A new preclinical femoral head osteonecrosis model in sheep

Introduction  

Animal models have been used as insight into the pathogenesis of osteonecrosis, even though most have failed to reproduce all stages of human disease, limiting progression in experimental treatment modalities. A new surgically induced animal model of femoral head osteonecrosis in sheep is presented.     

Maximizing ureteroscope deflection: "play it straight"

We studied simple maneuvers to optimize active deflection of the flexible ureteroscope. Up to 61 degrees of active deflection is lost if the ureteroscope is not kept in a straight alignment. Holding the ureteroscope taut, placing a super-stiff guidewire in the working channel, or using an access sheath maximizes active deflection.     

Stability of fibrin sealant in cerebrospinal fluid: an in vitro study

OBJECTIVE: The in vitro stability of fibrin sealant in cerebrospinal fluid (CSF) was investigated to verify the efficacy of intracranial application of fibrin sealant. METHODS: Human CSF was collected from 11 patients. Fibrin glue spheres (diameter, 5 mm) were incubated in CSF specimens at 37 degrees C. At 2, 4, 8, 24, and 48 hours, the diameter of the spheres was measured and the ultrastructure was evaluated by transmission electron microscopy. A control group consisted of sealant spheres in physiological saline (n = 2). RESULTS: In all CSF samples, the fibrin sealant did not degrade with time. The size, consistency, color, and shape of the sealant remained unchanged, even 48 hours after placement in the CSF. Transmission electron microscopic analysis of the fibrin sealant revealed an amorphous, fibrinous meshwork. No morphological differences existed between fibrin sealant complex placed in the CSF for different time periods and sealant placed in physiological saline. CONCLUSION: Within the limitations of this in vitro study, human CSF has no adverse effects on fibrin sealant in terms of alteration of structure and morphology. Fibrin sealant is stable in a CSF environment and can be effectively used in the cisternal or subarachnoidal space.     

Pharmacoeconomics of drug therapy for atopic dermatitis

Atopic dermatitis is an increasingly prevalent common childhood disease. While the majority of patients have mild disease, atopic dermatitis can cause considerable distress to patients and their caregivers, with significant social and financial cost to families. With a prevalence of 15 - 20% in Western countries, atopic dermatitis also has a considerable health and societal cost to the community. Many new treatments have been shown to be therapeutically effective, particularly in severe disease, including cyclosporin A (Neoral, Novartis AG), interferon, tacrolimus (Fujisawa Pharmaceutical Co. Ltd.) and iv. immunoglobulin. These are expensive when compared to standard treatments like emollients and topical corticosteroids and have significant adverse effects that limit their use. Additional costs related to monitoring are incurred and the long-term safety of these treatments is yet to be determined. However, an advantage over more traditional therapies is their ability to produce benefits even after treatment ceases. Treatments that produce long-term remissions have a greater likelihood of being cost-effective. With monetary constraints on healthcare and the importance governments place on reducing drug costs, economic evaluations are becoming an increasingly important factor for drug acceptance. Those evaluating cost-effectiveness should pay particular attention to the potential reduction in indirect and intangible costs. Unfortunately, there is a dearth of cost-effectiveness studies in atopic eczema and this needs to be addressed with some urgency.     

Is impingement the cause of jumper's knee? Dynamic and static magnetic resonance imaging of patellar tendinitis in an open-configuration system

BACKGROUND: Chronic overload is considered the main cause of patellar tendinitis, but it has been postulated that impingement of the inferior patellar pole against the patellar tendon during knee flexion could be responsible. HYPOTHESIS: The role of the patellar pole in patellar tendinitis can be determined by dynamic magnetic resonance imaging. STUDY DESIGN: Case-control study. METHODS: We compared 19 knees with patellar tendinitis and 32 asymptomatic knees of age-matched subjects using an open-configuration magnetic resonance imaging system. Dynamic sagittal images were obtained from full extension to 100 degrees of flexion with and without activation of the quadriceps muscle. The following measurements were made from the images: tendon-patella angle, anteroposterior diameter of the tendon, signal difference-to-noise ratio, the shape of the inferior patellar pole, and the location of the patellar tendon insertion. RESULTS: The tendon-patella angle was not significantly different between groups at any flexion angle, with or without quadriceps muscle activation. The insertion site of the patellar tendon differed significantly but not the shape of the inferior pole of the patella. The volume and the signal difference-to-noise ratio of zones of increased intratendinous signal as well as the anteroposterior diameter of the proximal patellar tendon were increased in symptomatic knees. CONCLUSIONS: The relationship between the patella and the patellar tendon was identical in both groups; therefore, chronic overload seems to be a major cause of patellar tendinitis.