Patient selection for shorter femoral stems.

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.

Impact of the method of initial stabilization for femoral shaft fractures in patients with multiple injuries at risk for complications (borderline patients).

OBJECTIVES: The timing of definitive fixation for major fractures in patients with multiple injuries is controversial. To address this gap, we randomized patients with blunt multiple injuries to either initial definitive stabilization of the femur shaft with an intramedullary nail or an external fixateur with later conversion to an intermedullary nail and documented the postoperative clinical condition. METHODS: Multiply injured patients with femoral shaft fractures were randomized to either initial (<24 hours) intramedullary femoral nailing or external fixation and later conversion to an intramedullary nail. Inclusion: New Injury Severity Score >16 points, or 3 fractures and Abbreviated Injury Scale score > or =2 points and another injury (Abbreviated Injury Scale score > or =2 points), and age 18 to 65 years. Exclusion: patients in unstable or critical condition. Patients were graded as stable or borderline (increased risk of systemic complications). OUTCOMES: : Incidence of acute lung injuries. RESULTS: Ten European Centers, 165 patients, mean age 32.7 +/- 11.7 years. Group intramedullary nailing, n = 94; group external fixation, n = 71. Preoperatively, 121 patients were stable and 44 patients were in borderline condition. After adjusting for differences in initial injury severity between the 2 treatment groups, the odds of developing acute lung injury were 6.69 times greater in borderline patients who underwent intramedullary nailing in comparison with those who underwent external fixation, P < 0.05. CONCLUSION: 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.

Angiotensin II-induced sudden arrhythmic death and electrical remodeling.

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 x kg(-1) x day(-1)) 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.