寰枢椎后路柔性固定的生物力学研究

目的分析细棒、PEEK棒固定对寰枢关节稳定性的影响。方法采用6具新鲜成人枕骨(occipital bone,Oc)~颈椎C4节段进行测试,模拟以下手术及固定状态:①完整状态;②损伤状态:枢椎齿状突II型骨折;③坚强固定:寰枢椎均采用普通椎弓根螺钉固定,直径3.5 mm钛棒连接;④PEEK棒:直径3.5 mm的PEEK棒连接;⑤细棒:直径2.0 mm钛棒连接。采用重复测量实验设计,在完整、损伤和不同的固定状态下,通过脊柱试验机对标本分别施加1.5 N·m的前屈/后伸、左/右侧弯和左/右轴向旋转的纯力偶矩。采用Optotrak三维运动测量系统连续采集标本运动,分析寰枢椎之间角度运动范围和中性区。结果采用直径3.5 mm的钛棒,2.0 mm的细棒以及3.5 mm的PEEK棒固定后,在前屈、后伸、侧弯和旋转方向上均显著减小了固定节段的运动范围(P<0.05)。直径3.5 mm和2.0 mm的棒固定后的运动范围,在各个方向上无显著性差异。PEEK棒固定的运动范围仅在侧弯方向上大于坚强固定(P=0.005),其他方向无显著性差异。3种固定方式在屈伸、侧弯和旋转方向上均显著减小了固定节段的中性区(P<0.05)。各种固定方式之间相比较,无显著性差异(P>0.05)。结论在寰枢关节采用直径2.0 mm的细棒固定,与坚强固定的稳定性相当。采用直径3.5 mm的PEEK棒固定,在前屈、后伸、旋转方向上与坚强固定的稳定性相当,在侧弯方向上弱于坚强固定。     

Weight-bearing in ankle fractures: An audit of UK practice

IntroductionThe purpose of this national study was to audit the weight-bearing practice of orthopaedic services in the National Health Service (NHS) in the treatment of operatively and non-operatively treated ankle fractures.MethodsA multicentre prospective two-week audit of all adult ankle fractures was conducted between July 3rd 2017 and July 17th 2017. Fractures were classified using the AO/OTA classification. Fractures fixed with syndesmosis screws or unstable fractures (>1 malleolus fractured or talar shift present) treated conservatively were excluded. No outcome data were collected. In line with NICE (The National Institute for Health and Care Excellence) criteria, “early” weight-bearing was defined as unrestricted weight-bearing on the affected leg within 3 weeks of injury or surgery and “delayed” weight-bearing as unrestricted weight-bearing permitted after 3 weeks.Results251 collaborators from 81 NHS hospitals collected data: 531 patients were managed non-operatively and 276 operatively. The mean age was 52.6 years and 50.5 respectively. 81% of non-operatively managed patients were instructed for early weight-bearing as recommended by NICE. In contrast, only 21% of operatively managed patients were instructed for early weight-bearing.DiscussionThe majority of patients with uni-malleolar ankle fractures which are managed non-operatively are treated in accordance with NICE guidance. There is notable variability amongst and within NHS hospitals in the weight-bearing instructions given to patients with operatively managed ankle fractures.ConclusionThis study demonstrates community equipoise and suggests that the randomized study to determine the most effective strategy for postoperative weight-bearing in ankle fractures described in the NICE research recommendation is feasible.     

后路枕骨髁螺钉技术研究进展

正枕骨、寰椎和枢椎共同构成了枕颈部活动的结构功能单位,即枕颈交界区~([1-2])。炎症、创伤、肿瘤及畸形等因素会导致枕颈交界区失稳,从而引起颈脊髓或神经根的损伤、麻痹及难以忍受的疼痛,甚至危及生命~([3-4])。后路内固定融合技术是治疗枕颈部失稳的重要手段,目前常用术式为枕骨螺钉技术,该技术较钢丝固定技术有更好的生物力学稳定     

Subdental synchondrosis and anatomy of the axis in aging: a histomorphometric study on 30 autopsy cases

During skeletal development the two ossification centers of the odontoid process are separated from the corpus of the axis by a subdental synchondrosis. This synchondrosis is thought to close and disappear spontaneously in adolescence although this has never been studied in detail. The basis of the dens is of clinical relevance as type II dens fractures are located here. To characterize the morphological architecture of the axis with particular attention to the subdental synchondrosis, the complete axis was harvested from thirty age-matched and gender-matched patients of the three different age groups at autopsy. The subdental synchondrosis and the bone structure of the dens, the basis of the dens and the body of C2 were analyzed by radiography, histology and quantitative histomorphometry. At the macroscopic level the persistency of the subdental synchondrosis in the adult cervical spine was detected in 87% (26 of 30) of the specimens. Histomorphometry revealed a residual disc blastema with an average size of 25.8% of the sagittal depth of the basis of the dens at this level. Bony integration of the synchondrosis was poor throughout all ages. Histologically a cartilaginous matrix composition of the subdental synchondrosis persisted throughout all groups. The trabecular microarchitecture demonstrated a significant reduction of bone volume and trabecular number as well as an increased trabecular separation within the basis of the dens as compared to the corpus or the dens of C2. This histomorphometric data regarding a poor integration of the synchondrosis into the trabecular network and the reduced bone mass within the basis of the dens might offer a previously underestimated explanation for the occurrence of type II dens fractures and their association with pseudoarthrosis, respectively.Matthias Gebauer and Christian Lohse contributed equally to this study and therefore share first authorship.     

外固定架治疗桡骨远端粉碎性骨折的疗效分析

目的:探讨闭合手法复位外固定架治疗桡骨远端粉碎性关节内骨折的临床疗效。方法:对29例桡骨远端粉碎性关节内骨折,通过外固定架的牵伸辅助复位,矫正桡骨的短缩、成角移位,恢复关节面的解剖关系,利用外固定架维持复位后的位置并进行功能练习。术后定期进行X线和腕关节功能的评价。结果:29例均获得随访,随访时间3~12个月,平均6.5个月。根据Aro功能评价:优9例,良17例,可2例,差1例,优良率89.66%。结论:外固定架能很好维持复位后的位置,恢复桡尺骨的相对长度和关节面的平整,使腕关节功能得到良好的恢复,因此是治疗桡骨远端粉碎性关节内骨折的有效方法。     

人工骨椎体成形术治疗胸腰椎爆裂骨折

目的:探讨经椎弓根人工骨植入椎体成形术治疗胸腰椎爆裂性骨折的方法和效果。方法:胸腰椎爆裂骨折12例,男8例,女4例;年龄28～61岁,平均47.5岁;受伤时间4～12d;术前Frankel分级:C级1例,D级3例,E级8例;受伤椎体:T112例,T122例,L15例,L23例;术前后突角11°～35°,平均24°;术前椎管占位率39%～85%,平均64.5%;术前伤椎椎体前缘高度平均为正常的47%。行后路切开复位短节段椎弓根钉内固定后,人工骨经伤椎椎弓根植入椎体成形术。结果:所有患者均获随访,时间3～19个月,平均13个月。脊柱后突角平均恢复20°,椎体高度平均恢复96%,椎管占位率平均恢复至7%。2例人工骨椎体内充填不足;无内固定松动、断裂、椎体高度变低及生理弧度丢失。神经功能恢复:1例术前Frankel分级C级及2例D级患者术后均恢复至E级。结论:经椎弓根人工骨植入椎体成形术重建了椎体高度,增加了脊椎前柱的抗压稳定性,使患者能早期活动,减少内固定物因应力过大造成的断钉、松动、椎体再压缩等并发症。