Three-dimensional finite element analysis of intramedullary nail with different materials in the treatment of intertrochanteric fractures

Intramedullary nails are the common treatment options for femoral intertrochanteric fractures. However, aseptic loosening is considered to be one of the primary forms of failure that can be caused by the stress shielding between the bone and implants. The matching in mechanical properties of implant and bone is a key issue to prevent this failure. Polyetheretherketone (PEEK) and Function-graded (FG) materials are widely used in clinical because of their excellent mechanical properties. In this study, to investigate the biomechanical behaviors of intramedullary nails made of Ti-6Al-4V alloy, Stainless Steel (SS), PEEK and two FG materials, three-dimensional finite element models of intertrochanteric fracture femur with intramedullary nail were constructed with ABAQUS. The maximum von Mises stress on the femoral fracture surface fixed by PEEK intramedullary nail was the largest, followed by FG intramedullary nail, which help stimulate bone growth and subsequently reduce fracture healing time. Compared with traditional metal intramedullary nails, PEEK and FG implants might increase von Mises stress along the same path in the proximal femur. The results showed that PEEK and FG intramedullary nails obviously changed the stress distributions in the bone and reduced stress shielding. This finding indicated that PEEK and FG intramedullary nails have the potential to become alternatives to the conventional metal intramedullary nails.     

内侧支撑髓内钉和股骨近端抗旋髓内钉治疗股骨转子间骨折A3.3型的生物力学研究

目的：A3型股骨转子间骨折是极其不稳定的骨折,临床上常常采用髓内治疗,但是髓内固定失败率高,股骨后内侧结构不能重建是主要原因。介绍一种可以早期重建股骨内侧支撑的新型内侧支撑髓内钉,通过生物力学试验验证力学效果。方法：利用人工股骨模型（Sawbones）制作内侧失支撑的A3.3型转子间骨折模型,分别用新型内侧支撑髓内钉（medial sustainable nail-Ⅱ,MSN-Ⅱ）和股骨近端抗旋髓内钉（proximal femoral nail anti-rotation,PFNA-Ⅱ）固定后,行轴向加载和轴向破坏试验,测定两种内固定物的轴向刚度、屈服载荷、头颈骨块的位移和断端扭转角度,比较两种内固定的生物力学差异,明确重建内侧支撑的髓内钉早期重建股骨内侧支撑的效果。结果：MSN-Ⅱ的轴向刚度、屈服载荷、当轴向载荷为1 800 N时头颈骨块的位移、破坏试验后的骨折断端扭转角度分别为（222.76±62.46）N/mm,（4 241.71±847.42）N,（11.51±0.62）mm,（1.71±0.10）°;PFNA-Ⅱ分别为（184.58±40.59）N/mm,（3 058.76±379.63）N,（16.15±1.36）mm,（2.52±0.26）°,两组差异均有统计学意义。结论：MSN-Ⅱ轴向刚度优于PFNA-Ⅱ,在固定A3.3型骨折时能耐受更大的载荷,具有更大的轴向和旋转稳定性,是重建A3型股骨转子间骨折内侧支撑有效的手段。     

新型冠状病毒肺炎疫情期间骨科急症处理原则的专家共识

自2019年12月以来,湖北省武汉市部分医院相继收治多个有华南海鲜市场暴露史的不明原因肺炎病例[1]。患者症状多为发热、乏力、干咳并逐渐出现呼吸困难,部分重症患者出现了急性呼吸窘迫综合征或脓毒症休克、甚至病死。2020年1月7日,我国研究人员首次从患者标本中检测出一种新型冠状病毒[2]。2020年1月20日,中华人民共和国国家卫生健康委员会发布2020年1号公告,将新型冠状病毒感染的肺炎纳入乙类传染病,并按照甲类传染病进行防疫、控制[3]。世界卫生组织将新型冠状病毒肺炎命名为"COVID-19"[4]。     

The Posttaumatic Adjustment Scale (PAS) is an effective measure in predicting psychological distress in patients following major trauma

AimsTo determine whether a psychological screening tool - the Posttraumatic Adjustment Scale (PAS), predicts later psychological distress for admissions to a Major Trauma Centre (MTC) and to identify whether there was an unmet need in relation to the psychological support offered.MethodsPatient demographics and details of their injuries were retrieved from the Trauma Audit & Research Network (TARN) database. All patients admitted to Leeds General Infirmary MTC were approached for inclusion in the study over a three-month period. The PAS was administered to all participants at baseline. Following discharge, patients were sent two validated psychological measures via post, the Impact of Events Scale – Revised (IES-R) and the Clinical Outcomes in Routine Evaluation System (CORE-10). Relationships between continuous variables were examined using a Spearman's rank test (SR). The diagnostic accuracy of the different psychological screening systems was examined and compared using Receiver Operator Characteristic (ROC) analysis.ResultsEighty-two patients completed the PAS, 26 of whom had been referred to clinical psychology and 56 who were not. Fifty-seven of these patients (70%) returned follow-up IES-R and CORE-10 data, 20 who had been referred to psychology and 37 who had not. The PAS-P score recorded shortly after admission correlated strongly with the CORE-10 (SR rs 0.54, p<0.0001) and IES-R (SR rs 0.63, p<0.0001) scores recorded at early follow up. A PAS-P of more than 10 predicted the development of PTSD symptoms (IES-R 33 or more) or moderate global psychological distress (CORE-10 15 or more) with 72% sensitivity and 71% specificity. To identify patients who went on to develop psychological symptoms according to either measure (IES-R 33 or more or CORE-10 15 or more), the PAS-P was more sensitive than clinician referral (71% vs 52%, p<0.05) with similar specificity (72% vs 75%, p=0.78).ConclusionsIn an unselected group of trauma inpatients treated in a MTC, the PAS is an effective means of identifying those who are likely to go on to suffer PTSD symptoms or psychological distress. It may useful to use the PAS as a measure to formalise psychology referrals.     

前交叉韧带翻修术中期疗效研究

目的评估前交叉韧带（anterior cruciate ligament，ACL）翻修术后的中期疗效以及相关影响因素分析。方法回顾分析 2009 年 4 月—2018 年 7 月行 ACL 翻修术且术后随访 2 年以上的 24 例患者临床资料。其中男 20 例，女 4 例；年龄中位数为 30 岁，四分位数间距（interquartile distance，IQR）为（25，36）岁。体质量指数中位数为 24.45 kg/m²，IQR 为（22.93，25.93） kg/m²。ACL 翻修术与重建术间隔时间中位数为 41 个月，IQR 为（15，85）个月。重建术失效直接原因：外伤 14 例，无明显诱因 8 例，感染 2 例。翻修术中共 14 例患者骨隧道位置不佳，均钻取全新隧道，余 10 例在原骨隧道基础上进行新鲜化；17 例患者采用自体肌腱翻修，7 例采用 LARS 人工韧带；16 例患者合并软骨损伤。术前、术后 1 年和末次随访时采用 Lysholm 评分、国际膝关节文献委员会（IKDC）评分及 Tegner 运动等级评分进行功能评价，末次随访时记录 Likert 患者满意度评分。 结果术后患者均获随访，随访时间中位数为 47 个月，IQR 为（32，61）个月。患者术后 1 年及末次随访时 Lysholm 评分、IKDC 评分、Tegner 运动等级评分均较术前明显提高（P<0.05），末次随访时与术后 1 年比较差异无统计学意义（P>0.05）。末次随访时 Likert 患者满意度评分中位数为 4.0 分，IQR 为（3.0，4.5）分。根据软骨损伤与否和移植物类型分组，组间比较末次随访时上述各评分，差异均无统计学意义（P>0.05）。末次随访时 2 例患者因外伤再次发生移植物断裂，均取自体髂骨填塞骨隧道，二期进行翻修；其余患者功能恢复满意。 结论ACL 翻修术前明确重建失败原因，术中选取合适的骨隧道和移植物，术后辅以积极的康复锻炼，可获得良好中期疗效。     

Small residual fracture gaps delay time to union in length stable femur fractures treated with intrameduallary fixation

ObjectivesThe purpose of this study was to investigate whether residual fracture gapping and translation at time of intramedullary nail (IMN) fixation for diaphyseal femur fractures were associated with delayed healing or nonunion.DesignRetrospective cohort studySettingLevel 1 trauma hospital, quaternary referral centerPatients/Participants/InterventionLength stable Winquist type 1 and 2 diaphyseal femur fractures treated with IMN at a single Level I trauma center were retrospectively reviewed.Main Outcome MeasureThe largest fracture gap and translation were evaluated on immediate anteroposterior (AP) and lateral postoperative radiographs. Radiographic healing was assessed using Radiographic Union Score in Femur (RUSF) scores at each follow-up. Radiographic union was defined as a RUSF score ≥8 and consolidation of at least 3 cortices. ANOVA and student's t-tests were used to evaluate the influence of fracture gap parameters on time to union (TTU) and nonunion rate. Patients were stratified to measured average gap and translation distances <1mm, 1-3mm and >3mm for portions of the analysis.ResultsSixty-six patients who underwent IMN with adequate follow-up were identified. A total of 93.9% of patients achieved union at an average of 2.8 months. Fractures with average AP/lateral gaps of <1mm, 1-2.9 mm, and >3mm had an average TTU of 70.1, 91.7, and 111.9 days respectively; fractures with larger residual gap sizes had a significantly longer TTU (p=0.009). Fractures with an average gap of 1-2.9mm and >3 mm had a significantly higher nonunion rate (1.5% and 4.5% respectively) compared to 0% nonunion in the <1 mm group (p=0.003).ConclusionResidual gapping following intramedullary fixation of length stable diaphyseal femur fractures is associated with a significant increase in likelihood of nonunion.SummaryResidual displacement of length stable femoral shaft fractures following intramedullary nailing can have a significantly negative impact on fracture healing. An average 3 mm AP/lateral residual fracture gap or a total of 6 mm of the AP + lateral fracture gap appeared to be a critical gap size with increased rates of nonunion and time to union. Therefore, we suggest minimizing the sum of the residual AP and lateral fracture gap to less than a total of 6 mm.     

股骨头坏死骨吸收区对股骨头内应力分布及疾病进展的影响

目的探讨股骨头坏死骨吸收区对股骨头内应力分布及疾病进展的影响。方法回顾性分析2014年4月至2018年9月诊断为ARCOⅡ、Ⅲ期股骨头坏死的患者94例(155髋),男77例,女17例;年龄(39.90±10.45)岁(范围18~64岁)。依据是否含骨吸收区将患髋分为有骨吸收区组和无骨吸收区组,比较两组ARCO分期的差异。在无骨吸收区组选取1例ARCOⅡ期髋关节,模拟5、7、10、14、18、23 mm六个不同直径大小的球形骨吸收区,通过有限元方法模拟人在慢速行走时的髋关节负重,观察分析股骨头不含骨吸收区以及含不同直径大小骨吸收区时坏死区最大应力、平均应力和骨吸收区周围1 mm区域内的最大应力值。结果有骨吸收区组67髋,其中ARCOⅡ期17髋、ARCOⅢ期50髋;无骨吸收区组88髋,其中ARCOⅡ期58髋、ARCOⅢ期30髋。有骨吸收区组ARCOⅢ期比例(74.6%,50/67)明显高于无骨吸收区组(34.1%,30/88),差异有统计学意义(χ^2=25.03,P=0.000)。有限元应力云图显示在骨吸收区的上方存在应力集中区;有骨吸收区组的骨吸收区周围1 mm区域内最大von Mises应力为(6.94±1.78)MPa,高于无骨吸收区组的(5.01±0.35)MPa,差异有统计学意义(t=3.139,P=0.026)。线性回归分析显示股骨头内坏死区的最大应力、平均应力以及骨吸收区周围1 mm区域内最大应力值与骨吸收区直径呈线性正相关。结论骨吸收区可增加坏死区的最大应力和平均应力,骨吸收区越大应力增加越明显;骨吸收区周围可产生应力集中区,加速股骨头塌陷。     

慢性髋关节疼痛患者的功能障碍及相关心理因素分析

目的 分析慢性髋关节疼痛患者功能障碍的特点,阐明其功能障碍与心理因素之间的关系。方法 收集2021年4月至2022年3月解放军总医院收治的55例慢性髋关节疼痛患者(患者组),34例健康受试者作为对照组。通过问卷调查采集患者一般人口学信息和临床资料。采用髋关节日常生活能力评分(HOSADL)、髋关节运动能力评分(HOS-SSS)、改良Harris髋关节评分(mHHS)、12项健康调查简表(SF-12)、视觉模拟评分(VAS)、医院焦虑抑郁量表(HADS)(分为HADS:A和HADS:D)、焦虑状态/特质问卷(STAI)、疼痛灾难化量表(PCS)、Pittsburgh睡眠质量指数(PSQI)进行评价,并分析与各项临床指标的相关性。结果 患者组mHHS、HOS-ADL、HOS-SSS、SF-12评分均显著低于对照组(|Z|> 6.251, P <0.001)。mHHS、HOS-ADL、HOS-SSS、SF-12评分均与PCS评分呈负相关(|r|> 0.480, P <0.01)。PCS的影响因素为HADS:A,HADS:D和HOS-ADL。结论 慢性髋关节疼痛患者功能...     

Recombinant human epidermal growth factor combined with vacuum sealing drainage for wound healing in Bama pigs

Background:Vacuum sealing drainage (VSD) and epidermal growth factor (EGF) both play an important role in the treatment of wounds.This study aims to explore the...     

成人单侧发育性髋关节发育不良患者下肢长度测量与分析

目的测量并分析成人单侧发育性髋关节发育不良（developmental dysplasia of the hip，DDH）患者影像学下肢长度差异的特点。方法回顾分析 2016 年 1 月—2018 年 6 月符合选择标准的 112 例单侧 DDH 患者临床资料。其中男 16 例，女 96 例；年龄 20～76 岁，平均 42.9 岁。DDH 根据 Crowe 分型，Ⅰ型 25 髋、Ⅱ型 26 髋、Ⅲ型 15 髋、Ⅳ型 46 髋（其中无继发臼形成的ⅣA 型 26 髋、有继发臼形成的ⅣB 型 20 髋）。摄站立位下肢全长 X 线片，测量以下参数：大转子下肢长度（greater trochanter leg length，GTLL）、大转子股骨长度（greater trochanter femoral length，GTFL）、小转子下肢长度（lesser trochanter leg length，LTLL）、小转子股骨长度（lesser trochanter femoral length，LTFL）、胫骨长度（tibial length，TL）、大小转子间距离（intertrochanteric distance，ITD）。比较健患侧上述参数，并计算各参数健患侧差值；以健患侧差值 5 mm 作为阈值，分别统计上述参数健侧较患侧>5 mm（健侧长）以及患侧较健侧>5 mm（患侧长）的例数；比较各影像学参数健患侧差值在不同 Crowe 分型之间以及 Crowe ⅣA 型和ⅣB 型之间的差异。结果健患侧 GTLL 和 LTFL 比较差异均无统计学意义（P>0.05）；患侧 LTLL 和 TL 长于健侧，GTFL 和 ITD 短于健侧，差异均有统计学意义（P<0.05）。TL、LTLL 患侧长构成比大于健侧长构成比，而 GTFL、ITD 健侧长构成比大于患侧长构成比，GTLL 和 LTFL 健侧长或患侧长构成比无明显差异。不同 Crowe 分型间比较显示，仅Ⅰ型和Ⅳ型间 TL 健患侧差值比较差异有统计学意义（P<0.05），其余各分型间各影像学参数健患侧差值比较差异均无统计学意义（P>0.05）。与 CroweⅣB 型比较，ⅣA 型 GTLL、TL 和 ITD 健患侧差值较大，差异均有统计学意义（P<0.05）；其余指标ⅣA 型和ⅣB 型间比较差异均无统计学意义（P>0.05）。 结论成人单侧 DDH 患者双下肢不等长，差异主要来自于 TL 和 ITD，术前规划时需注意这点。