基于钚内照射剂量重建的尿钚分析方法

钚的内照射剂量可通过生物样本的测定结果和摄入滞留或排泄函数修正的办法来确定。本文从原理、方法学、在剂量重建中的应用几方面综述了尿钚分析方法。尿钚分析方法主要包括α谱仪分析方法、裂变径迹分析方法，电感耦合等离子体、热电离、加速器等质谱分析方法，每种方法优势不同。本文可为基于钚内照射剂量重建尿钚分析方法的选择提供参考。     

Risks and benefits of timely screw removal after thoracolumbar spine fractures treated with non-fusion technique

BackgroundPercutaneous-short segment screw fixation (SSSF) without bone fusion has proven to be a safe and effective modality for thoracolumbar spine fractures (TLSFs). When fracture consolidation is confirmed, pedicle screws are no longer essential, but clear indications for screw removal following fracture consolidation have not been established.MethodsIn total, we enrolled 31 patients with TLSFs who underwent screw removal following treatment using percutaneous-SSSF without fusion. Plain radiographs, taken at different intervals, measured local kyphosis using Cobb’ angle (CA), vertebra body height (VBH), and the segmental motion angle (SMA). A visual analogue scale (VAS) and the Oswestry disability index (ODI) were applied pre-screw removal and at the last follow-up.ResultsThe overall mean CA deteriorated by 1.58° (p < 0.05) and the overall mean VBH decreased by 0.52 mm (p = 0.001). SMA preservation was achieved in 18 patients (58.1%) and kyphotic recurrence occurred in 4 patients (12.9%). SMA preservation was statistically significant in patients who underwent screw removal within 12 months following the primary operation (p = 0.002). Kyphotic recurrence occurred in patients with a CA ≥ 20° at injury (p < 0.001) with a median interval of 16.5 months after screw removal. No patients reported worsening pain or an increased ODI score after screw removal.ConclusionScrew removal within 12 months can be recommended for restoration of SMA with improvement in clinical outcomes. Although, TLSFs with CA ≥ 20° at the time of injury can help to predict kyphotic recurrence after screw removal, the clinical outcomes are less relevant.     

Does use of a quadrilateral surface plate improve outcome in elderly acetabular fractures?

BackgroundAcetabular fractures in the elderly frequently involve segmental quadrilateral plate injury, yet no consensus exists on how to best control the femoral head medial displacement. Quadrilateral surface plates (QSP) were developed to help buttress these challenging fractures. The study aims to 1) Determine the prevalence of segmental quadrilateral plate fractures (SQPF) in elderly patients; and 2) Assess if utilization of a QSP is associated with improved acetabulum fracture reduction and outcome.MethodsThis was a retrospective study conducted at a level-1 trauma centre. . All patients over 60-years that sustained an acetabular fracture between 2007 and 2019 were reviewed. Pre-operative pelvic radiographs and CT imaging were reviewed for 96 patients, to assess for SQPF. From the 96 patients reviewed, over one third of patients (n = 40, 41.6%) sustained a SQPF. Patients that had an acute-THA (n = 7) were excluded as were patients that underwent an ORIF but did not have a QSP or an anterior column buttress plate (n = 3). The remaining 30 formed the study’s cohort. We assessed the ability to achieve and maintain reduction in this elderly population, and compared outcomes using traditional anterior column buttress plates (ilioingual or intra-pelvic approach) versus an intra-pelvic pre-contoured buttress suprapectineal plate (QSP). Outcome measures included: fracture reduction using the Matta classification (desirable: anatomical/imperfect and poor), re-operations, conversion to THA and Oxford Hip Score (OHS) (for the preserved hips).ResultsTen patients had an ORIF with utilization of a QSP (QSP-group), and 20 had an ORIF but did not have the QSP (non-QSP-group). There was no difference in patient demographics between groups. Fracture patterns were also similar (p = 0.6). Postoperative fracture reduction was desirable (anatomical/imperfect) in 17 patients and poor in 13. Improved ability to achieve a desirable reduction was seen in the QSP-group (p = 0.02). Conversion to THA was significantly lower in patients that had a desirable fracture reduction (appropriate: 3/17; poor: 7/13). No patients in the QSP-group have required a THA to-date, compared to 10/20 patients in the non-QSP-group (p = 0.01). The mean time to THA was 1.6 ± 2.1 year. There was no difference in OHS between the two groups (34.4 ± 10.3).ConclusionElderly acetabulum fractures have a high incidence (approaching 40%) of segmental QPF. Desirable (anatomical/imperfect) fracture reduction was associated with improved outcome. The use of a QSP was associated with improved ability to achieve an appropriate reduction. A QSP should be considered as they are both reliable and reproducible with a significantly improved fracture reduction and lower conversion to THA.     

经直接前方入路切开复位与闭合复位治疗股骨颈骨折的疗效对比

目的 比较经直接前方入路（DAA）切开复位与闭合复位经皮空心螺钉内固定治疗股骨颈骨折的临床疗效。方法 回顾性分析2015年12月～2018年12月因股骨颈骨折在我院分别行切开复位（n=46）和闭合复位空心螺钉内固定（n=46）治疗的患者，统计患者基本资料，骨折Garden类型，从受伤到手术治疗时间，手术时间，术中出血量，术后Garden复位指数，术后1 d、术后3、6、12及24月患髋Harris功能评分，并统计术后骨折不愈合率及股骨头缺血坏死发生率；采用Spearman相关分析及Logistic多元回归分析，研究影响股骨颈骨折术后股骨头缺血坏死的因素。结果 切开复位组术中出血量、手术时间大于闭合复位组，但术后Garden复位指数优于闭合复位组（均P＜0.05）；术后6、12月切开复位组患髋Harris功能评分优于闭合复位组（P＜0.05）；术后24月内切开复位组患者股骨头缺血坏死率显著低于闭合复位组（P=0.01）；两组骨折不愈合率无统计学差异（P=0.06）。Spearman相关分析发现，股骨颈骨折Garden分型与股骨颈骨折术后股骨头缺血坏死发生率呈显著正相关（R=0.521，P＜0.001），但Logistic多元回归分析未能发现影响股骨颈骨折术后股骨头坏死发生率的相关因素。结论 DAA入路切开复位空心螺钉内固定治疗股骨颈骨折比闭合复位经皮空心螺钉内固定质量更佳，术后12月内患髋功能更好，术后24月内股骨头缺血坏死发生率更低。     

Change in Pull-Out Force during Resorption of Magnesium Compression Screws for Osteosynthesis of Mandibular Condylar Fractures

Background: Magnesium has been used as degradable fixation material for osteosynthesis, but it seems that mechanical strength is still a current issue in these fixations. The aim of this study was to evaluate the axial pull-out force of compression headless screws made of magnesium alloy during their resorption. Methods: The tests included screws made for osteosynthesis of the mandible head: 2.2 mm diameter magnesium alloy MgYREZr (42 screws) and 2.5 mm diameter polylactic-co-glycolic acid (PLGA) (42 pieces, control). The screws were resorbed in Sørensen’s buffer for 2, 4, 8, 12, and 16 weeks, and force was measured as the screw was pulled out from the polyurethane block. Results: The force needed to pull the screw out was significantly higher for MgYREZr screws than for PLGA ones (p < 0.01). Within eight weeks, the pull-out force for MgYREZr significantly decreased to one third of its initial value (p < 0.01). The dynamics of this decrease were greater than those of the pull-out force for PLGA screws (p < 0.05). After these eight weeks, the values for metal and polymer screws equalized. It seems that the described reduction of force requires taking into account when using magnesium screws. This will provide more stable resorbable metallic osteosynthesis.     

3D打印头膜固定技术在头部肿瘤放疗的应用研究

目的 为头部放疗患者定制个体化3D打印头膜,通过与热塑头膜对比,评价其材质的物理特性及该技术的摆位精准度。方法 分别将3D打印头膜和热塑头膜置于固体水表面,通过电离室和胶片测量深度5cm处和表面剂量来进行剂量学评估。选取30例头部放疗患者随机分为对照组和试验组,分别采用热塑头膜和3D打印头膜进行固定,通过CBCT获取患者X、Y、Z方向的平移和旋转摆位误差来进行临床摆位误差评估。结果 深度5cm处两种材质对射线衰减率均<1%。表面位置热塑头膜剂量升高27%,3D打印头膜升高18%。两组患者各取116组摆位误差数据,对照组和试验组X、Y、Z方向平均平移误差分别为1.29mm和1.16mm、1.42mm和1.24mm、1.38mm和1.16mm;平均旋转摆位误差分别为1.29°和1.08°、1.02°和0.96°、1.01°和1.00°。与对照组相比,试验组患者在Y、Z方向平移摆位误差和X方向旋转摆位误差不同(P<0.05),其他方向相近(P>0.05)。结论 3D打印头膜体位固定技术符合现代放疗的精准摆位要求,具有较高的临床实用价值,可用于进一步临床研究。     

Endurance Behavior of Cemented Tibial Tray Fixation Under Anterior Shear and Internal-External Torsional Shear Testing: A New Methodological Approach

BackgroundEarly total knee arthroplasty failures continue to surface in the literature. Cementation technique and implant design are two of the most important scenarios that can affect implant survivorship. Our objectives were to develop a more suitable preclinical test to evaluate the endurance of the implant-cement-bone interface under anterior shear and internal-external (I/E) torsional shear testing condition in a biomechanical sawbones.MethodsImplants tested included the AS VEGA System PS and the AS Columbus CR/PS (Aesculap AG, Germany), with zirconium nitride (ZrN) coating. Tibial implants were evaluated under anterior shear and I/E torsional shear conditions with 6 samples in 4 test groups. For the evaluation of the I/E torsional shear endurance behavior, a test setup was created allowing for clinically relevant I/E rotation with simultaneous high axial/tibio-femoral load. The test was performed with an I/E displacement of ±17.2°, for 1 million cycles with an axial preload of 3,000 N.ResultsAfter the anterior shear test an implant-cement-bone fixation strength for the AS VEGA System tibial tray of 2,674 ± 754 N and for the AS Columbus CR/PS tibial tray of 2,177 ± 429 N was determined (P = .191). After I/E rotational shear testing an implant-cement-bone fixation strength for the AS VEGA System PS tray of 2,561 ± 519 N and for the AS Columbus CR/PS tray of 2,824 ± 515 N was resulted (P = .39).ConclusionBoth methods had varying degrees of failure modes from debonding to failure of the sawbones foam. These two intense biomechanical loading tests are more strenuous and more representative of clinical activity.     

双腔微导管在颈内动脉慢性闭塞再通治疗中的应用

目的 探讨双腔微导管在颈内动脉慢性闭塞病变血管再通治疗中应用的可行性、安全性和技术优势。      

单侧外固定治疗重度Pilon骨折的临床疗效探究

目的探讨单侧外固定治疗重度Pilon骨折的临床疗效。方法回顾性分析2017年6月-2018年12月南京中大医院江北院区骨科收治的重度Pilon骨折患者100例,男性54例,女性46例;年龄18~65岁,平均35.5岁;Ruedi-AllgowerⅡ型39例,Ⅲ型61例。按照不同固定方法分为常规固定组和单侧外固定组,各50例,比较两组患者住院时间、完全负重下地时间、骨折愈合时间,评价治疗前及治疗后3个月踝关节活动度、踝关节功能恢复情况、疼痛程度,并统计患者的治疗效果及并发症发生情况。结果单侧外固定组住院时间、完全负重下地时间、骨折愈合时间分别为(16.50±1.50)d、(132.56±10.25)d、(14.16±0.69)周,均短于常规固定组(19.25±2.35)d、(198.65±16.58)d、(17.58±1.50)周(t/P=6.975/0.001、23.970/0.001、14.650/0.001)。治疗后3个月,单侧外固定组踝关节Mazur评分为(85.67±6.59)分,显著高于常规固定组(62.78±3.45)分,VAS评分为(2.23±0.36)分,低于常规固定组(4.59±0.89)分(t/P=21.760/0.001、17.380/0.001);单侧外固定组患者踝关节活动度分别为(17.29±0.16)°、(28.36±1.23)°、(19.68±0.16)°、(16.89±2.12)°,均高于常规固定组(10.62±1.25)°、(21.57±2.58)°、(14.36±1.62)°、(14.25±0.57)°(t/P=37.430/0.001、16.800/0.001、23.110/0.001、8.503/0.001)。单侧外固定组治疗优良率为90.00%,显著高于常规固定组74.00%(χ^2/P=4.336/0.037)。单侧外固定组总并发症发生率为4.00%,显著低于常规固定组的18.00%(χ^2/P=5.005/0.025)。结论单侧外固定支架治疗重度Pilon骨折可有效减轻患者疼痛症状,提高患者踝关节活动度,恢复患者功能,治疗效果显著,安全性较高。