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Background Immobilization in external rotation after a first-time shoulder dislocation was introduced to reduce the risk of recurrence compared to immobilization in internal rotation, but its efficacy remains controversial. The purpose of this study was to determine the long-term effect of immobilization in external rotation after a first-time shoulder dislocation. Methods Between October 2000 and March 2004, 198 patients with a first-time anterior dislocation of the shoulder (average age 28) were randomly assigned to immobilization in external rotation (ER group = 104 shoulders) or internal rotation (IR group = 94 shoulders) for 3 weeks. At an average 2-year follow-up, 159 patients (80.3%) were available for evaluation. In the current study, these 159 patients were further followed up and interviewed by telephone. The following items were evaluated: recurrent instability, apprehensive feeling, surgical intervention, limitation in the range of motion, return to sports, and the single assessment numeric evaluation (SANE) score. Results The average follow-up period was 18.2 years (range, 16 – 20 years). Fifty-six patients were available for follow-up with the follow-up rate of 35%. The recurrent patients were 6/27 (22%) in the ER group and 6/29 (21%) in the IR group (p = 0.889). The surgically stabilized patients were 3/27 (11%) in the ER group and 10/29 (34%) in the IR group (p = 0.038). In total, the recurrence rate was 9/27 (33%) in the ER group and 16/29 (55%) in the IR group (p = 0.100). Adding the surgical cases and those with the SANE score ≤ 70% as failure cases, the failure rate was significantly lower in the ER group (26%) than in the IR group (52%) (p = 0.048). Among those who survived without surgical intervention, there were no significant differences in apprehensive feeling, return to sports, limited range of motion, and the SANE score between the groups. Conclusions Immobilization in external rotation reduced the risk of surgical intervention compared to internal rotation in the long-term.

Spherical radioactive caesium (Cs)-bearing microparticles (CsMPs) were emitted during the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident in March, 2011. The emission source (timing) and formation process of these particles remain unclear. In this study, the isotopic ratios of uranium (235U and 238U) and caesium (133Cs, 134Cs, 135Cs, and 137Cs) isotopes in the five spherical CsMPs (ca. 2 μm in size) sampled at 50 km west of the FDNPP were determined using secondary ion mass spectrometry and laser ablation-ICPMS, respectively. Results showed that the 235U/238U ratios of CsMPs were homogeneous (1.93 ± 0.03, N = 4) and close to those estimated for the fuel cores in units 2 and 3, and that the Cs isotopic ratios of CsMP were identical to those of units 2 and 3. These results indicated that U and Cs in the spherical CsMPs originated exclusively from the fuel melt in the reactors. Based on a thorough review of literatures related to the detailed atmospheric releases of radionuclides, the flow of plumes from the FDNPP reactor units during the accident and the U and Cs isotopic ratio results in this study, we hereby suggest that the spherical CsMPs originate only from the fuel in unit 2 on the night of 14 March to the morning of 15 March. The variation range of the analysed 235U/238U isotopic ratios for the four spherical particles was extremely narrow. Thus, U may have been homogenised in the source through the formation of fuel melt, which ultimately evaporating and taken into CsMPs in the reactor and was released from the unit 2.

Scapulohumeral rhythm (SHR) provides insight to neuromuscular control and fundamental biomechanics of the shoulder. This rhythm often is disrupted in pathologic shoulders. As the first step, we sought to quantify SHR in healthy subjects for diagnostic assessment of shoulder function. Ten healthy shoulders were studied. Three-dimensional models of the humerus and scapula were created from computed tomography scans. Dynamic shoulder motion was recorded by use of single-plane fluoroscopy during arm abduction with 0-kg and 3-kg handheld loads. Shoulder kinematics were quantified by use of model-based 3-dimensional-to-2-dimensional registration techniques. SHR decreased (more scapular motion) with increasing abduction. With a 3-kg load, scapulothoracic motion was significantly reduced through the range of 35 degrees to 45 degrees of glenohumeral motion. Muscular stabilization of the scapula increased with external loading, as shown by decreased SHR during early lifting. Dynamic scapular stabilization provides a critical platform for upper extremity activity.

A laser ablation-inductively coupled plasma-mass spectrometric (LA-ICPMS) technique utilizing a titanium-sapphire (TiS) femtosecond laser (fs-laser) has been developed for elemental and isotopic analysis. The signal intensity profile, depth of the ablation pit and level of elemental fractionation were investigated in order to evaluate the analytical capability of the present fs-laser ablation-ICPMS technique. The signal intensity profile of (57)Fe, obtained from iron sulfide (FeS(2)), demonstrated that the resulting signal intensity of (57)Fe achieved by the fs-laser ablation was almost 4-times higher than that obtained by ArF excimer laser ablation under a similar energy fluence (5 J/cm(2)). In fs-laser ablation, there is no significant difference in a depth of the ablation pit between glass and zircon material, while in ArF laser ablation, the resulting crater depth on the zircon crystal was almost half the level than that obtained for glass material. Both the thermal-induced and particle size-related elemental fractionations, which have been thought to be main sources of analytical error in the LA-ICPMS analysis, were measured on a Harvard 91500 zircon crystal. The resulting fractionation indexes on the (206)Pb/(238)U (f(Pb/U)) and (238)U/(232)Th (f(U/Th)) ratios obtained by the present fs-laser ablation system were significantly smaller than those obtained by a conventional ArF excimer laser ablation system, demonstrative of smaller elemental fractionation. Using the present fs-laser ablation technique, the time profile of the signal intensity of (56)Fe and the isotopic ratios ((57)Fe/(54)Fe and (56)Fe/(54)Fe) have been measured on a natural pyrite (FeS(2)) sample. Repeatability in signal intensity of (56)Fe achieved by the fs-laser ablation system was significantly better than that obtained by ArF excimer laser ablation. Moreover, the resulting precision in (57)Fe/(54)Fe and (56)Fe/(54)Fe ratio measurements could be improved by the fs-laser ablation system. The data obtained here clearly demonstrate that, even with the fundamental wavelength (NIR operating at 780 nm), the fs-laser ablation system has the potential to become a significant tool for in-situ elemental and isotopic analysis of geochemical samples including heavy minerals and metallic materials.

The purpose of this study was to investigate glenohumeral translation in-vivo during active shoulder abduction in the scapular plane. Three-dimensional (3D) models of 9 shoulders were created from CT scans. Fluoroscopic views aligned to the plane of the scapula were recorded during active arm abduction with neutral rotation. 3D motions were determined using model-based 3D-to-two-dimensional (2D) registration. Humeral translation was referenced to the glenoid center in the superior/inferior direction. The humerus moved an average of 1.7 mm superior with arm abduction, from an inferior location to the glenoid center. The humeral head was centered within 1 mm from the glenoid center above 80 degrees abduction. Variability in glenohumeral translation between shoulders decreased significantly from initial to final arm abduction. Our findings agree with some authors' observations of inferior-to-central translation of the humerus and behavior as a congruent ball and socket. We believe this information will help improve the understanding of shoulder function.

Anterior glenoid fractures associated with glenohumeral instability are normally treated with open fixation of the fragment. However, recent technical development enables this procedure to be performed under arthroscopic control using screws or even suture anchors if the fragment is small enough. We developed a unique method of stabilizing a larger fragment with suture anchors and the use of a clear imaging method of three-dimensional computed tomography (3D-CT) with the humeral head eliminated, preoperatively and postoperatively. In the present article, we report a detailed method of arthroscopic stabilization for a consecutive series of 8 patients, with an average of 27% bone loss (fragment size) against the lower part of the circular glenoid portion, using suture anchors.

In shoulder arthroscopy, cannulas with large diameters (7-9 mm) are commonly used both in the lateral decubitus and the beachchair position because they ensure the easy introduction of instruments into the intra-articular space and provide a clear arthroscopic view through the application of high intra-articular pressure. On the other hand, fluid extravasation and the resulting inconvenience due to the narrowing of the intra-articular working space are also obvious issues. Consequently, this makes arthroscopic stabilization surgery all the more challenging. To avoid these shortcomings of this procedure, we believe cannulas should be used only when necessary such as for knot tying and for transtendon portals. In this article, we report a unique and original method of arthroscopic Bankart repair in the beachchair position with limited use of cannulas of smaller diameter (5 mm) and its advantages over ordinary arthroscopic techniques using large-diameter cannulas in terms of preventing fluid extravasation and keeping a wide working space, which facilitates beneficial intra-articular techniques.

Background: Knowledge regarding the morphology of the glenoid rim is important when patients with recurrent anterior glenohumeral instability are assessed. Ordinary imaging techniques are not always sensitive enough to demonstrate the morphology of the glenoid rim accurately. We developed a method of three-dimensionally reconstructed computed tomography with elimination of the humeral head to evaluate glenoid morphology. The purpose of the present study was to quantify glenoid osseous defects and to define their characteristics in patients with recurrent anterior instability. Methods: The morphology of the glenoid rim in 100 consecutive shoulders with recurrent unilateral anterior glenohumeral instability was evaluated on three-dimensionally reconstructed computed tomography images with the humeral head eliminated. The configuration of the glenoid rim was evaluated on both en face and oblique views. Concurrently, we also investigated seventy-five normal glenoids, including both glenoids in ten normal volunteers. Shoulders without an osseous fragment at the anteroinferior portion of the glenoid were compared with the contralateral shoulder in the same patient to determine if the glenoid morphology was normal. In shoulders with an osseous fragment, the fragment was evaluated quantitatively and its size was classified as large (>20% of the glenoid fossa), medium (5% to 20%), or small (

Laser ablation in liquid (LAL) is widely used for the micro fabrications or production of nano-particles of various materials. In this study, we have evaluated the analytical capability of the LAL as a new sampling technique for elemental and isotopic analysis of solid samples. The solid sample was set into the deionized water, and the laser ablation was carried out within the water using a Ti:S femtosecond laser operating at fundamental wavelength (780 nm). The laser-induced sample particles were directly trapped and collected in the ambient water with high efficiency. We have investigated the possible elemental and isotopic fractionation during the LAL sampling. Five isotopic ratios (208Pb/238U, 238U/232Th, 208Pb/206Pb, 56Fe/54Fe and 57Fe/54Fe) were measured on the resulting sample particles obtained with various ablation conditions (fluence and repetition rate) using ICP-mass spectrometry (ICP-MS). Series of experiments revealed that either with the higher fluence (>200 J cm−2) or with higher repetition rate (>250 Hz), the resulting 208Pb/238U ratios varied significantly (>1%) from those obtained with source materials (hence, NIST SRM 610). For the 238U/232Th, 208Pb/206Pb, 56Fe/54Fe and 57Fe/54Fe ratios, the measured values did not vary measurably (

We describe 3 cases of an all-arthroscopic technique for repair of a humeral avulsion of the glenohumeral ligament (HAGL) lesion and the postoperative clinical outcomes. From a technical perspective, the most critical part of the surgeries was the anchor insertion at an optimal position on the humerus in order to achieve proper tension of the glenohumeral ligament. The arm-free beach-chair position, which facilitates maximum internal rotation, use of a 70 degrees angled arthroscope, and an anterior-inferior trans-subscapularis tendon portal were considered key factors to accomplish this procedure.