Subsidence of monoblock and modular titanium fluted tapered stems in revision hip arthroplasty: A retrospective multicentre comparison study

BackgroundTapered, fluted, titanium (TFT) stems have shown good clinical outcomes in revision total hip arthroplasty (rTHA), however concerns exist regarding early subsidence. This study compares subsidence between a modern monoblock 3-degree and a modular 2-degree TFT stem in rTHA.MethodsA retrospective, international multicentre comparative study was conducted including 64 rTHA in 63 patients. A monoblock TFT stem was used in 37 cases and a modular TFT stem was used in 27 cases. Patient demographics, Paprosky femoral bone loss classification, bicortical contact and stem subsidence were recorded at minimum four week follow up.ResultsThere was no statistically significant difference in overall subsidence (p = 0.318) or the rate of subsidence >10 mm between stems. Mean subsidence was 2.13 mm in the monoblock group and 3.15 mm in the modular group. Two stems subsided >10 mm: one in each group. There was no difference in bicortical contact between groups (p = 0.98). No re-revisions were performed.ConclusionsWe found no difference in subsidence between the two stems. Surgeons may consider the use of monoblock stems in rTHA as they have comparably low rates of subsidence and eliminate the small but potentially catastrophic risk of implant fracture at modular junctions associated with modular stems.     

Long-Term Follow-Up Results of Anterior Cervical Inter-Body Fusion with Stand-Alone Cages

ObjectiveThe purpose of this study was to evaluate long-term follow-up radiologic/clinical outcomes of patients who underwent anterior cervical discectomy and inter-body fusion (ACDF) with stand-alone cages (SAC) in a single academic institution.MethodsTotal 99 patients who underwent ACDF with SAC between February 2004 and December 2012 were evaluated retrospectively. A total of 131 segments were enrolled in this study. Basic demographic information, radiographic [segmental subsidence rate, fusion rate, C2–7 global angle, and segmental angle changes)/clinical outcomes (by Odom''s criteria and visual analog score (VAS)] and complications were evaluated to determine the long-term outcomes.ResultsThe majority were males (55 vs. 44) with average age of 53.2. Mean follow-up period was 62.9 months. The segmental subsidence rate was 53.4% and fusion rate was 73.3%. In the subsidence group, anterior intervertebral height (AIH) had more tendency of subsiding than middle or posterior intervertebral height (p=0.01). The segmental angle led kyphotic change related to the subsidence of the AIH. Adjacent segmental disease was occurred in 18 (18.2%) patients. Total 6 (6%) reoperations were performed at the index level. There was no statistical significance between clinical and radiological outcomes. But, overall long-term clinical outcome by Odom''s criteria was unsatisfactory (64.64%). The neck and arm VAS score were increased by over time.ConclusionLong-term outcomes of ACDF with SAC group were acceptable but not satisfactory. For optimal decision making, more additional comparative long-term outcome data is needed between ACDF with SAC and ACDF with plating.     

A prospective study of hip revision surgery using the Exeter long-stem prosthesis: function, subsidence, and complications for 57 patients

Background  

The long-stem Exeter femoral component is commonly used in revision hip surgery. Subsidence of the femoral stem in primary hip arthroplasty has been studied extensively, but much less is known about its significance in revision surgery. This prospective study examined the relationship between radiological subsidence, Western Ontario and McMaster (WOMAC) osteoarthritis index pain score, patient satisfaction and complication rates for the long-stem Exeter hip prosthesis.     

3D打印个体化人工椎体在胸腰椎肿瘤整块切除后脊柱稳定性重建中的应用

目的探索3D打印个体化人工椎体在胸腰椎肿瘤整块切除后脊柱稳定性重建中的临床疗效。方法回顾性分析华中科技大学同济医学院附属同济医院2015年7月至2020年6月收治的接受一期后路全脊椎整块切除术的胸腰椎肿瘤患者28例,分为2组,每组14例。其中3D组使用3D打印个体化人工椎体重建,常规组使用钛笼重建。对比两组的住院时间、手术时间、术中出血量,记录术前、术后7 d及末次随访时视觉模拟评分(VAS),Frankel分级情况,测量节段高度及角度,评估临床疗效。结果两组患者住院时间、手术时间、术中出血量和VAS评分比较,差异无统计学意义。共8例患者Frankel评分获得一个等级的改善(28.6%)。3D组椎间高度丢失(1.9±2.2)mm,内植物沉降2例,沉降率14.3%;常规组椎间高度丢失(6.6±5.5)mm,内植物沉降8例,沉降率57.1%;两组比较差异有统计学意义(<0.05)。在节段角度丢失方面组间差异无统计学意义(=0.571)。3D组所有患者内固定良好,常规组1例患者发生断棒情况。结论 3D打印人工椎体可以更好地维持节段高度,降低椎间隙塌陷和内固定失败的风险。     

颈椎前融合保留终板的临床研究

目的比较保留颈椎椎体终板与否对融合间隙的影响。方法２４例颈前路融合术采用保留椎体终板的植骨方法，并与未保留终板组相比，评价两组植骨块沉陷、后凸畸形及骨性融合，并进行新鲜标本的生物力学测试。结果保留终板组融合节段高度平均降低０．９ｍｍ，后凸成角平均为２．５°；对照组融合节段高度平均降低２．８ｍｍ，后凸成角５．４°，两组相差非常显著（Ｐ＜０．０１）。生物力学实验表明，保留终板组椎体平均抗压强度为１３６０．２Ｎ，未保留终板组为８７７．１Ｎ，相差非常显著（Ｐ＜０．０１）。结论临床观察和生物力学实验均表明，保留终板能有效防止植骨块沉陷，并可获得良好的骨性融合     

颈前路钛网植骨融合术后钛网沉陷的原因探讨

目的：探讨颈前路钛网植骨融合术后钛网发生沉陷的原因及其对临床疗效的影响，并提出相应对策。方法：回顾性分析在我院行颈前路钛网植骨融合术的各类颈椎疾患患者179例，观察患者骨密度、钛网修剪及放置情况、终板处理情况、钢板类型、植骨及椎体撑开情况等。采用日本骨科学会（JOA）评分法评价神经功能的变化。结果：有17例患者发生钛网沉陷，沉陷的原因主要为骨密度下降、钛网修剪放置不当、术中过度撑开、终板刮除过多、使用非限制性钢板、采用同种异体骨植骨、螺钉进钉深度过浅和方向不当、钢板放置位置偏斜等。术后所有患者JOA评分比术前平均增加3．5分（P〈0．01）。162例未发生钛网下沉患者术后3个月和6个月的JOA评分比术前平均增加4．4分和4．7分：发生钛网下沉患者中。6例有临床症状者沉陷时和沉陷3个月时的JOA评分为2．9分和3．8分．7例无临床表现者为3．3分和3．9分．4例有临床症状行翻修手术者翻修术后1周和3个月时JOA评分比翻修前提高3．3分和3．7分。结论：颈前路钛网植骨融合术后可发生钛网下沉，骨质疏松患者应该避免使用钛网。手术时应尽可能增加钛网与终板接触面积，多保留相邻终板，选用限制性钢板，尽量选择自体骨植骨，避免椎间过度撑开等。防止术后钛网沉陷。     

沉降法测定大气真菌粒子含量的探讨

本工作用 ANDERSEN 生物粒子采样器法和平皿沉降法在北京西单对大气真菌粒子的含量进行了一年的对比观测实验。结果表明,在同一次大气真菌粒子沉降量的采样中,放置的采样皿数对测定结果没有明显影响。大气真菌粒子沉降量与大气真菌粒子含量呈非常显著的正相关关系。由本实验得出的关系式能较准确、简便的计算大气真菌粒子的含量。