Atraumatic osteonecrosis of the humeral head: pathophysiology and current concepts of evaluation and treatment.

The humeral head is considered the second most common site for osteonecrosis to occur after the femoral head. As seen in the femoral head, the circulatory implications characteristic of this condition are attributable to the interaction between a genetic predisposition and the exposure to certain risk factors. There is no consensus regarding the pathogenesis of osteonecrosis, yet the final common pathway results in disrupted blood supply, increased intraosseous pressure, and bone death. Disease staging using radiography and magnetic resonance imaging is predictive of disease progression and can help the orthopedic surgeon to guide treatment. Although there is a myriad of treatment modalities, there is a lack of high-quality evidence to conclude what is the most appropriate treatment option for each stage of humeral head osteonecrosis. Nonoperative treatment is the preferred option in early-stage disease, and it may prevent disease progression. Nonetheless, in some cases, disease progression occurs despite nonoperative measures, and surgical treatment is required. The purpose of this article is to provide an updated review of the available evidence on risk factors, diagnosis, and treatment of atraumatic humeral head osteonecrosis.

Síndrome de la bolsa de orina púrpura / Purple urine bag syndrome

Resumen El síndrome de la bolsa de orina púrpura es una condición clínica de prevalencia desconocida en Colombia debido al escaso reporte de casos a nivel nacional. Esta entidad se presenta exclusivamente en pacientes portadores de sonda vesical con factores de riesgo asociados como enfermedad renal crónica, patologías neurológicas, residentes de hogares geriátricos, sexo femenino, entre otros. La coloración púrpura de la orina se da en un ambiente urinario alcalino propiciado por bacterias específicas, en donde se genera una reacción de oxidación del indoxil sulfato en índigo e indirrubina por acción de las enzimas fosfatasas/sulfatasas de estos microorganismos, dichos pigmentos se mezclan generando la coloración púrpura en la bolsa urinaria. Se reporta el caso de un paciente masculino de 75 años con un cuadro clásico de síndrome de la bolsa urinaria púrpura, con el propósito de ampliar el conocimiento en la literatura nacional vigente. Adicionalmente, con esta publicación se busca que los profesionales de la salud comprendan los mecanismos fisiopatológicos por los cuales se produce esta entidad para saber abordarla apropiadamente.

Abstract Purple urine bag syndrome is a rare clinical condition, of unknown prevalence, with few reports published in our country that presents exclusively in catheterized patients with multiple risk factors, such as chronic kidney disease, neurological pathologies, residents of nursing homes and affects more females than males. The purple discoloration of urine is generated by indoxyl-sulfate degradation to indigo and indirubin lead by phosphatases/sulphatases enzymes produced by specific bacteria, associated to an alkaline urine environment, those two pigments combine which turns to purple discoloration appreciated in the urinary bag and catheter. The present case report is about a 75-year-old male, which appears with a classic clinical presentation. This case report has the objective, for health care workers, to remember the importance of basic care of urinary catheters, understand the underlying physiopathology and in consequence improve patient care.