['Sternum infection remains one of the primary causes of postoperative morbidity and mortality after median sternotomy. We report the clinical efficacy for primary reinforcement of the sternum with a new design of thorax support vest.', 'A prospective randomized study including 455 patients was started in September 2007 to evaluate the effectiveness of the Posthorax sternum vest (Epple Inc., Vienna, Austria). One hundred and seventy five patients were treated with the sternum dressing postoperatively (group A), 227 patients did not receive the vest (group B) and 53 patients refused it (group C). Several clinical and operative data were evaluated. All patients were recorded using the STS risk scoring analysis for mediastinitis after cardiac surgery.', "The median age and gender distribution were comparable in both groups. Preoperative data like renal failure, chronic obstructive pulmonary disease, peripheral artery disease, and myocardial infarction were not significant. There were more patients with diabetes in group A and C (A: 39.4%, B: 29.1%, C: 43.4%, p = 0.036). A total of 55.8% underwent coronary bypass grafting, 15.4% aortic valve replacement, 7.7% mitral valve repair and 21.1% concomitant cardiac procedures. The median risk factor analysis and body mass index were comparable. In the follow-up period up to 90 days, in group A we observed 0.6% sternum wound complications, in group B 4.9%, and in group C 9.4% (group A vs B: Fisher's exact test p = 0.0152 and group A vs C: p = 0.0029)."] Does a newly designed thorax support vest prevent sternum instability after median sternotomy?