螺旋形长型PHILOS接骨板治疗肱骨中上段骨折的生物力学研究

目的比较长型PHILOS接骨板(Synthes公司,瑞士)扭转成螺旋形前后的生物力学特性,为临床治疗肱骨中上段骨折提供生物力学依据。方法 12例Synbone人工骨(SYNBONE公司,瑞士)的右侧肱骨平均分为两组,对照组(n=6)采用10孔的长型PHILOS接骨板固定,实验组(n=6)采用相同的接骨板扭转成螺旋形后固定。肱骨中上段骨折造模后,利用万能力学试验机分别检测并比较两组接骨板固定后的整体构件在轴向拉伸和压缩、同向和反向扭转、前后及内外向三点弯曲6种加载方式下的生物力学特性。结果在100~500 N拉伸和压缩载荷下,实验组骨折断端位移分别较对照组增加约95%和58%;在0.6~3 N·m反向扭矩下,实验组扭转角度始终明显小于对照组,减少幅度达到55%~64%;在0.6~3 N·m的同向扭矩和1.5~7.5 N·m的前后向弯矩下,实验组的扭转角度和桡度均大于对照组,差异有显著性意义(P0.05);当内外向弯矩为1.5、3 N·m时,实验组与对照组的桡度差别无显著性意义(P0.05),而内外向弯矩为4.5、6、7.5 N·m时,实验组的桡度较对照组小20%~30%。实验组与对照组构件相比,拉伸和压缩刚度分别低49%和36%,同向和反向扭转刚度分别低19%和高150%,内外向和前后向弯曲刚度分别高18%和低70%,差异均有显著性意义(P0.05)。结论长型PHILOS接骨板扭转成螺旋形后固定肱骨中上段骨折的总体力学性能有所改善,可以满足临床对该类骨折的手术固定和术后康复需要。结合微创手术的优势,该技术有望在临床得到广泛应用。     

Outcomes of Second Look Exploration in Testicular Torsion of Children

Background:

Testicular torsion (TT), or twisting of the testicle resulting in a strangulation of the blood supply, occurs in men whose tissue surrounding the testicle is not well attached to the scrotum. It is important to emphasize that testicular torsion is a medical emergency.

Objectives:

The aim of this study is to evaluate the second look exploration and outcomes in TT.

Patients and Methods:

Seventy boys out of 124 patients underwent early exploration and 48 hours later second look exploration due to TT. All patients were checked with preoperative color-doppler ultrasonography (CDU) and intraoperative bleeding test. Data included age at admission, side of pathology, relation of TT with season of year, duration of preoperative history, degree of testicular torsion, CDU findings, and degree of bleeding; results of second look exploration, follow-up, and outcomes were analyzed.

Results:

Totally 70 patients were included in this study within five years, of which mean age was 28.6 ± 32.9 months (range 1 to 144), 48% of our patients had nausea and vomiting. Preoperative CDU showed absent/weak flow in 50 (71%) cases. Winter showed most frequently (44%) referred cases of testicular torsion. Orchidopexy was performed in 44 (63%) and orchidectomy in 26 (37%) cases after second look exploration. Mean follow-up duration was 3.1 ± 1.4 years. 4 (9%) cases in orchidopexy group developed testicular atrophy during follow-up, all four cases had a history of longer than 12 hours and grade II testicular bleeding test intra-operatively. Other orchidopexy patients salvaged. 26 patients, who were in grade III, underwent orchidectomy in second look exploration.

Conclusions:

TT requires emergency attention. The ischemia time of the testis is traditionally after 6 hours, and imaging or other diagnostic modality should not be a cause of delay. Early surgical exploration is modality of choice, and second look exploration after 48 hours can be more effective and salvageable in these patients.     

Torsion biomechanics of the spine following lumbar laminectomy: a human cadaver study

Purpose

Lumbar laminectomy affects spinal stability in shear loading. However, the effects of laminectomy on torsion biomechanics are unknown. The purpose of this study was to investigate the effect of laminectomy on torsion stiffness and torsion strength of lumbar spinal segments following laminectomy and whether these biomechanical parameters are affected by disc degeneration and bone mineral density (BMD).

Methods

Ten human cadaveric lumbar spines were obtained (age 75.5, range 59–88). Disc degeneration (MRI) and BMD (DXA) were assessed. Disc degeneration was classified according to Pfirrmann and dichotomized in mild or severe. BMD was defined as high BMD (≥median BMD) or low BMD (<median BMD). Laminectomy was performed either on L2 (5×) or L4 (5×). Twenty motion segments (L2–L3 and L4–L5) were isolated. The effects of laminectomy, disc degeneration and BMD on torsion stiffness (TS) and torsion moments to failure (TMF) were studied.

Results

Load–displacement curves showed a typical bi-phasic pattern with an early torsion stiffness (ETS), late torsion stiffness (LTS) and a TMF. Following laminectomy, ETS decreased 34.1 % (p < 0.001), LTS decreased 30.1 % (p = 0.027) and TMF decreased 17.6 % (p = 0.041). Disc degeneration (p < 0.001) and its interaction with laminectomy (p < 0.031) did significantly affect ETS. In the mildly degenerated group, ETS decreased 19.7 % from 7.6 Nm/degree (6.4–8.4) to 6.1 Nm/degree (1.5–10.3) following laminectomy. In the severely degenerated group, ETS decreased 22.3 % from 12.1 Nm/degree (4.6–21.9) to 9.4 Nm/degree (5.6–14.3) following laminectomy. In segments with low BMD, TMF was 40.7 % (p < 0.001) lower than segments with high BMD [34.9 Nm (range 23.7–51.2) versus 58.9 Nm (range 43.8–79.2)].

Conclusions

Laminectomy affects both torsion stiffness and torsion load to failure. In addition, torsional strength is strongly affected by BMD whereas disc degeneration affects torsional stiffness. Assessment of disc degeneration and BMD pre-operatively improves the understanding of the biomechanical effects of a lumbar laminectomy.     

Methods for Three-Dimensional Geometric Characterization of the Arterial Vasculature

Complex vascular anatomy often affects endovascular procedural outcome. Accurate quantitative assessment of three-dimensional (3D) in-vivo arterial morphology is therefore vital for endovascular device design, and preoperative planning of percutaneous interventions. The aim of this work was to establish geometric parameters describing arterial branch origin, trajectory, and vessel curvature in 3D space that eliminate the errors implicit in planar measurements. 3D branching parameters at visceral and aortic bifurcation sites, as well as arterial tortuosity were determined from vessel centerlines derived from magnetic resonance angiography data for three subjects. Errors in coronal measurements of 3D branching angles for the right and left renal arteries were 3.1 ± 3.4° and 7.5 ± 3.7°, respectively. Distortion of the anterior visceral branching angles from sagittal measurements was less pronounced. Asymmetry in branching and planarity of the common iliac arteries was observed at aortic bifurcations. The renal arteries possessed considerably greater 3D curvature than the abdominal aorta and common iliac vessels with mean average values of 0.114 ± 0.015 and 0.070 ± 0.019 mm⁻¹ for the left and right, respectively. In conclusion, planar projections misrepresented branch trajectory, vessel length, and tortuosity proving the importance of 3D geometric characterization for possible applications in planning of endovascular interventional procedures and providing parameters for endovascular device design.     

New echocardiographic applications for assessing global left ventricular diastolic function

A number of promising and highly technological echocardiographic imaging tools have recently been introduced to assess left ventricular diastolic function (i.e., the capacity of the ventricle to relax and fill). They permit quantification of distinct features of intraventricular blood flow velocity and pressure fields and myocardial tissue velocities. However, accurate interpretation of the new images and clinical indices is still cumbersome, as basic knowledge about intraventricular hemodynamics and ventricular wall mechanics is often insufficient. This review article provides a comprehensive and original overview of the hemodynamical and mechanical events that occur during diastole and discusses how this new information can be used in the clinical and research setting to evaluate diastolic function in the healthy and the diseased heart. It furthermore aims to explain the underpinnings of the techniques in such a way that the underlying biomechanical concepts (fluid dynamics and wall mechanics) become less obscure to cardiologists and echocardiographers and such that the biomedical engineers are given some insights into the avalanche of diastolic performance indices that currently exist.     

高频彩超对睾丸扭转的诊断价值

睾丸扭转亦称精索扭转，是泌尿外科常见急症之一，早期、正确诊断对制定治疗方案和预后有非常重要的意义。本文回顾性分析了11例经手术证实为睾丸扭转患者的高频彩超表现，旨在探讨其对睾丸扭转的诊断价值。     

Significant Increases in Serum CA125 and CA19-9 Following Torsion from an Adenofibroma of the Ovary: A Case Report

Significant increases in the serum levels of cancer antigen125 (CA 125) and carbohydrate antigen 19-9 (CA19-9) were observedover one month prior to the removal of an ovarian adenofibroma.The serum levels of CA125 and CA19-9 decreased rapidly aftersurgery. The surface of the tumor at surgery showed marked inflammation,probably induced by the necrosis produced by torsion. Pathologically,most of the tumor was necrotic, and histo immunochemical stainingof the viable cells was weak for CA125 but intense for CA19-9.Clinicopathological observations of the case suggested thatCA125 and CA19-9 might be stimulated in the cells by inflammationor that originally existing CAT25 and CA19-9 were released fromthe tumor cells following the cell necrosis.     

Imaging of the acute scrotum

The scrotum is a superficial structure and clinical examination is frequently not enough for making a specific diagnosis. In acute scrotal pain US can confirm the presumptive clinical diagnosis and provide additional relevant information. In testicular torsion, color-Doppler imaging has a central role since it has become possible to identify it at early stage by showing absence of perfusion in the affected testis before any gray-scale abnormality. Scintigraphy remains a satisfactory alternative in evaluating testicular torsion and should be used when color Doppler is inadequate, raising doubts about the suspected torsion. Diagnosis of torsion of testicular appendages is particularly difficult. Ischemic infarction shows a characteristic pattern at gray-scale and color-Doppler imaging, whereas hemorrhagic ischemia may require MRI. Inflammatory diseases of the scrotum can be easily investigated by echo color Doppler and conventional radiography, and CT can be particularly useful in the detection of gas bubbles. In scrotal trauma, scrotal hematoma, hematocele, intratesticular hematoma, and testicular rupture can be identified using gray-scale US with very good reliability. Magnetic resonance imaging is indicated when a small tear of tunica albuginea is suspected but not visualized on US. Received: 3 May 2000/Accepted: 8 June 2000