Study will enroll patients scheduled for hip arthroplasty. In each subject a flow-mediated dilatation capability (FMD) of the brachial artery will be measured prior to elective surgery, within 24 hours after surgery and 5-7 days after surgery. At each session the brachial artery diameter will be measured at rest, during cuff inflation and 50 seconds after cuff deflation. From above mentioned values the increase in the diameter of the artery during reactive hyperemia will be calculated.

Simultaneously with the ultrasound investigations, the blood for determination of the endothelial dysfunction markers will be collected.

The participants will be contacted again 3 months after the surgery and asked about the complications which may be associated with the surgery.

Cardiovascular complications, especially coronary heart disease, are one of the main causes of perioperative complications. Indicators of pre-clinical atherosclerosis, such as: endothelial dysfunction, increased arterial intima/media thickness (especially in the carotid arteries), carotid calcification and coronary calcification, suggest the presence of atherosclerotic process without the symptomatic presentation. Endothelial dysfunction is one of the earliest measurable changes that predict the development of atherosclerotic disease.

Surgery is a significant stress for the organism: it increases the release of free oxygen radicals and through oxidative stress it increases systemic inflammatory response and causes thromboembolic complications.

In the study 50 patients of both sexes 40-80 years of age scheduled for hip arthroplasty will be included. In each subject a flow-mediated dilatation capability (FMD) of the brachial artery will be measured prior to elective surgery, within 24 hours after surgery and 5-7 days after surgery. Measurement of the brachial artery flow-mediated dilatation capability (FMD): the brachial artery diameter will be measured 5 cm proximal to the antecubital fossa at rest, during cuff inflation and 50 seconds after cuff deflation. The cuff will be inflated for 4 min. From above mentioned values the increase in the diameter of the artery during reactive hyperemia will be calculated.

Simultaneously with the ultrasound investigations, the blood for determination of the inflammatory and endothelial dysfunction markers (CRP, IL-6, IL-8, IL-10, IL-18, TNFa, VW Factor, Selectin P, selectin E) will be collected.

The participants will be contacted again 3 months after the surgery and asked about the complications which may be associated with the surgery.

Inclusion Criteria:

• scheduled hip arthroplasty under spinal anesthesia

Exclusion Criteria:

• Acute coronary syndrome or cerebrovascular syndrome in the last 6 months
• Acute venous thrombosis in the last 6 months
• Episode of rheumatoid arthritis in the last 3 months or permanent therapy with prednisolone >4mg/day
• Acute illness or hospitalization in the last month
• Chronic kidney failure on dialysis
• Hepatic failure
• Active malignant disease
• Immunosuppression after organ transplantation
• Pregnancy
• No informed consent after oral and written information