Total knee and hip arthroplasty for osteoarthritis is performed on still broader indications even in elderly patients with previous or current medical conditions. Especially comorbidity like cardiovascular diseases and conditions with increased risk of bleeding or previous thrombo-embolic events are major challenges.

To facilitate safe use of ropivacaine as an analgesic, information on the concentrations levels after autologous blood transfusion following local infiltration analgesia is very crucial. However, very limited data are available. To verify the safety of autologous blood transfusion, ropivacaine concentrations were studied in 52 patients undergoing either total knee arthroplasty or total hip arthroplasty.

Inclusion Criteria:

• Clinical diagnosis for hip arthroplasty
• Clinical diagnosis for knee arthroplasty

Exclusion Criteria:

• Patients < 18 years
• Lack of informed consent
• Inability to read/understand Danish
• Bilateral diagnosis
• Cancer diagnosis

Primary care clinic.