Biomechanical comparison of three internal fixation configurations for low transcondylar fractures of the distal humerus

BackgroundWe aimed to evaluate the biomechanical stiffness and strength of different internal fixation configurations and find suitable treatment strategies for low transcondylar fractures of the distal humerus.Methods and materialsThirty 4^th generation composite humeri were used to create low transcondylar fracture models that were fixed by orthogonal and parallel double plates as well as posterolateral plate and medial screw (PPMS) configurations (n=10 in each group) using an anatomical locking compression plate-screw system and fully threaded medial cortical screws. Posterior bending (maximum 50 N), axial loading (maximum 200 N) and internal rotation (maximum 10 N·m) were tested, in that order, for each specimen. Stiffness under different biomechanical settings among different configurations were compared. Another 18 sets of fracture models were created using these three configurations (n=6 in each group) and the load to failure under axial loading among different configurations was compared.ResultsUnder posterior bending, the stiffness of parallel group was higher than orthogonal group (P<0.001), and orthogonal group was higher than PPMS group (P<0.001). Under axial loading, the stiffness of parallel group was higher than orthogonal group (P=0.001) and PPMS group (P<0.001); however, the difference between orthogonal and PPMS group was not statistically significant (P>0.05). Under internal rotation, the stiffness of parallel group was higher than orthogonal group (P=0.044), and orthogonal group was higher than PPMS group (P=0.029). In failure test under axial loading, the load to failure in the orthogonal group was lower than parallel group (P=0.009) and PPMS group (P=0.021), but the difference between parallel group and PPMS group was not statistically significant (P>0.05). All specimens in orthogonal group demonstrated “distal medial failure”; most specimens had “distal medial and trochlear failure” in the parallel group; most specimens exhibited “contact failure” in the PPMS group.ConclusionFor treating low transcondylar fractures, the overall stiffness and strength of the parallel configuration were superior to those of the orthogonal and PPMS configurations. Nevertheless, the PPMS configuration can provide adequate stability and stiffness comparable to double-plate configurations under axial loading. Therefore, the PPMS construct may have certain clinical value.     

闭合复位经皮穿针治疗移位的肱骨外科颈骨折

目的总结闭合复位经皮穿针治疗移位的肱骨外科颈骨折的方法及结果。方法2001年1月～2002年12月,采用闭合复位、经皮穿针治疗移位的肱骨外科颈骨折46例,仅对其中随访资料完整的34例患者进行分析。结果34例获得22个月(10～34个月)的平均随访。采用Constant-Murley评分方法,平均Constant-Murley绝对值为92分(76～100分),优良占86%(29/34),可占14%(5/34),无差病例。所有骨折在术后6～8周愈合,无固定失效,未出现肱骨头坏死病例。结论闭合复位经皮穿针治疗移位的肱骨外科颈骨折手术时间短、软组织损伤小、固定可靠,术后可早期功能锻炼,取针简便。     

Macroscopic and Histological Evaluations of Meniscal Allograft Transplantation Using Gamma Irradiated Meniscus: A Comparative in Vivo Animal Study

Background:

Many studies suggest that the gamma irradiation decreases allograft strength in a dose-dependent manner. However, no study has demonstrated that this decrease in strength translates into higher failure rate in meniscal allograft transplantation (MAT). The aim of this study was to investigate the effects of gamma irradiation on macroscopic and histological alterations of transplanted meniscal tissue and joint cartilage after MAT.

Methods:

Medial total meniscectomies were performed on the right knees of 60 New Zealand white rabbits. All meniscal allografts were divided into three groups (20 in each group) and then sterilized with 0 Mrad, 1.5 Mrad, or 2.5 Mrad of gamma irradiation. For each group, 5 menisci were randomly chosen for scanning electron microscopic (SEM) analysis and the remaining 15 were prepared for MAT surgeries. Forty-five right knees received MAT surgeries (0 Mrad group, 1.5 Mrad group, 2.5 Mrad group, 15 in each group), whereas the remaining 15 only received medial meniscectomy (Meni group). The left knees of the Meni group were chosen as the Sham group (n = 15). All the rabbits were sacrificed at week 24 postoperatively. Cartilage of the medial compartment of each group was evaluated macroscopically using the International Cartilage Repair Society (ICRS) score and then histologically using the Mankin score based on the Masson Trichrome staining.

Results:

The SEM analysis confirmed that the meniscal collagen fibers would be significantly damaged as the dose of gamma irradiation increased. At week 24, the overall scores of macroscopic evaluations of the transplanted meniscal tissue showed no significant differences among the three groups receiving MAT surgeries, except for 2 in the 2.5 Mrad group presented partial radial tears at midbody. The ICRS scores and the Mankin scores showed the lowest in the Sham group and the highest in the Meni group (P < 0.05). For the three groups receiving MAT surgeries, the 2.5 Mrad group showed significant higher ICRS scores and Mankin scores than both the 0 Mrad group and the 1.5 Mrad group (P < 0.05). Whereas the 1.5 Mrad group presented similar results to the 0 Mrad group concerning both the ICRS scores and the Mankin scores.

Conclusions:

The current in vivo animal study proved that although the meniscal collagen fibers were damaged after gamma irradiation, the failure rate of MAT surgeries might not significantly increase if the irradiation dose was <1.5 Mrad for New Zealand white rabbits.     

保守治疗旋后-外旋型踝关节骨折的分析

目的探讨保守治疗旋后-外旋型踝关节骨折的中、长期疗效。方法自1999年2月～2004年8月,对采用保守治疗(闭合复位石膏制动)并得到随访的43例成人旋后-外旋型踝关节骨折临床资料进行分析。其中旋后-外旋型Ⅰ度骨折5例,Ⅱ度骨折10例,Ⅲ度骨折0例,Ⅳ度骨折28例。结果平均随访69个月(16～84个月)。按照美国足踝骨科协会(AOFAS)推荐的足踝评分系统评分,旋后-外旋型Ⅰ度:5例评分为满意;Ⅱ度:9例满意,1例不满意;Ⅳ度:26例满意,2例不满意。结论大部分旋后-外旋型踝关节骨折保守治疗中、长期随访效果满意。对于合并难复性或不稳定性距骨脱位以及后踝骨折块大于胫骨远端关节面25%的患者,保守治疗效果不满意,应当手术治疗。     

服用氯吡格雷的老年髋部骨折患者尽早手术的安全性研究

目的:探讨服用氯吡格雷的老年髋部骨折患者尽早手术的安全性。方法:回顾性分析2016年11月至2017年4月期间北京积水潭医院创伤骨科连续收治的242例老年髋部骨折患者资料。将服用氯吡格雷且停药4 d以内手术患者纳入研究组,共20例,年龄中位数为80（77,81）岁;男6例,女14例。手术方式：股骨颈骨折空心钉固定2例,...     

扩髓与非扩髓型股骨髓内针术后免疫因子释放水平的研究

目的通过检测部分免疫介质的释放水平,探讨在应用髓内针治疗股骨干骨折术后早期对机体免疫功能的影响.方法选择股骨干闭合骨折患者59例,男55例,女4例,平均年龄32.1岁,按伤情分为轻伤组(n=43)和中度伤组(n=16),采取闭合复位带锁髓内针固定治疗.轻伤组扩髓23例、非扩髓23例,中度伤组扩髓7例、非扩髓6例,分别于术前24 h和术后1、24、48 h通过ELISA法检测患者血中TNF、IL-6、IL-8、IL-10的水平,通过蛋白分析测定CRP的水平;同时选取22例健康志愿者作为正常对照组.结果轻、中度创伤患者术后各炎症指标均较术前有所上升;IL-6、IL-8、IL-10在术后1 h呈上升趋势,术后24 h达到高峰,术后48 h 三种因子水平均开始下降,但尚未恢复正常;TNF、CRP术后1 h仍较术前有所下降,但在术后24 h均出现明显上升,到术后48 h再次回落;轻伤与中度伤组不同时段的免疫指标均与对照组有明显差异(P《0.05).不同伤情患者扩髓后各免疫指标均高于非扩髓者,但除中度伤组中IL-10在术后24 h有差异显著性意义(P=0.047)外,其它指标差异均无显著性意义(P》0.05). 2例患者术后出现SIRS,观察发现与非SIRS患者相比各项免疫指标并无显著差别.结论对于轻、中度创伤患者,髓内针会造成机体免疫介质再次大量释放,但经机体免疫调节后不会产生严重的影响;不同方式髓内针固定对术后早期机体的免疫系统的影响没有显著的差异,但以IL-10为代表的免疫抑制因子很可能随着伤情的加重在应用髓内针,尤其是扩髓型髓内针时出现短期内大量释放,从而加重机体的免疫抑制.     

股骨颈骨折临床研究的若干问题与新概念

骨质疏松是引起股骨颈骨折的重要因素。骨质疏松的程度对于骨折的粉碎情况(特别是股骨颈后外侧粉碎)及内固定后的牢固与否有直接影响。年青人股骨颈骨折则多为严重创伤所致。Garden分型是目前应用最为广泛的股骨颈骨折分型。近年来许多医生发现Garden分型在临床应用中存在一些问题,建议将股骨颈骨折简单地分为无移位型(GardenⅠ、Ⅱ型)及移位型(GardenⅢ、GardenⅣ型)。人工关节置换术曾被广泛应用老年人移位型骨折。对于人工关节置换术的应用,不是简单根据年龄及移位程度来定,而应严格掌握适应证。股骨颈骨折后继发的股骨头缺血坏死尚无单独的诊断标准,目前仍然普遍借用股骨头无菌性坏死的Fi-cat-Arlet分期。核磁共振是目前唯一可以早期诊断股骨头缺血坏死并了解其病变范围和位置的方法。     

Sneppen Ⅱ型距骨体骨折的手术技巧及疗效分析

目的探讨距骨体SneppenⅡ型骨折的手术技巧及疗效。方法对1998年1月～2004年12月收治的21例距骨体SneppenⅡ型骨折患者的随访资料进行总结。术前常规行距骨CT扫描，根据距骨体主要移位骨折块的位置选择内侧和（或）外侧入路。手术大多采用内踝截骨入路，15例采用半螺纹钛钉或空心钉固定，3例采用可吸收钉固定，3例采用克氏针固定。结果所有患者获得12～90个月（平均38个月）随访。术后6例出现距骨缺血性坏死，其中5例踝关节及距下关节均出现创伤性关节炎；另有3例踝关节和5例距下关节出现创伤性关节炎。5例行关节融合术。踝关节功能采用美国足踝骨科协会（AOFAS）评分：优8例，良5例，可3例，差5例，优良率为61．9％。结论距骨体SneppenⅡ型骨折应通过选择正确的手术入路，尽量使骨折达到解剖复位及保护血运的效果；术后力争早期主动无痛进行踝关节功能锻炼。     

骨折患者疼痛现状及影响因素分析

目的调查住院骨折患者的疼痛现状,并探讨其影响因素。方法应用自行设计的疼痛评估单对364例患者进行评估。结果 364例患者中,术前出现中度及以上疼痛的患者占46.43%,术后为38.18%;出现中度以上疼痛的时间点主要集中在术后12 h以内,占58.27%;应用杜冷丁、泰勒宁和镇痛泵的比例分别为9.89%、32.97%和34.62%。影响患者术前、术后疼痛程度的影响因素包括住院天数、文化程度、年龄和有无配偶。结论护理工作者应根据患者年龄、文化程度和社会支持的不同采取针对性的干预措施,提高其疼痛控制水平。     

伴有骶髂关节完全性前脱位的骨盆骨折治疗

目的：总结伴有骶髂关节完全性前脱位的骨盆骨折的治疗经验。方法：对北京积水潭医院2008年2月至2014年3月收治的6例伴有骶髂关节完全性前脱位骨盆骨折的资料进行回顾性分析,描述患者病史、损伤程度、急诊救治等特征,通过影像学判断损伤情况,给予手术治疗,术后功能锻炼,并对患者进行随访以评估术后恢复情况,总结治疗经验。结果：全部6例患者术后愈合良好,无感染和术后神经症状出现,X线示骶髂关节复位良好。随访1.6年（8个月至2年）,患者6个月后Majeed功能评分优2例、良2例、可1例、差1例,评分差的病例主要表现为持续疼痛,肢体活动能力下降,行走长距离时需用手杖,有跛行。评分低的2例患者不能恢复原有工作。结论：伴有骶髂关节完全性前脱位的骨盆骨折是一种特殊类型的损伤,急诊处理困难,应尽早手术,前方入路有利于脱位的复位和固定。