Computer-assisted navigation for intramedullary nail fixation of intertrochanteric femur fractures: A randomized,controlled trial

IntroductionLag screw cutout is one of the most commonly reported complications following intramedullary nail fixation of intertrochanteric femur fractures. However, its occurrence can be minimized by a well-positioned implant, with a short Tip-to-Apex Distance (TAD). Computer-assisted navigation systems provide surgeons with the ability to track screw placement in real-time. This could allow for improved lag screw placement and potentially reduce radiation exposure to the patient and surgeon.MethodsBetween Oct 2014 and Jan 2016, patients with intertrochanteric femur fractures being treated with intramedullary nail fixation by one of three fellowship-trained orthopaedic traumatologists were enrolled. Inclusion criteria were low-energy mechanism of injury and fracture class 31-A1/A2. Open fractures and patients with multiple injuries to the lower extremity were excluded. Patients were randomly assigned to computer-assisted navigation or a conventional fluoroscopic technique for lag screw placement. The primary outcomes were TAD, measured by postoperative anteroposterior and lateral x-rays by an independent reviewer, and radiation exposure measured in seconds of fluoroscopy time. Surgical time was also recorded.Results50 patients were randomized, 26 to the computer-assisted navigation group and 24 to the control group. The mean manually-measured TAD in the computer-assisted navigation group was 14.1 mm ± 3.2 and in the control group was 14.9 mm ± 3.0 (p = 0.394). There was no difference between groups in total radiation time (navigation: 58.8 s ± 23.6, control: 56.5 s ± 28.5, p = 0.337) or radiation time during lag screw placement (navigation: 19.4 s ± 8.8, control: 18.8 s ± 8.0, p = 0.522). The surgical time was significantly longer in the computer-assisted navigation group with a mean surgical time of 45.8 min ± 9.8 compared to 38.4 min ± 9.3 in the control group (p = 0.009).ConclusionsComputer-assisted navigation consistently produced excellent TADs, however it was not significantly better than conventional methods when done by fellowship-trained orthopaedic traumatologists. Surgeons with a lower volume trauma practice could potentially benefit from computer-assisted navigation to obtain better TAD.     

髋臼前后柱拉力螺钉结合重建钢板固定治疗髋臼横断骨折

目的回顾分析髋臼前后柱螺钉结合重建钢板固定治疗髋臼横断骨折的疗效。方法本组患者共36例,采用Kochher-Langenback入路14例,髂腹股沟入路12例,扩展型髂股入路6例,前后联合入路4例。本组病例中采用后路重建钢板结合前柱螺钉固定21例,前路重建钢板结合后柱螺钉固定15例。结果随访时间6~27个月,平均19.6个月。复位评估参照Matta标准,解剖复位22例（61.11%）;满意复位10例（27.78%）;复位不满意4例（11.11%）。关节功能按改良Merled Aubigne6分法和Epstein标准评定,优23例（63.89%）,良8例（22.22%）,可3例（8.33%）,差2例（5.56%）,优良率86.11%。异位骨化4例,按Brooker分级：Ⅰ-Ⅱ级3例,Ⅲ~Ⅳ级1例。深静脉栓塞2例,经非手术治疗而愈,坐骨神经医源性损伤1例,经治疗6月后恢复,股骨头坏死3例。结论髋臼前后柱螺钉固定结合钛板治疗髋臼横断骨折,创伤较少,固定坚强,治疗效果良好。     

The adaptive effect of narrowing the interocular separation on the AC/A ratio

The purpose of this study was to determine whether the response AC/A ratio could be altered when the subject's interpupillary distance (IPD) was optically halved. We measured the changes in the AC/A ratio for 10 subjects after using the optical device for 30 min. Accommodative response was measured using a Canon R-1 optometer, and vergence response was measured with an ASL 210 Eye Movement Monitor. The average AC/A ratios were 1.20+/-0.35 (SD) (MA/D) and 0.84+/-0.39 (MA/D) before and after wearing the device, respectively. The decrease in AC/A ratio was statistically significant (p=0.01). This was mainly caused by a reduction in the slope of the accommodative vergence. The results of this study suggest that the AC/A ratio can be decreased if an IPD-narrowing device is used. A possible application of this mechanism in the study of myopia is discussed.     

Time factors in larynx tumor radiotherapy: lag times and intertumor heterogeneity in clinical datasets from four centers

Purpose: To use the time-dependent linear-quadratic model, both in the standard form and in a form modified to incorporate intertumor heterogeneity, in a reanalysis of 4 datasets for larynx tumor control, to provide more representative and direct estimates of the lag period, the time factor (λ/), and the clonogen population inactivation dose ([lnk]/).

Methods and Materials: The data comprised 2,225 patients treated in Edinburgh (UK), Glasgow (UK), Manchester (UK), or Toronto (Canada), with tumor control assessed after at least 2 years. Heterogeneity in each series was taken into account using the coefficient of variation (CV) of the clonogen radiosensitivity (). Maximum likelihood techniques were used to provide best estimates of the parameters, and also direct estimation of the more stable parameter ratios of interest.

Results: The use of different heterogeneity factors for the different series allowed common dose/time parameters to be fitted across all four series in a way not possible using the standard model, enabling the inherent effect of heterogeneity in flattening dose-response curves and in reducing time factors to be separated from the underlying more-representative values. Radiosensitivity CVs were calculated to be 30% (Edinburgh), 36% (Glasgow), 40% (Manchester), and 71% (Toronto). The lag phase was 32 days (95% CL 20–38 days) which was longer than the value of 23 days (11–36 days) deduced using the standard model without the heterogeneity parameter. The time factor was 1.2 (0.8–2.2) Gy/day, again greater than the value of 0.80 (0.54–1.41) Gy/day derived using the standard model. Similar larger time factors and longer lag periods could be reproduced using the standard model either by using a parameterization based on parameter ratios, or by omitting the discordant Toronto data and refitting just the data from the three UK centers.

Conclusion: It was concluded that the heterogeneity model provides a better representation of the time factor for tumor control when data are analyzed comprising different stages of disease treated at different centers. The model allows different amounts of heterogeneity in different series, which tend to flatten dose-responses curves and reduce time factors, to be taken in to account. Also, direct maximum likelihood estimates can be made of the lag period, the time factor (λ/), and the fractionation sensitivity (β/), as well as the clonogen population inactivation dose (lnk)/. Values of these parameter ratios are more robust and stable than the individual parameter values. The results of the present analysis using a total of 2,225 patients from four centers indicate that the average lag period may be somewhat longer and the average time factor somewhat greater (and the 95% confidence limits of the time factor exclude previous estimates), than the values deduced previously using simpler models and more diverse multi-center datasets.     

Characterisation with stable isotopes of the presence of a lag phase in the gastric emptying of liquids

Summary Background Gastric emptying of non-nutrient liquids usually lacks the presence of an initial delay phase (lag phase), and so it has been considered to be monoexponential with an initial rapid phase followed by a slower emptying phase. However a lag phase in the gastric emptying of liquids can be found if there is a high caloric density in the liquid meal. Aims of the study To characterise with stable isotopes the presence of a lag phase in the gastric emptying of non-sold meals. Methods Healthy volunteers ingested a low caloric liquid meal (345 KJ/200 mL) (LCLM), a high caloric liquid meal (1135 KJ/180 mL) (HCLM) or a semisolid meal (1403 KJ/500 mL) (SSM). Test meals were labelled with ¹³C-acetate. Breath samples were collected for ^13>CO₂ measurement and data were fitted to a power exponential function. Results Non-solid meals can have different behaviour related to the initial emptying. The presence of a lag phase in the gastric emptying of liquids was not masked by the processing of the tracer previous to its detection in breath. While the LCLM and SSM showed a rapid initial emptying phase (no lag phase), the HCLM has an initial slow emptying phase. The slower gastric emptying of the HCLM compared to the SSM was related to the presence of a lag phase in the gastric emptying of the HCLM. Conclusions The ¹³C-acetate breath test is very accurate to identify and study the lag phase if present of liquid meals.     

逆行耻骨上支髓内螺钉固定应用解剖研究

目的探讨耻骨上支髓内螺钉的正确进钉方法和位置,为临床应用提供解剖学基础。方法解剖6具成人尸体,制成骨性骨盆标本。在直视下,以克氏针模拟逆行耻骨上支髓内螺钉固定法。分别测量钉长、进钉点与耻骨结节的关系、螺钉与两侧髂前上棘和耻骨结节构成平面的夹角、与矢状面的夹角及耻骨上支直径等。结果对于耻骨上支内1／2、外1／2的骨折,平均钉长、螺钉与两侧髂前上棘和耻骨结节构成平面及矢状面的夹角,最窄处直径为皆有差异。结论耻骨上支髓内螺钉固定对于耻骨支不同部位的骨折进钉点和进钉方向不同,用于治疗骨盆前环的耻骨支骨折是安全、可行的。     

脉搏氧饱和度仪反应迟滞时间在小儿麻醉诱导中的作用

目的研究脉搏氧饱和度仪反应迟滞时间在小儿麻醉诱导中的作用。方法将80例择期整形外科手术的小儿随机平均分成Ⅰ组和Ⅱ组。静脉麻醉诱导前小儿用MaplesonD环路自主预吸氧2min。在麻醉诱导后的无通气期,观察SpO2降至99%、95%和90%(仅Ⅰ组)的时间。Ⅰ组和Ⅱ组小儿分别在SpO2降低至90%和95%时给氧。结果SpO2降至99%和95%所需的时间在两组之间无明显差别。由于脉搏氧饱和度仪的反应迟滞时间,再建人工呼吸后小儿的SpO2在5～30秒内仍然继续下降,并达其最低值。SpO2在Ⅰ组和Ⅱ组降至的最低值分别为(78.09±1.65)%和(90.71±0.43)。结论在应用脉搏氧饱和度仪监测时,在小儿预氧后的无通气期,一旦发现SpO2≤95%,应立即给氧人工通气,以免发生低氧血症。     

集合不足型外隐斜合并调节不足三种治疗方法的比较

目的 比较集合调节训练、三棱镜配戴矫正和近视屈光过矫在集合不足型外隐斜合并调节不足患者中的疗效.方法 横断面研究,将10～35岁的60名确诊为集合不足型外隐斜合并调节不足患者随机分为3组,每组20例,A组行三棱镜配戴矫正,B组行近视屈光过矫-0.50 D戴镜矫正,C组行集合调节视功能训练,于3个月后复查隐斜度和视功能采用配对t检验和单因采方差分析 结果 复查各项视功能参数3组患者之间差异有统计学总义 A组患者隐斜度增加(t=1 2.65,P＜0.01),近距正相对融合范围减小(t=12.65,P＜0.01),症状先短暂缓解后加重;B组患者隐斜度增加(t=4.63,P＜0.01),近距正E相对融合范围减小(t＝6.71,P＜0.01),调节幅度减小(t=14.3,P＜0.01),症状明显加重;C组患者隐斜度显著减小(t=-11.61,P＜0.01),近距正相对融合范围显著增大(t=-22.40,P＜0.01),调节幅度显著增大(t=-31.06,P＜0.01),症状明显改善 结论 集合不足型外隐斜合并调节不足患者采用集合调节视功能训练能明显改善症状,减少近距隐斜度,增加近距正相对融合范围和调节幅度,是一种有效可行的治疗方法.     

两种拟调节型人工晶状体植入术后视功能对比分析

目的 比较超声乳化术后植入可调节人工晶状体和多焦点人工晶状体的视功能.方法 30例白内障患者按自愿原则,采用非随机对照方式分成两组,试验组①10例患者(10只眼)植入Tetraflex可调节人工晶状体.试验组②20例患者(30只眼)植入+3.0D ReSTOR多焦点人工晶状体.术后6个月以ETDRS视力表检测患者最佳矫正远视力及在最佳矫正远视力基础上获得的近视力、中距离视力,综合验光仪检测近点及调节幅度.结果 随访期间所有患者均无明显的术后并发症.试验组①最佳矫正远视力为(-0.21±0.06)LogMAR,近视力为J3/40cm,试验组②为(-0.23±0.09)LogMAR,近视力为J1/35cm,两组比较近视力差异有统计学意义(P=0.035).试验组①术后主观近点为(39±10)cm,试验组②为(35±9)cm,两组比较差异无统计学意义(P=0.80).试验组①术后调节幅度为(1.94±0.13)D,试验组②为(2.08±0.63)D,两组比较差异有统计学意义(P=0.048).结论 可调节人工晶状体与多焦点人工晶状体植入术后均可使患者的视近困难得以改善.医生应根据患者情况为其选择合适的人工晶状体.

Abstract：

Objective To compare the visual performance of accommodative IOLS and that of multifocal IOLs implantation after phacoemulsification. Methods A total of 40 eyes from 30 patients undergoing phacoemulsification received intraocular lens based on the principle of voluntary. Ten eyes from 20 patients who had implantation of Tetraflex accommodative intraocular lens were randomized into group 1. Thirty eyes from 20 patients who had implantation of +3.0 aspheric ReSTOR multifocal intraocular lens were randomized into group 2. Main outcome measures included best corrected distance visual acuity, distance corrected near vision, near point, intermediate vision, and the accommodation amplitude. All the clinical data were obtained at 6months postoperatively. Results No patients had undergone any complications. At 6 months postoperatively,best corrected distance visual acuity were similar between the groupl and group2 (-0.23± 0.09LogMAR versus-0.14 ± 0.08LogMAR, P =0.085). Distance corrected near vision were similar between the two groups (J3/40cm versusJ1/35cm, P =0.035). Subjective near point were similar between the two groups [(39± 10) cm versus (35± 9) cm F=0.065, P=0.80]. The accommodation amplitude were similar between the two groups [(1.94± 0.13)D versus (2.08± 0.63)D, P =0.093]. The defocus line showed a double-peak in group 2 and single peak in group 1 which declined at intermediate distance. Conclusions Both accommodative IOLs and multifocal IOLs can correct presbyopia effectively after operation. It is best to prefer the proper IOLs for patients.     

远视足矫对屈光性调节性内斜视患者正视化的影响

目的 探讨屈光性调节性内斜视患者配戴完全远视矫正眼镜对正视化的影响.方法 临床病例对照研究.收集1990～1997年期间在中山大学眼科中心66例屈光性调节性内斜视和95例远视不伴有内斜的患儿进行回顾性调查研究.共计161例,322只眼,全部患者用1％Atropine睫状肌麻痹剂散瞳验光,将远视性屈光不正完全矫正的屈光性调节性内斜患者66例(132只眼)归为足矫组,远视性屈光不正部分矫正的普通远视患者95例(190只眼)归为欠矫组,采用重复测量资料分析方法比较两组患者3、5、7、9岁时远视性屈光不正的变化趋势.结果 足矫组患者,3岁屈光度(+5.45±2.22)D,5岁屈光度(+5.64±1.99)D,7岁屈光度(+5.48±2.05)D,9岁屈光度(+5.30±1.93)D.欠矫组患者,3岁屈光度(+3.98±2.14)D,5岁(+4.26±2.48)D,7岁(+3.97±2.43)D,9岁(+3.44±2.48)D.3～5岁,足矫组的远视屈光度增加+0.19 D,欠矫组增加+0.28 D(P ＜0.05);5～7岁,足矫组的远视屈光度下降+0.16 D,而欠矫组下降+0.29 D(P ＜0.05);7～9岁,足矫组的远视屈光度下降+0.18 D,欠矫组下降+0.53 D(P＜0.05).将两组患儿的研究始末的屈光度改变作比较,足矫组从3～9岁远视屈光度平均减少了+0.15 D,欠矫组则平均减小了+0.54 D.结论 配戴足度远视镜的3～9岁屈光性调节性内斜视儿童的正视化过程比远视欠矫的远视性屈光不正儿童慢.