Distal biceps rupture: Evaluation and management

Injury to the distal biceps occurs in certain high risk groups. Anatomical continuity of the lacertus fibrosus has bearing on the extent of retraction of the torn tendon stump. The objective of clinical and imaging evaluation is to discriminate between tendinosis, partial tear, acute complete tear and chronic complete tear. A complete tear of the distal biceps tendon can be diagnosed clinically with the Hook test. The traditional Hook test and the resisted Hook test are useful clinical tests. Though x-rays are routinely done, MRI remains the investigation of choice. Non-operative treatment has a role in selected patients with partial tear or patients with complete tear who have low functional demands. Operative treatment is the recommended treatment for complete tear of the distal biceps and is associated with good functional outcome and patient satisfaction.     

An uncommon cause of acute right ventricular failure and high mixed venous oxygen saturation

Ruptured sinus of Valsalva aneurysms are rare. We report a case in which the usual clinical manifestations were not present and the patient was initially treated as an acute pulmonary embolus. Despite three negative echocardiograms an intra-cardiac shunt was suspected because of a persistently elevated mixed venous oxygen saturation. Cardiac catheterisation confirmed the diagnosis. Surgical repair was performed and post operative recovery was uneventful.     

Conservative management of a major post-intubation tracheal injury and review of current management

Tracheal rupture represents a rare but serious complication of intubation. We discuss a case of a major post-intubation rupture. After investigation with CT scan tracheoscopy and bronchoscopy a low tracheostomy was formed protecting the rupture from pressure changes associated with ventilation. The patient was managed with minimal surgical intervention, low tracheostomy with antibiotic cover and monitoring in the intensive care unit for 24 h before being woken and moved to a ward after 48 h. The patient made a full and uncomplicated recovery and was discharged 2 weeks after the original injury. Most of the literature on the subject is made up of review of case reports that conclude management of such a major tear must be with surgical repair. This however confers significant morbidity and an associated high mortality. We suggest an alternative management protocol.     

Damage mechanics and load failure of fiber-reinforced composite fixed partial dentures

OBJECTIVES: Damage mechanics has been defined as the study of the initiation (initial failure) and accumulation of damage to and including rupture (final failure). This study was designed to evaluate the effect of increasing fiber-reinforced composite (FRC) substructure within a standardized fixed partial denture (FPD) model on the failure performance, in terms of damage mechanics. METHODS: The two FRC restorative systems, Targis/Vectris (TV) (Ivoclar Vivadent) and EverStick (ES) (Stick Tech with Gradia, GC Corp.), were used to restore the molar FPD model (1.5 mm axial and 2.0 mm occlusal reduction). Templates were used to standardize substructure designs with 0, 18, 43, and 66% cross-sectional FRC volume fraction (V(FRC)) of fiber substructure. Specimens (n = 5) were homogenized at 29 points and stored for 1 week at 37 degrees C in distilled water. Specimens were luted with calcium hydroxide, then statically loaded until failure. Initial failure (IF), final failure (FF) and the mode of failure were recorded. RESULTS: The lowest mean load to initial failure was 530 N (TV 18%) and the highest was 1208 N (ES 66%). Linear regression analysis calculated the Pearson's correlation coefficient (r) for the interactions between V(FRC) and IF (ES: r = 0.7879, TV: r = 0.6184), V(FRC) and FF (ES: r = 0.912, TV: r = 0.8152), and between IF and FF (ES: r = 0.892, TV: r = 0.7237). Unreinforced specimens universally fractured instantaneously. SIGNIFICANCE: The highest loads to initial and final failure were yielded by specimens with the highest cross-sectional V(FRC).     

主动脉窦瘤破裂的外科治疗：附16例报告

低温体外循环下手术治疗主动窦瘤破裂１６例，采用右房切口１例，右室流出道切口１１例，窦瘤破入腔和主动脉根部双切口４例。单纯窦瘤破口修补２例；双头垫片针窦瘤基部与空间隔踬同并列间断褥式缝合修补３例；     

脾动脉栓塞治疗外伤性脾破裂28例临床疗效观察

目的：探讨脾动脉栓塞术对外伤性脾破裂的疗效及并发症的处理。方法：采用Seldinger法行脾动脉栓塞术治疗外伤性脾破裂28例。结果：所有患者出血立即停止，其中4例行2次栓塞。28例均有脾区疼痛，22例发热。脾动脉栓塞5天后血小板、白细胞上升近1倍，7天后恢复至正常范围。28例随访6－36月，查免疫球蛋白、CT等结果满意，未有再出血及发生暴发性感染。结论：脾动脉栓塞不但有良好的止血作用，而且能保留脾脏的免疫功能，可在非手术治疗失败时选用，是外伤性脾破裂的一种有效治疗方法。     

Small bowel rupture after blunt trauma: Computed tomographic signs and their sensitivity

The purpose of this study is to describe the characteristic computed tomographic (CT) signs of small bowel perforation after blunt abdominal trauma and to evaluate their sensitivity. Nineteen preoperative CT scans were obtained from 16 patients with surgically proven small bowel rupture secondary to blunt abdominal trauma. Only the CT findings described in the original CT reports were used. Eleven of 19 CT scans (58 %) had findings that were unequivocal for bowel rupture (i.e., extraluminal air and/or extravasation of oral contrast medium). Seven CT scans (37 %) had findings that were suggestive of severe small bowel injury (i.e., focal small bowel wall thickening and/or free peritoneal fluid without other accompanying organ injuries). In all, 95 % of cases of small bowel rupture had either pathognomonic or suggestive CT findings. One CT scan did not demonstrate small bowel wall thickening, although a hemoperitoneum was present. CT is a sensitive method for suggesting severe small bowel injury and rupture secondary to blunt abdominal trauma.     

非特异性相互作用的断裂力与寿命测量

目的　探讨量化非特异性相互作用在特异性选择素－配体分子相互作用中的贡献。方法　利用光镊技术，对牛血清白蛋白(Bovine serum albumin, BSA)封闭的玻璃小球间的非特异性作用进行了系统测量，得出不同加载率下的断裂力以及不同外力作用下的寿命分布。结果　实验结果表明，非特异性作用同样表现出断裂力随加载率增加而增大的趋势。在较低加载率下，非特异性断裂力与选择素－配体特异性断裂力大小、增大趋势基本一致；随着加载率增加，二者的差别逐渐显著，前者的断裂力增加速率远低于后者。同样外力作用下，非特异性作用的寿命平均值比特异性作用要小；不同外力作用下，非特异性作用的寿命随外力增大仅略有下降，与特异性作用中逆锁键－滑移键转化现象有明显不同。结论　该研究结果将为正确评估非特异性相互作用对选择素－配体特异性相互作用实验结果的影响提供基础。     

Effects of Creep and Cyclic Loading on the Mechanical Properties and Failure of Human Achilles Tendons

The Achilles tendon is one of the most frequently injured tendons in humans, and yet the mechanisms underlying its injury are not well understood. This study examines the ex vivo mechanical behavior of excised human Achilles tendons to elucidate the relationships between mechanical loading and Achilles tendon injury. Eighteen tendons underwent creep testing at constant stresses from 35 to 75 MPa. Another 25 tendons underwent sinusoidal cyclic loading at 1 Hz between a minimum stress of 10 MPa and maximum stresses of 30–80 MPa. For the creep specimens, there was no significant relationship between applied stress and time to failure, but time to failure decreased exponentially with increasing initial strain (strain when target stress is first reached) and decreasing failure strain. For the cyclically loaded specimens, secant modulus decreased and cyclic energy dissipation increased over time. Time and cycles to failure decreased exponentially with increasing applied stress, increasing initial strain (peak strain from first loading cycle), and decreasing failure strain. For both creep and cyclic loading, initial strain was the best predictor of time or cycles to failure, supporting the hypothesis that strain is the primary mechanical parameter governing tendon damage accumulation and injury. The cyclically loaded specimens failed faster than would be expected if only time-dependent damage occurred, suggesting that repetitive loading also contributes to Achilles tendon injuries. © 2003 Biomedical Engineering Society. PAC2003: 8719Rr