Standard versus customised locking plates for fixation of schatzker ii tibial plateau fractures

Aim3D-printed implants could improve the capture of fracture fragments for improved stability of tibial plateau fracture fixation. The aim of this study was to compare the biomechanical strength of fixation constructs using standard and customised 3D-printed proximal tibial locking plates for fixation of tibial plateau fractures.MethodsThis is a biomechanical study utilising six pairs of cadaveric tibiae. Fractures were created in an identical fashion using an osteotome and mallet, and fixed using either a standard, commercially-available proximal tibia locking plate or a customised 3D-printed plate. Design and production of the customised plates followed a “3D printing at point-of-care” model. Customised stainless steel 316 L plates were produced within a local additive manufacturing laboratory based upon pre-operative CT scans. Determination of implant choice within each cadaver pair was performed via simple randomisation. Following fracture fixation, the tibiae were skeletalised and biomechanically tested using a customised loading jig and a size-matched femoral knee prosthesis. The constructs were loaded cyclically from 100 N to approximately three times the cadaveric body-weight at 5 Hz for 10 000 cycles. Every 1000 cycles, the test was paused and the tibia was physically checked for failure. If failure had not occurred by the end of the testing cycle, the construct was loaded to failure and the load at which the construct failed was noted.ResultsFixation constructs using the 3D-printed plates performed comparably to those using the standard plates. There was no significant difference in the degree of fracture fragment displacement in both constructs. Overall longitudinal construct stiffness and load to failure was higher in the 3D-plates group but this did not reach statistical significance.ConclusionProduction of customised plates for proximal tibia fractures at point-of-care is feasible, however fixation constructs with these plates did not provide any biomechanical advantage over standard plates in terms of axial loading stiffness.     

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.     

Effect of Dexmedetomidine infusion during hip fracture surgery on hemodynamic parameters and blood loss: A triple-blinded Randomized Clinical Trial

Introduction In this study, we aim to assess the intra-operative effect of dexmedetomidine administration on the hemodynamic parameters and bleeding volume during hip fracture surgery.Patients and methods we designed and implemented a triple-blinded randomized clinical trial to objectively compare the effects of 0.5 µg/kg/h infusion of dexmedetomidine with placebo (equal amount of normal saline) during hip fracture surgery. All included cases were between 30 and 70 years old and underwent surgery for fixation of a proximal femur fracture from September 26, 2020 until February 15, 2021. They were all ASA class I or II with preoperative hemoglobin levels of 10 mg/dL or higher. Surgical blood loss and hemodynamic parameters were documented.Results 76 patients were enrolled. There were no significant differences in baseline patient characteristics. The bleeding rate was 620 ± 190.0 mL for the normal saline group and 476 ± 177.98 mL in the dexmedetomidine group (P = 0.04). No significant effect on hemodynamic parameters was observed.Conclusion Based on the current study, intravenous infusion of dexmedetomidine during hip fracture surgery under general anesthesia reduced the amount of intraoperative bleeding without causing any significant hemodynamic disturbances.Registration number IRCT20191222045857N1 (Iranian Registry of Clinical Trials)     

胫骨干骨折带锁髓内钉固定和钢板螺钉固定的对比研究

目的：对照回顾性分析带锁髓内钉和钢板内固定两种方法治疗胫骨干骨折的效果。方法：髓内钉组32例（35处骨折）,根据AO分型,42A型11处,42B型18处,42C型6处;钢板组42例（45处骨折）,42A型10处,42B型22处,42C型13处。平均伤后手术时间在髓内钉和钢板组分别为3d和3.5d。随访评估患者手术时间,活动度,愈合时间,术后并发症之间的差别。结果：术后平均随访13个月（8～26个月）。髓内钉组平均手术时间为84min,钢板螺钉组平均为93min。髓内钉组踝关节平均背屈度为13°（0°～20°）,钢板组为11°（0°～20°）;跖屈分别为41°（30°～50°）,47°（30°～50°）。愈合时间髓内钉组平均为3.3个月,钢板螺钉平均为3.5个月。术后X线片显示髓内钉固定有1例出现旋转畸形,钢板组有3例出现成角畸形,均为胫骨远端1/3骨折。结论：在治疗胫骨骨折方面,带锁髓内钉和钢板内固定两种方法都可以取得理想的效果。     

保留胫骨止点的腘绳肌腱移植重建膝交叉韧带

目的 研究保留胫骨止点的自体腘绳肌肌腱移植重建交叉韧带的优缺点。方法 自2001年7月至2005年3月间我院收治交叉韧带断裂患者33例，前交叉韧带断裂17例，后交叉韧带断裂10例，前后交叉韧带断裂并外侧副韧带断裂3例，前后交叉韧带并内侧副韧带断裂3例。其中男性28例，女性5例。平均年龄28．2岁（18-45岁）。平均随访时间3．9年（范围0．5～5年）。使用特制取腱器将半腱肌腱和股薄肌腱从肌腹中抽出，回折锁边缝合成四股，穿过胫骨和股骨隧道。远端经过骨孔以界面钉固定或经过骨桥固定。结果 按照JOA膝关节韧带损伤疗效判定标准，手术前后评分分别为46．0分和79．8分，Lysholm膝关节评分标准手术前后分别为54．4分和80．3分（P〈0．001）。胫骨前移：术前平均10．9mm（范围9～13mm），术后平均3．6mm（范围0～7mm）（P〈0．001）。结论 保留胫骨止点的腘绳肌肌腱移植，可以适用于前后交叉韧带重建，其优点是取材方便，并发症少，胫骨隧道不再需要内固定。     

同伴互助学习应用于骨盆骨折教学的效果分析

目的　探讨同伴互助学习在卓越医师班骨科临床见习教学中的可行性及有效性。方法　选取40位在内蒙古医科大学见习的2014级卓越医师班学生,按照随机原则将学生分为实验组和对照组,试验组接受同伴互助学习教学,对照组接受普通教学。见习结束时进行理论知识与实践技能测验,最后以调查问卷形式完成自我测评及课程评价。采用SPSS 19.0进行t检验和卡方检验。结果　实验组理论成绩及实践操作能力成绩均高于对照组,且差异有统计学意义[理论成绩：（97.2±0.7）分vs.（90.2±1.3）分;实践操作成绩：（98.5±2.4）分vs.（89.2±1.5）分;病例分析：（98.1±0.8）分vs.（92.3±2.8）分,P＜0.05]。 参与同伴互助学习对掌握骨科专业基础理论知识和基本临床实践技能的自我评价较满意。结论　将同伴互助学习运用于见习课教学中,不仅能够激发学生的学习热情,而且能够提高学生自主学习的主动性,并且能够帮助卓越医师班学生在见习课中更好地掌握基础理论和临床基本实践技能。     

组织工程关节软骨梯度仿生支架的研究进展

由于良好的机械性能和生物相容性,组织工程支架已经成为修复和再生关节软骨缺损的重要方法。随着组织工程技术的不断发展,过去十年已经开发和测试了许多支架的制备和形成方法,但是理想再生支架的制备一直存在争议。关节软骨作为人体关节内的承重组织,其基质结构和细胞组成呈带状,并且从软骨表层至软骨下骨存在着几个平滑的自然梯度,包括细胞...     

羟基磷灰石表面修饰人工角膜钛支架的生物相容性：电镜观察

背景：人工角膜是双眼角膜盲患者复明的希望,提高人工角膜材料的生物相容性使人工角膜与宿主角膜达到生物愈合是目前人工角膜的研究方向。 目的：扫描电子显微镜观察经羟基磷灰石表面修饰能否增加人工角膜纯钛支架的生物相容性。 方法：采用酸碱两步预处理法在人工角膜钛支架表面快速沉积羟基磷灰石涂层。将第4~6代兔角膜基质成纤维细胞直接接种于羟基磷灰石修饰的钛支架、纯钛支架及玻璃表面,3,24,48,72 h后,扫描电子显微镜观察材料表面的细胞黏附,伸展及增殖情况;将18只正常新西兰白兔随机分为2组,于右眼角膜基质层内分别植入羟基磷灰石修饰的钛支架、纯钛支架,术后6,12周取出人工角膜支架,扫描电子显微镜观察材料表面角膜组织贴附生长状态。 结果与结论：体外实验显示,细胞接种3 h和24 h后,细胞扩展面积及细胞张力丝长度：羟基磷灰石修饰的钛支架>玻璃>纯钛表面,羟基磷灰石修饰的钛支架表面的活细胞数多于其他材料表面(P < 0.05)。72 h后,羟基磷灰石修饰的钛支架表面完全被胶原覆盖。体内实验显示,扫描电子显微镜观察羟基磷灰石修饰的钛支架表面细胞外基质生长良好,与羟基磷灰石贴附紧密。而纯钛支架仅为角膜组织简单包裹。说明人工角膜纯钛支架经羟基磷灰石表面修饰后,其生物相容性增加。 关键词：人工角膜;羟基磷灰石;钛;表面改性;生物相容性;扫描电子显微镜 doi:10.3969/j.issn.1673-8225.2010.29.007     

通道下肌间隙入路腰椎固定融合术并发神经损伤的原因及预防

目的总结通道下肌间隙入路腰椎固定融合术并发神经损伤的特点,分析损伤原因并提出预防措施。方法武警浙江省总队医院2012年6月—2015年12月由同一组医师采用通道下肌间隙入路固定融合术治疗的腰椎病变患者277例,其中9例出现神经损伤(男4例、女5例),年龄42~78岁,平均56.7岁。腰丛损伤1例,马尾神经损伤1例,神经根损伤7例。手术操作损伤3例,螺钉位置不正确损伤2例,血肿压迫2例,混合因素1例,原因不明1例。予非手术治疗5例,再次手术4例。结果 9例患者随访9~36个月,平均22.5个月。末次随访时,手术操作直接损伤的3例中2例部分恢复,1例完全恢复;2例椎弓根螺钉位置不正确所致的神经根损伤完全恢复;2例血肿压迫所致神经损伤者1例完全恢复,另1例大部分恢复;混合因素导致马尾神经损伤的1例患者部分恢复;损伤原因不明的1例完全恢复。结论通道下肌间隙入路腰椎固定融合术的神经并发症以神经根损伤多见。神经损伤有显露和手术方式的客观原因,但术者的操作可能是更主要的因素。术前应严格选择病例、术中操作要谨慎细致,以预防神经损伤的发生。