CoCr and 659 ceramic patients). The pooled, weighted mean wear rate was 0.063 mm/year (standard deviation [SD]: 0.061, confidence interval [CI]: 0.049-0.077) for CoCr and 0.047 mm/year (SD: 0.057, CI: 0.033-0.062; P < .01) for ceramic (P < .01). A meta-analysis of 4 studies directly comparing ceramic and CoCr found that CoCr heads demonstrated 0.029 mm/year more wear than ceramic heads (95% CI: 0.026-0.059, P = .306). Mean wear for 32-mm heads was significantly higher for ceramic (P < .01), while mean wear for 36-mm heads was significantly higher for CoCr (P < .01).ConclusionFourth-generation ceramic femoral heads were found to have significantly lower wear rates than CoCr heads. Unlike previous studies, this meta-analysis included only in vivo studies and those with the same generation of highly XLPE liners.     

Comparison of surf lifesaver pressure point control and a commercial arterial tourniquet for major lower limb haemorrhage: A randomised controlled crossover pilot trial

Objective

This pilot study compared non-medically trained surf lifesavers' (SLS) ability, after infographic training, to occlude the femoral artery using a pressure point (PP) versus an arterial tourniquet (AT).

Methods

Using a crossover design, eight SLS applied PP and AT to a participant's leg to occlude the femoral artery. Arterial flow, application time and perceived difficulty were recorded.

Results

PP achieved 89.7% and 50.8% blood flow reduction for PP and AT, respectively. Average application time was 50.63 and 113.5 s for PP and AT, respectively. Perceived difficulty using a Likert scale from 0 to 10 (0 being no difficulty and 10 being maximal difficulty) was 2.75 and 3.50 for PP and AT, respectively.

Conclusion

Infographic-trained SLS showed superior blood flow occlusion using PP. This pilot study will inform a larger trial for untrained beachgoers.     

股骨颈动力交叉钉系统治疗中青年Pauwels Ⅱ～Ⅲ型股骨颈骨折的疗效

目的 探讨股骨颈动力交叉钉系统(femoral neck system, FNS)治疗中青年Pauwels Ⅱ～Ⅲ型股骨颈骨折的疗效。方法 回顾性分析上海第六人民医院海口骨科与糖尿病医院及中南大学湘雅医学院附属海口医院骨科医学中心,于2021年2月至2022年6月期间收治的13例股骨颈骨折患者临床资料。其中男8例,女5例,年龄为(50.92±14.09)岁。骨折Pauwels分型,Ⅱ型4例,Ⅲ型9例。对患者术前、术后的髋关节Harris评分、Barthel 指数评分、疼痛视觉模拟评分 (visual analogue scale,VAS)进行统计学比较。结果 本研究13例患者随访时间12～28个月,平均(18.08±5.20)个月。髋关节Harris评分术前与术后比较差异有统计学意义 [(18.08±6.70)分 vs. (89.46±4.35)分,P < 0.001];Barthel 指数评分术前与术后比较差异有统计学意义[(23.38±7.07) 分 vs. (79.92±22.17) 分,P < 0.001]。VAS评分术前与术后比较差异有统计学意义[(8.08±1.32)分vs (0.69±0.75) 分,P < 0.001]。手术时间(52.08±11.54)分钟、骨折愈合时间(4±0.71)周、并发症发生率2/13、术中出血量(68.77±20.45)ml、部分负重时间(4.08±0.95)周、完全负重时间(7.15±0.90)周、术中透视(12.77±2.17)次、住院时间(5.85±1.66)天、骨折复位质量(Garden 对线指数 I级8、Ⅱ级5)、股骨颈短缩(轻度1,中度1)、医疗费用(51599±5701)元。结论 股骨颈动力交叉钉系统治疗中青年PauwelsⅡ～Ⅲ型股骨颈骨折的疗效良好,且有创伤小、骨折块愈合好、并发症少等优点,值得临床医师借鉴。     

*外泌体对激素性股骨头坏死治疗中的作用研究进展

激素性股骨头缺血性坏死(Steroid Induced Avascular Necrosis of the Femoral Head, SANFH)是骨科中一种具有高致 残率的慢性破坏性疾病,外泌体是由内吞膜衍生而来的纳米级囊泡,包含脂质、蛋白质、核酸和代谢产物等活性物质,是细胞与 细胞间通讯的主要参与者。外泌体可以将生物活性物质转移至靶细胞,从而引起靶细胞的表型改变,进而调节器官的修复和 再生。本文就不同来源外泌体(富血小板血浆、间充质干细胞及其他干细胞)对激素性股骨头缺血性坏死的作用及机制进行综 述,以期为激素性股骨头坏死提供潜在的以细胞为基础的治疗新途径。     

Alterations of sympathetic nerve fibers in avascular necrosis of femoral head

Objectives: Avascular necrosis of the femoral head (ANFH) was mainly due to alterations of bone vascularity. And noradrenaline (NA), as the neurotransmitter of the sympathetic nervous system (SNS), leads to the vasoconstriction by activating its α-Receptor. This study was to explore the nerve fiber density of the femoral head in the rabbit model of ANFH. Methods: Twenty New Zealand white rabbits were used in this study. The rabbit model of ANFH was established by the injection of methylprednisolone acetate. The nerve fiber density and distribution in the femoral head was determined using an Olympus BH2 microscope. Results: Significant fewer sympathetic nerve fibers was found in the ANFH intertrochanteric bone samples (P = 0.036) with osteonecrosis. The number of sympathetic nerve fibers was compared between the two groups. And less sympathetic nerve fibers were found in later stage ANFH samples in comparison with those of early stages. Conclusions: ANFH might be preceded by an inflammatory reaction, and an inflammatory response might lead to arthritic changes in tissue samples, which in turn reduces the number of sympathetic nerve fibers.     

MRI tracking of transplanted iron‐labeled mesenchymal stromal cells in an immune‐compromised mouse model of critical limb ischemia

Peripheral arterial disease is a clinical problem in which mesenchymal stromal cell (MSC) transplantation may offer substantial benefit by promoting the generation of new blood vessels and improving limb ischemia and wound healing via their potent paracrine activities. MRI allows for the noninvasive tracking of cells over time using iron oxide contrast agents to label cells before they are injected or transplanted. However, a major limitation of the tracking of iron oxide‐labeled cells with MRI is the possibility that dead or dying cells will transfer the iron oxide label to local bystander macrophages, making it very difficult to distinguish between viable transplanted cells and endogenous macrophages in the images. In this study, a severely immune‐compromised mouse, with limited macrophage activity, was investigated to examine cell tracking in a system in which bystander cell uptake of dead, iron‐labeled cells or free iron particles was minimized. MRI was used to track the fate of MSCs over 21 days after their intramuscular transplantation in mice with a femoral artery ligation. In all mice, a region of signal loss was observed at the injection site and the volume of signal hypointensity diminished over time. Fluorescence and light microscopy showed that iron‐positive MSCs persisted at the transplant site and often appeared to be integrated in perivascular niches. This was compared with MSC transplantation in immune‐competent mice with femoral artery ligation. In these mice, the regions of signal loss caused by iron‐labeled MSC cleared more slowly, and histology revealed iron particles trapped at the site of cell transplantation and associated with areas of inflammation. Copyright © 2012 John Wiley & Sons, Ltd.