有限元评估尖顶距与股距尖顶距对股骨转子间骨折髓内钉内固定术后稳定性的影响

文题释义：尖顶距：是指术后即刻的正、侧位X射线片上拉力螺钉尖至股骨头颈中轴线与股骨头关节面交点的距离之和，并校正放大率后所得值，以毫米为单位。目前较为主流的观点是尖顶距值≤25 mm可有效减少拉力螺钉切出股骨头的可能性。股距尖顶距：股距尖顶距是在尖顶距的基础上提出的。正位片上，于内侧皮质做一条平行于股骨颈中轴线的切线，该线与股骨头关节面的交点至螺钉尖端的距离即为正位片上的股距尖顶距；侧位片上，为拉力螺钉尖至股骨头颈中轴线与股骨头关节面交点的距离；将正、侧位片上的股距尖顶距相加再予以校正后得到股距尖顶距的值。股距尖顶距更强调正位片上偏下的螺钉位置。 背景：尖顶距被广泛应用于预测拉力螺钉切出的可能性，但是一些临床研究发现在正位片上当拉力螺钉位于股骨头中心偏下的位置时更稳定，于是为了更准确评估拉力螺钉位置, 提出了股距尖顶距的概念，但是其应用价值还需要进一步验证。 目的：利用尖顶距和股距尖顶距的标准公式，将拉力螺钉放入股骨头内不同的区域，应用有限元方法对模型的稳定性进行评估并对比。 方法：利用CT影像数据建立左股骨有限元模型，用3D扫描加建模建立捷迈解剖型髓内钉内置物有限元模型，按照尖顶距15，20，25，30，35 mm将拉力螺钉分别放入股骨头内中间区域和前上、前下、后上、后下5个对应的象限，建立24个内固定模型。同时计算当拉力螺钉位于股骨头中间时对应的股距尖顶距，将拉力螺钉放入后上、后下、前上、前下4个象限，建立16个股距尖顶距模型。然后给模型垂直向下的力，比较以尖顶距和股距尖顶距为标准建立的有限元模型的稳定性。结果与结论：①以尖顶距为标准置入拉力螺钉，当拉力螺钉位于前上象限，尖顶距为35 mm时，股骨头最大轴向位移与无拉力螺钉时差值最小，为0.008 205 5 mm，当拉力螺钉位于股骨头后下象限，尖顶距为20 mm时，股骨头最大轴向位移与无拉力螺钉时差值最大，为0.023 524 0 mm。以股距尖顶距为标准置入拉力螺钉，当拉力螺钉位于前上象限，股距尖顶距为37.886 mm时，股骨头最大轴向位移与无拉力螺钉时差值最小，为0.008 794 1 mm，当拉力螺钉位于股骨头后下象限，股距尖顶距为25.256 mm时，股骨头最大轴向位移与无拉力螺钉时差值最大，为0.023 183 2 mm。②将拉力螺钉按照尖顶距和股距尖顶距的标准放入股骨头内，拉力螺钉位于股骨头中心偏后上方时，股骨骨折近端的最大主应力增高明显，平均值分别为82.339 4，79.118 8 MPa；拉力螺钉位于股骨头中心偏后下方时，股骨骨折近端的平均最大主应力值减小，分别为49.535 9，49.642 8 MPa。提示：在评估尖顶距和股距尖顶距对股骨转子间骨折髓内钉内固定模型稳定性的影响时，股距尖顶距并未较尖顶距表现出明显优势；股骨骨折近端的稳定性受到拉力螺钉位置的影响更大，当拉力螺钉位于股骨头下后象限时，稳定性最好。ORCID: 0000-0002-7707-3553(乔文) 中国组织工程研究杂志出版内容重点：人工关节；骨植入物；脊柱；骨折；内固定；数字化骨科；组织工程     

“One-piece” patient-specific reconstruction plate for double-barrel fibula-based mandibular reconstruction

Segmental mandibular defects require reconstruction. The fibula flap serves as a versatile flap in restoring mandibular contour and bony height. With the advances in computer-aided design and additive manufacturing technology, an innovative “one-piece” patient-specific reconstruction plate to facilitate double-barrel fibula flap shaping and bone securing was developed; the plate is described in this study. The “one-piece” plate is fabricated with individualized specifications and is mainly composed of three components: the long-bar reconstruction plate, a short-bar plate, and connecting bars. Our initial experiences showed that mandibular reconstructive surgery was greatly facilitated by the “one-piece” reconstruction plate for double-barrel fibula flap reconstruction and achieved satisfactory outcomes. A well-designed clinical trial is required to confirm the superiority of the “one-piece” reconstruction plate in the future. ClinicalTrials.gov registration: NCT03057223.     

Epidemiology,classification, treatment and mortality of Talus fractures: An observational study of 1794 talus fractures from the Swedish Fracture Register

BackgroundEpidemiological data on talus fractures from large nationwide and multicenter studies are rare. This study aims to describe the epidemiology, fracture classification and treatment regimens of talus fractures in a large adult Swedish population.MethodsThis observational study is based on data from the Swedish Fracture Register (SFR) including talar fractures in patients ≥18 with a sustained fracture between 2012 and 2021. Epidemiological data on sex, age, injury date, injury mechanism and type (high or low energy trauma), fracture classification (side, type), initial treatment and mortality were analysed.ResultsWe included 1794 talus fractures (1757 patients, 60 % men). Mean age was 40.3 years (range 18–96), and a biphasic age distribution was seen in women. High-energy trauma caused 33 % of all talus fractures. Of all talus fractures, 817 (45.5 %) were classified as AO/OTA type A fractures (avulsion), 370 (20.6 %) as type B (neck) and 435 (24.2 %) as type C (body). The remaining 172 (9.6 %) talus fractures were not classified/unclassifiable. Men were in the majority in all fracture groups except A1. For type A1–3, B1 and C1–2 fractures, most patients were treated non-operatively; in B2–3 and C3 fractures most patients received operative management. Fracture fixation with screws was the dominating surgical treatment. The overall 30-day mortality was 0.2 %.ConclusionTalus fractures are most commonly encountered in young and middle-aged men. In contrast to men, a biphasic age distribution was observed in women. Approximately half of the talus fractures are avulsions. Operative treatment, mostly screw fixation, is performed in more complex fracture configurations (B2, B3 and C3 fractures).Level of evidenceIV, retrospective observational cohort study     

84例产褥感染的临床特点及常见致病微生物耐药性分析

目的 研究产褥感染的危险因素及常见致病微生物耐药情况，为临床治疗提供参考。方法 回顾性分析我院2017 年1 月～2019 年12 月发生的84 例产褥感染病例的临床资料，与同时期未发生产褥感染的200 例产妇进行对照研究，分析产褥感染的影响因素，并对分离获得的致病微生物进行耐药性分析。结果 感染组妊娠糖尿病、产钳助产、宫口开全后中转剖宫产患者的分布率高于对照组，差异有统计学意义（P＜0.05）；经多因素Logistic 回归分析，妊娠糖尿病是产褥感染的独立影响因素（P＜0.05）。本研究中共检出致病微生物40 株，其中革兰阴性菌13 株（占32.50%），革兰阳性菌10 株（占25.00%），支原体16 株（占40.00%），衣原体1 株（占2.50%），革兰阴性菌中以大肠埃希菌最常见，对二代头孢菌素类抗生素耐药率20%。革兰阳性菌以金黄色葡萄球菌最常见，对青霉素及头孢菌素耐药率高，未发现对亚胺培南及万古霉素耐药。结论 产钳助产、妊娠糖尿病、宫口开全后中转剖宫产是产褥感染可能的危险因素，其中，妊娠糖尿病是产褥感染的独立危险因素。目前临床常见致病微生物谱及耐药率未发生明显变化。