Color changes of polyetheretherketone (PEEK) and polyoxymethelene (POM) denture resins on single and combined staining/cleansing action by CIELab and CIEDE2000 formulas

PurposeThe purpose of study was to investigate the long-term effect of staining and/or cleansing solutions on the color stability of two non-metal removable partial denture materials.MethodsOne hundred disks (25×3 mm) of polyoxymethylene (POM) and polyetheretherketone (PEEK) were immersed in water, wine, coffee, cleanser and combo bath, simulating normal daily use. Color parameters in the CIELAB system was measured every 30 cycles up to 240 using a contact colorimeter and color differences estimated using ΔE_ab and ΔE₀₀ formulas. Two-way repeated measures ANOVAs and regression analyses were performed at α = 0.05.ResultsRegression analysis indicated a strong R² between color changes and number of cycles, for both materials. Tests of within-subjects effects for the ΔE_ab revealed significant differences among cycles and between the materials in the wine and coffee baths (p < 0.001). Significant materialXcycles interactions were also recorded with all staining baths. ΔE₀₀ values were lower than ΔE_ab up to 63.6%. Tests within and between-subjects effects for the ΔE₀₀ gave similar but not the same with ΔE_ab results.ConclusionsΔE₀₀ found to correlate well with ΔE_ab. Long term exposure of both materials showed a progressive discoloration in all except control baths. POM discolored more than PEEK in coffee, and combo baths but not in cleanser. Discoloration was smaller in combo bath (where a cleanser was also used) indicating the effectiveness of a cleanser to prevent long term discoloration of both materials.     

后路椎体次全切钛网植入内固定治疗胸腰椎爆裂骨折

目的探讨经后路椎体次全切钛网植骨融合椎弓根钉内固定治疗胸腰椎爆裂骨折的临床疗效。方法 2012年6月~2014年6月,笔者运用胸腰椎损伤评分系统(TLICS评分)和脊柱载荷评分系统(LSC评分),对纳入的35例成人[男性21例,女性14例;年龄26~45岁,平均(37.4±6.3)岁]胸腰椎爆裂骨折,采用一期经后路椎弓根内固定撑开复位,伤椎椎体次全切,椎管减压,钛网植骨融合手术。采用美国脊柱损伤学会分级(ASIA)进行神经功能评估,通过X线和CT评估术前、术后及末次随访时伤椎椎体高度、椎管占位情况和椎间融合情况。结果手术均顺利完成,6例术后并发脑脊液漏,余无严重并发症发生。所有病例均获随访,随访时间平均为(15.3±6.8)个月,除5例患者术前神经功能为A级外,余30例患者神经功能均有不同程度提高。术后影像学显示减压及复位效果满意,末次随访时植骨全部获得骨性融合,无假关节形成。结论经后路椎体次全切减压,前中柱重建脊柱序列,固定融合治疗胸腰椎爆裂骨折手术操作相对简便,减压彻底,并发症少,有效恢复椎体高度及椎管容积,是胸腰椎骨折的一种有效治疗方法。     

n—HA／PA66Cage在腰椎融合术中的生物安全性研究

目的评价新型纳米羟基磷灰石／聚酰胺66融合器（nano-hydroxyapatite／polyamide66Cage,n—HA／PA66Cage）植人人体内可能引起的全身毒性反应及对人体局部组织的影响。方法2012年2月至2012年4月将n—FLA／PA66Cage通过腰椎后路经椎间孔进行腰椎椎体融合植入20例患者体内,通过对研究对象检查术前、术后4d、术后2个月等3个时期的血压、脉搏、体温、免疫球蛋白A、G、M、补体C3、C4、谷丙转氨酶、谷草转氨酶、肌酐、尿素、白细胞、红细胞、血红蛋白、血小板、C反应蛋白、血沉、局部反应等指标。结果n—HA／PA66Cage植人人体后,除了术后4d白细胞、红细胞、血红蛋白、血小板等血常规、C反应蛋白、血沉等检查与术前相比,存在统计学差异（P〈0．05）;在不同时相,其他检查结果之间无统计学意义（P〉0．05）。结论新型n—HA／PA66Cage具有良好的生物安全性。     

Comparison of anterior cervical fusion by titanium mesh cage versus nano-hydroxyapatite/polyamide cage following single-level corpectomy

Purpose

The titanium mesh cage (TMC) is a typical metal cage device which has been widely used in cervical reconstruction for decades. Nano-hydroxyapatite/polyamide-66 (n-HA/PA66) cage is a novel biomimetic non-metal cage device growing in popularity in many medical centres in recent years. There has been no comparison of the efficacy between these two anterior reconstructing cages. The purpose of this study was to compare the radiographic and clinical outcomes of these two different devices.

Methods

Sixty-seven eligible patients with single-level ACCF using TMC or n-HA/PA66 cage for cervical degenerative diseases, with four-year minimum follow-up, were included in this prospective non-randomised comparative study. Their radiographic (cage subsidence, fusion status, segmental sagittal alignment [SSA]) and clinical (VAS and JOA scales) data before surgery and at each follow-up was recorded completely.

Results

The fusion rate of the n-HA/PA66 group was higher than TMC at one year after surgery (94 % vs. 84 %) though their finial fusion rates were similar (97 % vs. 94 %). Finial n-HA/PA66 cage subsidence was 1.5 mm with 6 % of severe subsidence over three millimetres, which was significantly lower than the respective 2.9 mm and 22 % of TMC (P < 0.0001). Lastly, SSA, VAS and JOA in TMC group were worse than in the n-HA/PA66 group (P = 0.235, 0.034 and 0.007, respectively).

Conclusions

The n-HA/PA66 cage is associated with earlier radiographic fusion, less subsidence and better clinical results than TMC within four years after one-level ACCF. With the added benefit of radiolucency, the n-HA/PA66 cage may be superior to TMC in anterior cervical construction.     

Revision of Complex Acetabular Defects Using Cages with the Aid of Rapid Prototyping

This study details a method using rapid prototyping (RP) technique to assist in acetabular revision with complex bone defects. Hemi-pelvic RP models were built among 25 patients with complex acetabular bone defects. Each patient was scheduled to undergo revision using either commercially available or customized cages based on individualized RP models. Average follow-up was 4.4 years (range, 1 to 9 years). The average Harris hip score was 36.1 (range, 20 to 58) preoperatively and reached an average of 82.6 (range, 60–96) at the last follow-up. No mechanical failure or loosening was observed. One patient experienced hip dislocation 4 days postoperatively. The resultant findings of this study merit consideration of RP as a helpful clinical complement for dealing with some complex bone defect of acetabulum.     

Biomechanical evaluation and comparison of polyetheretherketone rod system to traditional titanium rod fixation on adjacent levels

PurposeAdjacent segment degeneration or fracture of the vertebral body was commonly reported in rigid fusion. Use of semirigid instruments such as PEEK rod system could be an alternative treatment. However, the biomechanical implications of using PEEK rod systems are not well understood. Purpose of this study was to compare a PEEK rod fixation system to traditional titanium rod fixation via a finite element analysis.MethodsA lumbar spine model from L2–L5 vertebral bodies was constructed. A fusion model, created by modifying the intact lumbar model, was used to simulate anterior interbody and posterolateral lumbar fusion. Loading was applied through flexion, extension, lateral bending, torsion.ResultsThe greatest increase in stress was estimated at the upper disc adjacent to the titanium rod with interbody fusion. The lower increase in stress on adjacent segments occurred with PEEK rod fixation without fusion and noninstrumented posterolateral lumbar fusion models. With the same fusion or nonfusion procedures, the stress on discs and facet joints of adjacent segments in the PEEK rod group decreased by 5–25% of that in the titanium rod group for all loading conditions.ConclusionIn comparison with rigid fixation, some potential advantages of using PEEK rod systems include a reduced stress on adjacent segment disc and facet joint, and the elastic ability of PEEK rod fixation allows for a greater range of motion, which may reduce the incidence of clinical complications seen with rigid fusion devices.     

Alternative grafts in anterior cervical fusion

Objective

The present retrospective study was conducted to compare the clinical and radiographic outcomes in patients undergoing anterior cervical discectomy with fusion (ACDF) using carbon fiber reinforced polymer (CFRP) cages, or allograft.

Methods

We retrospectively reviewed cases of ACDF using allograft in 20 patients, and CFRP in 19 who had sequential radiographs before and after surgery, and at 1 year.

Results

There were no apparent significant differences between the 2 groups in age (p = 0.057), gender (p = 0.635), or complications (p = 0.648). At 12 months, there were no cases of construct failure, and fusion appeared to have been achieved in patients of both groups. Lordosis was increased significantly in both groups after surgery (p < 0.001 in allograft and p = 0.025 in CFRP), and was maintained up until 1 year (p < 0.018 in allograft and p = 0.05 in CFRP) without a difference between groups (p = 0.721). Anterior interbody height was significantly increased (p < 0.001 in both groups at each time points) after surgery, without a significant difference between groups (p > 0.21). This increase in height was greatest in magnitude immediately after surgery, and declined with the passage of time. There was no detectable health-related quality of life difference between allograft and CFRP group after surgery (p > 0.05).

Conclusion

The present study demonstrates that CFRP cages appear to have comparable fusion rates, restoration of lordosis and disc space height, and complication rates to patients who undergo ACDF with allograft.     

颈前路零切迹自锁融合器治疗跳跃型颈椎病早期疗效观察

目的观察分析颈前路零切迹自锁融合器治疗跳跃型颈椎病的早期临床疗效,评价手术对邻近颈椎退变的影响。方法回顾性分析自2013-06—2014-06采用颈前路零切迹自锁融合器治疗的跨节段颈椎病13例,共置入椎间融合器26枚。结果本组手术时间80~120(95.00±11.18)min,术中出血量70~120(93.85±16.60)ml。术后吞咽困难1例,予以对症处理后有所好转,末次随访时无症状。定期随访至术后1年。术后随访大多数患者椎间盘未见明显退变,1例Kellgren颈椎退变分级由0级退变为1级;1例Miyazaki椎间盘退变分级由Ⅰ级退变为Ⅱ级,1例由Ⅱ级退变为Ⅲ级。术后1周VAS评分、术后6个月JOA评分较术前明显改善,差异有统计学意义(P0.05)。术后椎间隙高度(7.45±0.21)mm,较术前明显增高,差异有统计学意义(P0.05)。结论颈前路零切迹自锁融合器治疗跳跃型颈椎病的初期疗效满意,临床症状缓解明显,颈椎椎间隙融合率高,并发症少,可减缓邻近颈椎的退变。     

双插片自稳式融合器治疗颈椎间盘突出症的疗效观察

目的评价颈前路减压双插片自稳式融合器(ROI-C)植骨融合治疗颈椎间盘突出症的临床疗效。方法回顾性分析自2011-10—2014-09采用颈前路减压ROI-C植骨融合治疗的34例颈椎间盘突出症,统计手术时间、术中出血量、并发症,测量术前术后颈椎曲度、病变节段椎间隙高度,并以植骨融合率、NDI指数、JOA评分、Odom标准评价临床疗效。结果本组随访时间14~31个月,平均21.6个月。单节段手术时间75~100 min,平均88 min。双节段手术时间105~125 min,平均113 min。术中出血量70~310 ml,平均195 ml。术后1例出现声音嘶哑,2例出现轻度吞咽困难,无切口感染。术后6个月,所有患者均获得骨性融合。末次随访时NDI指数(t=14.530,P0.001)、JOA评分(t=7.100,P=0.000 1)、椎间隙高度(t=3.620,P=0.000 4)及颈椎曲度(t=7.690,P0.001)均较术前明显改善,差异有统计学意义(P0.01)。末次随访时采用Odom标准评定疗效:优24例,良7例,可3例,优良率91.2%。结论颈前路减压ROC-I植骨融合治疗颈椎间盘突出症是一种创伤小和有效的手术方法,具有并发症少、疗效好的优点。