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。     

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,包括细胞表型和数量、特异性的生长因子、基质的组成、纤维的排列、力学性能、营养和氧气的消耗量等均有较为明显的不同。因此,在再生支架的设计中有必要通过重现这些梯度来原位再生关节软骨。最近的文献报道已经有许多新型的梯度仿生支架用于模拟天然关节软骨的自然梯度,这些支架在结构上呈现出不同的机械、物理、化学或者生物梯度,并且取得了不错的修复效果。通过检索关于梯度支架治疗关节软骨缺损的相关文献,首先对天然关节软骨组织的结构、生物化学、生物力学、营养代谢等梯度特性进行研究和总结,然后对目前关节软骨梯度支架的最新设计和构建进行了归类,其次从材料构成(如水凝胶、纳米材料等)以及制备工艺(如静电纺丝、3D打印等)进一步加深对梯度支架的认识,最后讨论了梯度仿生支架在软骨原位组织工程技术中的前景和挑战,为梯度支架成功用于临床转化提供理论基础。     

肩关节后方不稳的诊疗现状

肩关节后方不稳发生率明显低于前方不稳,但是临床上诊疗难度大,误诊和漏诊率较高。其病因、临床表现治疗策略与前方不稳完全不同。因此,深入认识肩关节周围解剖结构、掌握检查方法、基于解剖和受伤方式对肩不稳进行分型对提高诊断准确率具有关键作用。CT三维重建对肱骨头及肩盂骨缺损的评估和核磁共振造影(magnetic resonance angiography,MRA)对于后方盂唇及关节囊病变评估有助于精确诊断。治疗方法分为保守治疗及手术治疗。对肌性不稳建议保守治疗。创伤性及发育不良性不稳建议手术治疗,具体根据肩盂侧或肱骨头侧损伤行不同术式。肩盂侧损伤根据骨缺损情况行软组织手术、植骨手术或截骨手术来重建后方稳定结构;肱骨头侧缺损则根据前方骨缺损面积行植骨术或肩胛下肌填塞术。手术方式有开放手术和关节镜手术,前者优势在于学习曲线短,固定牢固;后者优势在于微创操作及可以多角度观察病变部位并精确控制骨块位置。本文对将上述问题加以综述。     

中国脆性骨折术后规范化抗骨质疏松治疗指南(2021)

骨质疏松症是一种全身性的骨骼系统疾病,其特征是骨量减少和骨组织显微结构退化,导致骨骼脆性增加,骨折风险增高。根据其发病原因可分为原发性骨质疏松和继发性骨质疏松两大类。本指南仅针对原发性骨质疏松症引起的脆性骨折所制定。脆性骨折亦称为骨质疏松性骨折,是骨质疏松症的最严重后果.