Intramedullary stabilization of the femur fracture can affect the outcome in patients with multiple injuries. In stable patients, primary femoral nailing is associated with shorter ventilation time. In borderline patients, it is associated with a higher incidence of lung dysfunctions when compared with those who underwent external fixation and later conversion to intermedullary nail. Therefore, the preoperative condition should be when deciding on the type of initial fixation to perform in patients with multiple blunt injuries.

Rats harboring the human renin and angiotensinogen genes (dTGR) feature angiotensin (ANG) II/ hypertension-induced cardiac damage and die suddenly between wk 7 and 8. We observed by electrocardiogram (ECG) telemetry that ventricular tachycardia (VT) is a common terminal event in these animals. Our aim was to investigate electrical remodeling. We used ECG telemetry, noninvasive cardiac magnetic field mapping (CMFM) at wk 5 and 7, and performed in vivo programmed electrical stimulation at wk 7. We also investigated whether or not losartan (Los; 30 mg ⅐ kg Ϫ1 ⅐ day Ϫ1 ) would prevent electrical remodeling. Cardiac hypertrophy and systolic blood pressure progressively increased in dTGR compared with Sprague-Dawley (SD) controls. Already by wk 5, untreated dTGR showed increased perivascular and interstitial fibrosis, connective tissue growth factor expression, and monocyte infiltration compared with SD rats, differences that progressed through time. Left-ventricular mRNA expression of potassium channel subunit Kv4.3 and gap-junction protein connexin 43 were significantly reduced in dTGR compared with Los-treated dTGR and SD. CMFM showed that depolarization and repolarization were prolonged and inhomogeneous. Los ameliorated all disturbances. VT could be induced in 88% of dTGR but only in 33% of Los-treated dTGR and could not be induced in SD. Untreated dTGR show electrical remodeling and probably die from VT. Los treatment reduces myocardial remodeling and predisposition to arrhythmias. ANG II target organ damage induces VT. magnetocardiography; noninvasive mapping; double-transgenic rat model; in vivo electrophysiological study ELECTRICAL REMODELING INVOLVES acquired changes in cardiac structure or function that promote the occurrence of atrial or ventricular cardiac arrhythmias (22). On the molecular level, electrical remodeling involves changes in function and expression of membrane ion channels, gap-junction proteins, Ca 2ϩ -cycling proteins, and extracellular matrix composition. All these factors predispose to arrhythmogenic mechanisms such as early and delayed afterdepolarizations and reentry (13). The multifactorial origin of electrical remodeling has been extensively studied in cardiac ischemia and heart failure. However, electrical remodeling in hypertension is less well defined. Patients with hypertension-induced left-ventricular hypertrophy are at increased risk for arrhythmias, which contribute to a twofold increase in cardiovascular mortality (7). Monitoring electrical remodeling is challenging. The standard 12-lead electrocardiogram (ECG), ECG-based body surface potential mapping, and signal-averaged ECG are correlated with an increased risk to develop malignant arrhythmias. However, the positive predictive accuracy is unacceptably low or not sufficiently tested in randomized trials (14).Multichannel cardiac magnetic field mapping (CMFM) reflects the magnetic fields generated by the myocardial electrical currents occurring during the cardiac cycle. CMFM signals have several advantages: 1) they are littl...

The right patient selection with the correct surgical treatment are prerequisite for a positive result in total hip arthroplasty (THA). Short stem implants demand a shorter anchoring length in accordance with the proper indication. Although appropriate indications for short stems have been discussed in the literature, there currently is no clear definition. The lack of an accepted categorization of short hip stems complicates the situation further. This article briefly reviews the literature and highlights the authors' results and experiences in short stem THA in an effort to establish a proper discrimination between indications and contraindications for the Metha short stem. Results presented include a retrospective data collection and follow-up examination of 126 patients who underwent short stem THA with 2- and 4-year results. Anchoring principles of the short stem are reviewed, and a complication and failure analysis based on 7 femoral revisions in 1092 short stem THAs is presented. Selection criteria for short stem THA are patients younger than 70 years with primary osteoarthritis and dysplastic femoral deformities, and indications of avascular head necrosis. Adequate bone quality must be confirmed intraoperatively, assessing whether the bone structure in the area of the femoral neck is strong enough to support the short stem load transmission. Coxa vara and high dysplastic femoral neck antetorsion are contraindications for short stems. Wide and short femoral necks, implant undersizing, and a deep stem position below the femoral osteotomy compromise stability and must be avoided with an appropriate surgical technique. Long-term data are not yet available.

Locked plating of patella fractures is a reliable alternative treatment with good functional outcomes and low complication rates.

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The incidence of periprosthetic fractures is increasing because of the increasing age and the rising number of joint replacements. Elderly patients are endangered because of a higher rate of co-morbidity such as osteoporosis or cardiovascular diseases. The treatment of periprosthetic fractures depends on these preconditions and has to solve the problem after an exact analysis of the fracture. An understanding of the biomechanical principles and risk factors is necessary for an effective treatment. Intraoperative and postoperative periprosthetic fractures will be discussed with emphasis on classification and treatment. The aim has to be an early functional postoperative treatment with partial/full weight bearing in order to avoid postoperative complications. In discussing the scope of periprosthetic fractures, the site, incidence, treatment and outcome of periprosthetic fractures of the hip and knee will be outlined.

Cementless revision hip arthroplasty is described as state of the art, especially in cases of advanced bone loss of the femur. A requirement for a good result from cement-free revision hip arthroplasty is classification of the bone defect and the presence of a mechanically stable anchorage in the area of the original implant or, in cases of bone defects, distal to the original area in stable diaphyseal bone. The possibility of the accumulation of autografts or allogeneic osseous grafts and the entire removal of the cement and debris has been postulated. The advantages of cementless revision hip arthroplasty include regeneration of the bone stock and the often available modularity of the revision hip system, which allows adaptation to different bone configurations and also allows a partial change of the prosthesis in rerevision cases, such as in cases of sintering or derotation. Cemented revision arthroplasty should be done only in special cases, such as with marginal bone defects or for older patients with a short life expectancy.

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