Arthroscopy of the Patello-Femoral Joint

Arthroscopy of the knee joint was performed in 126 patients complaining of symptoms in the patello-femoral joint. in about one-third of these cases the arthroscopic findings in the patello-femoral joint were normal, whereas the remainder had varying degrees of chondromalacia or arthrosis. the classification of changes agreed well with an independent classification carried out in conjunction with surgery. in one-third of the cases there were additional findings which could explain the knee symptoms, more than half of these being degenerative changes reminiscent of an early gonarthrosis located in the femuro-tibial joint. There were no complications arising from the arthroscopy procedure which was well tolerated by the patients. It is concluded that arthroscopy is a helpful tool for differential diagnosis in patients with patello-femoral pain and for classification of degenerative changes in this joint.     

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目的 探讨机用PathfileTM镍钛锉联合手用ProTaper镍钛器械在磨牙狭窄根管的预备效果。方法 选择2011年8月至2012年2月广州市天河区人民医院口腔科门诊需行根管治疗的磨牙根管狭窄患者125例(患牙125颗),采用PathfileTM镍钛锉进行根管预处理,以手用Pro Taper镍钛器械完成根管预备,侧向加压技术充填根管,根据治疗前后的X线片评价根管预备和充填效果。结果 125颗患牙的419个根管中,409个形态好,7个未能完全疏通,无台阶、根尖堵塞、根管偏移及侧壁穿孔等并发症发生,有3根器械折断于根尖段。恰填403个根管,10个根管因未完全疏通、无法到达根尖孔或断针而欠填,6个根管超填。结论 采用机用PathfileTM镍钛锉疏通狭窄根管的根尖段后再以手用ProTaper镍钛器械完成根管预备,可获得良好的成形效果且较少出现并发症。     

Haematogenous Osteomyelitis of the Patella: Report of Three Cases

Three cases of osteomyelitis of the patella are reported. One presented as an acute septic arthritis and another developed a sterile arthritis despite antibiotics. The clinical signs, diagnosis and treatment are discussed. Treatment with rest and antibiotics failed to cure the disease. in all three cases a sequestrectomy was carried out resulting in healing of the affected patella and recovery of knee mobility.     

关节镜辅助下无头加压螺钉固定治疗髌骨横型骨折?

目的：探讨关节镜下采用无头加压螺钉(HCS)固定治疗髌骨横型骨折的临床疗效。方法选择髌骨橫型骨折患者19例,采用关节镜辅助下无头加压螺钉固定治疗,术后复查并随访。结果术后3~5周行 X 线片骨折线模糊或消失,髌骨关节面平整无位移,术后骨折愈合时间平均8周;患侧膝末次膝关节活动范围[(135.42±5.82)°]与健侧活动范围[(139.38±6.55)°]差异无统计学意义(P >0.05)。末次随访膝关节 Lysholm 评分86~100分,平均(93.7±4.14)分,显著高于术前评分65.7分(P <0.05);随访期内无骨折移位,内固定物脱落、断裂等并发症。结论关节镜辅助下 HCS 固定治疗髌骨横行骨折,关节功能恢复快,且术后并发症少,是治疗髌骨橫型骨折的有效方法之一。     

Torsional Resistance of WaveOne Gold and Reciproc Blue according to the Loading Methods

IntroductionThis study aimed to compare the torsional resistances and fracture modes of WaveOne Gold (Dentsply Sirona, Ballaigues, Switzerland) and Reciproc Blue (VDW, Munich, Germany) using the repetitive torsional loading (RTL) method and the conventional single-rotation (STL) method.MethodsA 3-mm file tip was fixed with a brass plate, and a torsional load was applied using a custom device. In the RTL method, the file was driven counterclockwise at 50 rpm until it achieved the preset torque of 0.5 Ncm; thereafter, it was returned to its original position. This recovery of the file to its original position was defined as 1 torsional loading cycle; the number of repetitive load cycles until fracture was counted. In the STL method, the files were rotated at a constant rate of 2 rpm in a counterclockwise direction until file fracture. The fragments fractured by the 2 methods were compared under a scanning electron microscope to examine the topographic features of the fractured surfaces and longitudinal aspects.ResultsWith the RTL method, Reciproc Blue showed a higher number of repetitive load cycles until fracture than WaveOne Gold (P < .05). With the STL method, Reciproc Blue also had a higher ultimate strength than WaveOne Gold (P < .05). Scanning electron microscopic findings of the fractured specimens from the 2 test methods showed different features of torsional failure.ConclusionsWithin the study limitations, both the RTL and STL methods conferred similar torsional resistance. Therefore, the clinically relevant RTL method with repetitive and reciprocation motion can be used for testing torsional resistance.     

A Paradigm Shift for Torsional Stiffness of Nickel-Titanium Rotary Instruments: A Finite Element Analysis

IntroductionThe aim of this study was to investigate the influence of mass and the polar moment of inertia on the torsional behavior of nickel-titanium rotary instruments to understand which parameter of cross-sectional design had a key role in terms of torsional resistance.MethodsFour different instrument models were designed and meshed using computer-aided engineering software (SolidWorks; Dassault Systems, Waltham, MA). Instrument models shared the same characteristics, except for cross-sectional design; triangle, rectangle, square, and hollow square geometry was selected. Finite element analysis was performed simulating a static torsional test using the FEEPlus internal solver (Solid Works). Von Mises stress and torsional load at fracture were calculated by the software. Linear regression analysis was performed to investigate the relationship of the polar moment of inertia, cross-sectional area, inner core radius, and mass per volume on the torsional resistance of nickel-titanium rotary instruments.ResultsThe polar moment of inertia positively affected the maximum torsional load with the highest level of correlation (R² = 0.917). It could be stated that the higher the polar moment of inertia is, the more maximum torsional load at fracture is present. Mass and cross-sectional area had a lower level of correlation compared with the polar moment of inertia (R² = 0.5533). According to this, 2 instruments with the same mass/mm and/or cross-sectional area could have different torsional resistance.ConclusionsThe polar moment of inertia can be considered as the most important cross-sectional factor in determining the torsional resistance of rotary instruments over metal mass and cross-sectional area.     

根管机械预备与牙本质微裂

根管机械预备是根管治疗术的关键步骤,在清除感染源和根管成形的同时,为化学冲洗和根管充填创造空间。但有学者认为镍钛器械会在机械预备过程中引起牙本质微裂,继而引发微渗漏、牙根纵裂,对根管治疗的预后产生不利影响。文章就根管机械预备过程中形成牙本质微裂的原因、预防及争议做一介绍。     

Tube Technique with Light-curing Composite for Removing Fractured Root Canal Instruments: Influence of Polymerization Cycles and Mechanical Exposure

IntroductionThe purpose of this study was to investigate the influence of both polymerization cycles and mechanical exposure procedures on the adhesion of instrument fragments using a modified tube technique with a light-curing composite.MethodsEighty Mtwo instruments (size 15.05; VDW, Munich, Germany) were cut at a diameter of 35/100 mm and clamped in a vice with an overlap of 2 mm. Matching cannulas were filled with SDR composite (Dentsply, York, PA) and placed over the instruments. Prime & Bond Active (Dentsply Sirona, Bensheim, Germany) was used as the bonding material. Glass fiber was inserted from the opposite side into the cannula, and 1, 2, 4, or 6 polymerization cycles of 30 seconds were applied (800 mW/mm²) (n = 20/group). Sixty further identical instruments (n = 20/group) were divided into the following groups: group 1, cut at 10 mm and left unprepared (taper = 5%); group 2, parallelized using diamond instruments (taper = 0%); and group 3, prepared in a way that an inverted conical taper resulted (taper = 2%). Polymerization was performed for 2 minutes. The failure load and mode of failure were determined using a tensile testing device (2 mm/min). Data were statistically analyzed using the Kruskal-Wallis or chi-square test.ResultsThe failure load increased significantly with the number of polymerization cycles (P < .0001). More than 4 polymerization cycles had no further benefit (P > .05). The failure load in the inverted conical group was significantly lower (P < .0001) compared with the parallel and the unprepared groups. Adhesive failure was significantly more frequent in groups 2 and 3 (20/20) than in group 1 (16/20) (P < .05).ConclusionsBoth the number of polymerization cycles and the mechanical exposure procedures had a significant impact on the adhesive force when using the tube technique.     

空心钉结合张力带治疗髌骨骨折

<正>2010年1月~2013年12月,我科采用空心钉张力带固定治疗43例髌骨骨折患者,取得良好疗效,报道如下。1材料与方法1.1病例资料本组43例,男31例,女12例,年龄20~65岁。均为闭合横形髌骨骨折。1.2手术方法腰麻或硬膜外麻醉。髌骨前方纵行切口,复位髌骨,用布巾钳临时固定,在髌骨中内、中外1/3处分别钻入2枚克氏针,距关节面约3 mm,C