RESUMEN
Patients who have total hip (THR) or knee (TKR) replacement have an elevated risk of venous thromboembolism (VTE). The American College of Chest Physicians guidelines recommend prophylactic anticoagulation. The aim of the study was to examine pharmacologic prophylaxis against VTE among patients with THR or TKR and to assess demographic and clinical correlates related to VTE prophylaxis. Using 15 years of data (1995-2009) from an electronic medical record system for an inner-city public hospital in the United States, we examined pharmacologic prophylaxis against VTE and associated factors in patients after THR (n = 242) and TKR (n = 317). Before the early 2000s, aspirin was the most common prophylaxis agent (THR, 61% and TKR, 65%), and 26% of patients with THR and 19% of patients with TKR did not receive prophylaxis. Enoxaparin use has increased since 2000, and warfarin is now the most common prophylaxis agent (THR, 70% and TKR, 61%). After controlling for time period, factors associated with prophylaxis pattern included obesity, hip fracture, and the surgeon's number of years in practice. VTE prophylaxis medications in patients with total joint replacement have changed over 15 years, in trends generally consistent with the evolution of guidelines. Obesity, history of hip fracture, and physician's experience are associated with the prescription of VTE prophylaxis medications.
Asunto(s)
Artroplastia de Reemplazo de Cadera/efectos adversos , Artroplastia de Reemplazo de Rodilla/efectos adversos , Registros Electrónicos de Salud , Tromboembolia Venosa/prevención & control , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
Multidetector computed tomography (CT) is an excellent way to supplement the radiographic evaluation of problematic hip prostheses. Multidetector CT is well suited for assessing periprosthetic bone, determining precise acetabular cup position, and evaluating periprosthetic fluid collections or ossified masses. Metal implants pose a number of challenges in the performance and interpretation of CT examinations. However, metal artifacts can be minimized by decreasing the detector collimation and pitch, increasing the kilovolt peak and milliampere-seconds, and using appropriate reconstruction algorithms and section thickness. Image interpretation requires a basic understanding of hip reconstruction and hip implants, as well as use of a systematic method of analysis that incorporates prior radiographic findings and CT findings. Radiologists must be familiar with the normal and abnormal CT appearances of hip prostheses and be able to recognize common complications on CT scans.
Asunto(s)
Artefactos , Articulación de la Cadera/diagnóstico por imagen , Prótesis de Cadera/efectos adversos , Inestabilidad de la Articulación/diagnóstico por imagen , Infecciones Relacionadas con Prótesis/diagnóstico por imagen , Infecciones Relacionadas con Prótesis/etiología , Tomografía Computarizada por Rayos X/métodos , Articulación de la Cadera/cirugía , Humanos , Inestabilidad de la Articulación/etiología , Metales , Intensificación de Imagen Radiográfica/métodosRESUMEN
Surface replacement (SR) was introduced as a bone-conserving alternative to total hip arthroplasty (THA) 3 decades ago, then was abandoned due to polyethylene wear, stress shielding, and loosening. Improved bearing surfaces have renewed interest in SR. This study examined long-term SR outcome compared to an age- and time-matched THA cohort. Average age was 47 years at index procedure with 16 years follow-up (range, 5-28). Revision rates were 86% and 40% in SR and THA groups, respectively. However, at 20 years, with an end point of either intact SR or primary THA in the SR group, survivorship was 64% +/- 6% versus 39% +/- 7% unrevised in THA cohort. Contemporary and rapidly changing technology may result in longer-term SR success and improved THA longevity in young patients.
Asunto(s)
Artroplastia de Reemplazo de Cadera , Articulación de la Cadera/cirugía , Adulto , Anciano , Trasplante Óseo , Femenino , Luxación Congénita de la Cadera/cirugía , Humanos , Artropatías/cirugía , Masculino , Persona de Mediana Edad , Evaluación de Resultado en la Atención de Salud , Reoperación , Estudios Retrospectivos , Resultado del TratamientoRESUMEN
The introduction of multichannel CT scanners provides both radiologists and surgeons with a new tool to image patients with orthopedic hardware. The key parameters that have made it possible to image the implants and the surrounding bone with multichannel CT are the higher available technical factors (kVp and mAs) coupled with the ability to acquire thin slices over a large scan region. These properties make it possible to produce high-quality multiplanar reformations that facilitate visualization of the orthopedic device and the surrounding bone. An important consideration for multichannel CT imaging of hardware is the reduction of cone beam artifacts caused by the geometry of multichannel CT scanners. This artifact is reduced by using a narrower x-ray beam collimation and a low pitch setting. This article discusses CT scan parameters and image postprocessing used at our institution and illustrates common clinical problems encountered when imaging implanted orthopedic devices. These include fracture healing, loosening of joint prostheses, evaluation of particle disease, and the use of CT for preoperative planning in revision arthroplasty.