The distal radioulnar joint. Anatomy, biomechanics, and triangular fibrocartilage complex abnormalities

The distal radioulnar joint plays an intricate part in the function of the wrist and thus in the function of the entire upper extremity. The radius and hand move in relation to and function about the distal ulna. Significant loads are transmitted to the forearm unit through the distal ulna via the triangular fibrocartilage complex. The anatomic relationships between the distal radius and ulna and ulnar carpus are precise, and even minor modification in these relationships leads to significant load changes and resultant pain syndromes. Evaluation of a patient with ulnar wrist pain is, at best, difficult. Despite a careful and thorough history and physical examination and the use of sophisticated ancillary diagnostic studies, some patients with distal radioulnar joint and ulnar carpal complex problems remain diagnostic and therapeutic mysteries. These patients are best followed; exploratory surgery is rarely satisfying to either the patient or the surgeon. Armed with an understanding of the normal anatomy and biomechanics, the examination of such a patient and subsequent treatment should become a challenge that is rewarding for both patient and treating physician.     

The anti-aggregating properties of vascular endothelium: interactions between prostacyclin and nitric oxide

1. The interactions between endothelium-derived nitric oxide (NO) and prostacyclin as inhibitors of platelet aggregation were examined. 2. Porcine aortic endothelial cells treated with indomethacin and stimulated with bradykinin (10-100 nM) released NO in quantities sufficient to account for the inhibition of platelet aggregation attributed to endothelium-derived relaxing factor (EDRF). 3. In the absence of indomethacin, stimulation of the cells with bradykinin (1-3 nM) released small amounts of prostacyclin and EDRF which synergistically inhibited platelet aggregation. 4. EDRF and authentic NO also caused disaggregation of platelets aggregated either with collagen or with U46619. 5. A reciprocal potentiation of both the anti- and the dis-aggregating activity was also observed between low concentrations of prostacyclin and authentic NO or EDRF released from endothelial cells. 6. It is likely that interactions between prostacyclin and NO released by the endothelium play a role in the homeostatic regulation of platelet-vessel wall interactions.     

Melioidosis. Forgotten, but not gone!

Melioidosis, infection by the soil bacterium Pseudomonas pseudomallei, has the potential for prolonged latency with recrudescence into an acute, often fulminating, and fatal infection. Although the organism is never found in North America, infection is endemic in areas of southeast Asia, and populations of service personnel exposed during the Vietnam war and southeast Asian immigrants are at risk of severe recrudescent disease. Diagnosis, however, has been missed or delayed because of lack of familiarity with this disease. We present a case of recrudescent melioidosis that illustrates the difficulties encountered in diagnosis and treatment. This case involves a 76-year-old Vietnam veteran who presented with melioidosis of the bone 18 years after exposure to the organism and 10 years after a missed diagnosis of latent pulmonary disease. This case illustrates the protean nature of latent infection and the difficulty of selecting successful antibiotic therapy.     

Benefits and limitations of burn wound excision

This review is intended to provide a balanced view of the role of surgical burn wound excision and closure within the larger context of the total care and rehabilitation of patients with burn injury. The historical background leading to present practice is outlined. The salient technical and logistical problems associated with the performance of wound excision are discussed, with emphasis on the necessity for expeditiously completing these procedures which are associated with major blood loss. A realistic analysis of the results of excisional therapy in patients with burns of varying severity is presented. Benefits attributable to the surgical phase of therapy become progressively more difficult to identify as the size of deep burns increases beyond 20% of total body surface area.

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Resumen La presente revisión propone proveer una visión equilibrada del papel de la resección tangencial quirúrgica de la quemadura y su cierre en el contexto más amplio del cuidado total y la rehabilitación de pacientes con lesiones térmicas. Se hace un recuento de los antecedentes históricos y se discuten los más prominentes problemas técnicos y logísticos relacionados con la resección tangencial de la quemadura con énfasis en la necesidad de implementar en forma expedita estos procedimientos, los cuales se asocian con pérdidas mayores de sangre. Se presenta el análisis realista de los resultados de la resección tangencial en pacientes con quemaduras de gravedad variable. Los beneficios atribuibles a la fase quirúrgica de la terapia se hacen progresivamente más difíciles de identificar en cuanto la extensión y profundidad sobrepasan el 20% de la superficie corporal.

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Résumé Cette article fait le point sur les avantages et inconvénients respectifs de l'excision et la suture dans le cadre du traitement et la rééducation des grands brûlés. L'historique de cette technique est résumée. Les principaux problèmes de technique et de logistique de l'excision des brûlures sont discutés, en soulignant la nécessité d'assurer un geste rapide enfin de réduire les pertes sanguines. Une analyse réaliste des résultats de la technique excisionnelle des brûlures de sévérité variable est présentée. Les bénéfices directement en rapport avec la chirurgie deviennent plus difficiles à apprécier lorsque la surface brûlée dépasse 20 % de la surface corporéelle.

     

Comparison between continuous and intermittent infusion regimens of cimetidine in ulcer patients

The relative effectiveness of intermittent infusions and primed continuous infusions of cimetidine in the maintenance of intragastric pH greater than or equal to 4.0 was evaluated in a double-blind crossover trial in 26 patients who had active or healed gastroduodenal ulcers. During the intermittent phase, each patient received 300 mg cimetidine intravenously every 6 hours. During the continuous infusion phase, each patient was given a continuous infusion of 37.5 mg cimetidine per hour, preceded by a priming dose of 300 mg cimetidine that was given for 15 minutes. Intragastric pH was monitored continuously. During the last 12 hours of the study, the continuous infusion regimen provided 20% more time in which the pH was more [corrected] than 4.0 with 25% less medication than did the intermittent infusion regimen.     

Fine needle aspiration cytology: an in vitro study of cell yield

To investigate the effect of needle size and number of passes into a tumour mass on the cell yield from a fine needle aspirate, an in vitro study was undertaken in 19 consecutive tumours removed surgically for biopsy. Different needle sizes (23G, 21G, 19G) passed in random order, five, ten and fifteen times into the tumours, were compared. The type of tumour, needle size and number of passes independently and significantly influenced cell yield. A 21G(green) needle passed into the tumour at least 10 times was the most efficient in obtaining cells. This in vitro study could explain the variation in the reported accuracy of fine needle aspiration cytology from groups using different techniques and is perhaps one reason why the highest diagnostic accuracy and the lowest rate of unsatisfactory aspirates comes from a centre which uses a 21G needle and at least 10 passes through the tumour.     

Multiple aneurysms in Beh?et's disease

Beh?et's disease is characterized by recurrent ulcers of the mouth and genitalia and relapsing iritis. It is now recognized as a chronic multisystem disease affecting the skin, mucous membranes, eye, joints, central nervous system, and blood vessels. One of the known vascular complications of Beh?et's disease is aneurysm formation or venous thrombosis. The two patients with Beh?et's disease in this report developed multiple aneurysms over a short time span. Vascular surgeons dealing with young adults with peripheral aneurysms must be aware of this uncommon yet challenging clinical entity.